utils.py

import asyncio
import atexit
import base64
import binascii
import calendar
import codecs
import collections
import collections.abc
import contextlib
import datetime
import email.header
import email.utils
import errno
import gzip
import hashlib
import hmac
import html.entities
import html.parser
import http.client
import http.cookiejar
import inspect
import io
import itertools
import json
import locale
import math
import mimetypes
import operator
import os
import platform
import random
import re
import shlex
import socket
import ssl
import struct
import subprocess
import sys
import tempfile
import time
import traceback
import types
import unicodedata
import urllib.error
import urllib.parse
import urllib.request
import xml.etree.ElementTree
import zlib

from .compat import functools  # isort: split
from .compat import (
    compat_etree_fromstring,
    compat_expanduser,
    compat_HTMLParseError,
    compat_os_name,
    compat_shlex_quote,
)
from .dependencies import brotli, certifi, websockets, xattr
from .socks import ProxyType, sockssocket


def register_socks_protocols():
    # "Register" SOCKS protocols
    # In Python < 2.6.5, urlsplit() suffers from bug https://bugs.python.org/issue7904
    # URLs with protocols not in urlparse.uses_netloc are not handled correctly
    for scheme in ('socks', 'socks4', 'socks4a', 'socks5'):
        if scheme not in urllib.parse.uses_netloc:
            urllib.parse.uses_netloc.append(scheme)


# This is not clearly defined otherwise
compiled_regex_type = type(re.compile(''))


def random_user_agent():
    _USER_AGENT_TPL = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/%s Safari/537.36'
    _CHROME_VERSIONS = (
        '90.0.4430.212',
        '90.0.4430.24',
        '90.0.4430.70',
        '90.0.4430.72',
        '90.0.4430.85',
        '90.0.4430.93',
        '91.0.4472.101',
        '91.0.4472.106',
        '91.0.4472.114',
        '91.0.4472.124',
        '91.0.4472.164',
        '91.0.4472.19',
        '91.0.4472.77',
        '92.0.4515.107',
        '92.0.4515.115',
        '92.0.4515.131',
        '92.0.4515.159',
        '92.0.4515.43',
        '93.0.4556.0',
        '93.0.4577.15',
        '93.0.4577.63',
        '93.0.4577.82',
        '94.0.4606.41',
        '94.0.4606.54',
        '94.0.4606.61',
        '94.0.4606.71',
        '94.0.4606.81',
        '94.0.4606.85',
        '95.0.4638.17',
        '95.0.4638.50',
        '95.0.4638.54',
        '95.0.4638.69',
        '95.0.4638.74',
        '96.0.4664.18',
        '96.0.4664.45',
        '96.0.4664.55',
        '96.0.4664.93',
        '97.0.4692.20',
    )
    return _USER_AGENT_TPL % random.choice(_CHROME_VERSIONS)


SUPPORTED_ENCODINGS = [
    'gzip', 'deflate'
]
if brotli:
    SUPPORTED_ENCODINGS.append('br')

std_headers = {
    'User-Agent': random_user_agent(),
    'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
    'Accept-Language': 'en-us,en;q=0.5',
    'Sec-Fetch-Mode': 'navigate',
}


USER_AGENTS = {
    'Safari': 'Mozilla/5.0 (X11; Linux x86_64; rv:10.0) AppleWebKit/533.20.25 (KHTML, like Gecko) Version/5.0.4 Safari/533.20.27',
}


NO_DEFAULT = object()
IDENTITY = lambda x: x

ENGLISH_MONTH_NAMES = [
    'January', 'February', 'March', 'April', 'May', 'June',
    'July', 'August', 'September', 'October', 'November', 'December']

MONTH_NAMES = {
    'en': ENGLISH_MONTH_NAMES,
    'fr': [
        'janvier', 'février', 'mars', 'avril', 'mai', 'juin',
        'juillet', 'août', 'septembre', 'octobre', 'novembre', 'décembre'],
    # these follow the genitive grammatical case (dopełniacz)
    # some websites might be using nominative, which will require another month list
    # https://en.wikibooks.org/wiki/Polish/Noun_cases
    'pl': ['stycznia', 'lutego', 'marca', 'kwietnia', 'maja', 'czerwca',
           'lipca', 'sierpnia', 'września', 'października', 'listopada', 'grudnia'],
}

# From https://github.com/python/cpython/blob/3.11/Lib/email/_parseaddr.py#L36-L42
TIMEZONE_NAMES = {
    'UT': 0, 'UTC': 0, 'GMT': 0, 'Z': 0,
    'AST': -4, 'ADT': -3,  # Atlantic (used in Canada)
    'EST': -5, 'EDT': -4,  # Eastern
    'CST': -6, 'CDT': -5,  # Central
    'MST': -7, 'MDT': -6,  # Mountain
    'PST': -8, 'PDT': -7   # Pacific
}

# needed for sanitizing filenames in restricted mode
ACCENT_CHARS = dict(zip('ÂÃÄÀÁÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖŐØŒÙÚÛÜŰÝÞßàáâãäåæçèéêëìíîïðñòóôõöőøœùúûüűýþÿ',
                        itertools.chain('AAAAAA', ['AE'], 'CEEEEIIIIDNOOOOOOO', ['OE'], 'UUUUUY', ['TH', 'ss'],
                                        'aaaaaa', ['ae'], 'ceeeeiiiionooooooo', ['oe'], 'uuuuuy', ['th'], 'y')))

DATE_FORMATS = (
    '%d %B %Y',
    '%d %b %Y',
    '%B %d %Y',
    '%B %dst %Y',
    '%B %dnd %Y',
    '%B %drd %Y',
    '%B %dth %Y',
    '%b %d %Y',
    '%b %dst %Y',
    '%b %dnd %Y',
    '%b %drd %Y',
    '%b %dth %Y',
    '%b %dst %Y %I:%M',
    '%b %dnd %Y %I:%M',
    '%b %drd %Y %I:%M',
    '%b %dth %Y %I:%M',
    '%Y %m %d',
    '%Y-%m-%d',
    '%Y.%m.%d.',
    '%Y/%m/%d',
    '%Y/%m/%d %H:%M',
    '%Y/%m/%d %H:%M:%S',
    '%Y%m%d%H%M',
    '%Y%m%d%H%M%S',
    '%Y%m%d',
    '%Y-%m-%d %H:%M',
    '%Y-%m-%d %H:%M:%S',
    '%Y-%m-%d %H:%M:%S.%f',
    '%Y-%m-%d %H:%M:%S:%f',
    '%d.%m.%Y %H:%M',
    '%d.%m.%Y %H.%M',
    '%Y-%m-%dT%H:%M:%SZ',
    '%Y-%m-%dT%H:%M:%S.%fZ',
    '%Y-%m-%dT%H:%M:%S.%f0Z',
    '%Y-%m-%dT%H:%M:%S',
    '%Y-%m-%dT%H:%M:%S.%f',
    '%Y-%m-%dT%H:%M',
    '%b %d %Y at %H:%M',
    '%b %d %Y at %H:%M:%S',
    '%B %d %Y at %H:%M',
    '%B %d %Y at %H:%M:%S',
    '%H:%M %d-%b-%Y',
)

DATE_FORMATS_DAY_FIRST = list(DATE_FORMATS)
DATE_FORMATS_DAY_FIRST.extend([
    '%d-%m-%Y',
    '%d.%m.%Y',
    '%d.%m.%y',
    '%d/%m/%Y',
    '%d/%m/%y',
    '%d/%m/%Y %H:%M:%S',
    '%d-%m-%Y %H:%M',
])

DATE_FORMATS_MONTH_FIRST = list(DATE_FORMATS)
DATE_FORMATS_MONTH_FIRST.extend([
    '%m-%d-%Y',
    '%m.%d.%Y',
    '%m/%d/%Y',
    '%m/%d/%y',
    '%m/%d/%Y %H:%M:%S',
])

PACKED_CODES_RE = r"}\('(.+)',(\d+),(\d+),'([^']+)'\.split\('\|'\)"
JSON_LD_RE = r'(?is)<script[^>]+type=(["\']?)application/ld\+json\1[^>]*>\s*(?P<json_ld>{.+?}|\[.+?\])\s*</script>'

NUMBER_RE = r'\d+(?:\.\d+)?'


@functools.cache
def preferredencoding():
    """Get preferred encoding.

    Returns the best encoding scheme for the system, based on
    locale.getpreferredencoding() and some further tweaks.
    """
    try:
        pref = locale.getpreferredencoding()
        'TEST'.encode(pref)
    except Exception:
        pref = 'UTF-8'

    return pref


def write_json_file(obj, fn):
    """ Encode obj as JSON and write it to fn, atomically if possible """

    tf = tempfile.NamedTemporaryFile(
        prefix=f'{os.path.basename(fn)}.', dir=os.path.dirname(fn),
        suffix='.tmp', delete=False, mode='w', encoding='utf-8')

    try:
        with tf:
            json.dump(obj, tf, ensure_ascii=False)
        if sys.platform == 'win32':
            # Need to remove existing file on Windows, else os.rename raises
            # WindowsError or FileExistsError.
            with contextlib.suppress(OSError):
                os.unlink(fn)
        with contextlib.suppress(OSError):
            mask = os.umask(0)
            os.umask(mask)
            os.chmod(tf.name, 0o666 & ~mask)
        os.rename(tf.name, fn)
    except Exception:
        with contextlib.suppress(OSError):
            os.remove(tf.name)
        raise


def find_xpath_attr(node, xpath, key, val=None):
    """ Find the xpath xpath[@key=val] """
    assert re.match(r'^[a-zA-Z_-]+$', key)
    expr = xpath + ('[@%s]' % key if val is None else f"[@{key}='{val}']")
    return node.find(expr)

# On python2.6 the xml.etree.ElementTree.Element methods don't support
# the namespace parameter


def xpath_with_ns(path, ns_map):
    components = [c.split(':') for c in path.split('/')]
    replaced = []
    for c in components:
        if len(c) == 1:
            replaced.append(c[0])
        else:
            ns, tag = c
            replaced.append('{%s}%s' % (ns_map[ns], tag))
    return '/'.join(replaced)


def xpath_element(node, xpath, name=None, fatal=False, default=NO_DEFAULT):
    def _find_xpath(xpath):
        return node.find(xpath)

    if isinstance(xpath, str):
        n = _find_xpath(xpath)
    else:
        for xp in xpath:
            n = _find_xpath(xp)
            if n is not None:
                break

    if n is None:
        if default is not NO_DEFAULT:
            return default
        elif fatal:
            name = xpath if name is None else name
            raise ExtractorError('Could not find XML element %s' % name)
        else:
            return None
    return n


def xpath_text(node, xpath, name=None, fatal=False, default=NO_DEFAULT):
    n = xpath_element(node, xpath, name, fatal=fatal, default=default)
    if n is None or n == default:
        return n
    if n.text is None:
        if default is not NO_DEFAULT:
            return default
        elif fatal:
            name = xpath if name is None else name
            raise ExtractorError('Could not find XML element\'s text %s' % name)
        else:
            return None
    return n.text


def xpath_attr(node, xpath, key, name=None, fatal=False, default=NO_DEFAULT):
    n = find_xpath_attr(node, xpath, key)
    if n is None:
        if default is not NO_DEFAULT:
            return default
        elif fatal:
            name = f'{xpath}[@{key}]' if name is None else name
            raise ExtractorError('Could not find XML attribute %s' % name)
        else:
            return None
    return n.attrib[key]


def get_element_by_id(id, html, **kwargs):
    """Return the content of the tag with the specified ID in the passed HTML document"""
    return get_element_by_attribute('id', id, html, **kwargs)


def get_element_html_by_id(id, html, **kwargs):
    """Return the html of the tag with the specified ID in the passed HTML document"""
    return get_element_html_by_attribute('id', id, html, **kwargs)


def get_element_by_class(class_name, html):
    """Return the content of the first tag with the specified class in the passed HTML document"""
    retval = get_elements_by_class(class_name, html)
    return retval[0] if retval else None


def get_element_html_by_class(class_name, html):
    """Return the html of the first tag with the specified class in the passed HTML document"""
    retval = get_elements_html_by_class(class_name, html)
    return retval[0] if retval else None


def get_element_by_attribute(attribute, value, html, **kwargs):
    retval = get_elements_by_attribute(attribute, value, html, **kwargs)
    return retval[0] if retval else None


def get_element_html_by_attribute(attribute, value, html, **kargs):
    retval = get_elements_html_by_attribute(attribute, value, html, **kargs)
    return retval[0] if retval else None


def get_elements_by_class(class_name, html, **kargs):
    """Return the content of all tags with the specified class in the passed HTML document as a list"""
    return get_elements_by_attribute(
        'class', r'[^\'"]*(?<=[\'"\s])%s(?=[\'"\s])[^\'"]*' % re.escape(class_name),
        html, escape_value=False)


def get_elements_html_by_class(class_name, html):
    """Return the html of all tags with the specified class in the passed HTML document as a list"""
    return get_elements_html_by_attribute(
        'class', r'[^\'"]*(?<=[\'"\s])%s(?=[\'"\s])[^\'"]*' % re.escape(class_name),
        html, escape_value=False)


def get_elements_by_attribute(*args, **kwargs):
    """Return the content of the tag with the specified attribute in the passed HTML document"""
    return [content for content, _ in get_elements_text_and_html_by_attribute(*args, **kwargs)]


def get_elements_html_by_attribute(*args, **kwargs):
    """Return the html of the tag with the specified attribute in the passed HTML document"""
    return [whole for _, whole in get_elements_text_and_html_by_attribute(*args, **kwargs)]


def get_elements_text_and_html_by_attribute(attribute, value, html, *, tag=r'[\w:.-]+', escape_value=True):
    """
    Return the text (content) and the html (whole) of the tag with the specified
    attribute in the passed HTML document
    """
    if not value:
        return

    quote = '' if re.match(r'''[\s"'`=<>]''', value) else '?'

    value = re.escape(value) if escape_value else value

    partial_element_re = rf'''(?x)
        <(?P<tag>{tag})
         (?:\s(?:[^>"']|"[^"]*"|'[^']*')*)?
         \s{re.escape(attribute)}\s*=\s*(?P<_q>['"]{quote})(?-x:{value})(?P=_q)
        '''

    for m in re.finditer(partial_element_re, html):
        content, whole = get_element_text_and_html_by_tag(m.group('tag'), html[m.start():])

        yield (
            unescapeHTML(re.sub(r'^(?P<q>["\'])(?P<content>.*)(?P=q)$', r'\g<content>', content, flags=re.DOTALL)),
            whole
        )


class HTMLBreakOnClosingTagParser(html.parser.HTMLParser):
    """
    HTML parser which raises HTMLBreakOnClosingTagException upon reaching the
    closing tag for the first opening tag it has encountered, and can be used
    as a context manager
    """

    class HTMLBreakOnClosingTagException(Exception):
        pass

    def __init__(self):
        self.tagstack = collections.deque()
        html.parser.HTMLParser.__init__(self)

    def __enter__(self):
        return self

    def __exit__(self, *_):
        self.close()

    def close(self):
        # handle_endtag does not return upon raising HTMLBreakOnClosingTagException,
        # so data remains buffered; we no longer have any interest in it, thus
        # override this method to discard it
        pass

    def handle_starttag(self, tag, _):
        self.tagstack.append(tag)

    def handle_endtag(self, tag):
        if not self.tagstack:
            raise compat_HTMLParseError('no tags in the stack')
        while self.tagstack:
            inner_tag = self.tagstack.pop()
            if inner_tag == tag:
                break
        else:
            raise compat_HTMLParseError(f'matching opening tag for closing {tag} tag not found')
        if not self.tagstack:
            raise self.HTMLBreakOnClosingTagException()


# XXX: This should be far less strict
def get_element_text_and_html_by_tag(tag, html):
    """
    For the first element with the specified tag in the passed HTML document
    return its' content (text) and the whole element (html)
    """
    def find_or_raise(haystack, needle, exc):
        try:
            return haystack.index(needle)
        except ValueError:
            raise exc
    closing_tag = f'</{tag}>'
    whole_start = find_or_raise(
        html, f'<{tag}', compat_HTMLParseError(f'opening {tag} tag not found'))
    content_start = find_or_raise(
        html[whole_start:], '>', compat_HTMLParseError(f'malformed opening {tag} tag'))
    content_start += whole_start + 1
    with HTMLBreakOnClosingTagParser() as parser:
        parser.feed(html[whole_start:content_start])
        if not parser.tagstack or parser.tagstack[0] != tag:
            raise compat_HTMLParseError(f'parser did not match opening {tag} tag')
        offset = content_start
        while offset < len(html):
            next_closing_tag_start = find_or_raise(
                html[offset:], closing_tag,
                compat_HTMLParseError(f'closing {tag} tag not found'))
            next_closing_tag_end = next_closing_tag_start + len(closing_tag)
            try:
                parser.feed(html[offset:offset + next_closing_tag_end])
                offset += next_closing_tag_end
            except HTMLBreakOnClosingTagParser.HTMLBreakOnClosingTagException:
                return html[content_start:offset + next_closing_tag_start], \
                    html[whole_start:offset + next_closing_tag_end]
        raise compat_HTMLParseError('unexpected end of html')


class HTMLAttributeParser(html.parser.HTMLParser):
    """Trivial HTML parser to gather the attributes for a single element"""

    def __init__(self):
        self.attrs = {}
        html.parser.HTMLParser.__init__(self)

    def handle_starttag(self, tag, attrs):
        self.attrs = dict(attrs)
        raise compat_HTMLParseError('done')


class HTMLListAttrsParser(html.parser.HTMLParser):
    """HTML parser to gather the attributes for the elements of a list"""

    def __init__(self):
        html.parser.HTMLParser.__init__(self)
        self.items = []
        self._level = 0

    def handle_starttag(self, tag, attrs):
        if tag == 'li' and self._level == 0:
            self.items.append(dict(attrs))
        self._level += 1

    def handle_endtag(self, tag):
        self._level -= 1


def extract_attributes(html_element):
    """Given a string for an HTML element such as
    <el
         a="foo" B="bar" c="&98;az" d=boz
         empty= noval entity="&amp;"
         sq='"' dq="'"
    >
    Decode and return a dictionary of attributes.
    {
        'a': 'foo', 'b': 'bar', c: 'baz', d: 'boz',
        'empty': '', 'noval': None, 'entity': '&',
        'sq': '"', 'dq': '\''
    }.
    """
    parser = HTMLAttributeParser()
    with contextlib.suppress(compat_HTMLParseError):
        parser.feed(html_element)
        parser.close()
    return parser.attrs


def parse_list(webpage):
    """Given a string for an series of HTML <li> elements,
    return a dictionary of their attributes"""
    parser = HTMLListAttrsParser()
    parser.feed(webpage)
    parser.close()
    return parser.items


def clean_html(html):
    """Clean an HTML snippet into a readable string"""

    if html is None:  # Convenience for sanitizing descriptions etc.
        return html

    html = re.sub(r'\s+', ' ', html)
    html = re.sub(r'(?u)\s?<\s?br\s?/?\s?>\s?', '\n', html)
    html = re.sub(r'(?u)<\s?/\s?p\s?>\s?<\s?p[^>]*>', '\n', html)
    # Strip html tags
    html = re.sub('<.*?>', '', html)
    # Replace html entities
    html = unescapeHTML(html)
    return html.strip()


class LenientJSONDecoder(json.JSONDecoder):
    def __init__(self, *args, transform_source=None, ignore_extra=False, **kwargs):
        self.transform_source, self.ignore_extra = transform_source, ignore_extra
        super().__init__(*args, **kwargs)

    def decode(self, s):
        if self.transform_source:
            s = self.transform_source(s)
        try:
            if self.ignore_extra:
                return self.raw_decode(s.lstrip())[0]
            return super().decode(s)
        except json.JSONDecodeError as e:
            if e.pos is not None:
                raise type(e)(f'{e.msg} in {s[e.pos-10:e.pos+10]!r}', s, e.pos)
            raise


def sanitize_open(filename, open_mode):
    """Try to open the given filename, and slightly tweak it if this fails.

    Attempts to open the given filename. If this fails, it tries to change
    the filename slightly, step by step, until it's either able to open it
    or it fails and raises a final exception, like the standard open()
    function.

    It returns the tuple (stream, definitive_file_name).
    """
    if filename == '-':
        if sys.platform == 'win32':
            import msvcrt

            # stdout may be any IO stream, e.g. when using contextlib.redirect_stdout
            with contextlib.suppress(io.UnsupportedOperation):
                msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
        return (sys.stdout.buffer if hasattr(sys.stdout, 'buffer') else sys.stdout, filename)

    for attempt in range(2):
        try:
            try:
                if sys.platform == 'win32':
                    # FIXME: An exclusive lock also locks the file from being read.
                    # Since windows locks are mandatory, don't lock the file on windows (for now).
                    # Ref: https://github.com/yt-dlp/yt-dlp/issues/3124
                    raise LockingUnsupportedError()
                stream = locked_file(filename, open_mode, block=False).__enter__()
            except OSError:
                stream = open(filename, open_mode)
            return stream, filename
        except OSError as err:
            if attempt or err.errno in (errno.EACCES,):
                raise
            old_filename, filename = filename, sanitize_path(filename)
            if old_filename == filename:
                raise


def timeconvert(timestr):
    """Convert RFC 2822 defined time string into system timestamp"""
    timestamp = None
    timetuple = email.utils.parsedate_tz(timestr)
    if timetuple is not None:
        timestamp = email.utils.mktime_tz(timetuple)
    return timestamp


def sanitize_filename(s, restricted=False, is_id=NO_DEFAULT):
    """Sanitizes a string so it could be used as part of a filename.
    @param restricted   Use a stricter subset of allowed characters
    @param is_id        Whether this is an ID that should be kept unchanged if possible.
                        If unset, yt-dlp's new sanitization rules are in effect
    """
    if s == '':
        return ''

    def replace_insane(char):
        if restricted and char in ACCENT_CHARS:
            return ACCENT_CHARS[char]
        elif not restricted and char == '\n':
            return '\0 '
        elif is_id is NO_DEFAULT and not restricted and char in '"*:<>?|/\\':
            # Replace with their full-width unicode counterparts
            return {'/': '\u29F8', '\\': '\u29f9'}.get(char, chr(ord(char) + 0xfee0))
        elif char == '?' or ord(char) < 32 or ord(char) == 127:
            return ''
        elif char == '"':
            return '' if restricted else '\''
        elif char == ':':
            return '\0_\0-' if restricted else '\0 \0-'
        elif char in '\\/|*<>':
            return '\0_'
        if restricted and (char in '!&\'()[]{}$;`^,#' or char.isspace() or ord(char) > 127):
            return '\0_'
        return char

    # Replace look-alike Unicode glyphs
    if restricted and (is_id is NO_DEFAULT or not is_id):
        s = unicodedata.normalize('NFKC', s)
    s = re.sub(r'[0-9]+(?::[0-9]+)+', lambda m: m.group(0).replace(':', '_'), s)  # Handle timestamps
    result = ''.join(map(replace_insane, s))
    if is_id is NO_DEFAULT:
        result = re.sub(r'(\0.)(?:(?=\1)..)+', r'\1', result)  # Remove repeated substitute chars
        STRIP_RE = r'(?:\0.|[ _-])*'
        result = re.sub(f'^\0.{STRIP_RE}|{STRIP_RE}\0.$', '', result)  # Remove substitute chars from start/end
    result = result.replace('\0', '') or '_'

    if not is_id:
        while '__' in result:
            result = result.replace('__', '_')
        result = result.strip('_')
        # Common case of "Foreign band name - English song title"
        if restricted and result.startswith('-_'):
            result = result[2:]
        if result.startswith('-'):
            result = '_' + result[len('-'):]
        result = result.lstrip('.')
        if not result:
            result = '_'
    return result


def sanitize_path(s, force=False):
    """Sanitizes and normalizes path on Windows"""
    if sys.platform == 'win32':
        force = False
        drive_or_unc, _ = os.path.splitdrive(s)
    elif force:
        drive_or_unc = ''
    else:
        return s

    norm_path = os.path.normpath(remove_start(s, drive_or_unc)).split(os.path.sep)
    if drive_or_unc:
        norm_path.pop(0)
    sanitized_path = [
        path_part if path_part in ['.', '..'] else re.sub(r'(?:[/<>:"\|\\?\*]|[\s.]$)', '#', path_part)
        for path_part in norm_path]
    if drive_or_unc:
        sanitized_path.insert(0, drive_or_unc + os.path.sep)
    elif force and s and s[0] == os.path.sep:
        sanitized_path.insert(0, os.path.sep)
    return os.path.join(*sanitized_path)


def sanitize_url(url, *, scheme='http'):
    # Prepend protocol-less URLs with `http:` scheme in order to mitigate
    # the number of unwanted failures due to missing protocol
    if url is None:
        return
    elif url.startswith('//'):
        return f'{scheme}:{url}'
    # Fix some common typos seen so far
    COMMON_TYPOS = (
        # https://github.com/ytdl-org/youtube-dl/issues/15649
        (r'^httpss://', r'https://'),
        # https://bx1.be/lives/direct-tv/
        (r'^rmtp([es]?)://', r'rtmp\1://'),
    )
    for mistake, fixup in COMMON_TYPOS:
        if re.match(mistake, url):
            return re.sub(mistake, fixup, url)
    return url


def extract_basic_auth(url):
    parts = urllib.parse.urlsplit(url)
    if parts.username is None:
        return url, None
    url = urllib.parse.urlunsplit(parts._replace(netloc=(
        parts.hostname if parts.port is None
        else '%s:%d' % (parts.hostname, parts.port))))
    auth_payload = base64.b64encode(
        ('%s:%s' % (parts.username, parts.password or '')).encode())
    return url, f'Basic {auth_payload.decode()}'


def sanitized_Request(url, *args, **kwargs):
    url, auth_header = extract_basic_auth(escape_url(sanitize_url(url)))
    if auth_header is not None:
        headers = args[1] if len(args) >= 2 else kwargs.setdefault('headers', {})
        headers['Authorization'] = auth_header
    return urllib.request.Request(url, *args, **kwargs)


def expand_path(s):
    """Expand shell variables and ~"""
    return os.path.expandvars(compat_expanduser(s))


def orderedSet(iterable, *, lazy=False):
    """Remove all duplicates from the input iterable"""
    def _iter():
        seen = []  # Do not use set since the items can be unhashable
        for x in iterable:
            if x not in seen:
                seen.append(x)
                yield x

    return _iter() if lazy else list(_iter())


def _htmlentity_transform(entity_with_semicolon):
    """Transforms an HTML entity to a character."""
    entity = entity_with_semicolon[:-1]

    # Known non-numeric HTML entity
    if entity in html.entities.name2codepoint:
        return chr(html.entities.name2codepoint[entity])

    # TODO: HTML5 allows entities without a semicolon.
    # E.g. '&Eacuteric' should be decoded as 'Éric'.
    if entity_with_semicolon in html.entities.html5:
        return html.entities.html5[entity_with_semicolon]

    mobj = re.match(r'#(x[0-9a-fA-F]+|[0-9]+)', entity)
    if mobj is not None:
        numstr = mobj.group(1)
        if numstr.startswith('x'):
            base = 16
            numstr = '0%s' % numstr
        else:
            base = 10
        # See https://github.com/ytdl-org/youtube-dl/issues/7518
        with contextlib.suppress(ValueError):
            return chr(int(numstr, base))

    # Unknown entity in name, return its literal representation
    return '&%s;' % entity


def unescapeHTML(s):
    if s is None:
        return None
    assert isinstance(s, str)

    return re.sub(
        r'&([^&;]+;)', lambda m: _htmlentity_transform(m.group(1)), s)


def escapeHTML(text):
    return (
        text
        .replace('&', '&amp;')
        .replace('<', '&lt;')
        .replace('>', '&gt;')
        .replace('"', '&quot;')
        .replace("'", '&#39;')
    )


def process_communicate_or_kill(p, *args, **kwargs):
    deprecation_warning(f'"{__name__}.process_communicate_or_kill" is deprecated and may be removed '
                        f'in a future version. Use "{__name__}.Popen.communicate_or_kill" instead')
    return Popen.communicate_or_kill(p, *args, **kwargs)


class Popen(subprocess.Popen):
    if sys.platform == 'win32':
        _startupinfo = subprocess.STARTUPINFO()
        _startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
    else:
        _startupinfo = None

    @staticmethod
    def _fix_pyinstaller_ld_path(env):
        """Restore LD_LIBRARY_PATH when using PyInstaller
            Ref: https://github.com/pyinstaller/pyinstaller/blob/develop/doc/runtime-information.rst#ld_library_path--libpath-considerations
                 https://github.com/yt-dlp/yt-dlp/issues/4573
        """
        if not hasattr(sys, '_MEIPASS'):
            return

        def _fix(key):
            orig = env.get(f'{key}_ORIG')
            if orig is None:
                env.pop(key, None)
            else:
                env[key] = orig

        _fix('LD_LIBRARY_PATH')  # Linux
        _fix('DYLD_LIBRARY_PATH')  # macOS

    def __init__(self, *args, env=None, text=False, **kwargs):
        if env is None:
            env = os.environ.copy()
        self._fix_pyinstaller_ld_path(env)

        if text is True:
            kwargs['universal_newlines'] = True  # For 3.6 compatibility
            kwargs.setdefault('encoding', 'utf-8')
            kwargs.setdefault('errors', 'replace')
        super().__init__(*args, env=env, **kwargs, startupinfo=self._startupinfo)

    def communicate_or_kill(self, *args, **kwargs):
        try:
            return self.communicate(*args, **kwargs)
        except BaseException:  # Including KeyboardInterrupt
            self.kill(timeout=None)
            raise

    def kill(self, *, timeout=0):
        super().kill()
        if timeout != 0:
            self.wait(timeout=timeout)

    @classmethod
    def run(cls, *args, timeout=None, **kwargs):
        with cls(*args, **kwargs) as proc:
            default = '' if proc.text_mode else b''
            stdout, stderr = proc.communicate_or_kill(timeout=timeout)
            return stdout or default, stderr or default, proc.returncode


def get_subprocess_encoding():
    if sys.platform == 'win32' and sys.getwindowsversion()[0] >= 5:
        # For subprocess calls, encode with locale encoding
        # Refer to http://stackoverflow.com/a/9951851/35070
        encoding = preferredencoding()
    else:
        encoding = sys.getfilesystemencoding()
    if encoding is None:
        encoding = 'utf-8'
    return encoding


def encodeFilename(s, for_subprocess=False):
    assert isinstance(s, str)
    return s


def decodeFilename(b, for_subprocess=False):
    return b


def encodeArgument(s):
    # Legacy code that uses byte strings
    # Uncomment the following line after fixing all post processors
    # assert isinstance(s, str), 'Internal error: %r should be of type %r, is %r' % (s, str, type(s))
    return s if isinstance(s, str) else s.decode('ascii')


def decodeArgument(b):
    return b


def decodeOption(optval):
    if optval is None:
        return optval
    if isinstance(optval, bytes):
        optval = optval.decode(preferredencoding())

    assert isinstance(optval, str)
    return optval


_timetuple = collections.namedtuple('Time', ('hours', 'minutes', 'seconds', 'milliseconds'))


def timetuple_from_msec(msec):
    secs, msec = divmod(msec, 1000)
    mins, secs = divmod(secs, 60)
    hrs, mins = divmod(mins, 60)
    return _timetuple(hrs, mins, secs, msec)


def formatSeconds(secs, delim=':', msec=False):
    time = timetuple_from_msec(secs * 1000)
    if time.hours:
        ret = '%d%s%02d%s%02d' % (time.hours, delim, time.minutes, delim, time.seconds)
    elif time.minutes:
        ret = '%d%s%02d' % (time.minutes, delim, time.seconds)
    else:
        ret = '%d' % time.seconds
    return '%s.%03d' % (ret, time.milliseconds) if msec else ret


def _ssl_load_windows_store_certs(ssl_context, storename):
    # Code adapted from _load_windows_store_certs in https://github.com/python/cpython/blob/main/Lib/ssl.py
    try:
        certs = [cert for cert, encoding, trust in ssl.enum_certificates(storename)
                 if encoding == 'x509_asn' and (
                     trust is True or ssl.Purpose.SERVER_AUTH.oid in trust)]
    except PermissionError:
        return
    for cert in certs:
        with contextlib.suppress(ssl.SSLError):
            ssl_context.load_verify_locations(cadata=cert)


def make_HTTPS_handler(params, **kwargs):
    opts_check_certificate = not params.get('nocheckcertificate')
    context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
    context.check_hostname = opts_check_certificate
    if params.get('legacyserverconnect'):
        context.options |= 4  # SSL_OP_LEGACY_SERVER_CONNECT
        # Allow use of weaker ciphers in Python 3.10+. See https://bugs.python.org/issue43998
        context.set_ciphers('DEFAULT')
    elif (
        sys.version_info < (3, 10)
        and ssl.OPENSSL_VERSION_INFO >= (1, 1, 1)
        and not ssl.OPENSSL_VERSION.startswith('LibreSSL')
    ):
        # Backport the default SSL ciphers and minimum TLS version settings from Python 3.10 [1].
        # This is to ensure consistent behavior across Python versions, and help avoid fingerprinting
        # in some situations [2][3].
        # Python 3.10 only supports OpenSSL 1.1.1+ [4]. Because this change is likely
        # untested on older versions, we only apply this to OpenSSL 1.1.1+ to be safe.
        # LibreSSL is excluded until further investigation due to cipher support issues [5][6].
        # 1. https://github.com/python/cpython/commit/e983252b516edb15d4338b0a47631b59ef1e2536
        # 2. https://github.com/yt-dlp/yt-dlp/issues/4627
        # 3. https://github.com/yt-dlp/yt-dlp/pull/5294
        # 4. https://peps.python.org/pep-0644/
        # 5. https://peps.python.org/pep-0644/#libressl-support
        # 6. https://github.com/yt-dlp/yt-dlp/commit/5b9f253fa0aee996cf1ed30185d4b502e00609c4#commitcomment-89054368
        context.set_ciphers('@SECLEVEL=2:ECDH+AESGCM:ECDH+CHACHA20:ECDH+AES:DHE+AES:!aNULL:!eNULL:!aDSS:!SHA1:!AESCCM')
        context.minimum_version = ssl.TLSVersion.TLSv1_2

    context.verify_mode = ssl.CERT_REQUIRED if opts_check_certificate else ssl.CERT_NONE
    if opts_check_certificate:
        if has_certifi and 'no-certifi' not in params.get('compat_opts', []):
            context.load_verify_locations(cafile=certifi.where())
        else:
            try:
                context.load_default_certs()
                # Work around the issue in load_default_certs when there are bad certificates. See:
                # https://github.com/yt-dlp/yt-dlp/issues/1060,
                # https://bugs.python.org/issue35665, https://bugs.python.org/issue45312
            except ssl.SSLError:
                # enum_certificates is not present in mingw python. See https://github.com/yt-dlp/yt-dlp/issues/1151
                if sys.platform == 'win32' and hasattr(ssl, 'enum_certificates'):
                    for storename in ('CA', 'ROOT'):
                        _ssl_load_windows_store_certs(context, storename)
                context.set_default_verify_paths()

    client_certfile = params.get('client_certificate')
    if client_certfile:
        try:
            context.load_cert_chain(
                client_certfile, keyfile=params.get('client_certificate_key'),
                password=params.get('client_certificate_password'))
        except ssl.SSLError:
            raise YoutubeDLError('Unable to load client certificate')

    # Some servers may reject requests if ALPN extension is not sent. See:
    # https://github.com/python/cpython/issues/85140
    # https://github.com/yt-dlp/yt-dlp/issues/3878
    with contextlib.suppress(NotImplementedError):
        context.set_alpn_protocols(['http/1.1'])

    return YoutubeDLHTTPSHandler(params, context=context, **kwargs)


def bug_reports_message(before=';'):
    from .update import REPOSITORY

    msg = (f'please report this issue on  https://github.com/{REPOSITORY}/issues?q= , '
           'filling out the appropriate issue template. Confirm you are on the latest version using  yt-dlp -U')

    before = before.rstrip()
    if not before or before.endswith(('.', '!', '?')):
        msg = msg[0].title() + msg[1:]

    return (before + ' ' if before else '') + msg


class YoutubeDLError(Exception):
    """Base exception for YoutubeDL errors."""
    msg = None

    def __init__(self, msg=None):
        if msg is not None:
            self.msg = msg
        elif self.msg is None:
            self.msg = type(self).__name__
        super().__init__(self.msg)


network_exceptions = [urllib.error.URLError, http.client.HTTPException, socket.error]
if hasattr(ssl, 'CertificateError'):
    network_exceptions.append(ssl.CertificateError)
network_exceptions = tuple(network_exceptions)


class ExtractorError(YoutubeDLError):
    """Error during info extraction."""

    def __init__(self, msg, tb=None, expected=False, cause=None, video_id=None, ie=None):
        """ tb, if given, is the original traceback (so that it can be printed out).
        If expected is set, this is a normal error message and most likely not a bug in yt-dlp.
        """
        if sys.exc_info()[0] in network_exceptions:
            expected = True

        self.orig_msg = str(msg)
        self.traceback = tb
        self.expected = expected
        self.cause = cause
        self.video_id = video_id
        self.ie = ie
        self.exc_info = sys.exc_info()  # preserve original exception
        if isinstance(self.exc_info[1], ExtractorError):
            self.exc_info = self.exc_info[1].exc_info
        super().__init__(self.__msg)

    @property
    def __msg(self):
        return ''.join((
            format_field(self.ie, None, '[%s] '),
            format_field(self.video_id, None, '%s: '),
            self.orig_msg,
            format_field(self.cause, None, ' (caused by %r)'),
            '' if self.expected else bug_reports_message()))

    def format_traceback(self):
        return join_nonempty(
            self.traceback and ''.join(traceback.format_tb(self.traceback)),
            self.cause and ''.join(traceback.format_exception(None, self.cause, self.cause.__traceback__)[1:]),
            delim='\n') or None

    def __setattr__(self, name, value):
        super().__setattr__(name, value)
        if getattr(self, 'msg', None) and name not in ('msg', 'args'):
            self.msg = self.__msg or type(self).__name__
            self.args = (self.msg, )  # Cannot be property


class UnsupportedError(ExtractorError):
    def __init__(self, url):
        super().__init__(
            'Unsupported URL: %s' % url, expected=True)
        self.url = url


class RegexNotFoundError(ExtractorError):
    """Error when a regex didn't match"""
    pass


class GeoRestrictedError(ExtractorError):
    """Geographic restriction Error exception.

    This exception may be thrown when a video is not available from your
    geographic location due to geographic restrictions imposed by a website.
    """

    def __init__(self, msg, countries=None, **kwargs):
        kwargs['expected'] = True
        super().__init__(msg, **kwargs)
        self.countries = countries


class UserNotLive(ExtractorError):
    """Error when a channel/user is not live"""

    def __init__(self, msg=None, **kwargs):
        kwargs['expected'] = True
        super().__init__(msg or 'The channel is not currently live', **kwargs)


class DownloadError(YoutubeDLError):
    """Download Error exception.

    This exception may be thrown by FileDownloader objects if they are not
    configured to continue on errors. They will contain the appropriate
    error message.
    """

    def __init__(self, msg, exc_info=None):
        """ exc_info, if given, is the original exception that caused the trouble (as returned by sys.exc_info()). """
        super().__init__(msg)
        self.exc_info = exc_info


class EntryNotInPlaylist(YoutubeDLError):
    """Entry not in playlist exception.

    This exception will be thrown by YoutubeDL when a requested entry
    is not found in the playlist info_dict
    """
    msg = 'Entry not found in info'


class SameFileError(YoutubeDLError):
    """Same File exception.

    This exception will be thrown by FileDownloader objects if they detect
    multiple files would have to be downloaded to the same file on disk.
    """
    msg = 'Fixed output name but more than one file to download'

    def __init__(self, filename=None):
        if filename is not None:
            self.msg += f': {filename}'
        super().__init__(self.msg)


class PostProcessingError(YoutubeDLError):
    """Post Processing exception.

    This exception may be raised by PostProcessor's .run() method to
    indicate an error in the postprocessing task.
    """


class DownloadCancelled(YoutubeDLError):
    """ Exception raised when the download queue should be interrupted """
    msg = 'The download was cancelled'


class ExistingVideoReached(DownloadCancelled):
    """ --break-on-existing triggered """
    msg = 'Encountered a video that is already in the archive, stopping due to --break-on-existing'


class RejectedVideoReached(DownloadCancelled):
    """ --break-on-reject triggered """
    msg = 'Encountered a video that did not match filter, stopping due to --break-on-reject'


class MaxDownloadsReached(DownloadCancelled):
    """ --max-downloads limit has been reached. """
    msg = 'Maximum number of downloads reached, stopping due to --max-downloads'


class ReExtractInfo(YoutubeDLError):
    """ Video info needs to be re-extracted. """

    def __init__(self, msg, expected=False):
        super().__init__(msg)
        self.expected = expected


class ThrottledDownload(ReExtractInfo):
    """ Download speed below --throttled-rate. """
    msg = 'The download speed is below throttle limit'

    def __init__(self):
        super().__init__(self.msg, expected=False)


class UnavailableVideoError(YoutubeDLError):
    """Unavailable Format exception.

    This exception will be thrown when a video is requested
    in a format that is not available for that video.
    """
    msg = 'Unable to download video'

    def __init__(self, err=None):
        if err is not None:
            self.msg += f': {err}'
        super().__init__(self.msg)


class ContentTooShortError(YoutubeDLError):
    """Content Too Short exception.

    This exception may be raised by FileDownloader objects when a file they
    download is too small for what the server announced first, indicating
    the connection was probably interrupted.
    """

    def __init__(self, downloaded, expected):
        super().__init__(f'Downloaded {downloaded} bytes, expected {expected} bytes')
        # Both in bytes
        self.downloaded = downloaded
        self.expected = expected


class XAttrMetadataError(YoutubeDLError):
    def __init__(self, code=None, msg='Unknown error'):
        super().__init__(msg)
        self.code = code
        self.msg = msg

        # Parsing code and msg
        if (self.code in (errno.ENOSPC, errno.EDQUOT)
                or 'No space left' in self.msg or 'Disk quota exceeded' in self.msg):
            self.reason = 'NO_SPACE'
        elif self.code == errno.E2BIG or 'Argument list too long' in self.msg:
            self.reason = 'VALUE_TOO_LONG'
        else:
            self.reason = 'NOT_SUPPORTED'


class XAttrUnavailableError(YoutubeDLError):
    pass


def _create_http_connection(ydl_handler, http_class, is_https, *args, **kwargs):
    hc = http_class(*args, **kwargs)
    source_address = ydl_handler._params.get('source_address')

    if source_address is not None:
        # This is to workaround _create_connection() from socket where it will try all
        # address data from getaddrinfo() including IPv6. This filters the result from
        # getaddrinfo() based on the source_address value.
        # This is based on the cpython socket.create_connection() function.
        # https://github.com/python/cpython/blob/master/Lib/socket.py#L691
        def _create_connection(address, timeout=socket._GLOBAL_DEFAULT_TIMEOUT, source_address=None):
            host, port = address
            err = None
            addrs = socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM)
            af = socket.AF_INET if '.' in source_address[0] else socket.AF_INET6
            ip_addrs = [addr for addr in addrs if addr[0] == af]
            if addrs and not ip_addrs:
                ip_version = 'v4' if af == socket.AF_INET else 'v6'
                raise OSError(
                    "No remote IP%s addresses available for connect, can't use '%s' as source address"
                    % (ip_version, source_address[0]))
            for res in ip_addrs:
                af, socktype, proto, canonname, sa = res
                sock = None
                try:
                    sock = socket.socket(af, socktype, proto)
                    if timeout is not socket._GLOBAL_DEFAULT_TIMEOUT:
                        sock.settimeout(timeout)
                    sock.bind(source_address)
                    sock.connect(sa)
                    err = None  # Explicitly break reference cycle
                    return sock
                except OSError as _:
                    err = _
                    if sock is not None:
                        sock.close()
            if err is not None:
                raise err
            else:
                raise OSError('getaddrinfo returns an empty list')
        if hasattr(hc, '_create_connection'):
            hc._create_connection = _create_connection
        hc.source_address = (source_address, 0)

    return hc


def handle_youtubedl_headers(headers):
    filtered_headers = headers

    if 'Youtubedl-no-compression' in filtered_headers:
        filtered_headers = {k: v for k, v in filtered_headers.items() if k.lower() != 'accept-encoding'}
        del filtered_headers['Youtubedl-no-compression']

    return filtered_headers


class YoutubeDLHandler(urllib.request.HTTPHandler):
    """Handler for HTTP requests and responses.

    This class, when installed with an OpenerDirector, automatically adds
    the standard headers to every HTTP request and handles gzipped and
    deflated responses from web servers. If compression is to be avoided in
    a particular request, the original request in the program code only has
    to include the HTTP header "Youtubedl-no-compression", which will be
    removed before making the real request.

    Part of this code was copied from:

    http://techknack.net/python-urllib2-handlers/

    Andrew Rowls, the author of that code, agreed to release it to the
    public domain.
    """

    def __init__(self, params, *args, **kwargs):
        urllib.request.HTTPHandler.__init__(self, *args, **kwargs)
        self._params = params

    def http_open(self, req):
        conn_class = http.client.HTTPConnection

        socks_proxy = req.headers.get('Ytdl-socks-proxy')
        if socks_proxy:
            conn_class = make_socks_conn_class(conn_class, socks_proxy)
            del req.headers['Ytdl-socks-proxy']

        return self.do_open(functools.partial(
            _create_http_connection, self, conn_class, False),
            req)

    @staticmethod
    def deflate(data):
        if not data:
            return data
        try:
            return zlib.decompress(data, -zlib.MAX_WBITS)
        except zlib.error:
            return zlib.decompress(data)

    @staticmethod
    def brotli(data):
        if not data:
            return data
        return brotli.decompress(data)

    def http_request(self, req):
        # According to RFC 3986, URLs can not contain non-ASCII characters, however this is not
        # always respected by websites, some tend to give out URLs with non percent-encoded
        # non-ASCII characters (see telemb.py, ard.py [#3412])
        # urllib chokes on URLs with non-ASCII characters (see http://bugs.python.org/issue3991)
        # To work around aforementioned issue we will replace request's original URL with
        # percent-encoded one
        # Since redirects are also affected (e.g. http://www.southpark.de/alle-episoden/s18e09)
        # the code of this workaround has been moved here from YoutubeDL.urlopen()
        url = req.get_full_url()
        url_escaped = escape_url(url)

        # Substitute URL if any change after escaping
        if url != url_escaped:
            req = update_Request(req, url=url_escaped)

        for h, v in self._params.get('http_headers', std_headers).items():
            # Capitalize is needed because of Python bug 2275: http://bugs.python.org/issue2275
            # The dict keys are capitalized because of this bug by urllib
            if h.capitalize() not in req.headers:
                req.add_header(h, v)

        if 'Accept-encoding' not in req.headers:
            req.add_header('Accept-encoding', ', '.join(SUPPORTED_ENCODINGS))

        req.headers = handle_youtubedl_headers(req.headers)

        return super().do_request_(req)

    def http_response(self, req, resp):
        old_resp = resp
        # gzip
        if resp.headers.get('Content-encoding', '') == 'gzip':
            content = resp.read()
            gz = gzip.GzipFile(fileobj=io.BytesIO(content), mode='rb')
            try:
                uncompressed = io.BytesIO(gz.read())
            except OSError as original_ioerror:
                # There may be junk add the end of the file
                # See http://stackoverflow.com/q/4928560/35070 for details
                for i in range(1, 1024):
                    try:
                        gz = gzip.GzipFile(fileobj=io.BytesIO(content[:-i]), mode='rb')
                        uncompressed = io.BytesIO(gz.read())
                    except OSError:
                        continue
                    break
                else:
                    raise original_ioerror
            resp = urllib.request.addinfourl(uncompressed, old_resp.headers, old_resp.url, old_resp.code)
            resp.msg = old_resp.msg
            del resp.headers['Content-encoding']
        # deflate
        if resp.headers.get('Content-encoding', '') == 'deflate':
            gz = io.BytesIO(self.deflate(resp.read()))
            resp = urllib.request.addinfourl(gz, old_resp.headers, old_resp.url, old_resp.code)
            resp.msg = old_resp.msg
            del resp.headers['Content-encoding']
        # brotli
        if resp.headers.get('Content-encoding', '') == 'br':
            resp = urllib.request.addinfourl(
                io.BytesIO(self.brotli(resp.read())), old_resp.headers, old_resp.url, old_resp.code)
            resp.msg = old_resp.msg
            del resp.headers['Content-encoding']
        # Percent-encode redirect URL of Location HTTP header to satisfy RFC 3986 (see
        # https://github.com/ytdl-org/youtube-dl/issues/6457).
        if 300 <= resp.code < 400:
            location = resp.headers.get('Location')
            if location:
                # As of RFC 2616 default charset is iso-8859-1 that is respected by python 3
                location = location.encode('iso-8859-1').decode()
                location_escaped = escape_url(location)
                if location != location_escaped:
                    del resp.headers['Location']
                    resp.headers['Location'] = location_escaped
        return resp

    https_request = http_request
    https_response = http_response


def make_socks_conn_class(base_class, socks_proxy):
    assert issubclass(base_class, (
        http.client.HTTPConnection, http.client.HTTPSConnection))

    url_components = urllib.parse.urlparse(socks_proxy)
    if url_components.scheme.lower() == 'socks5':
        socks_type = ProxyType.SOCKS5
    elif url_components.scheme.lower() in ('socks', 'socks4'):
        socks_type = ProxyType.SOCKS4
    elif url_components.scheme.lower() == 'socks4a':
        socks_type = ProxyType.SOCKS4A

    def unquote_if_non_empty(s):
        if not s:
            return s
        return urllib.parse.unquote_plus(s)

    proxy_args = (
        socks_type,
        url_components.hostname, url_components.port or 1080,
        True,  # Remote DNS
        unquote_if_non_empty(url_components.username),
        unquote_if_non_empty(url_components.password),
    )

    class SocksConnection(base_class):
        def connect(self):
            self.sock = sockssocket()
            self.sock.setproxy(*proxy_args)
            if isinstance(self.timeout, (int, float)):
                self.sock.settimeout(self.timeout)
            self.sock.connect((self.host, self.port))

            if isinstance(self, http.client.HTTPSConnection):
                if hasattr(self, '_context'):  # Python > 2.6
                    self.sock = self._context.wrap_socket(
                        self.sock, server_hostname=self.host)
                else:
                    self.sock = ssl.wrap_socket(self.sock)

    return SocksConnection


class YoutubeDLHTTPSHandler(urllib.request.HTTPSHandler):
    def __init__(self, params, https_conn_class=None, *args, **kwargs):
        urllib.request.HTTPSHandler.__init__(self, *args, **kwargs)
        self._https_conn_class = https_conn_class or http.client.HTTPSConnection
        self._params = params

    def https_open(self, req):
        kwargs = {}
        conn_class = self._https_conn_class

        if hasattr(self, '_context'):  # python > 2.6
            kwargs['context'] = self._context
        if hasattr(self, '_check_hostname'):  # python 3.x
            kwargs['check_hostname'] = self._check_hostname

        socks_proxy = req.headers.get('Ytdl-socks-proxy')
        if socks_proxy:
            conn_class = make_socks_conn_class(conn_class, socks_proxy)
            del req.headers['Ytdl-socks-proxy']

        try:
            return self.do_open(
                functools.partial(_create_http_connection, self, conn_class, True), req, **kwargs)
        except urllib.error.URLError as e:
            if (isinstance(e.reason, ssl.SSLError)
                    and getattr(e.reason, 'reason', None) == 'SSLV3_ALERT_HANDSHAKE_FAILURE'):
                raise YoutubeDLError('SSLV3_ALERT_HANDSHAKE_FAILURE: Try using --legacy-server-connect')
            raise


def is_path_like(f):
    return isinstance(f, (str, bytes, os.PathLike))


class YoutubeDLCookieJar(http.cookiejar.MozillaCookieJar):
    """
    See [1] for cookie file format.

    1. https://curl.haxx.se/docs/http-cookies.html
    """
    _HTTPONLY_PREFIX = '#HttpOnly_'
    _ENTRY_LEN = 7
    _HEADER = '''# Netscape HTTP Cookie File
# This file is generated by yt-dlp.  Do not edit.

'''
    _CookieFileEntry = collections.namedtuple(
        'CookieFileEntry',
        ('domain_name', 'include_subdomains', 'path', 'https_only', 'expires_at', 'name', 'value'))

    def __init__(self, filename=None, *args, **kwargs):
        super().__init__(None, *args, **kwargs)
        if is_path_like(filename):
            filename = os.fspath(filename)
        self.filename = filename

    @staticmethod
    def _true_or_false(cndn):
        return 'TRUE' if cndn else 'FALSE'

    @contextlib.contextmanager
    def open(self, file, *, write=False):
        if is_path_like(file):
            with open(file, 'w' if write else 'r', encoding='utf-8') as f:
                yield f
        else:
            if write:
                file.truncate(0)
            yield file

    def _really_save(self, f, ignore_discard=False, ignore_expires=False):
        now = time.time()
        for cookie in self:
            if (not ignore_discard and cookie.discard
                    or not ignore_expires and cookie.is_expired(now)):
                continue
            name, value = cookie.name, cookie.value
            if value is None:
                # cookies.txt regards 'Set-Cookie: foo' as a cookie
                # with no name, whereas http.cookiejar regards it as a
                # cookie with no value.
                name, value = '', name
            f.write('%s\n' % '\t'.join((
                cookie.domain,
                self._true_or_false(cookie.domain.startswith('.')),
                cookie.path,
                self._true_or_false(cookie.secure),
                str_or_none(cookie.expires, default=''),
                name, value
            )))

    def save(self, filename=None, *args, **kwargs):
        """
        Save cookies to a file.
        Code is taken from CPython 3.6
        https://github.com/python/cpython/blob/8d999cbf4adea053be6dbb612b9844635c4dfb8e/Lib/http/cookiejar.py#L2091-L2117 """

        if filename is None:
            if self.filename is not None:
                filename = self.filename
            else:
                raise ValueError(http.cookiejar.MISSING_FILENAME_TEXT)

        # Store session cookies with `expires` set to 0 instead of an empty string
        for cookie in self:
            if cookie.expires is None:
                cookie.expires = 0

        with self.open(filename, write=True) as f:
            f.write(self._HEADER)
            self._really_save(f, *args, **kwargs)

    def load(self, filename=None, ignore_discard=False, ignore_expires=False):
        """Load cookies from a file."""
        if filename is None:
            if self.filename is not None:
                filename = self.filename
            else:
                raise ValueError(http.cookiejar.MISSING_FILENAME_TEXT)

        def prepare_line(line):
            if line.startswith(self._HTTPONLY_PREFIX):
                line = line[len(self._HTTPONLY_PREFIX):]
            # comments and empty lines are fine
            if line.startswith('#') or not line.strip():
                return line
            cookie_list = line.split('\t')
            if len(cookie_list) != self._ENTRY_LEN:
                raise http.cookiejar.LoadError('invalid length %d' % len(cookie_list))
            cookie = self._CookieFileEntry(*cookie_list)
            if cookie.expires_at and not cookie.expires_at.isdigit():
                raise http.cookiejar.LoadError('invalid expires at %s' % cookie.expires_at)
            return line

        cf = io.StringIO()
        with self.open(filename) as f:
            for line in f:
                try:
                    cf.write(prepare_line(line))
                except http.cookiejar.LoadError as e:
                    if f'{line.strip()} '[0] in '[{"':
                        raise http.cookiejar.LoadError(
                            'Cookies file must be Netscape formatted, not JSON. See  '
                            'https://github.com/yt-dlp/yt-dlp/wiki/FAQ#how-do-i-pass-cookies-to-yt-dlp')
                    write_string(f'WARNING: skipping cookie file entry due to {e}: {line!r}\n')
                    continue
        cf.seek(0)
        self._really_load(cf, filename, ignore_discard, ignore_expires)
        # Session cookies are denoted by either `expires` field set to
        # an empty string or 0. MozillaCookieJar only recognizes the former
        # (see [1]). So we need force the latter to be recognized as session
        # cookies on our own.
        # Session cookies may be important for cookies-based authentication,
        # e.g. usually, when user does not check 'Remember me' check box while
        # logging in on a site, some important cookies are stored as session
        # cookies so that not recognizing them will result in failed login.
        # 1. https://bugs.python.org/issue17164
        for cookie in self:
            # Treat `expires=0` cookies as session cookies
            if cookie.expires == 0:
                cookie.expires = None
                cookie.discard = True


class YoutubeDLCookieProcessor(urllib.request.HTTPCookieProcessor):
    def __init__(self, cookiejar=None):
        urllib.request.HTTPCookieProcessor.__init__(self, cookiejar)

    def http_response(self, request, response):
        return urllib.request.HTTPCookieProcessor.http_response(self, request, response)

    https_request = urllib.request.HTTPCookieProcessor.http_request
    https_response = http_response


class YoutubeDLRedirectHandler(urllib.request.HTTPRedirectHandler):
    """YoutubeDL redirect handler

    The code is based on HTTPRedirectHandler implementation from CPython [1].

    This redirect handler solves two issues:
     - ensures redirect URL is always unicode under python 2
     - introduces support for experimental HTTP response status code
       308 Permanent Redirect [2] used by some sites [3]

    1. https://github.com/python/cpython/blob/master/Lib/urllib/request.py
    2. https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/308
    3. https://github.com/ytdl-org/youtube-dl/issues/28768
    """

    http_error_301 = http_error_303 = http_error_307 = http_error_308 = urllib.request.HTTPRedirectHandler.http_error_302

    def redirect_request(self, req, fp, code, msg, headers, newurl):
        """Return a Request or None in response to a redirect.

        This is called by the http_error_30x methods when a
        redirection response is received.  If a redirection should
        take place, return a new Request to allow http_error_30x to
        perform the redirect.  Otherwise, raise HTTPError if no-one
        else should try to handle this url.  Return None if you can't
        but another Handler might.
        """
        m = req.get_method()
        if (not (code in (301, 302, 303, 307, 308) and m in ("GET", "HEAD")
                 or code in (301, 302, 303) and m == "POST")):
            raise urllib.error.HTTPError(req.full_url, code, msg, headers, fp)
        # Strictly (according to RFC 2616), 301 or 302 in response to
        # a POST MUST NOT cause a redirection without confirmation
        # from the user (of urllib.request, in this case).  In practice,
        # essentially all clients do redirect in this case, so we do
        # the same.

        # Be conciliant with URIs containing a space.  This is mainly
        # redundant with the more complete encoding done in http_error_302(),
        # but it is kept for compatibility with other callers.
        newurl = newurl.replace(' ', '%20')

        CONTENT_HEADERS = ("content-length", "content-type")
        # NB: don't use dict comprehension for python 2.6 compatibility
        newheaders = {k: v for k, v in req.headers.items() if k.lower() not in CONTENT_HEADERS}

        # A 303 must either use GET or HEAD for subsequent request
        # https://datatracker.ietf.org/doc/html/rfc7231#section-6.4.4
        if code == 303 and m != 'HEAD':
            m = 'GET'
        # 301 and 302 redirects are commonly turned into a GET from a POST
        # for subsequent requests by browsers, so we'll do the same.
        # https://datatracker.ietf.org/doc/html/rfc7231#section-6.4.2
        # https://datatracker.ietf.org/doc/html/rfc7231#section-6.4.3
        if code in (301, 302) and m == 'POST':
            m = 'GET'

        return urllib.request.Request(
            newurl, headers=newheaders, origin_req_host=req.origin_req_host,
            unverifiable=True, method=m)


def extract_timezone(date_str):
    m = re.search(
        r'''(?x)
            ^.{8,}?                                              # >=8 char non-TZ prefix, if present
            (?P<tz>Z|                                            # just the UTC Z, or
                (?:(?<=.\b\d{4}|\b\d{2}:\d\d)|                   # preceded by 4 digits or hh:mm or
                   (?<!.\b[a-zA-Z]{3}|[a-zA-Z]{4}|..\b\d\d))     # not preceded by 3 alpha word or >= 4 alpha or 2 digits
                   [ ]?                                          # optional space
                (?P<sign>\+|-)                                   # +/-
                (?P<hours>[0-9]{2}):?(?P<minutes>[0-9]{2})       # hh[:]mm
            $)
        ''', date_str)
    if not m:
        m = re.search(r'\d{1,2}:\d{1,2}(?:\.\d+)?(?P<tz>\s*[A-Z]+)$', date_str)
        timezone = TIMEZONE_NAMES.get(m and m.group('tz').strip())
        if timezone is not None:
            date_str = date_str[:-len(m.group('tz'))]
        timezone = datetime.timedelta(hours=timezone or 0)
    else:
        date_str = date_str[:-len(m.group('tz'))]
        if not m.group('sign'):
            timezone = datetime.timedelta()
        else:
            sign = 1 if m.group('sign') == '+' else -1
            timezone = datetime.timedelta(
                hours=sign * int(m.group('hours')),
                minutes=sign * int(m.group('minutes')))
    return timezone, date_str


def parse_iso8601(date_str, delimiter='T', timezone=None):
    """ Return a UNIX timestamp from the given date """

    if date_str is None:
        return None

    date_str = re.sub(r'\.[0-9]+', '', date_str)

    if timezone is None:
        timezone, date_str = extract_timezone(date_str)

    with contextlib.suppress(ValueError):
        date_format = f'%Y-%m-%d{delimiter}%H:%M:%S'
        dt = datetime.datetime.strptime(date_str, date_format) - timezone
        return calendar.timegm(dt.timetuple())


def date_formats(day_first=True):
    return DATE_FORMATS_DAY_FIRST if day_first else DATE_FORMATS_MONTH_FIRST


def unified_strdate(date_str, day_first=True):
    """Return a string with the date in the format YYYYMMDD"""

    if date_str is None:
        return None
    upload_date = None
    # Replace commas
    date_str = date_str.replace(',', ' ')
    # Remove AM/PM + timezone
    date_str = re.sub(r'(?i)\s*(?:AM|PM)(?:\s+[A-Z]+)?', '', date_str)
    _, date_str = extract_timezone(date_str)

    for expression in date_formats(day_first):
        with contextlib.suppress(ValueError):
            upload_date = datetime.datetime.strptime(date_str, expression).strftime('%Y%m%d')
    if upload_date is None:
        timetuple = email.utils.parsedate_tz(date_str)
        if timetuple:
            with contextlib.suppress(ValueError):
                upload_date = datetime.datetime(*timetuple[:6]).strftime('%Y%m%d')
    if upload_date is not None:
        return str(upload_date)


def unified_timestamp(date_str, day_first=True):
    if date_str is None:
        return None

    date_str = re.sub(r'\s+', ' ', re.sub(
        r'(?i)[,|]|(mon|tues?|wed(nes)?|thu(rs)?|fri|sat(ur)?)(day)?', '', date_str))

    pm_delta = 12 if re.search(r'(?i)PM', date_str) else 0
    timezone, date_str = extract_timezone(date_str)

    # Remove AM/PM + timezone
    date_str = re.sub(r'(?i)\s*(?:AM|PM)(?:\s+[A-Z]+)?', '', date_str)

    # Remove unrecognized timezones from ISO 8601 alike timestamps
    m = re.search(r'\d{1,2}:\d{1,2}(?:\.\d+)?(?P<tz>\s*[A-Z]+)$', date_str)
    if m:
        date_str = date_str[:-len(m.group('tz'))]

    # Python only supports microseconds, so remove nanoseconds
    m = re.search(r'^([0-9]{4,}-[0-9]{1,2}-[0-9]{1,2}T[0-9]{1,2}:[0-9]{1,2}:[0-9]{1,2}\.[0-9]{6})[0-9]+$', date_str)
    if m:
        date_str = m.group(1)

    for expression in date_formats(day_first):
        with contextlib.suppress(ValueError):
            dt = datetime.datetime.strptime(date_str, expression) - timezone + datetime.timedelta(hours=pm_delta)
            return calendar.timegm(dt.timetuple())

    timetuple = email.utils.parsedate_tz(date_str)
    if timetuple:
        return calendar.timegm(timetuple) + pm_delta * 3600 - timezone.total_seconds()


def determine_ext(url, default_ext='unknown_video'):
    if url is None or '.' not in url:
        return default_ext
    guess = url.partition('?')[0].rpartition('.')[2]
    if re.match(r'^[A-Za-z0-9]+$', guess):
        return guess
    # Try extract ext from URLs like http://example.com/foo/bar.mp4/?download
    elif guess.rstrip('/') in KNOWN_EXTENSIONS:
        return guess.rstrip('/')
    else:
        return default_ext


def subtitles_filename(filename, sub_lang, sub_format, expected_real_ext=None):
    return replace_extension(filename, sub_lang + '.' + sub_format, expected_real_ext)


def datetime_from_str(date_str, precision='auto', format='%Y%m%d'):
    R"""
    Return a datetime object from a string.
    Supported format:
        (now|today|yesterday|DATE)([+-]\d+(microsecond|second|minute|hour|day|week|month|year)s?)?

    @param format       strftime format of DATE
    @param precision    Round the datetime object: auto|microsecond|second|minute|hour|day
                        auto: round to the unit provided in date_str (if applicable).
    """
    auto_precision = False
    if precision == 'auto':
        auto_precision = True
        precision = 'microsecond'
    today = datetime_round(datetime.datetime.utcnow(), precision)
    if date_str in ('now', 'today'):
        return today
    if date_str == 'yesterday':
        return today - datetime.timedelta(days=1)
    match = re.match(
        r'(?P<start>.+)(?P<sign>[+-])(?P<time>\d+)(?P<unit>microsecond|second|minute|hour|day|week|month|year)s?',
        date_str)
    if match is not None:
        start_time = datetime_from_str(match.group('start'), precision, format)
        time = int(match.group('time')) * (-1 if match.group('sign') == '-' else 1)
        unit = match.group('unit')
        if unit == 'month' or unit == 'year':
            new_date = datetime_add_months(start_time, time * 12 if unit == 'year' else time)
            unit = 'day'
        else:
            if unit == 'week':
                unit = 'day'
                time *= 7
            delta = datetime.timedelta(**{unit + 's': time})
            new_date = start_time + delta
        if auto_precision:
            return datetime_round(new_date, unit)
        return new_date

    return datetime_round(datetime.datetime.strptime(date_str, format), precision)


def date_from_str(date_str, format='%Y%m%d', strict=False):
    R"""
    Return a date object from a string using datetime_from_str

    @param strict  Restrict allowed patterns to "YYYYMMDD" and
                   (now|today|yesterday)(-\d+(day|week|month|year)s?)?
    """
    if strict and not re.fullmatch(r'\d{8}|(now|today|yesterday)(-\d+(day|week|month|year)s?)?', date_str):
        raise ValueError(f'Invalid date format "{date_str}"')
    return datetime_from_str(date_str, precision='microsecond', format=format).date()


def datetime_add_months(dt, months):
    """Increment/Decrement a datetime object by months."""
    month = dt.month + months - 1
    year = dt.year + month // 12
    month = month % 12 + 1
    day = min(dt.day, calendar.monthrange(year, month)[1])
    return dt.replace(year, month, day)


def datetime_round(dt, precision='day'):
    """
    Round a datetime object's time to a specific precision
    """
    if precision == 'microsecond':
        return dt

    unit_seconds = {
        'day': 86400,
        'hour': 3600,
        'minute': 60,
        'second': 1,
    }
    roundto = lambda x, n: ((x + n / 2) // n) * n
    timestamp = calendar.timegm(dt.timetuple())
    return datetime.datetime.utcfromtimestamp(roundto(timestamp, unit_seconds[precision]))


def hyphenate_date(date_str):
    """
    Convert a date in 'YYYYMMDD' format to 'YYYY-MM-DD' format"""
    match = re.match(r'^(\d\d\d\d)(\d\d)(\d\d)$', date_str)
    if match is not None:
        return '-'.join(match.groups())
    else:
        return date_str


class DateRange:
    """Represents a time interval between two dates"""

    def __init__(self, start=None, end=None):
        """start and end must be strings in the format accepted by date"""
        if start is not None:
            self.start = date_from_str(start, strict=True)
        else:
            self.start = datetime.datetime.min.date()
        if end is not None:
            self.end = date_from_str(end, strict=True)
        else:
            self.end = datetime.datetime.max.date()
        if self.start > self.end:
            raise ValueError('Date range: "%s" , the start date must be before the end date' % self)

    @classmethod
    def day(cls, day):
        """Returns a range that only contains the given day"""
        return cls(day, day)

    def __contains__(self, date):
        """Check if the date is in the range"""
        if not isinstance(date, datetime.date):
            date = date_from_str(date)
        return self.start <= date <= self.end

    def __str__(self):
        return f'{self.start.isoformat()} - {self.end.isoformat()}'

    def __eq__(self, other):
        return (isinstance(other, DateRange)
                and self.start == other.start and self.end == other.end)


def platform_name():
    """ Returns the platform name as a str """
    deprecation_warning(f'"{__name__}.platform_name" is deprecated, use "platform.platform" instead')
    return platform.platform()


@functools.cache
def system_identifier():
    python_implementation = platform.python_implementation()
    if python_implementation == 'PyPy' and hasattr(sys, 'pypy_version_info'):
        python_implementation += ' version %d.%d.%d' % sys.pypy_version_info[:3]
    libc_ver = []
    with contextlib.suppress(OSError):  # We may not have access to the executable
        libc_ver = platform.libc_ver()

    return 'Python %s (%s %s %s) - %s (%s%s)' % (
        platform.python_version(),
        python_implementation,
        platform.machine(),
        platform.architecture()[0],
        platform.platform(),
        ssl.OPENSSL_VERSION,
        format_field(join_nonempty(*libc_ver, delim=' '), None, ', %s'),
    )


@functools.cache
def get_windows_version():
    ''' Get Windows version. returns () if it's not running on Windows '''
    if compat_os_name == 'nt':
        return version_tuple(platform.win32_ver()[1])
    else:
        return ()


def write_string(s, out=None, encoding=None):
    assert isinstance(s, str)
    out = out or sys.stderr

    if compat_os_name == 'nt' and supports_terminal_sequences(out):
        s = re.sub(r'([\r\n]+)', r' \1', s)

    enc, buffer = None, out
    if 'b' in getattr(out, 'mode', ''):
        enc = encoding or preferredencoding()
    elif hasattr(out, 'buffer'):
        buffer = out.buffer
        enc = encoding or getattr(out, 'encoding', None) or preferredencoding()

    buffer.write(s.encode(enc, 'ignore') if enc else s)
    out.flush()


def deprecation_warning(msg, *, printer=None, stacklevel=0, **kwargs):
    from . import _IN_CLI
    if _IN_CLI:
        if msg in deprecation_warning._cache:
            return
        deprecation_warning._cache.add(msg)
        if printer:
            return printer(f'{msg}{bug_reports_message()}', **kwargs)
        return write_string(f'ERROR: {msg}{bug_reports_message()}\n', **kwargs)
    else:
        import warnings
        warnings.warn(DeprecationWarning(msg), stacklevel=stacklevel + 3)


deprecation_warning._cache = set()


def bytes_to_intlist(bs):
    if not bs:
        return []
    if isinstance(bs[0], int):  # Python 3
        return list(bs)
    else:
        return [ord(c) for c in bs]


def intlist_to_bytes(xs):
    if not xs:
        return b''
    return struct.pack('%dB' % len(xs), *xs)


class LockingUnsupportedError(OSError):
    msg = 'File locking is not supported'

    def __init__(self):
        super().__init__(self.msg)


# Cross-platform file locking
if sys.platform == 'win32':
    import ctypes
    import ctypes.wintypes
    import msvcrt

    class OVERLAPPED(ctypes.Structure):
        _fields_ = [
            ('Internal', ctypes.wintypes.LPVOID),
            ('InternalHigh', ctypes.wintypes.LPVOID),
            ('Offset', ctypes.wintypes.DWORD),
            ('OffsetHigh', ctypes.wintypes.DWORD),
            ('hEvent', ctypes.wintypes.HANDLE),
        ]

    kernel32 = ctypes.WinDLL('kernel32')
    LockFileEx = kernel32.LockFileEx
    LockFileEx.argtypes = [
        ctypes.wintypes.HANDLE,     # hFile
        ctypes.wintypes.DWORD,      # dwFlags
        ctypes.wintypes.DWORD,      # dwReserved
        ctypes.wintypes.DWORD,      # nNumberOfBytesToLockLow
        ctypes.wintypes.DWORD,      # nNumberOfBytesToLockHigh
        ctypes.POINTER(OVERLAPPED)  # Overlapped
    ]
    LockFileEx.restype = ctypes.wintypes.BOOL
    UnlockFileEx = kernel32.UnlockFileEx
    UnlockFileEx.argtypes = [
        ctypes.wintypes.HANDLE,     # hFile
        ctypes.wintypes.DWORD,      # dwReserved
        ctypes.wintypes.DWORD,      # nNumberOfBytesToLockLow
        ctypes.wintypes.DWORD,      # nNumberOfBytesToLockHigh
        ctypes.POINTER(OVERLAPPED)  # Overlapped
    ]
    UnlockFileEx.restype = ctypes.wintypes.BOOL
    whole_low = 0xffffffff
    whole_high = 0x7fffffff

    def _lock_file(f, exclusive, block):
        overlapped = OVERLAPPED()
        overlapped.Offset = 0
        overlapped.OffsetHigh = 0
        overlapped.hEvent = 0
        f._lock_file_overlapped_p = ctypes.pointer(overlapped)

        if not LockFileEx(msvcrt.get_osfhandle(f.fileno()),
                          (0x2 if exclusive else 0x0) | (0x0 if block else 0x1),
                          0, whole_low, whole_high, f._lock_file_overlapped_p):
            # NB: No argument form of "ctypes.FormatError" does not work on PyPy
            raise BlockingIOError(f'Locking file failed: {ctypes.FormatError(ctypes.GetLastError())!r}')

    def _unlock_file(f):
        assert f._lock_file_overlapped_p
        handle = msvcrt.get_osfhandle(f.fileno())
        if not UnlockFileEx(handle, 0, whole_low, whole_high, f._lock_file_overlapped_p):
            raise OSError('Unlocking file failed: %r' % ctypes.FormatError())

else:
    try:
        import fcntl

        def _lock_file(f, exclusive, block):
            flags = fcntl.LOCK_EX if exclusive else fcntl.LOCK_SH
            if not block:
                flags |= fcntl.LOCK_NB
            try:
                fcntl.flock(f, flags)
            except BlockingIOError:
                raise
            except OSError:  # AOSP does not have flock()
                fcntl.lockf(f, flags)

        def _unlock_file(f):
            try:
                fcntl.flock(f, fcntl.LOCK_UN)
            except OSError:
                fcntl.lockf(f, fcntl.LOCK_UN)

    except ImportError:

        def _lock_file(f, exclusive, block):
            raise LockingUnsupportedError()

        def _unlock_file(f):
            raise LockingUnsupportedError()


class locked_file:
    locked = False

    def __init__(self, filename, mode, block=True, encoding=None):
        if mode not in {'r', 'rb', 'a', 'ab', 'w', 'wb'}:
            raise NotImplementedError(mode)
        self.mode, self.block = mode, block

        writable = any(f in mode for f in 'wax+')
        readable = any(f in mode for f in 'r+')
        flags = functools.reduce(operator.ior, (
            getattr(os, 'O_CLOEXEC', 0),  # UNIX only
            getattr(os, 'O_BINARY', 0),  # Windows only
            getattr(os, 'O_NOINHERIT', 0),  # Windows only
            os.O_CREAT if writable else 0,  # O_TRUNC only after locking
            os.O_APPEND if 'a' in mode else 0,
            os.O_EXCL if 'x' in mode else 0,
            os.O_RDONLY if not writable else os.O_RDWR if readable else os.O_WRONLY,
        ))

        self.f = os.fdopen(os.open(filename, flags, 0o666), mode, encoding=encoding)

    def __enter__(self):
        exclusive = 'r' not in self.mode
        try:
            _lock_file(self.f, exclusive, self.block)
            self.locked = True
        except OSError:
            self.f.close()
            raise
        if 'w' in self.mode:
            try:
                self.f.truncate()
            except OSError as e:
                if e.errno not in (
                    errno.ESPIPE,  # Illegal seek - expected for FIFO
                    errno.EINVAL,  # Invalid argument - expected for /dev/null
                ):
                    raise
        return self

    def unlock(self):
        if not self.locked:
            return
        try:
            _unlock_file(self.f)
        finally:
            self.locked = False

    def __exit__(self, *_):
        try:
            self.unlock()
        finally:
            self.f.close()

    open = __enter__
    close = __exit__

    def __getattr__(self, attr):
        return getattr(self.f, attr)

    def __iter__(self):
        return iter(self.f)


@functools.cache
def get_filesystem_encoding():
    encoding = sys.getfilesystemencoding()
    return encoding if encoding is not None else 'utf-8'


def shell_quote(args):
    quoted_args = []
    encoding = get_filesystem_encoding()
    for a in args:
        if isinstance(a, bytes):
            # We may get a filename encoded with 'encodeFilename'
            a = a.decode(encoding)
        quoted_args.append(compat_shlex_quote(a))
    return ' '.join(quoted_args)


def smuggle_url(url, data):
    """ Pass additional data in a URL for internal use. """

    url, idata = unsmuggle_url(url, {})
    data.update(idata)
    sdata = urllib.parse.urlencode(
        {'__youtubedl_smuggle': json.dumps(data)})
    return url + '#' + sdata


def unsmuggle_url(smug_url, default=None):
    if '#__youtubedl_smuggle' not in smug_url:
        return smug_url, default
    url, _, sdata = smug_url.rpartition('#')
    jsond = urllib.parse.parse_qs(sdata)['__youtubedl_smuggle'][0]
    data = json.loads(jsond)
    return url, data


def format_decimal_suffix(num, fmt='%d%s', *, factor=1000):
    """ Formats numbers with decimal sufixes like K, M, etc """
    num, factor = float_or_none(num), float(factor)
    if num is None or num < 0:
        return None
    POSSIBLE_SUFFIXES = 'kMGTPEZY'
    exponent = 0 if num == 0 else min(int(math.log(num, factor)), len(POSSIBLE_SUFFIXES))
    suffix = ['', *POSSIBLE_SUFFIXES][exponent]
    if factor == 1024:
        suffix = {'k': 'Ki', '': ''}.get(suffix, f'{suffix}i')
    converted = num / (factor ** exponent)
    return fmt % (converted, suffix)


def format_bytes(bytes):
    return format_decimal_suffix(bytes, '%.2f%sB', factor=1024) or 'N/A'


def lookup_unit_table(unit_table, s, strict=False):
    num_re = NUMBER_RE if strict else NUMBER_RE.replace(R'\.', '[,.]')
    units_re = '|'.join(re.escape(u) for u in unit_table)
    m = (re.fullmatch if strict else re.match)(
        rf'(?P<num>{num_re})\s*(?P<unit>{units_re})\b', s)
    if not m:
        return None

    num = float(m.group('num').replace(',', '.'))
    mult = unit_table[m.group('unit')]
    return round(num * mult)


def parse_bytes(s):
    """Parse a string indicating a byte quantity into an integer"""
    return lookup_unit_table(
        {u: 1024**i for i, u in enumerate(['', *'KMGTPEZY'])},
        s.upper(), strict=True)


def parse_filesize(s):
    if s is None:
        return None

    # The lower-case forms are of course incorrect and unofficial,
    # but we support those too
    _UNIT_TABLE = {
        'B': 1,
        'b': 1,
        'bytes': 1,
        'KiB': 1024,
        'KB': 1000,
        'kB': 1024,
        'Kb': 1000,
        'kb': 1000,
        'kilobytes': 1000,
        'kibibytes': 1024,
        'MiB': 1024 ** 2,
        'MB': 1000 ** 2,
        'mB': 1024 ** 2,
        'Mb': 1000 ** 2,
        'mb': 1000 ** 2,
        'megabytes': 1000 ** 2,
        'mebibytes': 1024 ** 2,
        'GiB': 1024 ** 3,
        'GB': 1000 ** 3,
        'gB': 1024 ** 3,
        'Gb': 1000 ** 3,
        'gb': 1000 ** 3,
        'gigabytes': 1000 ** 3,
        'gibibytes': 1024 ** 3,
        'TiB': 1024 ** 4,
        'TB': 1000 ** 4,
        'tB': 1024 ** 4,
        'Tb': 1000 ** 4,
        'tb': 1000 ** 4,
        'terabytes': 1000 ** 4,
        'tebibytes': 1024 ** 4,
        'PiB': 1024 ** 5,
        'PB': 1000 ** 5,
        'pB': 1024 ** 5,
        'Pb': 1000 ** 5,
        'pb': 1000 ** 5,
        'petabytes': 1000 ** 5,
        'pebibytes': 1024 ** 5,
        'EiB': 1024 ** 6,
        'EB': 1000 ** 6,
        'eB': 1024 ** 6,
        'Eb': 1000 ** 6,
        'eb': 1000 ** 6,
        'exabytes': 1000 ** 6,
        'exbibytes': 1024 ** 6,
        'ZiB': 1024 ** 7,
        'ZB': 1000 ** 7,
        'zB': 1024 ** 7,
        'Zb': 1000 ** 7,
        'zb': 1000 ** 7,
        'zettabytes': 1000 ** 7,
        'zebibytes': 1024 ** 7,
        'YiB': 1024 ** 8,
        'YB': 1000 ** 8,
        'yB': 1024 ** 8,
        'Yb': 1000 ** 8,
        'yb': 1000 ** 8,
        'yottabytes': 1000 ** 8,
        'yobibytes': 1024 ** 8,
    }

    return lookup_unit_table(_UNIT_TABLE, s)


def parse_count(s):
    if s is None:
        return None

    s = re.sub(r'^[^\d]+\s', '', s).strip()

    if re.match(r'^[\d,.]+$', s):
        return str_to_int(s)

    _UNIT_TABLE = {
        'k': 1000,
        'K': 1000,
        'm': 1000 ** 2,
        'M': 1000 ** 2,
        'kk': 1000 ** 2,
        'KK': 1000 ** 2,
        'b': 1000 ** 3,
        'B': 1000 ** 3,
    }

    ret = lookup_unit_table(_UNIT_TABLE, s)
    if ret is not None:
        return ret

    mobj = re.match(r'([\d,.]+)(?:$|\s)', s)
    if mobj:
        return str_to_int(mobj.group(1))


def parse_resolution(s, *, lenient=False):
    if s is None:
        return {}

    if lenient:
        mobj = re.search(r'(?P<w>\d+)\s*[xX×,]\s*(?P<h>\d+)', s)
    else:
        mobj = re.search(r'(?<![a-zA-Z0-9])(?P<w>\d+)\s*[xX×,]\s*(?P<h>\d+)(?![a-zA-Z0-9])', s)
    if mobj:
        return {
            'width': int(mobj.group('w')),
            'height': int(mobj.group('h')),
        }

    mobj = re.search(r'(?<![a-zA-Z0-9])(\d+)[pPiI](?![a-zA-Z0-9])', s)
    if mobj:
        return {'height': int(mobj.group(1))}

    mobj = re.search(r'\b([48])[kK]\b', s)
    if mobj:
        return {'height': int(mobj.group(1)) * 540}

    return {}


def parse_bitrate(s):
    if not isinstance(s, str):
        return
    mobj = re.search(r'\b(\d+)\s*kbps', s)
    if mobj:
        return int(mobj.group(1))


def month_by_name(name, lang='en'):
    """ Return the number of a month by (locale-independently) English name """

    month_names = MONTH_NAMES.get(lang, MONTH_NAMES['en'])

    try:
        return month_names.index(name) + 1
    except ValueError:
        return None


def month_by_abbreviation(abbrev):
    """ Return the number of a month by (locale-independently) English
        abbreviations """

    try:
        return [s[:3] for s in ENGLISH_MONTH_NAMES].index(abbrev) + 1
    except ValueError:
        return None


def fix_xml_ampersands(xml_str):
    """Replace all the '&' by '&amp;' in XML"""
    return re.sub(
        r'&(?!amp;|lt;|gt;|apos;|quot;|#x[0-9a-fA-F]{,4};|#[0-9]{,4};)',
        '&amp;',
        xml_str)


def setproctitle(title):
    assert isinstance(title, str)

    # Workaround for https://github.com/yt-dlp/yt-dlp/issues/4541
    try:
        import ctypes
    except ImportError:
        return

    try:
        libc = ctypes.cdll.LoadLibrary('libc.so.6')
    except OSError:
        return
    except TypeError:
        # LoadLibrary in Windows Python 2.7.13 only expects
        # a bytestring, but since unicode_literals turns
        # every string into a unicode string, it fails.
        return
    title_bytes = title.encode()
    buf = ctypes.create_string_buffer(len(title_bytes))
    buf.value = title_bytes
    try:
        libc.prctl(15, buf, 0, 0, 0)
    except AttributeError:
        return  # Strange libc, just skip this


def remove_start(s, start):
    return s[len(start):] if s is not None and s.startswith(start) else s


def remove_end(s, end):
    return s[:-len(end)] if s is not None and s.endswith(end) else s


def remove_quotes(s):
    if s is None or len(s) < 2:
        return s
    for quote in ('"', "'", ):
        if s[0] == quote and s[-1] == quote:
            return s[1:-1]
    return s


def get_domain(url):
    """
    This implementation is inconsistent, but is kept for compatibility.
    Use this only for "webpage_url_domain"
    """
    return remove_start(urllib.parse.urlparse(url).netloc, 'www.') or None


def url_basename(url):
    path = urllib.parse.urlparse(url).path
    return path.strip('/').split('/')[-1]


def base_url(url):
    return re.match(r'https?://[^?#]+/', url).group()


def urljoin(base, path):
    if isinstance(path, bytes):
        path = path.decode()
    if not isinstance(path, str) or not path:
        return None
    if re.match(r'^(?:[a-zA-Z][a-zA-Z0-9+-.]*:)?//', path):
        return path
    if isinstance(base, bytes):
        base = base.decode()
    if not isinstance(base, str) or not re.match(
            r'^(?:https?:)?//', base):
        return None
    return urllib.parse.urljoin(base, path)


class HEADRequest(urllib.request.Request):
    def get_method(self):
        return 'HEAD'


class PUTRequest(urllib.request.Request):
    def get_method(self):
        return 'PUT'


def int_or_none(v, scale=1, default=None, get_attr=None, invscale=1):
    if get_attr and v is not None:
        v = getattr(v, get_attr, None)
    try:
        return int(v) * invscale // scale
    except (ValueError, TypeError, OverflowError):
        return default


def str_or_none(v, default=None):
    return default if v is None else str(v)


def str_to_int(int_str):
    """ A more relaxed version of int_or_none """
    if isinstance(int_str, int):
        return int_str
    elif isinstance(int_str, str):
        int_str = re.sub(r'[,\.\+]', '', int_str)
        return int_or_none(int_str)


def float_or_none(v, scale=1, invscale=1, default=None):
    if v is None:
        return default
    try:
        return float(v) * invscale / scale
    except (ValueError, TypeError):
        return default


def bool_or_none(v, default=None):
    return v if isinstance(v, bool) else default


def strip_or_none(v, default=None):
    return v.strip() if isinstance(v, str) else default


def url_or_none(url):
    if not url or not isinstance(url, str):
        return None
    url = url.strip()
    return url if re.match(r'^(?:(?:https?|rt(?:m(?:pt?[es]?|fp)|sp[su]?)|mms|ftps?):)?//', url) else None


def request_to_url(req):
    if isinstance(req, urllib.request.Request):
        return req.get_full_url()
    else:
        return req


def strftime_or_none(timestamp, date_format, default=None):
    datetime_object = None
    try:
        if isinstance(timestamp, (int, float)):  # unix timestamp
            # Using naive datetime here can break timestamp() in Windows
            # Ref: https://github.com/yt-dlp/yt-dlp/issues/5185, https://github.com/python/cpython/issues/94414
            datetime_object = datetime.datetime.fromtimestamp(timestamp, datetime.timezone.utc)
        elif isinstance(timestamp, str):  # assume YYYYMMDD
            datetime_object = datetime.datetime.strptime(timestamp, '%Y%m%d')
        date_format = re.sub(  # Support %s on windows
            r'(?<!%)(%%)*%s', rf'\g<1>{int(datetime_object.timestamp())}', date_format)
        return datetime_object.strftime(date_format)
    except (ValueError, TypeError, AttributeError):
        return default


def parse_duration(s):
    if not isinstance(s, str):
        return None
    s = s.strip()
    if not s:
        return None

    days, hours, mins, secs, ms = [None] * 5
    m = re.match(r'''(?x)
            (?P<before_secs>
                (?:(?:(?P<days>[0-9]+):)?(?P<hours>[0-9]+):)?(?P<mins>[0-9]+):)?
            (?P<secs>(?(before_secs)[0-9]{1,2}|[0-9]+))
            (?P<ms>[.:][0-9]+)?Z?$
        ''', s)
    if m:
        days, hours, mins, secs, ms = m.group('days', 'hours', 'mins', 'secs', 'ms')
    else:
        m = re.match(
            r'''(?ix)(?:P?
                (?:
                    [0-9]+\s*y(?:ears?)?,?\s*
                )?
                (?:
                    [0-9]+\s*m(?:onths?)?,?\s*
                )?
                (?:
                    [0-9]+\s*w(?:eeks?)?,?\s*
                )?
                (?:
                    (?P<days>[0-9]+)\s*d(?:ays?)?,?\s*
                )?
                T)?
                (?:
                    (?P<hours>[0-9]+)\s*h(?:ours?)?,?\s*
                )?
                (?:
                    (?P<mins>[0-9]+)\s*m(?:in(?:ute)?s?)?,?\s*
                )?
                (?:
                    (?P<secs>[0-9]+)(?P<ms>\.[0-9]+)?\s*s(?:ec(?:ond)?s?)?\s*
                )?Z?$''', s)
        if m:
            days, hours, mins, secs, ms = m.groups()
        else:
            m = re.match(r'(?i)(?:(?P<hours>[0-9.]+)\s*(?:hours?)|(?P<mins>[0-9.]+)\s*(?:mins?\.?|minutes?)\s*)Z?$', s)
            if m:
                hours, mins = m.groups()
            else:
                return None

    if ms:
        ms = ms.replace(':', '.')
    return sum(float(part or 0) * mult for part, mult in (
        (days, 86400), (hours, 3600), (mins, 60), (secs, 1), (ms, 1)))


def prepend_extension(filename, ext, expected_real_ext=None):
    name, real_ext = os.path.splitext(filename)
    return (
        f'{name}.{ext}{real_ext}'
        if not expected_real_ext or real_ext[1:] == expected_real_ext
        else f'{filename}.{ext}')


def replace_extension(filename, ext, expected_real_ext=None):
    name, real_ext = os.path.splitext(filename)
    return '{}.{}'.format(
        name if not expected_real_ext or real_ext[1:] == expected_real_ext else filename,
        ext)


def check_executable(exe, args=[]):
    """ Checks if the given binary is installed somewhere in PATH, and returns its name.
    args can be a list of arguments for a short output (like -version) """
    try:
        Popen.run([exe] + args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    except OSError:
        return False
    return exe


def _get_exe_version_output(exe, args):
    try:
        # STDIN should be redirected too. On UNIX-like systems, ffmpeg triggers
        # SIGTTOU if yt-dlp is run in the background.
        # See https://github.com/ytdl-org/youtube-dl/issues/955#issuecomment-209789656
        stdout, _, ret = Popen.run([encodeArgument(exe)] + args, text=True,
                                   stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
        if ret:
            return None
    except OSError:
        return False
    return stdout


def detect_exe_version(output, version_re=None, unrecognized='present'):
    assert isinstance(output, str)
    if version_re is None:
        version_re = r'version\s+([-0-9._a-zA-Z]+)'
    m = re.search(version_re, output)
    if m:
        return m.group(1)
    else:
        return unrecognized


def get_exe_version(exe, args=['--version'],
                    version_re=None, unrecognized=('present', 'broken')):
    """ Returns the version of the specified executable,
    or False if the executable is not present """
    unrecognized = variadic(unrecognized)
    assert len(unrecognized) in (1, 2)
    out = _get_exe_version_output(exe, args)
    if out is None:
        return unrecognized[-1]
    return out and detect_exe_version(out, version_re, unrecognized[0])


def frange(start=0, stop=None, step=1):
    """Float range"""
    if stop is None:
        start, stop = 0, start
    sign = [-1, 1][step > 0] if step else 0
    while sign * start < sign * stop:
        yield start
        start += step


class LazyList(collections.abc.Sequence):
    """Lazy immutable list from an iterable
    Note that slices of a LazyList are lists and not LazyList"""

    class IndexError(IndexError):
        pass

    def __init__(self, iterable, *, reverse=False, _cache=None):
        self._iterable = iter(iterable)
        self._cache = [] if _cache is None else _cache
        self._reversed = reverse

    def __iter__(self):
        if self._reversed:
            # We need to consume the entire iterable to iterate in reverse
            yield from self.exhaust()
            return
        yield from self._cache
        for item in self._iterable:
            self._cache.append(item)
            yield item

    def _exhaust(self):
        self._cache.extend(self._iterable)
        self._iterable = []  # Discard the emptied iterable to make it pickle-able
        return self._cache

    def exhaust(self):
        """Evaluate the entire iterable"""
        return self._exhaust()[::-1 if self._reversed else 1]

    @staticmethod
    def _reverse_index(x):
        return None if x is None else ~x

    def __getitem__(self, idx):
        if isinstance(idx, slice):
            if self._reversed:
                idx = slice(self._reverse_index(idx.start), self._reverse_index(idx.stop), -(idx.step or 1))
            start, stop, step = idx.start, idx.stop, idx.step or 1
        elif isinstance(idx, int):
            if self._reversed:
                idx = self._reverse_index(idx)
            start, stop, step = idx, idx, 0
        else:
            raise TypeError('indices must be integers or slices')
        if ((start or 0) < 0 or (stop or 0) < 0
                or (start is None and step < 0)
                or (stop is None and step > 0)):
            # We need to consume the entire iterable to be able to slice from the end
            # Obviously, never use this with infinite iterables
            self._exhaust()
            try:
                return self._cache[idx]
            except IndexError as e:
                raise self.IndexError(e) from e
        n = max(start or 0, stop or 0) - len(self._cache) + 1
        if n > 0:
            self._cache.extend(itertools.islice(self._iterable, n))
        try:
            return self._cache[idx]
        except IndexError as e:
            raise self.IndexError(e) from e

    def __bool__(self):
        try:
            self[-1] if self._reversed else self[0]
        except self.IndexError:
            return False
        return True

    def __len__(self):
        self._exhaust()
        return len(self._cache)

    def __reversed__(self):
        return type(self)(self._iterable, reverse=not self._reversed, _cache=self._cache)

    def __copy__(self):
        return type(self)(self._iterable, reverse=self._reversed, _cache=self._cache)

    def __repr__(self):
        # repr and str should mimic a list. So we exhaust the iterable
        return repr(self.exhaust())

    def __str__(self):
        return repr(self.exhaust())


class PagedList:

    class IndexError(IndexError):
        pass

    def __len__(self):
        # This is only useful for tests
        return len(self.getslice())

    def __init__(self, pagefunc, pagesize, use_cache=True):
        self._pagefunc = pagefunc
        self._pagesize = pagesize
        self._pagecount = float('inf')
        self._use_cache = use_cache
        self._cache = {}

    def getpage(self, pagenum):
        page_results = self._cache.get(pagenum)
        if page_results is None:
            page_results = [] if pagenum > self._pagecount else list(self._pagefunc(pagenum))
        if self._use_cache:
            self._cache[pagenum] = page_results
        return page_results

    def getslice(self, start=0, end=None):
        return list(self._getslice(start, end))

    def _getslice(self, start, end):
        raise NotImplementedError('This method must be implemented by subclasses')

    def __getitem__(self, idx):
        assert self._use_cache, 'Indexing PagedList requires cache'
        if not isinstance(idx, int) or idx < 0:
            raise TypeError('indices must be non-negative integers')
        entries = self.getslice(idx, idx + 1)
        if not entries:
            raise self.IndexError()
        return entries[0]


class OnDemandPagedList(PagedList):
    """Download pages until a page with less than maximum results"""

    def _getslice(self, start, end):
        for pagenum in itertools.count(start // self._pagesize):
            firstid = pagenum * self._pagesize
            nextfirstid = pagenum * self._pagesize + self._pagesize
            if start >= nextfirstid:
                continue

            startv = (
                start % self._pagesize
                if firstid <= start < nextfirstid
                else 0)
            endv = (
                ((end - 1) % self._pagesize) + 1
                if (end is not None and firstid <= end <= nextfirstid)
                else None)

            try:
                page_results = self.getpage(pagenum)
            except Exception:
                self._pagecount = pagenum - 1
                raise
            if startv != 0 or endv is not None:
                page_results = page_results[startv:endv]
            yield from page_results

            # A little optimization - if current page is not "full", ie. does
            # not contain page_size videos then we can assume that this page
            # is the last one - there are no more ids on further pages -
            # i.e. no need to query again.
            if len(page_results) + startv < self._pagesize:
                break

            # If we got the whole page, but the next page is not interesting,
            # break out early as well
            if end == nextfirstid:
                break


class InAdvancePagedList(PagedList):
    """PagedList with total number of pages known in advance"""

    def __init__(self, pagefunc, pagecount, pagesize):
        PagedList.__init__(self, pagefunc, pagesize, True)
        self._pagecount = pagecount

    def _getslice(self, start, end):
        start_page = start // self._pagesize
        end_page = self._pagecount if end is None else min(self._pagecount, end // self._pagesize + 1)
        skip_elems = start - start_page * self._pagesize
        only_more = None if end is None else end - start
        for pagenum in range(start_page, end_page):
            page_results = self.getpage(pagenum)
            if skip_elems:
                page_results = page_results[skip_elems:]
                skip_elems = None
            if only_more is not None:
                if len(page_results) < only_more:
                    only_more -= len(page_results)
                else:
                    yield from page_results[:only_more]
                    break
            yield from page_results


class PlaylistEntries:
    MissingEntry = object()
    is_exhausted = False

    def __init__(self, ydl, info_dict):
        self.ydl = ydl

        # _entries must be assigned now since infodict can change during iteration
        entries = info_dict.get('entries')
        if entries is None:
            raise EntryNotInPlaylist('There are no entries')
        elif isinstance(entries, list):
            self.is_exhausted = True

        requested_entries = info_dict.get('requested_entries')
        self.is_incomplete = requested_entries is not None
        if self.is_incomplete:
            assert self.is_exhausted
            self._entries = [self.MissingEntry] * max(requested_entries or [0])
            for i, entry in zip(requested_entries, entries):
                self._entries[i - 1] = entry
        elif isinstance(entries, (list, PagedList, LazyList)):
            self._entries = entries
        else:
            self._entries = LazyList(entries)

    PLAYLIST_ITEMS_RE = re.compile(r'''(?x)
        (?P<start>[+-]?\d+)?
        (?P<range>[:-]
            (?P<end>[+-]?\d+|inf(?:inite)?)?
            (?::(?P<step>[+-]?\d+))?
        )?''')

    @classmethod
    def parse_playlist_items(cls, string):
        for segment in string.split(','):
            if not segment:
                raise ValueError('There is two or more consecutive commas')
            mobj = cls.PLAYLIST_ITEMS_RE.fullmatch(segment)
            if not mobj:
                raise ValueError(f'{segment!r} is not a valid specification')
            start, end, step, has_range = mobj.group('start', 'end', 'step', 'range')
            if int_or_none(step) == 0:
                raise ValueError(f'Step in {segment!r} cannot be zero')
            yield slice(int_or_none(start), float_or_none(end), int_or_none(step)) if has_range else int(start)

    def get_requested_items(self):
        playlist_items = self.ydl.params.get('playlist_items')
        playlist_start = self.ydl.params.get('playliststart', 1)
        playlist_end = self.ydl.params.get('playlistend')
        # For backwards compatibility, interpret -1 as whole list
        if playlist_end in (-1, None):
            playlist_end = ''
        if not playlist_items:
            playlist_items = f'{playlist_start}:{playlist_end}'
        elif playlist_start != 1 or playlist_end:
            self.ydl.report_warning('Ignoring playliststart and playlistend because playlistitems was given', only_once=True)

        for index in self.parse_playlist_items(playlist_items):
            for i, entry in self[index]:
                yield i, entry
                if not entry:
                    continue
                try:
                    # TODO: Add auto-generated fields
                    self.ydl._match_entry(entry, incomplete=True, silent=True)
                except (ExistingVideoReached, RejectedVideoReached):
                    return

    def get_full_count(self):
        if self.is_exhausted and not self.is_incomplete:
            return len(self)
        elif isinstance(self._entries, InAdvancePagedList):
            if self._entries._pagesize == 1:
                return self._entries._pagecount

    @functools.cached_property
    def _getter(self):
        if isinstance(self._entries, list):
            def get_entry(i):
                try:
                    entry = self._entries[i]
                except IndexError:
                    entry = self.MissingEntry
                    if not self.is_incomplete:
                        raise self.IndexError()
                if entry is self.MissingEntry:
                    raise EntryNotInPlaylist(f'Entry {i + 1} cannot be found')
                return entry
        else:
            def get_entry(i):
                try:
                    return type(self.ydl)._handle_extraction_exceptions(lambda _, i: self._entries[i])(self.ydl, i)
                except (LazyList.IndexError, PagedList.IndexError):
                    raise self.IndexError()
        return get_entry

    def __getitem__(self, idx):
        if isinstance(idx, int):
            idx = slice(idx, idx)

        # NB: PlaylistEntries[1:10] => (0, 1, ... 9)
        step = 1 if idx.step is None else idx.step
        if idx.start is None:
            start = 0 if step > 0 else len(self) - 1
        else:
            start = idx.start - 1 if idx.start >= 0 else len(self) + idx.start

        # NB: Do not call len(self) when idx == [:]
        if idx.stop is None:
            stop = 0 if step < 0 else float('inf')
        else:
            stop = idx.stop - 1 if idx.stop >= 0 else len(self) + idx.stop
        stop += [-1, 1][step > 0]

        for i in frange(start, stop, step):
            if i < 0:
                continue
            try:
                entry = self._getter(i)
            except self.IndexError:
                self.is_exhausted = True
                if step > 0:
                    break
                continue
            yield i + 1, entry

    def __len__(self):
        return len(tuple(self[:]))

    class IndexError(IndexError):
        pass


def uppercase_escape(s):
    unicode_escape = codecs.getdecoder('unicode_escape')
    return re.sub(
        r'\\U[0-9a-fA-F]{8}',
        lambda m: unicode_escape(m.group(0))[0],
        s)


def lowercase_escape(s):
    unicode_escape = codecs.getdecoder('unicode_escape')
    return re.sub(
        r'\\u[0-9a-fA-F]{4}',
        lambda m: unicode_escape(m.group(0))[0],
        s)


def escape_rfc3986(s):
    """Escape non-ASCII characters as suggested by RFC 3986"""
    return urllib.parse.quote(s, b"%/;:@&=+$,!~*'()?#[]")


def escape_url(url):
    """Escape URL as suggested by RFC 3986"""
    url_parsed = urllib.parse.urlparse(url)
    return url_parsed._replace(
        netloc=url_parsed.netloc.encode('idna').decode('ascii'),
        path=escape_rfc3986(url_parsed.path),
        params=escape_rfc3986(url_parsed.params),
        query=escape_rfc3986(url_parsed.query),
        fragment=escape_rfc3986(url_parsed.fragment)
    ).geturl()


def parse_qs(url, **kwargs):
    return urllib.parse.parse_qs(urllib.parse.urlparse(url).query, **kwargs)


def read_batch_urls(batch_fd):
    def fixup(url):
        if not isinstance(url, str):
            url = url.decode('utf-8', 'replace')
        BOM_UTF8 = ('\xef\xbb\xbf', '\ufeff')
        for bom in BOM_UTF8:
            if url.startswith(bom):
                url = url[len(bom):]
        url = url.lstrip()
        if not url or url.startswith(('#', ';', ']')):
            return False
        # "#" cannot be stripped out since it is part of the URI
        # However, it can be safely stripped out if following a whitespace
        return re.split(r'\s#', url, 1)[0].rstrip()

    with contextlib.closing(batch_fd) as fd:
        return [url for url in map(fixup, fd) if url]


def urlencode_postdata(*args, **kargs):
    return urllib.parse.urlencode(*args, **kargs).encode('ascii')


def update_url_query(url, query):
    if not query:
        return url
    parsed_url = urllib.parse.urlparse(url)
    qs = urllib.parse.parse_qs(parsed_url.query)
    qs.update(query)
    return urllib.parse.urlunparse(parsed_url._replace(
        query=urllib.parse.urlencode(qs, True)))


def update_Request(req, url=None, data=None, headers=None, query=None):
    req_headers = req.headers.copy()
    req_headers.update(headers or {})
    req_data = data or req.data
    req_url = update_url_query(url or req.get_full_url(), query)
    req_get_method = req.get_method()
    if req_get_method == 'HEAD':
        req_type = HEADRequest
    elif req_get_method == 'PUT':
        req_type = PUTRequest
    else:
        req_type = urllib.request.Request
    new_req = req_type(
        req_url, data=req_data, headers=req_headers,
        origin_req_host=req.origin_req_host, unverifiable=req.unverifiable)
    if hasattr(req, 'timeout'):
        new_req.timeout = req.timeout
    return new_req


def _multipart_encode_impl(data, boundary):
    content_type = 'multipart/form-data; boundary=%s' % boundary

    out = b''
    for k, v in data.items():
        out += b'--' + boundary.encode('ascii') + b'\r\n'
        if isinstance(k, str):
            k = k.encode()
        if isinstance(v, str):
            v = v.encode()
        # RFC 2047 requires non-ASCII field names to be encoded, while RFC 7578
        # suggests sending UTF-8 directly. Firefox sends UTF-8, too
        content = b'Content-Disposition: form-data; name="' + k + b'"\r\n\r\n' + v + b'\r\n'
        if boundary.encode('ascii') in content:
            raise ValueError('Boundary overlaps with data')
        out += content

    out += b'--' + boundary.encode('ascii') + b'--\r\n'

    return out, content_type


def multipart_encode(data, boundary=None):
    '''
    Encode a dict to RFC 7578-compliant form-data

    data:
        A dict where keys and values can be either Unicode or bytes-like
        objects.
    boundary:
        If specified a Unicode object, it's used as the boundary. Otherwise
        a random boundary is generated.

    Reference: https://tools.ietf.org/html/rfc7578
    '''
    has_specified_boundary = boundary is not None

    while True:
        if boundary is None:
            boundary = '---------------' + str(random.randrange(0x0fffffff, 0xffffffff))

        try:
            out, content_type = _multipart_encode_impl(data, boundary)
            break
        except ValueError:
            if has_specified_boundary:
                raise
            boundary = None

    return out, content_type


def variadic(x, allowed_types=(str, bytes, dict)):
    return x if isinstance(x, collections.abc.Iterable) and not isinstance(x, allowed_types) else (x,)


def dict_get(d, key_or_keys, default=None, skip_false_values=True):
    for val in map(d.get, variadic(key_or_keys)):
        if val is not None and (val or not skip_false_values):
            return val
    return default


def try_call(*funcs, expected_type=None, args=[], kwargs={}):
    for f in funcs:
        try:
            val = f(*args, **kwargs)
        except (AttributeError, KeyError, TypeError, IndexError, ValueError, ZeroDivisionError):
            pass
        else:
            if expected_type is None or isinstance(val, expected_type):
                return val


def try_get(src, getter, expected_type=None):
    return try_call(*variadic(getter), args=(src,), expected_type=expected_type)


def filter_dict(dct, cndn=lambda _, v: v is not None):
    return {k: v for k, v in dct.items() if cndn(k, v)}


def merge_dicts(*dicts):
    merged = {}
    for a_dict in dicts:
        for k, v in a_dict.items():
            if (v is not None and k not in merged
                    or isinstance(v, str) and merged[k] == ''):
                merged[k] = v
    return merged


def encode_compat_str(string, encoding=preferredencoding(), errors='strict'):
    return string if isinstance(string, str) else str(string, encoding, errors)


US_RATINGS = {
    'G': 0,
    'PG': 10,
    'PG-13': 13,
    'R': 16,
    'NC': 18,
}


TV_PARENTAL_GUIDELINES = {
    'TV-Y': 0,
    'TV-Y7': 7,
    'TV-G': 0,
    'TV-PG': 0,
    'TV-14': 14,
    'TV-MA': 17,
}


def parse_age_limit(s):
    # isinstance(False, int) is True. So type() must be used instead
    if type(s) is int:  # noqa: E721
        return s if 0 <= s <= 21 else None
    elif not isinstance(s, str):
        return None
    m = re.match(r'^(?P<age>\d{1,2})\+?$', s)
    if m:
        return int(m.group('age'))
    s = s.upper()
    if s in US_RATINGS:
        return US_RATINGS[s]
    m = re.match(r'^TV[_-]?(%s)$' % '|'.join(k[3:] for k in TV_PARENTAL_GUIDELINES), s)
    if m:
        return TV_PARENTAL_GUIDELINES['TV-' + m.group(1)]
    return None


def strip_jsonp(code):
    return re.sub(
        r'''(?sx)^
            (?:window\.)?(?P<func_name>[a-zA-Z0-9_.$]*)
            (?:\s*&&\s*(?P=func_name))?
            \s*\(\s*(?P<callback_data>.*)\);?
            \s*?(?://[^\n]*)*$''',
        r'\g<callback_data>', code)


def js_to_json(code, vars={}, *, strict=False):
    # vars is a dict of var, val pairs to substitute
    STRING_QUOTES = '\'"'
    STRING_RE = '|'.join(rf'{q}(?:\\.|[^\\{q}])*{q}' for q in STRING_QUOTES)
    COMMENT_RE = r'/\*(?:(?!\*/).)*?\*/|//[^\n]*\n'
    SKIP_RE = fr'\s*(?:{COMMENT_RE})?\s*'
    INTEGER_TABLE = (
        (fr'(?s)^(0[xX][0-9a-fA-F]+){SKIP_RE}:?$', 16),
        (fr'(?s)^(0+[0-7]+){SKIP_RE}:?$', 8),
    )

    def process_escape(match):
        JSON_PASSTHROUGH_ESCAPES = R'"\bfnrtu'
        escape = match.group(1) or match.group(2)

        return (Rf'\{escape}' if escape in JSON_PASSTHROUGH_ESCAPES
                else R'\u00' if escape == 'x'
                else '' if escape == '\n'
                else escape)

    def fix_kv(m):
        v = m.group(0)
        if v in ('true', 'false', 'null'):
            return v
        elif v in ('undefined', 'void 0'):
            return 'null'
        elif v.startswith('/*') or v.startswith('//') or v.startswith('!') or v == ',':
            return ''

        if v[0] in STRING_QUOTES:
            escaped = re.sub(r'(?s)(")|\\(.)', process_escape, v[1:-1])
            return f'"{escaped}"'

        for regex, base in INTEGER_TABLE:
            im = re.match(regex, v)
            if im:
                i = int(im.group(1), base)
                return f'"{i}":' if v.endswith(':') else str(i)

        if v in vars:
            try:
                if not strict:
                    json.loads(vars[v])
            except json.JSONDecodeError:
                return json.dumps(vars[v])
            else:
                return vars[v]

        if not strict:
            return f'"{v}"'

        raise ValueError(f'Unknown value: {v}')

    def create_map(mobj):
        return json.dumps(dict(json.loads(js_to_json(mobj.group(1) or '[]', vars=vars))))

    code = re.sub(r'new Map\((\[.*?\])?\)', create_map, code)
    if not strict:
        code = re.sub(r'new Date\((".+")\)', r'\g<1>', code)
        code = re.sub(r'new \w+\((.*?)\)', lambda m: json.dumps(m.group(0)), code)

    return re.sub(rf'''(?sx)
        {STRING_RE}|
        {COMMENT_RE}|,(?={SKIP_RE}[\]}}])|
        void\s0|(?:(?<![0-9])[eE]|[a-df-zA-DF-Z_$])[.a-zA-Z_$0-9]*|
        \b(?:0[xX][0-9a-fA-F]+|0+[0-7]+)(?:{SKIP_RE}:)?|
        [0-9]+(?={SKIP_RE}:)|
        !+
        ''', fix_kv, code)


def qualities(quality_ids):
    """ Get a numeric quality value out of a list of possible values """
    def q(qid):
        try:
            return quality_ids.index(qid)
        except ValueError:
            return -1
    return q


POSTPROCESS_WHEN = ('pre_process', 'after_filter', 'video', 'before_dl', 'post_process', 'after_move', 'after_video', 'playlist')


DEFAULT_OUTTMPL = {
    'default': '%(title)s [%(id)s].%(ext)s',
    'chapter': '%(title)s - %(section_number)03d %(section_title)s [%(id)s].%(ext)s',
}
OUTTMPL_TYPES = {
    'chapter': None,
    'subtitle': None,
    'thumbnail': None,
    'description': 'description',
    'annotation': 'annotations.xml',
    'infojson': 'info.json',
    'link': None,
    'pl_video': None,
    'pl_thumbnail': None,
    'pl_description': 'description',
    'pl_infojson': 'info.json',
}

# As of [1] format syntax is:
#  %[mapping_key][conversion_flags][minimum_width][.precision][length_modifier]type
# 1. https://docs.python.org/2/library/stdtypes.html#string-formatting
STR_FORMAT_RE_TMPL = r'''(?x)
    (?<!%)(?P<prefix>(?:%%)*)
    %
    (?P<has_key>\((?P<key>{0})\))?
    (?P<format>
        (?P<conversion>[#0\-+ ]+)?
        (?P<min_width>\d+)?
        (?P<precision>\.\d+)?
        (?P<len_mod>[hlL])?  # unused in python
        {1}  # conversion type
    )
'''


STR_FORMAT_TYPES = 'diouxXeEfFgGcrs'


def limit_length(s, length):
    """ Add ellipses to overly long strings """
    if s is None:
        return None
    ELLIPSES = '...'
    if len(s) > length:
        return s[:length - len(ELLIPSES)] + ELLIPSES
    return s


def version_tuple(v):
    return tuple(int(e) for e in re.split(r'[-.]', v))


def is_outdated_version(version, limit, assume_new=True):
    if not version:
        return not assume_new
    try:
        return version_tuple(version) < version_tuple(limit)
    except ValueError:
        return not assume_new


def ytdl_is_updateable():
    """ Returns if yt-dlp can be updated with -U """

    from .update import is_non_updateable

    return not is_non_updateable()


def args_to_str(args):
    # Get a short string representation for a subprocess command
    return ' '.join(compat_shlex_quote(a) for a in args)


def error_to_compat_str(err):
    return str(err)


def error_to_str(err):
    return f'{type(err).__name__}: {err}'


def mimetype2ext(mt, default=NO_DEFAULT):
    if not isinstance(mt, str):
        if default is not NO_DEFAULT:
            return default
        return None

    MAP = {
        # video
        '3gpp': '3gp',
        'mp2t': 'ts',
        'mp4': 'mp4',
        'mpeg': 'mpeg',
        'mpegurl': 'm3u8',
        'quicktime': 'mov',
        'webm': 'webm',
        'vp9': 'vp9',
        'x-flv': 'flv',
        'x-m4v': 'm4v',
        'x-matroska': 'mkv',
        'x-mng': 'mng',
        'x-mp4-fragmented': 'mp4',
        'x-ms-asf': 'asf',
        'x-ms-wmv': 'wmv',
        'x-msvideo': 'avi',

        # application (streaming playlists)
        'dash+xml': 'mpd',
        'f4m+xml': 'f4m',
        'hds+xml': 'f4m',
        'vnd.apple.mpegurl': 'm3u8',
        'vnd.ms-sstr+xml': 'ism',
        'x-mpegurl': 'm3u8',

        # audio
        'audio/mp4': 'm4a',
        # Per RFC 3003, audio/mpeg can be .mp1, .mp2 or .mp3.
        # Using .mp3 as it's the most popular one
        'audio/mpeg': 'mp3',
        'audio/webm': 'webm',
        'audio/x-matroska': 'mka',
        'audio/x-mpegurl': 'm3u',
        'midi': 'mid',
        'ogg': 'ogg',
        'wav': 'wav',
        'wave': 'wav',
        'x-aac': 'aac',
        'x-flac': 'flac',
        'x-m4a': 'm4a',
        'x-realaudio': 'ra',
        'x-wav': 'wav',

        # image
        'avif': 'avif',
        'bmp': 'bmp',
        'gif': 'gif',
        'jpeg': 'jpg',
        'png': 'png',
        'svg+xml': 'svg',
        'tiff': 'tif',
        'vnd.wap.wbmp': 'wbmp',
        'webp': 'webp',
        'x-icon': 'ico',
        'x-jng': 'jng',
        'x-ms-bmp': 'bmp',

        # caption
        'filmstrip+json': 'fs',
        'smptett+xml': 'tt',
        'ttaf+xml': 'dfxp',
        'ttml+xml': 'ttml',
        'x-ms-sami': 'sami',

        # misc
        'gzip': 'gz',
        'json': 'json',
        'xml': 'xml',
        'zip': 'zip',
    }

    mimetype = mt.partition(';')[0].strip().lower()
    _, _, subtype = mimetype.rpartition('/')

    ext = traverse_obj(MAP, mimetype, subtype, subtype.rsplit('+')[-1])
    if ext:
        return ext
    elif default is not NO_DEFAULT:
        return default
    return subtype.replace('+', '.')


def ext2mimetype(ext_or_url):
    if not ext_or_url:
        return None
    if '.' not in ext_or_url:
        ext_or_url = f'file.{ext_or_url}'
    return mimetypes.guess_type(ext_or_url)[0]


def parse_codecs(codecs_str):
    # http://tools.ietf.org/html/rfc6381
    if not codecs_str:
        return {}
    split_codecs = list(filter(None, map(
        str.strip, codecs_str.strip().strip(',').split(','))))
    vcodec, acodec, scodec, hdr = None, None, None, None
    for full_codec in split_codecs:
        parts = re.sub(r'0+(?=\d)', '', full_codec).split('.')
        if parts[0] in ('avc1', 'avc2', 'avc3', 'avc4', 'vp9', 'vp8', 'hev1', 'hev2',
                        'h263', 'h264', 'mp4v', 'hvc1', 'av1', 'theora', 'dvh1', 'dvhe'):
            if vcodec:
                continue
            vcodec = full_codec
            if parts[0] in ('dvh1', 'dvhe'):
                hdr = 'DV'
            elif parts[0] == 'av1' and traverse_obj(parts, 3) == '10':
                hdr = 'HDR10'
            elif parts[:2] == ['vp9', '2']:
                hdr = 'HDR10'
        elif parts[0] in ('flac', 'mp4a', 'opus', 'vorbis', 'mp3', 'aac', 'ac-4',
                          'ac-3', 'ec-3', 'eac3', 'dtsc', 'dtse', 'dtsh', 'dtsl'):
            acodec = acodec or full_codec
        elif parts[0] in ('stpp', 'wvtt'):
            scodec = scodec or full_codec
        else:
            write_string(f'WARNING: Unknown codec {full_codec}\n')
    if vcodec or acodec or scodec:
        return {
            'vcodec': vcodec or 'none',
            'acodec': acodec or 'none',
            'dynamic_range': hdr,
            **({'scodec': scodec} if scodec is not None else {}),
        }
    elif len(split_codecs) == 2:
        return {
            'vcodec': split_codecs[0],
            'acodec': split_codecs[1],
        }
    return {}


def get_compatible_ext(*, vcodecs, acodecs, vexts, aexts, preferences=None):
    assert len(vcodecs) == len(vexts) and len(acodecs) == len(aexts)

    allow_mkv = not preferences or 'mkv' in preferences

    if allow_mkv and max(len(acodecs), len(vcodecs)) > 1:
        return 'mkv'  # TODO: any other format allows this?

    # TODO: All codecs supported by parse_codecs isn't handled here
    COMPATIBLE_CODECS = {
        'mp4': {
            'av1', 'hevc', 'avc1', 'mp4a', 'ac-4',  # fourcc (m3u8, mpd)
            'h264', 'aacl', 'ec-3',  # Set in ISM
        },
        'webm': {
            'av1', 'vp9', 'vp8', 'opus', 'vrbs',
            'vp9x', 'vp8x',  # in the webm spec
        },
    }

    sanitize_codec = functools.partial(try_get, getter=lambda x: x[0].split('.')[0].replace('0', ''))
    vcodec, acodec = sanitize_codec(vcodecs), sanitize_codec(acodecs)

    for ext in preferences or COMPATIBLE_CODECS.keys():
        codec_set = COMPATIBLE_CODECS.get(ext, set())
        if ext == 'mkv' or codec_set.issuperset((vcodec, acodec)):
            return ext

    COMPATIBLE_EXTS = (
        {'mp3', 'mp4', 'm4a', 'm4p', 'm4b', 'm4r', 'm4v', 'ismv', 'isma', 'mov'},
        {'webm', 'weba'},
    )
    for ext in preferences or vexts:
        current_exts = {ext, *vexts, *aexts}
        if ext == 'mkv' or current_exts == {ext} or any(
                ext_sets.issuperset(current_exts) for ext_sets in COMPATIBLE_EXTS):
            return ext
    return 'mkv' if allow_mkv else preferences[-1]


def urlhandle_detect_ext(url_handle, default=NO_DEFAULT):
    getheader = url_handle.headers.get

    cd = getheader('Content-Disposition')
    if cd:
        m = re.match(r'attachment;\s*filename="(?P<filename>[^"]+)"', cd)
        if m:
            e = determine_ext(m.group('filename'), default_ext=None)
            if e:
                return e

    meta_ext = getheader('x-amz-meta-name')
    if meta_ext:
        e = meta_ext.rpartition('.')[2]
        if e:
            return e

    return mimetype2ext(getheader('Content-Type'), default=default)


def encode_data_uri(data, mime_type):
    return 'data:%s;base64,%s' % (mime_type, base64.b64encode(data).decode('ascii'))


def age_restricted(content_limit, age_limit):
    """ Returns True iff the content should be blocked """

    if age_limit is None:  # No limit set
        return False
    if content_limit is None:
        return False  # Content available for everyone
    return age_limit < content_limit


# List of known byte-order-marks (BOM)
BOMS = [
    (b'\xef\xbb\xbf', 'utf-8'),
    (b'\x00\x00\xfe\xff', 'utf-32-be'),
    (b'\xff\xfe\x00\x00', 'utf-32-le'),
    (b'\xff\xfe', 'utf-16-le'),
    (b'\xfe\xff', 'utf-16-be'),
]


def is_html(first_bytes):
    """ Detect whether a file contains HTML by examining its first bytes. """

    encoding = 'utf-8'
    for bom, enc in BOMS:
        while first_bytes.startswith(bom):
            encoding, first_bytes = enc, first_bytes[len(bom):]

    return re.match(r'^\s*<', first_bytes.decode(encoding, 'replace'))


def determine_protocol(info_dict):
    protocol = info_dict.get('protocol')
    if protocol is not None:
        return protocol

    url = sanitize_url(info_dict['url'])
    if url.startswith('rtmp'):
        return 'rtmp'
    elif url.startswith('mms'):
        return 'mms'
    elif url.startswith('rtsp'):
        return 'rtsp'

    ext = determine_ext(url)
    if ext == 'm3u8':
        return 'm3u8' if info_dict.get('is_live') else 'm3u8_native'
    elif ext == 'f4m':
        return 'f4m'

    return urllib.parse.urlparse(url).scheme


def render_table(header_row, data, delim=False, extra_gap=0, hide_empty=False):
    """ Render a list of rows, each as a list of values.
    Text after a \t will be right aligned """
    def width(string):
        return len(remove_terminal_sequences(string).replace('\t', ''))

    def get_max_lens(table):
        return [max(width(str(v)) for v in col) for col in zip(*table)]

    def filter_using_list(row, filterArray):
        return [col for take, col in itertools.zip_longest(filterArray, row, fillvalue=True) if take]

    max_lens = get_max_lens(data) if hide_empty else []
    header_row = filter_using_list(header_row, max_lens)
    data = [filter_using_list(row, max_lens) for row in data]

    table = [header_row] + data
    max_lens = get_max_lens(table)
    extra_gap += 1
    if delim:
        table = [header_row, [delim * (ml + extra_gap) for ml in max_lens]] + data
        table[1][-1] = table[1][-1][:-extra_gap * len(delim)]  # Remove extra_gap from end of delimiter
    for row in table:
        for pos, text in enumerate(map(str, row)):
            if '\t' in text:
                row[pos] = text.replace('\t', ' ' * (max_lens[pos] - width(text))) + ' ' * extra_gap
            else:
                row[pos] = text + ' ' * (max_lens[pos] - width(text) + extra_gap)
    ret = '\n'.join(''.join(row).rstrip() for row in table)
    return ret


def _match_one(filter_part, dct, incomplete):
    # TODO: Generalize code with YoutubeDL._build_format_filter
    STRING_OPERATORS = {
        '*=': operator.contains,
        '^=': lambda attr, value: attr.startswith(value),
        '$=': lambda attr, value: attr.endswith(value),
        '~=': lambda attr, value: re.search(value, attr),
    }
    COMPARISON_OPERATORS = {
        **STRING_OPERATORS,
        '<=': operator.le,  # "<=" must be defined above "<"
        '<': operator.lt,
        '>=': operator.ge,
        '>': operator.gt,
        '=': operator.eq,
    }

    if isinstance(incomplete, bool):
        is_incomplete = lambda _: incomplete
    else:
        is_incomplete = lambda k: k in incomplete

    operator_rex = re.compile(r'''(?x)
        (?P<key>[a-z_]+)
        \s*(?P<negation>!\s*)?(?P<op>%s)(?P<none_inclusive>\s*\?)?\s*
        (?:
            (?P<quote>["\'])(?P<quotedstrval>.+?)(?P=quote)|
            (?P<strval>.+?)
        )
        ''' % '|'.join(map(re.escape, COMPARISON_OPERATORS.keys())))
    m = operator_rex.fullmatch(filter_part.strip())
    if m:
        m = m.groupdict()
        unnegated_op = COMPARISON_OPERATORS[m['op']]
        if m['negation']:
            op = lambda attr, value: not unnegated_op(attr, value)
        else:
            op = unnegated_op
        comparison_value = m['quotedstrval'] or m['strval'] or m['intval']
        if m['quote']:
            comparison_value = comparison_value.replace(r'\%s' % m['quote'], m['quote'])
        actual_value = dct.get(m['key'])
        numeric_comparison = None
        if isinstance(actual_value, (int, float)):
            # If the original field is a string and matching comparisonvalue is
            # a number we should respect the origin of the original field
            # and process comparison value as a string (see
            # https://github.com/ytdl-org/youtube-dl/issues/11082)
            try:
                numeric_comparison = int(comparison_value)
            except ValueError:
                numeric_comparison = parse_filesize(comparison_value)
                if numeric_comparison is None:
                    numeric_comparison = parse_filesize(f'{comparison_value}B')
                if numeric_comparison is None:
                    numeric_comparison = parse_duration(comparison_value)
        if numeric_comparison is not None and m['op'] in STRING_OPERATORS:
            raise ValueError('Operator %s only supports string values!' % m['op'])
        if actual_value is None:
            return is_incomplete(m['key']) or m['none_inclusive']
        return op(actual_value, comparison_value if numeric_comparison is None else numeric_comparison)

    UNARY_OPERATORS = {
        '': lambda v: (v is True) if isinstance(v, bool) else (v is not None),
        '!': lambda v: (v is False) if isinstance(v, bool) else (v is None),
    }
    operator_rex = re.compile(r'''(?x)
        (?P<op>%s)\s*(?P<key>[a-z_]+)
        ''' % '|'.join(map(re.escape, UNARY_OPERATORS.keys())))
    m = operator_rex.fullmatch(filter_part.strip())
    if m:
        op = UNARY_OPERATORS[m.group('op')]
        actual_value = dct.get(m.group('key'))
        if is_incomplete(m.group('key')) and actual_value is None:
            return True
        return op(actual_value)

    raise ValueError('Invalid filter part %r' % filter_part)


def match_str(filter_str, dct, incomplete=False):
    """ Filter a dictionary with a simple string syntax.
    @returns           Whether the filter passes
    @param incomplete  Set of keys that is expected to be missing from dct.
                       Can be True/False to indicate all/none of the keys may be missing.
                       All conditions on incomplete keys pass if the key is missing
    """
    return all(
        _match_one(filter_part.replace(r'\&', '&'), dct, incomplete)
        for filter_part in re.split(r'(?<!\\)&', filter_str))


def match_filter_func(filters):
    if not filters:
        return None
    filters = set(variadic(filters))

    interactive = '-' in filters
    if interactive:
        filters.remove('-')

    def _match_func(info_dict, incomplete=False):
        if not filters or any(match_str(f, info_dict, incomplete) for f in filters):
            return NO_DEFAULT if interactive and not incomplete else None
        else:
            video_title = info_dict.get('title') or info_dict.get('id') or 'entry'
            filter_str = ') | ('.join(map(str.strip, filters))
            return f'{video_title} does not pass filter ({filter_str}), skipping ..'
    return _match_func


class download_range_func:
    def __init__(self, chapters, ranges):
        self.chapters, self.ranges = chapters, ranges

    def __call__(self, info_dict, ydl):
        if not self.ranges and not self.chapters:
            yield {}

        warning = ('There are no chapters matching the regex' if info_dict.get('chapters')
                   else 'Cannot match chapters since chapter information is unavailable')
        for regex in self.chapters or []:
            for i, chapter in enumerate(info_dict.get('chapters') or []):
                if re.search(regex, chapter['title']):
                    warning = None
                    yield {**chapter, 'index': i}
        if self.chapters and warning:
            ydl.to_screen(f'[info] {info_dict["id"]}: {warning}')

        yield from ({'start_time': start, 'end_time': end} for start, end in self.ranges or [])

    def __eq__(self, other):
        return (isinstance(other, download_range_func)
                and self.chapters == other.chapters and self.ranges == other.ranges)

    def __repr__(self):
        return f'{type(self).__name__}({self.chapters}, {self.ranges})'


def parse_dfxp_time_expr(time_expr):
    if not time_expr:
        return

    mobj = re.match(rf'^(?P<time_offset>{NUMBER_RE})s?$', time_expr)
    if mobj:
        return float(mobj.group('time_offset'))

    mobj = re.match(r'^(\d+):(\d\d):(\d\d(?:(?:\.|:)\d+)?)$', time_expr)
    if mobj:
        return 3600 * int(mobj.group(1)) + 60 * int(mobj.group(2)) + float(mobj.group(3).replace(':', '.'))


def srt_subtitles_timecode(seconds):
    return '%02d:%02d:%02d,%03d' % timetuple_from_msec(seconds * 1000)


def ass_subtitles_timecode(seconds):
    time = timetuple_from_msec(seconds * 1000)
    return '%01d:%02d:%02d.%02d' % (*time[:-1], time.milliseconds / 10)


def dfxp2srt(dfxp_data):
    '''
    @param dfxp_data A bytes-like object containing DFXP data
    @returns A unicode object containing converted SRT data
    '''
    LEGACY_NAMESPACES = (
        (b'http://www.w3.org/ns/ttml', [
            b'http://www.w3.org/2004/11/ttaf1',
            b'http://www.w3.org/2006/04/ttaf1',
            b'http://www.w3.org/2006/10/ttaf1',
        ]),
        (b'http://www.w3.org/ns/ttml#styling', [
            b'http://www.w3.org/ns/ttml#style',
        ]),
    )

    SUPPORTED_STYLING = [
        'color',
        'fontFamily',
        'fontSize',
        'fontStyle',
        'fontWeight',
        'textDecoration'
    ]

    _x = functools.partial(xpath_with_ns, ns_map={
        'xml': 'http://www.w3.org/XML/1998/namespace',
        'ttml': 'http://www.w3.org/ns/ttml',
        'tts': 'http://www.w3.org/ns/ttml#styling',
    })

    styles = {}
    default_style = {}

    class TTMLPElementParser:
        _out = ''
        _unclosed_elements = []
        _applied_styles = []

        def start(self, tag, attrib):
            if tag in (_x('ttml:br'), 'br'):
                self._out += '\n'
            else:
                unclosed_elements = []
                style = {}
                element_style_id = attrib.get('style')
                if default_style:
                    style.update(default_style)
                if element_style_id:
                    style.update(styles.get(element_style_id, {}))
                for prop in SUPPORTED_STYLING:
                    prop_val = attrib.get(_x('tts:' + prop))
                    if prop_val:
                        style[prop] = prop_val
                if style:
                    font = ''
                    for k, v in sorted(style.items()):
                        if self._applied_styles and self._applied_styles[-1].get(k) == v:
                            continue
                        if k == 'color':
                            font += ' color="%s"' % v
                        elif k == 'fontSize':
                            font += ' size="%s"' % v
                        elif k == 'fontFamily':
                            font += ' face="%s"' % v
                        elif k == 'fontWeight' and v == 'bold':
                            self._out += '<b>'
                            unclosed_elements.append('b')
                        elif k == 'fontStyle' and v == 'italic':
                            self._out += '<i>'
                            unclosed_elements.append('i')
                        elif k == 'textDecoration' and v == 'underline':
                            self._out += '<u>'
                            unclosed_elements.append('u')
                    if font:
                        self._out += '<font' + font + '>'
                        unclosed_elements.append('font')
                    applied_style = {}
                    if self._applied_styles:
                        applied_style.update(self._applied_styles[-1])
                    applied_style.update(style)
                    self._applied_styles.append(applied_style)
                self._unclosed_elements.append(unclosed_elements)

        def end(self, tag):
            if tag not in (_x('ttml:br'), 'br'):
                unclosed_elements = self._unclosed_elements.pop()
                for element in reversed(unclosed_elements):
                    self._out += '</%s>' % element
                if unclosed_elements and self._applied_styles:
                    self._applied_styles.pop()

        def data(self, data):
            self._out += data

        def close(self):
            return self._out.strip()

    def parse_node(node):
        target = TTMLPElementParser()
        parser = xml.etree.ElementTree.XMLParser(target=target)
        parser.feed(xml.etree.ElementTree.tostring(node))
        return parser.close()

    for k, v in LEGACY_NAMESPACES:
        for ns in v:
            dfxp_data = dfxp_data.replace(ns, k)

    dfxp = compat_etree_fromstring(dfxp_data)
    out = []
    paras = dfxp.findall(_x('.//ttml:p')) or dfxp.findall('.//p')

    if not paras:
        raise ValueError('Invalid dfxp/TTML subtitle')

    repeat = False
    while True:
        for style in dfxp.findall(_x('.//ttml:style')):
            style_id = style.get('id') or style.get(_x('xml:id'))
            if not style_id:
                continue
            parent_style_id = style.get('style')
            if parent_style_id:
                if parent_style_id not in styles:
                    repeat = True
                    continue
                styles[style_id] = styles[parent_style_id].copy()
            for prop in SUPPORTED_STYLING:
                prop_val = style.get(_x('tts:' + prop))
                if prop_val:
                    styles.setdefault(style_id, {})[prop] = prop_val
        if repeat:
            repeat = False
        else:
            break

    for p in ('body', 'div'):
        ele = xpath_element(dfxp, [_x('.//ttml:' + p), './/' + p])
        if ele is None:
            continue
        style = styles.get(ele.get('style'))
        if not style:
            continue
        default_style.update(style)

    for para, index in zip(paras, itertools.count(1)):
        begin_time = parse_dfxp_time_expr(para.attrib.get('begin'))
        end_time = parse_dfxp_time_expr(para.attrib.get('end'))
        dur = parse_dfxp_time_expr(para.attrib.get('dur'))
        if begin_time is None:
            continue
        if not end_time:
            if not dur:
                continue
            end_time = begin_time + dur
        out.append('%d\n%s --> %s\n%s\n\n' % (
            index,
            srt_subtitles_timecode(begin_time),
            srt_subtitles_timecode(end_time),
            parse_node(para)))

    return ''.join(out)


def cli_option(params, command_option, param, separator=None):
    param = params.get(param)
    return ([] if param is None
            else [command_option, str(param)] if separator is None
            else [f'{command_option}{separator}{param}'])


def cli_bool_option(params, command_option, param, true_value='true', false_value='false', separator=None):
    param = params.get(param)
    assert param in (True, False, None)
    return cli_option({True: true_value, False: false_value}, command_option, param, separator)


def cli_valueless_option(params, command_option, param, expected_value=True):
    return [command_option] if params.get(param) == expected_value else []


def cli_configuration_args(argdict, keys, default=[], use_compat=True):
    if isinstance(argdict, (list, tuple)):  # for backward compatibility
        if use_compat:
            return argdict
        else:
            argdict = None
    if argdict is None:
        return default
    assert isinstance(argdict, dict)

    assert isinstance(keys, (list, tuple))
    for key_list in keys:
        arg_list = list(filter(
            lambda x: x is not None,
            [argdict.get(key.lower()) for key in variadic(key_list)]))
        if arg_list:
            return [arg for args in arg_list for arg in args]
    return default


def _configuration_args(main_key, argdict, exe, keys=None, default=[], use_compat=True):
    main_key, exe = main_key.lower(), exe.lower()
    root_key = exe if main_key == exe else f'{main_key}+{exe}'
    keys = [f'{root_key}{k}' for k in (keys or [''])]
    if root_key in keys:
        if main_key != exe:
            keys.append((main_key, exe))
        keys.append('default')
    else:
        use_compat = False
    return cli_configuration_args(argdict, keys, default, use_compat)


class ISO639Utils:
    # See http://www.loc.gov/standards/iso639-2/ISO-639-2_utf-8.txt
    _lang_map = {
        'aa': 'aar',
        'ab': 'abk',
        'ae': 'ave',
        'af': 'afr',
        'ak': 'aka',
        'am': 'amh',
        'an': 'arg',
        'ar': 'ara',
        'as': 'asm',
        'av': 'ava',
        'ay': 'aym',
        'az': 'aze',
        'ba': 'bak',
        'be': 'bel',
        'bg': 'bul',
        'bh': 'bih',
        'bi': 'bis',
        'bm': 'bam',
        'bn': 'ben',
        'bo': 'bod',
        'br': 'bre',
        'bs': 'bos',
        'ca': 'cat',
        'ce': 'che',
        'ch': 'cha',
        'co': 'cos',
        'cr': 'cre',
        'cs': 'ces',
        'cu': 'chu',
        'cv': 'chv',
        'cy': 'cym',
        'da': 'dan',
        'de': 'deu',
        'dv': 'div',
        'dz': 'dzo',
        'ee': 'ewe',
        'el': 'ell',
        'en': 'eng',
        'eo': 'epo',
        'es': 'spa',
        'et': 'est',
        'eu': 'eus',
        'fa': 'fas',
        'ff': 'ful',
        'fi': 'fin',
        'fj': 'fij',
        'fo': 'fao',
        'fr': 'fra',
        'fy': 'fry',
        'ga': 'gle',
        'gd': 'gla',
        'gl': 'glg',
        'gn': 'grn',
        'gu': 'guj',
        'gv': 'glv',
        'ha': 'hau',
        'he': 'heb',
        'iw': 'heb',  # Replaced by he in 1989 revision
        'hi': 'hin',
        'ho': 'hmo',
        'hr': 'hrv',
        'ht': 'hat',
        'hu': 'hun',
        'hy': 'hye',
        'hz': 'her',
        'ia': 'ina',
        'id': 'ind',
        'in': 'ind',  # Replaced by id in 1989 revision
        'ie': 'ile',
        'ig': 'ibo',
        'ii': 'iii',
        'ik': 'ipk',
        'io': 'ido',
        'is': 'isl',
        'it': 'ita',
        'iu': 'iku',
        'ja': 'jpn',
        'jv': 'jav',
        'ka': 'kat',
        'kg': 'kon',
        'ki': 'kik',
        'kj': 'kua',
        'kk': 'kaz',
        'kl': 'kal',
        'km': 'khm',
        'kn': 'kan',
        'ko': 'kor',
        'kr': 'kau',
        'ks': 'kas',
        'ku': 'kur',
        'kv': 'kom',
        'kw': 'cor',
        'ky': 'kir',
        'la': 'lat',
        'lb': 'ltz',
        'lg': 'lug',
        'li': 'lim',
        'ln': 'lin',
        'lo': 'lao',
        'lt': 'lit',
        'lu': 'lub',
        'lv': 'lav',
        'mg': 'mlg',
        'mh': 'mah',
        'mi': 'mri',
        'mk': 'mkd',
        'ml': 'mal',
        'mn': 'mon',
        'mr': 'mar',
        'ms': 'msa',
        'mt': 'mlt',
        'my': 'mya',
        'na': 'nau',
        'nb': 'nob',
        'nd': 'nde',
        'ne': 'nep',
        'ng': 'ndo',
        'nl': 'nld',
        'nn': 'nno',
        'no': 'nor',
        'nr': 'nbl',
        'nv': 'nav',
        'ny': 'nya',
        'oc': 'oci',
        'oj': 'oji',
        'om': 'orm',
        'or': 'ori',
        'os': 'oss',
        'pa': 'pan',
        'pi': 'pli',
        'pl': 'pol',
        'ps': 'pus',
        'pt': 'por',
        'qu': 'que',
        'rm': 'roh',
        'rn': 'run',
        'ro': 'ron',
        'ru': 'rus',
        'rw': 'kin',
        'sa': 'san',
        'sc': 'srd',
        'sd': 'snd',
        'se': 'sme',
        'sg': 'sag',
        'si': 'sin',
        'sk': 'slk',
        'sl': 'slv',
        'sm': 'smo',
        'sn': 'sna',
        'so': 'som',
        'sq': 'sqi',
        'sr': 'srp',
        'ss': 'ssw',
        'st': 'sot',
        'su': 'sun',
        'sv': 'swe',
        'sw': 'swa',
        'ta': 'tam',
        'te': 'tel',
        'tg': 'tgk',
        'th': 'tha',
        'ti': 'tir',
        'tk': 'tuk',
        'tl': 'tgl',
        'tn': 'tsn',
        'to': 'ton',
        'tr': 'tur',
        'ts': 'tso',
        'tt': 'tat',
        'tw': 'twi',
        'ty': 'tah',
        'ug': 'uig',
        'uk': 'ukr',
        'ur': 'urd',
        'uz': 'uzb',
        've': 'ven',
        'vi': 'vie',
        'vo': 'vol',
        'wa': 'wln',
        'wo': 'wol',
        'xh': 'xho',
        'yi': 'yid',
        'ji': 'yid',  # Replaced by yi in 1989 revision
        'yo': 'yor',
        'za': 'zha',
        'zh': 'zho',
        'zu': 'zul',
    }

    @classmethod
    def short2long(cls, code):
        """Convert language code from ISO 639-1 to ISO 639-2/T"""
        return cls._lang_map.get(code[:2])

    @classmethod
    def long2short(cls, code):
        """Convert language code from ISO 639-2/T to ISO 639-1"""
        for short_name, long_name in cls._lang_map.items():
            if long_name == code:
                return short_name


class ISO3166Utils:
    # From http://data.okfn.org/data/core/country-list
    _country_map = {
        'AF': 'Afghanistan',
        'AX': 'Åland Islands',
        'AL': 'Albania',
        'DZ': 'Algeria',
        'AS': 'American Samoa',
        'AD': 'Andorra',
        'AO': 'Angola',
        'AI': 'Anguilla',
        'AQ': 'Antarctica',
        'AG': 'Antigua and Barbuda',
        'AR': 'Argentina',
        'AM': 'Armenia',
        'AW': 'Aruba',
        'AU': 'Australia',
        'AT': 'Austria',
        'AZ': 'Azerbaijan',
        'BS': 'Bahamas',
        'BH': 'Bahrain',
        'BD': 'Bangladesh',
        'BB': 'Barbados',
        'BY': 'Belarus',
        'BE': 'Belgium',
        'BZ': 'Belize',
        'BJ': 'Benin',
        'BM': 'Bermuda',
        'BT': 'Bhutan',
        'BO': 'Bolivia, Plurinational State of',
        'BQ': 'Bonaire, Sint Eustatius and Saba',
        'BA': 'Bosnia and Herzegovina',
        'BW': 'Botswana',
        'BV': 'Bouvet Island',
        'BR': 'Brazil',
        'IO': 'British Indian Ocean Territory',
        'BN': 'Brunei Darussalam',
        'BG': 'Bulgaria',
        'BF': 'Burkina Faso',
        'BI': 'Burundi',
        'KH': 'Cambodia',
        'CM': 'Cameroon',
        'CA': 'Canada',
        'CV': 'Cape Verde',
        'KY': 'Cayman Islands',
        'CF': 'Central African Republic',
        'TD': 'Chad',
        'CL': 'Chile',
        'CN': 'China',
        'CX': 'Christmas Island',
        'CC': 'Cocos (Keeling) Islands',
        'CO': 'Colombia',
        'KM': 'Comoros',
        'CG': 'Congo',
        'CD': 'Congo, the Democratic Republic of the',
        'CK': 'Cook Islands',
        'CR': 'Costa Rica',
        'CI': 'Côte d\'Ivoire',
        'HR': 'Croatia',
        'CU': 'Cuba',
        'CW': 'Curaçao',
        'CY': 'Cyprus',
        'CZ': 'Czech Republic',
        'DK': 'Denmark',
        'DJ': 'Djibouti',
        'DM': 'Dominica',
        'DO': 'Dominican Republic',
        'EC': 'Ecuador',
        'EG': 'Egypt',
        'SV': 'El Salvador',
        'GQ': 'Equatorial Guinea',
        'ER': 'Eritrea',
        'EE': 'Estonia',
        'ET': 'Ethiopia',
        'FK': 'Falkland Islands (Malvinas)',
        'FO': 'Faroe Islands',
        'FJ': 'Fiji',
        'FI': 'Finland',
        'FR': 'France',
        'GF': 'French Guiana',
        'PF': 'French Polynesia',
        'TF': 'French Southern Territories',
        'GA': 'Gabon',
        'GM': 'Gambia',
        'GE': 'Georgia',
        'DE': 'Germany',
        'GH': 'Ghana',
        'GI': 'Gibraltar',
        'GR': 'Greece',
        'GL': 'Greenland',
        'GD': 'Grenada',
        'GP': 'Guadeloupe',
        'GU': 'Guam',
        'GT': 'Guatemala',
        'GG': 'Guernsey',
        'GN': 'Guinea',
        'GW': 'Guinea-Bissau',
        'GY': 'Guyana',
        'HT': 'Haiti',
        'HM': 'Heard Island and McDonald Islands',
        'VA': 'Holy See (Vatican City State)',
        'HN': 'Honduras',
        'HK': 'Hong Kong',
        'HU': 'Hungary',
        'IS': 'Iceland',
        'IN': 'India',
        'ID': 'Indonesia',
        'IR': 'Iran, Islamic Republic of',
        'IQ': 'Iraq',
        'IE': 'Ireland',
        'IM': 'Isle of Man',
        'IL': 'Israel',
        'IT': 'Italy',
        'JM': 'Jamaica',
        'JP': 'Japan',
        'JE': 'Jersey',
        'JO': 'Jordan',
        'KZ': 'Kazakhstan',
        'KE': 'Kenya',
        'KI': 'Kiribati',
        'KP': 'Korea, Democratic People\'s Republic of',
        'KR': 'Korea, Republic of',
        'KW': 'Kuwait',
        'KG': 'Kyrgyzstan',
        'LA': 'Lao People\'s Democratic Republic',
        'LV': 'Latvia',
        'LB': 'Lebanon',
        'LS': 'Lesotho',
        'LR': 'Liberia',
        'LY': 'Libya',
        'LI': 'Liechtenstein',
        'LT': 'Lithuania',
        'LU': 'Luxembourg',
        'MO': 'Macao',
        'MK': 'Macedonia, the Former Yugoslav Republic of',
        'MG': 'Madagascar',
        'MW': 'Malawi',
        'MY': 'Malaysia',
        'MV': 'Maldives',
        'ML': 'Mali',
        'MT': 'Malta',
        'MH': 'Marshall Islands',
        'MQ': 'Martinique',
        'MR': 'Mauritania',
        'MU': 'Mauritius',
        'YT': 'Mayotte',
        'MX': 'Mexico',
        'FM': 'Micronesia, Federated States of',
        'MD': 'Moldova, Republic of',
        'MC': 'Monaco',
        'MN': 'Mongolia',
        'ME': 'Montenegro',
        'MS': 'Montserrat',
        'MA': 'Morocco',
        'MZ': 'Mozambique',
        'MM': 'Myanmar',
        'NA': 'Namibia',
        'NR': 'Nauru',
        'NP': 'Nepal',
        'NL': 'Netherlands',
        'NC': 'New Caledonia',
        'NZ': 'New Zealand',
        'NI': 'Nicaragua',
        'NE': 'Niger',
        'NG': 'Nigeria',
        'NU': 'Niue',
        'NF': 'Norfolk Island',
        'MP': 'Northern Mariana Islands',
        'NO': 'Norway',
        'OM': 'Oman',
        'PK': 'Pakistan',
        'PW': 'Palau',
        'PS': 'Palestine, State of',
        'PA': 'Panama',
        'PG': 'Papua New Guinea',
        'PY': 'Paraguay',
        'PE': 'Peru',
        'PH': 'Philippines',
        'PN': 'Pitcairn',
        'PL': 'Poland',
        'PT': 'Portugal',
        'PR': 'Puerto Rico',
        'QA': 'Qatar',
        'RE': 'Réunion',
        'RO': 'Romania',
        'RU': 'Russian Federation',
        'RW': 'Rwanda',
        'BL': 'Saint Barthélemy',
        'SH': 'Saint Helena, Ascension and Tristan da Cunha',
        'KN': 'Saint Kitts and Nevis',
        'LC': 'Saint Lucia',
        'MF': 'Saint Martin (French part)',
        'PM': 'Saint Pierre and Miquelon',
        'VC': 'Saint Vincent and the Grenadines',
        'WS': 'Samoa',
        'SM': 'San Marino',
        'ST': 'Sao Tome and Principe',
        'SA': 'Saudi Arabia',
        'SN': 'Senegal',
        'RS': 'Serbia',
        'SC': 'Seychelles',
        'SL': 'Sierra Leone',
        'SG': 'Singapore',
        'SX': 'Sint Maarten (Dutch part)',
        'SK': 'Slovakia',
        'SI': 'Slovenia',
        'SB': 'Solomon Islands',
        'SO': 'Somalia',
        'ZA': 'South Africa',
        'GS': 'South Georgia and the South Sandwich Islands',
        'SS': 'South Sudan',
        'ES': 'Spain',
        'LK': 'Sri Lanka',
        'SD': 'Sudan',
        'SR': 'Suriname',
        'SJ': 'Svalbard and Jan Mayen',
        'SZ': 'Swaziland',
        'SE': 'Sweden',
        'CH': 'Switzerland',
        'SY': 'Syrian Arab Republic',
        'TW': 'Taiwan, Province of China',
        'TJ': 'Tajikistan',
        'TZ': 'Tanzania, United Republic of',
        'TH': 'Thailand',
        'TL': 'Timor-Leste',
        'TG': 'Togo',
        'TK': 'Tokelau',
        'TO': 'Tonga',
        'TT': 'Trinidad and Tobago',
        'TN': 'Tunisia',
        'TR': 'Turkey',
        'TM': 'Turkmenistan',
        'TC': 'Turks and Caicos Islands',
        'TV': 'Tuvalu',
        'UG': 'Uganda',
        'UA': 'Ukraine',
        'AE': 'United Arab Emirates',
        'GB': 'United Kingdom',
        'US': 'United States',
        'UM': 'United States Minor Outlying Islands',
        'UY': 'Uruguay',
        'UZ': 'Uzbekistan',
        'VU': 'Vanuatu',
        'VE': 'Venezuela, Bolivarian Republic of',
        'VN': 'Viet Nam',
        'VG': 'Virgin Islands, British',
        'VI': 'Virgin Islands, U.S.',
        'WF': 'Wallis and Futuna',
        'EH': 'Western Sahara',
        'YE': 'Yemen',
        'ZM': 'Zambia',
        'ZW': 'Zimbabwe',
        # Not ISO 3166 codes, but used for IP blocks
        'AP': 'Asia/Pacific Region',
        'EU': 'Europe',
    }

    @classmethod
    def short2full(cls, code):
        """Convert an ISO 3166-2 country code to the corresponding full name"""
        return cls._country_map.get(code.upper())


class GeoUtils:
    # Major IPv4 address blocks per country
    _country_ip_map = {
        'AD': '46.172.224.0/19',
        'AE': '94.200.0.0/13',
        'AF': '149.54.0.0/17',
        'AG': '209.59.64.0/18',
        'AI': '204.14.248.0/21',
        'AL': '46.99.0.0/16',
        'AM': '46.70.0.0/15',
        'AO': '105.168.0.0/13',
        'AP': '182.50.184.0/21',
        'AQ': '23.154.160.0/24',
        'AR': '181.0.0.0/12',
        'AS': '202.70.112.0/20',
        'AT': '77.116.0.0/14',
        'AU': '1.128.0.0/11',
        'AW': '181.41.0.0/18',
        'AX': '185.217.4.0/22',
        'AZ': '5.197.0.0/16',
        'BA': '31.176.128.0/17',
        'BB': '65.48.128.0/17',
        'BD': '114.130.0.0/16',
        'BE': '57.0.0.0/8',
        'BF': '102.178.0.0/15',
        'BG': '95.42.0.0/15',
        'BH': '37.131.0.0/17',
        'BI': '154.117.192.0/18',
        'BJ': '137.255.0.0/16',
        'BL': '185.212.72.0/23',
        'BM': '196.12.64.0/18',
        'BN': '156.31.0.0/16',
        'BO': '161.56.0.0/16',
        'BQ': '161.0.80.0/20',
        'BR': '191.128.0.0/12',
        'BS': '24.51.64.0/18',
        'BT': '119.2.96.0/19',
        'BW': '168.167.0.0/16',
        'BY': '178.120.0.0/13',
        'BZ': '179.42.192.0/18',
        'CA': '99.224.0.0/11',
        'CD': '41.243.0.0/16',
        'CF': '197.242.176.0/21',
        'CG': '160.113.0.0/16',
        'CH': '85.0.0.0/13',
        'CI': '102.136.0.0/14',
        'CK': '202.65.32.0/19',
        'CL': '152.172.0.0/14',
        'CM': '102.244.0.0/14',
        'CN': '36.128.0.0/10',
        'CO': '181.240.0.0/12',
        'CR': '201.192.0.0/12',
        'CU': '152.206.0.0/15',
        'CV': '165.90.96.0/19',
        'CW': '190.88.128.0/17',
        'CY': '31.153.0.0/16',
        'CZ': '88.100.0.0/14',
        'DE': '53.0.0.0/8',
        'DJ': '197.241.0.0/17',
        'DK': '87.48.0.0/12',
        'DM': '192.243.48.0/20',
        'DO': '152.166.0.0/15',
        'DZ': '41.96.0.0/12',
        'EC': '186.68.0.0/15',
        'EE': '90.190.0.0/15',
        'EG': '156.160.0.0/11',
        'ER': '196.200.96.0/20',
        'ES': '88.0.0.0/11',
        'ET': '196.188.0.0/14',
        'EU': '2.16.0.0/13',
        'FI': '91.152.0.0/13',
        'FJ': '144.120.0.0/16',
        'FK': '80.73.208.0/21',
        'FM': '119.252.112.0/20',
        'FO': '88.85.32.0/19',
        'FR': '90.0.0.0/9',
        'GA': '41.158.0.0/15',
        'GB': '25.0.0.0/8',
        'GD': '74.122.88.0/21',
        'GE': '31.146.0.0/16',
        'GF': '161.22.64.0/18',
        'GG': '62.68.160.0/19',
        'GH': '154.160.0.0/12',
        'GI': '95.164.0.0/16',
        'GL': '88.83.0.0/19',
        'GM': '160.182.0.0/15',
        'GN': '197.149.192.0/18',
        'GP': '104.250.0.0/19',
        'GQ': '105.235.224.0/20',
        'GR': '94.64.0.0/13',
        'GT': '168.234.0.0/16',
        'GU': '168.123.0.0/16',
        'GW': '197.214.80.0/20',
        'GY': '181.41.64.0/18',
        'HK': '113.252.0.0/14',
        'HN': '181.210.0.0/16',
        'HR': '93.136.0.0/13',
        'HT': '148.102.128.0/17',
        'HU': '84.0.0.0/14',
        'ID': '39.192.0.0/10',
        'IE': '87.32.0.0/12',
        'IL': '79.176.0.0/13',
        'IM': '5.62.80.0/20',
        'IN': '117.192.0.0/10',
        'IO': '203.83.48.0/21',
        'IQ': '37.236.0.0/14',
        'IR': '2.176.0.0/12',
        'IS': '82.221.0.0/16',
        'IT': '79.0.0.0/10',
        'JE': '87.244.64.0/18',
        'JM': '72.27.0.0/17',
        'JO': '176.29.0.0/16',
        'JP': '133.0.0.0/8',
        'KE': '105.48.0.0/12',
        'KG': '158.181.128.0/17',
        'KH': '36.37.128.0/17',
        'KI': '103.25.140.0/22',
        'KM': '197.255.224.0/20',
        'KN': '198.167.192.0/19',
        'KP': '175.45.176.0/22',
        'KR': '175.192.0.0/10',
        'KW': '37.36.0.0/14',
        'KY': '64.96.0.0/15',
        'KZ': '2.72.0.0/13',
        'LA': '115.84.64.0/18',
        'LB': '178.135.0.0/16',
        'LC': '24.92.144.0/20',
        'LI': '82.117.0.0/19',
        'LK': '112.134.0.0/15',
        'LR': '102.183.0.0/16',
        'LS': '129.232.0.0/17',
        'LT': '78.56.0.0/13',
        'LU': '188.42.0.0/16',
        'LV': '46.109.0.0/16',
        'LY': '41.252.0.0/14',
        'MA': '105.128.0.0/11',
        'MC': '88.209.64.0/18',
        'MD': '37.246.0.0/16',
        'ME': '178.175.0.0/17',
        'MF': '74.112.232.0/21',
        'MG': '154.126.0.0/17',
        'MH': '117.103.88.0/21',
        'MK': '77.28.0.0/15',
        'ML': '154.118.128.0/18',
        'MM': '37.111.0.0/17',
        'MN': '49.0.128.0/17',
        'MO': '60.246.0.0/16',
        'MP': '202.88.64.0/20',
        'MQ': '109.203.224.0/19',
        'MR': '41.188.64.0/18',
        'MS': '208.90.112.0/22',
        'MT': '46.11.0.0/16',
        'MU': '105.16.0.0/12',
        'MV': '27.114.128.0/18',
        'MW': '102.70.0.0/15',
        'MX': '187.192.0.0/11',
        'MY': '175.136.0.0/13',
        'MZ': '197.218.0.0/15',
        'NA': '41.182.0.0/16',
        'NC': '101.101.0.0/18',
        'NE': '197.214.0.0/18',
        'NF': '203.17.240.0/22',
        'NG': '105.112.0.0/12',
        'NI': '186.76.0.0/15',
        'NL': '145.96.0.0/11',
        'NO': '84.208.0.0/13',
        'NP': '36.252.0.0/15',
        'NR': '203.98.224.0/19',
        'NU': '49.156.48.0/22',
        'NZ': '49.224.0.0/14',
        'OM': '5.36.0.0/15',
        'PA': '186.72.0.0/15',
        'PE': '186.160.0.0/14',
        'PF': '123.50.64.0/18',
        'PG': '124.240.192.0/19',
        'PH': '49.144.0.0/13',
        'PK': '39.32.0.0/11',
        'PL': '83.0.0.0/11',
        'PM': '70.36.0.0/20',
        'PR': '66.50.0.0/16',
        'PS': '188.161.0.0/16',
        'PT': '85.240.0.0/13',
        'PW': '202.124.224.0/20',
        'PY': '181.120.0.0/14',
        'QA': '37.210.0.0/15',
        'RE': '102.35.0.0/16',
        'RO': '79.112.0.0/13',
        'RS': '93.86.0.0/15',
        'RU': '5.136.0.0/13',
        'RW': '41.186.0.0/16',
        'SA': '188.48.0.0/13',
        'SB': '202.1.160.0/19',
        'SC': '154.192.0.0/11',
        'SD': '102.120.0.0/13',
        'SE': '78.64.0.0/12',
        'SG': '8.128.0.0/10',
        'SI': '188.196.0.0/14',
        'SK': '78.98.0.0/15',
        'SL': '102.143.0.0/17',
        'SM': '89.186.32.0/19',
        'SN': '41.82.0.0/15',
        'SO': '154.115.192.0/18',
        'SR': '186.179.128.0/17',
        'SS': '105.235.208.0/21',
        'ST': '197.159.160.0/19',
        'SV': '168.243.0.0/16',
        'SX': '190.102.0.0/20',
        'SY': '5.0.0.0/16',
        'SZ': '41.84.224.0/19',
        'TC': '65.255.48.0/20',
        'TD': '154.68.128.0/19',
        'TG': '196.168.0.0/14',
        'TH': '171.96.0.0/13',
        'TJ': '85.9.128.0/18',
        'TK': '27.96.24.0/21',
        'TL': '180.189.160.0/20',
        'TM': '95.85.96.0/19',
        'TN': '197.0.0.0/11',
        'TO': '175.176.144.0/21',
        'TR': '78.160.0.0/11',
        'TT': '186.44.0.0/15',
        'TV': '202.2.96.0/19',
        'TW': '120.96.0.0/11',
        'TZ': '156.156.0.0/14',
        'UA': '37.52.0.0/14',
        'UG': '102.80.0.0/13',
        'US': '6.0.0.0/8',
        'UY': '167.56.0.0/13',
        'UZ': '84.54.64.0/18',
        'VA': '212.77.0.0/19',
        'VC': '207.191.240.0/21',
        'VE': '186.88.0.0/13',
        'VG': '66.81.192.0/20',
        'VI': '146.226.0.0/16',
        'VN': '14.160.0.0/11',
        'VU': '202.80.32.0/20',
        'WF': '117.20.32.0/21',
        'WS': '202.4.32.0/19',
        'YE': '134.35.0.0/16',
        'YT': '41.242.116.0/22',
        'ZA': '41.0.0.0/11',
        'ZM': '102.144.0.0/13',
        'ZW': '102.177.192.0/18',
    }

    @classmethod
    def random_ipv4(cls, code_or_block):
        if len(code_or_block) == 2:
            block = cls._country_ip_map.get(code_or_block.upper())
            if not block:
                return None
        else:
            block = code_or_block
        addr, preflen = block.split('/')
        addr_min = struct.unpack('!L', socket.inet_aton(addr))[0]
        addr_max = addr_min | (0xffffffff >> int(preflen))
        return str(socket.inet_ntoa(
            struct.pack('!L', random.randint(addr_min, addr_max))))


class PerRequestProxyHandler(urllib.request.ProxyHandler):
    def __init__(self, proxies=None):
        # Set default handlers
        for type in ('http', 'https'):
            setattr(self, '%s_open' % type,
                    lambda r, proxy='__noproxy__', type=type, meth=self.proxy_open:
                        meth(r, proxy, type))
        urllib.request.ProxyHandler.__init__(self, proxies)

    def proxy_open(self, req, proxy, type):
        req_proxy = req.headers.get('Ytdl-request-proxy')
        if req_proxy is not None:
            proxy = req_proxy
            del req.headers['Ytdl-request-proxy']

        if proxy == '__noproxy__':
            return None  # No Proxy
        if urllib.parse.urlparse(proxy).scheme.lower() in ('socks', 'socks4', 'socks4a', 'socks5'):
            req.add_header('Ytdl-socks-proxy', proxy)
            # yt-dlp's http/https handlers do wrapping the socket with socks
            return None
        return urllib.request.ProxyHandler.proxy_open(
            self, req, proxy, type)


# Both long_to_bytes and bytes_to_long are adapted from PyCrypto, which is
# released into Public Domain
# https://github.com/dlitz/pycrypto/blob/master/lib/Crypto/Util/number.py#L387

def long_to_bytes(n, blocksize=0):
    """long_to_bytes(n:long, blocksize:int) : string
    Convert a long integer to a byte string.

    If optional blocksize is given and greater than zero, pad the front of the
    byte string with binary zeros so that the length is a multiple of
    blocksize.
    """
    # after much testing, this algorithm was deemed to be the fastest
    s = b''
    n = int(n)
    while n > 0:
        s = struct.pack('>I', n & 0xffffffff) + s
        n = n >> 32
    # strip off leading zeros
    for i in range(len(s)):
        if s[i] != b'\000'[0]:
            break
    else:
        # only happens when n == 0
        s = b'\000'
        i = 0
    s = s[i:]
    # add back some pad bytes.  this could be done more efficiently w.r.t. the
    # de-padding being done above, but sigh...
    if blocksize > 0 and len(s) % blocksize:
        s = (blocksize - len(s) % blocksize) * b'\000' + s
    return s


def bytes_to_long(s):
    """bytes_to_long(string) : long
    Convert a byte string to a long integer.

    This is (essentially) the inverse of long_to_bytes().
    """
    acc = 0
    length = len(s)
    if length % 4:
        extra = (4 - length % 4)
        s = b'\000' * extra + s
        length = length + extra
    for i in range(0, length, 4):
        acc = (acc << 32) + struct.unpack('>I', s[i:i + 4])[0]
    return acc


def ohdave_rsa_encrypt(data, exponent, modulus):
    '''
    Implement OHDave's RSA algorithm. See http://www.ohdave.com/rsa/

    Input:
        data: data to encrypt, bytes-like object
        exponent, modulus: parameter e and N of RSA algorithm, both integer
    Output: hex string of encrypted data

    Limitation: supports one block encryption only
    '''

    payload = int(binascii.hexlify(data[::-1]), 16)
    encrypted = pow(payload, exponent, modulus)
    return '%x' % encrypted


def pkcs1pad(data, length):
    """
    Padding input data with PKCS#1 scheme

    @param {int[]} data        input data
    @param {int}   length      target length
    @returns {int[]}           padded data
    """
    if len(data) > length - 11:
        raise ValueError('Input data too long for PKCS#1 padding')

    pseudo_random = [random.randint(0, 254) for _ in range(length - len(data) - 3)]
    return [0, 2] + pseudo_random + [0] + data


def _base_n_table(n, table):
    if not table and not n:
        raise ValueError('Either table or n must be specified')
    table = (table or '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ')[:n]

    if n and n != len(table):
        raise ValueError(f'base {n} exceeds table length {len(table)}')
    return table


def encode_base_n(num, n=None, table=None):
    """Convert given int to a base-n string"""
    table = _base_n_table(n, table)
    if not num:
        return table[0]

    result, base = '', len(table)
    while num:
        result = table[num % base] + result
        num = num // base
    return result


def decode_base_n(string, n=None, table=None):
    """Convert given base-n string to int"""
    table = {char: index for index, char in enumerate(_base_n_table(n, table))}
    result, base = 0, len(table)
    for char in string:
        result = result * base + table[char]
    return result


def decode_base(value, digits):
    deprecation_warning(f'{__name__}.decode_base is deprecated and may be removed '
                        f'in a future version. Use {__name__}.decode_base_n instead')
    return decode_base_n(value, table=digits)


def decode_packed_codes(code):
    mobj = re.search(PACKED_CODES_RE, code)
    obfuscated_code, base, count, symbols = mobj.groups()
    base = int(base)
    count = int(count)
    symbols = symbols.split('|')
    symbol_table = {}

    while count:
        count -= 1
        base_n_count = encode_base_n(count, base)
        symbol_table[base_n_count] = symbols[count] or base_n_count

    return re.sub(
        r'\b(\w+)\b', lambda mobj: symbol_table[mobj.group(0)],
        obfuscated_code)


def caesar(s, alphabet, shift):
    if shift == 0:
        return s
    l = len(alphabet)
    return ''.join(
        alphabet[(alphabet.index(c) + shift) % l] if c in alphabet else c
        for c in s)


def rot47(s):
    return caesar(s, r'''!"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~''', 47)


def parse_m3u8_attributes(attrib):
    info = {}
    for (key, val) in re.findall(r'(?P<key>[A-Z0-9-]+)=(?P<val>"[^"]+"|[^",]+)(?:,|$)', attrib):
        if val.startswith('"'):
            val = val[1:-1]
        info[key] = val
    return info


def urshift(val, n):
    return val >> n if val >= 0 else (val + 0x100000000) >> n


# Based on png2str() written by @gdkchan and improved by @yokrysty
# Originally posted at https://github.com/ytdl-org/youtube-dl/issues/9706
def decode_png(png_data):
    # Reference: https://www.w3.org/TR/PNG/
    header = png_data[8:]

    if png_data[:8] != b'\x89PNG\x0d\x0a\x1a\x0a' or header[4:8] != b'IHDR':
        raise OSError('Not a valid PNG file.')

    int_map = {1: '>B', 2: '>H', 4: '>I'}
    unpack_integer = lambda x: struct.unpack(int_map[len(x)], x)[0]

    chunks = []

    while header:
        length = unpack_integer(header[:4])
        header = header[4:]

        chunk_type = header[:4]
        header = header[4:]

        chunk_data = header[:length]
        header = header[length:]

        header = header[4:]  # Skip CRC

        chunks.append({
            'type': chunk_type,
            'length': length,
            'data': chunk_data
        })

    ihdr = chunks[0]['data']

    width = unpack_integer(ihdr[:4])
    height = unpack_integer(ihdr[4:8])

    idat = b''

    for chunk in chunks:
        if chunk['type'] == b'IDAT':
            idat += chunk['data']

    if not idat:
        raise OSError('Unable to read PNG data.')

    decompressed_data = bytearray(zlib.decompress(idat))

    stride = width * 3
    pixels = []

    def _get_pixel(idx):
        x = idx % stride
        y = idx // stride
        return pixels[y][x]

    for y in range(height):
        basePos = y * (1 + stride)
        filter_type = decompressed_data[basePos]

        current_row = []

        pixels.append(current_row)

        for x in range(stride):
            color = decompressed_data[1 + basePos + x]
            basex = y * stride + x
            left = 0
            up = 0

            if x > 2:
                left = _get_pixel(basex - 3)
            if y > 0:
                up = _get_pixel(basex - stride)

            if filter_type == 1:  # Sub
                color = (color + left) & 0xff
            elif filter_type == 2:  # Up
                color = (color + up) & 0xff
            elif filter_type == 3:  # Average
                color = (color + ((left + up) >> 1)) & 0xff
            elif filter_type == 4:  # Paeth
                a = left
                b = up
                c = 0

                if x > 2 and y > 0:
                    c = _get_pixel(basex - stride - 3)

                p = a + b - c

                pa = abs(p - a)
                pb = abs(p - b)
                pc = abs(p - c)

                if pa <= pb and pa <= pc:
                    color = (color + a) & 0xff
                elif pb <= pc:
                    color = (color + b) & 0xff
                else:
                    color = (color + c) & 0xff

            current_row.append(color)

    return width, height, pixels


def write_xattr(path, key, value):
    # Windows: Write xattrs to NTFS Alternate Data Streams:
    # http://en.wikipedia.org/wiki/NTFS#Alternate_data_streams_.28ADS.29
    if compat_os_name == 'nt':
        assert ':' not in key
        assert os.path.exists(path)

        try:
            with open(f'{path}:{key}', 'wb') as f:
                f.write(value)
        except OSError as e:
            raise XAttrMetadataError(e.errno, e.strerror)
        return

    # UNIX Method 1. Use xattrs/pyxattrs modules

    setxattr = None
    if getattr(xattr, '_yt_dlp__identifier', None) == 'pyxattr':
        # Unicode arguments are not supported in pyxattr until version 0.5.0
        # See https://github.com/ytdl-org/youtube-dl/issues/5498
        if version_tuple(xattr.__version__) >= (0, 5, 0):
            setxattr = xattr.set
    elif xattr:
        setxattr = xattr.setxattr

    if setxattr:
        try:
            setxattr(path, key, value)
        except OSError as e:
            raise XAttrMetadataError(e.errno, e.strerror)
        return

    # UNIX Method 2. Use setfattr/xattr executables
    exe = ('setfattr' if check_executable('setfattr', ['--version'])
           else 'xattr' if check_executable('xattr', ['-h']) else None)
    if not exe:
        raise XAttrUnavailableError(
            'Couldn\'t find a tool to set the xattrs. Install either the python "xattr" or "pyxattr" modules or the '
            + ('"xattr" binary' if sys.platform != 'linux' else 'GNU "attr" package (which contains the "setfattr" tool)'))

    value = value.decode()
    try:
        _, stderr, returncode = Popen.run(
            [exe, '-w', key, value, path] if exe == 'xattr' else [exe, '-n', key, '-v', value, path],
            text=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
    except OSError as e:
        raise XAttrMetadataError(e.errno, e.strerror)
    if returncode:
        raise XAttrMetadataError(returncode, stderr)


def random_birthday(year_field, month_field, day_field):
    start_date = datetime.date(1950, 1, 1)
    end_date = datetime.date(1995, 12, 31)
    offset = random.randint(0, (end_date - start_date).days)
    random_date = start_date + datetime.timedelta(offset)
    return {
        year_field: str(random_date.year),
        month_field: str(random_date.month),
        day_field: str(random_date.day),
    }


def find_available_port(interface=''):
    try:
        with socket.socket() as sock:
            sock.bind((interface, 0))
            return sock.getsockname()[1]
    except OSError:
        return None


# Templates for internet shortcut files, which are plain text files.
DOT_URL_LINK_TEMPLATE = '''\
[InternetShortcut]
URL=%(url)s
'''

DOT_WEBLOC_LINK_TEMPLATE = '''\
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
\t<key>URL</key>
\t<string>%(url)s</string>
</dict>
</plist>
'''

DOT_DESKTOP_LINK_TEMPLATE = '''\
[Desktop Entry]
Encoding=UTF-8
Name=%(filename)s
Type=Link
URL=%(url)s
Icon=text-html
'''

LINK_TEMPLATES = {
    'url': DOT_URL_LINK_TEMPLATE,
    'desktop': DOT_DESKTOP_LINK_TEMPLATE,
    'webloc': DOT_WEBLOC_LINK_TEMPLATE,
}


def iri_to_uri(iri):
    """
    Converts an IRI (Internationalized Resource Identifier, allowing Unicode characters) to a URI (Uniform Resource Identifier, ASCII-only).

    The function doesn't add an additional layer of escaping; e.g., it doesn't escape `%3C` as `%253C`. Instead, it percent-escapes characters with an underlying UTF-8 encoding *besides* those already escaped, leaving the URI intact.
    """

    iri_parts = urllib.parse.urlparse(iri)

    if '[' in iri_parts.netloc:
        raise ValueError('IPv6 URIs are not, yet, supported.')
        # Querying `.netloc`, when there's only one bracket, also raises a ValueError.

    # The `safe` argument values, that the following code uses, contain the characters that should not be percent-encoded. Everything else but letters, digits and '_.-' will be percent-encoded with an underlying UTF-8 encoding. Everything already percent-encoded will be left as is.

    net_location = ''
    if iri_parts.username:
        net_location += urllib.parse.quote(iri_parts.username, safe=r"!$%&'()*+,~")
        if iri_parts.password is not None:
            net_location += ':' + urllib.parse.quote(iri_parts.password, safe=r"!$%&'()*+,~")
        net_location += '@'

    net_location += iri_parts.hostname.encode('idna').decode()  # Punycode for Unicode hostnames.
    # The 'idna' encoding produces ASCII text.
    if iri_parts.port is not None and iri_parts.port != 80:
        net_location += ':' + str(iri_parts.port)

    return urllib.parse.urlunparse(
        (iri_parts.scheme,
            net_location,

            urllib.parse.quote_plus(iri_parts.path, safe=r"!$%&'()*+,/:;=@|~"),

            # Unsure about the `safe` argument, since this is a legacy way of handling parameters.
            urllib.parse.quote_plus(iri_parts.params, safe=r"!$%&'()*+,/:;=@|~"),

            # Not totally sure about the `safe` argument, since the source does not explicitly mention the query URI component.
            urllib.parse.quote_plus(iri_parts.query, safe=r"!$%&'()*+,/:;=?@{|}~"),

            urllib.parse.quote_plus(iri_parts.fragment, safe=r"!#$%&'()*+,/:;=?@{|}~")))

    # Source for `safe` arguments: https://url.spec.whatwg.org/#percent-encoded-bytes.


def to_high_limit_path(path):
    if sys.platform in ['win32', 'cygwin']:
        # Work around MAX_PATH limitation on Windows. The maximum allowed length for the individual path segments may still be quite limited.
        return '\\\\?\\' + os.path.abspath(path)

    return path


def format_field(obj, field=None, template='%s', ignore=NO_DEFAULT, default='', func=IDENTITY):
    val = traverse_obj(obj, *variadic(field))
    if (not val and val != 0) if ignore is NO_DEFAULT else val in variadic(ignore):
        return default
    return template % func(val)


def clean_podcast_url(url):
    return re.sub(r'''(?x)
        (?:
            (?:
                chtbl\.com/track|
                media\.blubrry\.com| # https://create.blubrry.com/resources/podcast-media-download-statistics/getting-started/
                play\.podtrac\.com
            )/[^/]+|
            (?:dts|www)\.podtrac\.com/(?:pts/)?redirect\.[0-9a-z]{3,4}| # http://analytics.podtrac.com/how-to-measure
            flex\.acast\.com|
            pd(?:
                cn\.co| # https://podcorn.com/analytics-prefix/
                st\.fm # https://podsights.com/docs/
            )/e
        )/''', '', url)


_HEX_TABLE = '0123456789abcdef'


def random_uuidv4():
    return re.sub(r'[xy]', lambda x: _HEX_TABLE[random.randint(0, 15)], 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx')


def make_dir(path, to_screen=None):
    try:
        dn = os.path.dirname(path)
        if dn and not os.path.exists(dn):
            os.makedirs(dn)
        return True
    except OSError as err:
        if callable(to_screen) is not None:
            to_screen('unable to create directory ' + error_to_compat_str(err))
        return False


def get_executable_path():
    from .update import _get_variant_and_executable_path

    return os.path.dirname(os.path.abspath(_get_variant_and_executable_path()[1]))


def get_user_config_dirs(package_name):
    # .config (e.g. ~/.config/package_name)
    xdg_config_home = os.getenv('XDG_CONFIG_HOME') or compat_expanduser('~/.config')
    yield os.path.join(xdg_config_home, package_name)

    # appdata (%APPDATA%/package_name)
    appdata_dir = os.getenv('appdata')
    if appdata_dir:
        yield os.path.join(appdata_dir, package_name)

    # home (~/.package_name)
    yield os.path.join(compat_expanduser('~'), f'.{package_name}')


def get_system_config_dirs(package_name):
    # /etc/package_name
    yield os.path.join('/etc', package_name)


def traverse_obj(
        obj, *paths, default=NO_DEFAULT, expected_type=None, get_all=True,
        casesense=True, is_user_input=False, traverse_string=False):
    """
    Safely traverse nested `dict`s and `Sequence`s

    >>> obj = [{}, {"key": "value"}]
    >>> traverse_obj(obj, (1, "key"))
    "value"

    Each of the provided `paths` is tested and the first producing a valid result will be returned.
    The next path will also be tested if the path branched but no results could be found.
    Supported values for traversal are `Mapping`, `Sequence` and `re.Match`.
    A value of None is treated as the absence of a value.

    The paths will be wrapped in `variadic`, so that `'key'` is conveniently the same as `('key', )`.

    The keys in the path can be one of:
        - `None`:           Return the current object.
        - `str`/`int`:      Return `obj[key]`. For `re.Match`, return `obj.group(key)`.
        - `slice`:          Branch out and return all values in `obj[key]`.
        - `Ellipsis`:       Branch out and return a list of all values.
        - `tuple`/`list`:   Branch out and return a list of all matching values.
                            Read as: `[traverse_obj(obj, branch) for branch in branches]`.
        - `function`:       Branch out and return values filtered by the function.
                            Read as: `[value for key, value in obj if function(key, value)]`.
                            For `Sequence`s, `key` is the index of the value.
        - `dict`            Transform the current object and return a matching dict.
                            Read as: `{key: traverse_obj(obj, path) for key, path in dct.items()}`.

        `tuple`, `list`, and `dict` all support nested paths and branches.

    @params paths           Paths which to traverse by.
    @param default          Value to return if the paths do not match.
    @param expected_type    If a `type`, only accept final values of this type.
                            If any other callable, try to call the function on each result.
    @param get_all          If `False`, return the first matching result, otherwise all matching ones.
    @param casesense        If `False`, consider string dictionary keys as case insensitive.

    The following are only meant to be used by YoutubeDL.prepare_outtmpl and are not part of the API

    @param is_user_input    Whether the keys are generated from user input.
                            If `True` strings get converted to `int`/`slice` if needed.
    @param traverse_string  Whether to traverse into objects as strings.
                            If `True`, any non-compatible object will first be
                            converted into a string and then traversed into.


    @returns                The result of the object traversal.
                            If successful, `get_all=True`, and the path branches at least once,
                            then a list of results is returned instead.
                            A list is always returned if the last path branches and no `default` is given.
    """
    is_sequence = lambda x: isinstance(x, collections.abc.Sequence) and not isinstance(x, (str, bytes))
    casefold = lambda k: k.casefold() if isinstance(k, str) else k

    if isinstance(expected_type, type):
        type_test = lambda val: val if isinstance(val, expected_type) else None
    else:
        type_test = lambda val: try_call(expected_type or IDENTITY, args=(val,))

    def apply_key(key, obj):
        if obj is None:
            return

        elif key is None:
            yield obj

        elif isinstance(key, (list, tuple)):
            for branch in key:
                _, result = apply_path(obj, branch)
                yield from result

        elif key is ...:
            if isinstance(obj, collections.abc.Mapping):
                yield from obj.values()
            elif is_sequence(obj):
                yield from obj
            elif isinstance(obj, re.Match):
                yield from obj.groups()
            elif traverse_string:
                yield from str(obj)

        elif callable(key):
            if is_sequence(obj):
                iter_obj = enumerate(obj)
            elif isinstance(obj, collections.abc.Mapping):
                iter_obj = obj.items()
            elif isinstance(obj, re.Match):
                iter_obj = enumerate((obj.group(), *obj.groups()))
            elif traverse_string:
                iter_obj = enumerate(str(obj))
            else:
                return
            yield from (v for k, v in iter_obj if try_call(key, args=(k, v)))

        elif isinstance(key, dict):
            iter_obj = ((k, _traverse_obj(obj, v)) for k, v in key.items())
            yield {k: v if v is not None else default for k, v in iter_obj
                   if v is not None or default is not NO_DEFAULT}

        elif isinstance(obj, collections.abc.Mapping):
            yield (obj.get(key) if casesense or (key in obj)
                   else next((v for k, v in obj.items() if casefold(k) == key), None))

        elif isinstance(obj, re.Match):
            if isinstance(key, int) or casesense:
                with contextlib.suppress(IndexError):
                    yield obj.group(key)
                    return

            if not isinstance(key, str):
                return

            yield next((v for k, v in obj.groupdict().items() if casefold(k) == key), None)

        else:
            if is_user_input:
                key = (int_or_none(key) if ':' not in key
                       else slice(*map(int_or_none, key.split(':'))))

            if not isinstance(key, (int, slice)):
                return

            if not is_sequence(obj):
                if not traverse_string:
                    return
                obj = str(obj)

            with contextlib.suppress(IndexError):
                yield obj[key]

    def apply_path(start_obj, path):
        objs = (start_obj,)
        has_branched = False

        for key in variadic(path):
            if is_user_input and key == ':':
                key = ...

            if not casesense and isinstance(key, str):
                key = key.casefold()

            if key is ... or isinstance(key, (list, tuple)) or callable(key):
                has_branched = True

            key_func = functools.partial(apply_key, key)
            objs = itertools.chain.from_iterable(map(key_func, objs))

        return has_branched, objs

    def _traverse_obj(obj, path, use_list=True):
        has_branched, results = apply_path(obj, path)
        results = LazyList(x for x in map(type_test, results) if x is not None)

        if get_all and has_branched:
            return results.exhaust() if results or use_list else None

        return results[0] if results else None

    for index, path in enumerate(paths, 1):
        use_list = default is NO_DEFAULT and index == len(paths)
        result = _traverse_obj(obj, path, use_list)
        if result is not None:
            return result

    return None if default is NO_DEFAULT else default


def traverse_dict(dictn, keys, casesense=True):
    deprecation_warning(f'"{__name__}.traverse_dict" is deprecated and may be removed '
                        f'in a future version. Use "{__name__}.traverse_obj" instead')
    return traverse_obj(dictn, keys, casesense=casesense, is_user_input=True, traverse_string=True)


def get_first(obj, keys, **kwargs):
    return traverse_obj(obj, (..., *variadic(keys)), **kwargs, get_all=False)


def time_seconds(**kwargs):
    t = datetime.datetime.now(datetime.timezone(datetime.timedelta(**kwargs)))
    return t.timestamp()


# create a JSON Web Signature (jws) with HS256 algorithm
# the resulting format is in JWS Compact Serialization
# implemented following JWT https://www.rfc-editor.org/rfc/rfc7519.html
# implemented following JWS https://www.rfc-editor.org/rfc/rfc7515.html
def jwt_encode_hs256(payload_data, key, headers={}):
    header_data = {
        'alg': 'HS256',
        'typ': 'JWT',
    }
    if headers:
        header_data.update(headers)
    header_b64 = base64.b64encode(json.dumps(header_data).encode())
    payload_b64 = base64.b64encode(json.dumps(payload_data).encode())
    h = hmac.new(key.encode(), header_b64 + b'.' + payload_b64, hashlib.sha256)
    signature_b64 = base64.b64encode(h.digest())
    token = header_b64 + b'.' + payload_b64 + b'.' + signature_b64
    return token


# can be extended in future to verify the signature and parse header and return the algorithm used if it's not HS256
def jwt_decode_hs256(jwt):
    header_b64, payload_b64, signature_b64 = jwt.split('.')
    # add trailing ='s that may have been stripped, superfluous ='s are ignored
    payload_data = json.loads(base64.urlsafe_b64decode(f'{payload_b64}==='))
    return payload_data


WINDOWS_VT_MODE = False if compat_os_name == 'nt' else None


@functools.cache
def supports_terminal_sequences(stream):
    if compat_os_name == 'nt':
        if not WINDOWS_VT_MODE:
            return False
    elif not os.getenv('TERM'):
        return False
    try:
        return stream.isatty()
    except BaseException:
        return False


def windows_enable_vt_mode():
    """Ref: https://bugs.python.org/issue30075 """
    if get_windows_version() < (10, 0, 10586):
        return

    import ctypes
    import ctypes.wintypes
    import msvcrt

    ENABLE_VIRTUAL_TERMINAL_PROCESSING = 0x0004

    dll = ctypes.WinDLL('kernel32', use_last_error=False)
    handle = os.open('CONOUT$', os.O_RDWR)
    try:
        h_out = ctypes.wintypes.HANDLE(msvcrt.get_osfhandle(handle))
        dw_original_mode = ctypes.wintypes.DWORD()
        success = dll.GetConsoleMode(h_out, ctypes.byref(dw_original_mode))
        if not success:
            raise Exception('GetConsoleMode failed')

        success = dll.SetConsoleMode(h_out, ctypes.wintypes.DWORD(
            dw_original_mode.value | ENABLE_VIRTUAL_TERMINAL_PROCESSING))
        if not success:
            raise Exception('SetConsoleMode failed')
    finally:
        os.close(handle)

    global WINDOWS_VT_MODE
    WINDOWS_VT_MODE = True
    supports_terminal_sequences.cache_clear()


_terminal_sequences_re = re.compile('\033\\[[^m]+m')


def remove_terminal_sequences(string):
    return _terminal_sequences_re.sub('', string)


def number_of_digits(number):
    return len('%d' % number)


def join_nonempty(*values, delim='-', from_dict=None):
    if from_dict is not None:
        values = (traverse_obj(from_dict, variadic(v)) for v in values)
    return delim.join(map(str, filter(None, values)))


def scale_thumbnails_to_max_format_width(formats, thumbnails, url_width_re):
    """
    Find the largest format dimensions in terms of video width and, for each thumbnail:
    * Modify the URL: Match the width with the provided regex and replace with the former width
    * Update dimensions

    This function is useful with video services that scale the provided thumbnails on demand
    """
    _keys = ('width', 'height')
    max_dimensions = max(
        (tuple(format.get(k) or 0 for k in _keys) for format in formats),
        default=(0, 0))
    if not max_dimensions[0]:
        return thumbnails
    return [
        merge_dicts(
            {'url': re.sub(url_width_re, str(max_dimensions[0]), thumbnail['url'])},
            dict(zip(_keys, max_dimensions)), thumbnail)
        for thumbnail in thumbnails
    ]


def parse_http_range(range):
    """ Parse value of "Range" or "Content-Range" HTTP header into tuple. """
    if not range:
        return None, None, None
    crg = re.search(r'bytes[ =](\d+)-(\d+)?(?:/(\d+))?', range)
    if not crg:
        return None, None, None
    return int(crg.group(1)), int_or_none(crg.group(2)), int_or_none(crg.group(3))


def read_stdin(what):
    eof = 'Ctrl+Z' if compat_os_name == 'nt' else 'Ctrl+D'
    write_string(f'Reading {what} from STDIN - EOF ({eof}) to end:\n')
    return sys.stdin


def determine_file_encoding(data):
    """
    Detect the text encoding used
    @returns (encoding, bytes to skip)
    """

    # BOM marks are given priority over declarations
    for bom, enc in BOMS:
        if data.startswith(bom):
            return enc, len(bom)

    # Strip off all null bytes to match even when UTF-16 or UTF-32 is used.
    # We ignore the endianness to get a good enough match
    data = data.replace(b'\0', b'')
    mobj = re.match(rb'(?m)^#\s*coding\s*:\s*(\S+)\s*$', data)
    return mobj.group(1).decode() if mobj else None, 0


class Config:
    own_args = None
    parsed_args = None
    filename = None
    __initialized = False

    def __init__(self, parser, label=None):
        self.parser, self.label = parser, label
        self._loaded_paths, self.configs = set(), []

    def init(self, args=None, filename=None):
        assert not self.__initialized
        self.own_args, self.filename = args, filename
        return self.load_configs()

    def load_configs(self):
        directory = ''
        if self.filename:
            location = os.path.realpath(self.filename)
            directory = os.path.dirname(location)
            if location in self._loaded_paths:
                return False
            self._loaded_paths.add(location)

        self.__initialized = True
        opts, _ = self.parser.parse_known_args(self.own_args)
        self.parsed_args = self.own_args
        for location in opts.config_locations or []:
            if location == '-':
                if location in self._loaded_paths:
                    continue
                self._loaded_paths.add(location)
                self.append_config(shlex.split(read_stdin('options'), comments=True), label='stdin')
                continue
            location = os.path.join(directory, expand_path(location))
            if os.path.isdir(location):
                location = os.path.join(location, 'yt-dlp.conf')
            if not os.path.exists(location):
                self.parser.error(f'config location {location} does not exist')
            self.append_config(self.read_file(location), location)
        return True

    def __str__(self):
        label = join_nonempty(
            self.label, 'config', f'"{self.filename}"' if self.filename else '',
            delim=' ')
        return join_nonempty(
            self.own_args is not None and f'{label[0].upper()}{label[1:]}: {self.hide_login_info(self.own_args)}',
            *(f'\n{c}'.replace('\n', '\n| ')[1:] for c in self.configs),
            delim='\n')

    @staticmethod
    def read_file(filename, default=[]):
        try:
            optionf = open(filename, 'rb')
        except OSError:
            return default  # silently skip if file is not present
        try:
            enc, skip = determine_file_encoding(optionf.read(512))
            optionf.seek(skip, io.SEEK_SET)
        except OSError:
            enc = None  # silently skip read errors
        try:
            # FIXME: https://github.com/ytdl-org/youtube-dl/commit/dfe5fa49aed02cf36ba9f743b11b0903554b5e56
            contents = optionf.read().decode(enc or preferredencoding())
            res = shlex.split(contents, comments=True)
        except Exception as err:
            raise ValueError(f'Unable to parse "{filename}": {err}')
        finally:
            optionf.close()
        return res

    @staticmethod
    def hide_login_info(opts):
        PRIVATE_OPTS = {'-p', '--password', '-u', '--username', '--video-password', '--ap-password', '--ap-username'}
        eqre = re.compile('^(?P<key>' + ('|'.join(re.escape(po) for po in PRIVATE_OPTS)) + ')=.+$')

        def _scrub_eq(o):
            m = eqre.match(o)
            if m:
                return m.group('key') + '=PRIVATE'
            else:
                return o

        opts = list(map(_scrub_eq, opts))
        for idx, opt in enumerate(opts):
            if opt in PRIVATE_OPTS and idx + 1 < len(opts):
                opts[idx + 1] = 'PRIVATE'
        return opts

    def append_config(self, *args, label=None):
        config = type(self)(self.parser, label)
        config._loaded_paths = self._loaded_paths
        if config.init(*args):
            self.configs.append(config)

    @property
    def all_args(self):
        for config in reversed(self.configs):
            yield from config.all_args
        yield from self.parsed_args or []

    def parse_known_args(self, **kwargs):
        return self.parser.parse_known_args(self.all_args, **kwargs)

    def parse_args(self):
        return self.parser.parse_args(self.all_args)


class WebSocketsWrapper:
    """Wraps websockets module to use in non-async scopes"""
    pool = None

    def __init__(self, url, headers=None, connect=True):
        self.loop = asyncio.new_event_loop()
        # XXX: "loop" is deprecated
        self.conn = websockets.connect(
            url, extra_headers=headers, ping_interval=None,
            close_timeout=float('inf'), loop=self.loop, ping_timeout=float('inf'))
        if connect:
            self.__enter__()
        atexit.register(self.__exit__, None, None, None)

    def __enter__(self):
        if not self.pool:
            self.pool = self.run_with_loop(self.conn.__aenter__(), self.loop)
        return self

    def send(self, *args):
        self.run_with_loop(self.pool.send(*args), self.loop)

    def recv(self, *args):
        return self.run_with_loop(self.pool.recv(*args), self.loop)

    def __exit__(self, type, value, traceback):
        try:
            return self.run_with_loop(self.conn.__aexit__(type, value, traceback), self.loop)
        finally:
            self.loop.close()
            self._cancel_all_tasks(self.loop)

    # taken from https://github.com/python/cpython/blob/3.9/Lib/asyncio/runners.py with modifications
    # for contributors: If there's any new library using asyncio needs to be run in non-async, move these function out of this class
    @staticmethod
    def run_with_loop(main, loop):
        if not asyncio.iscoroutine(main):
            raise ValueError(f'a coroutine was expected, got {main!r}')

        try:
            return loop.run_until_complete(main)
        finally:
            loop.run_until_complete(loop.shutdown_asyncgens())
            if hasattr(loop, 'shutdown_default_executor'):
                loop.run_until_complete(loop.shutdown_default_executor())

    @staticmethod
    def _cancel_all_tasks(loop):
        to_cancel = asyncio.all_tasks(loop)

        if not to_cancel:
            return

        for task in to_cancel:
            task.cancel()

        # XXX: "loop" is removed in python 3.10+
        loop.run_until_complete(
            asyncio.gather(*to_cancel, loop=loop, return_exceptions=True))

        for task in to_cancel:
            if task.cancelled():
                continue
            if task.exception() is not None:
                loop.call_exception_handler({
                    'message': 'unhandled exception during asyncio.run() shutdown',
                    'exception': task.exception(),
                    'task': task,
                })


def merge_headers(*dicts):
    """Merge dicts of http headers case insensitively, prioritizing the latter ones"""
    return {k.title(): v for k, v in itertools.chain.from_iterable(map(dict.items, dicts))}


def cached_method(f):
    """Cache a method"""
    signature = inspect.signature(f)

    @functools.wraps(f)
    def wrapper(self, *args, **kwargs):
        bound_args = signature.bind(self, *args, **kwargs)
        bound_args.apply_defaults()
        key = tuple(bound_args.arguments.values())[1:]

        cache = vars(self).setdefault('_cached_method__cache', {}).setdefault(f.__name__, {})
        if key not in cache:
            cache[key] = f(self, *args, **kwargs)
        return cache[key]
    return wrapper


class classproperty:
    """property access for class methods with optional caching"""
    def __new__(cls, func=None, *args, **kwargs):
        if not func:
            return functools.partial(cls, *args, **kwargs)
        return super().__new__(cls)

    def __init__(self, func, *, cache=False):
        functools.update_wrapper(self, func)
        self.func = func
        self._cache = {} if cache else None

    def __get__(self, _, cls):
        if self._cache is None:
            return self.func(cls)
        elif cls not in self._cache:
            self._cache[cls] = self.func(cls)
        return self._cache[cls]


class Namespace(types.SimpleNamespace):
    """Immutable namespace"""

    def __iter__(self):
        return iter(self.__dict__.values())

    @property
    def items_(self):
        return self.__dict__.items()


MEDIA_EXTENSIONS = Namespace(
    common_video=('avi', 'flv', 'mkv', 'mov', 'mp4', 'webm'),
    video=('3g2', '3gp', 'f4v', 'mk3d', 'divx', 'mpg', 'ogv', 'm4v', 'wmv'),
    common_audio=('aiff', 'alac', 'flac', 'm4a', 'mka', 'mp3', 'ogg', 'opus', 'wav'),
    audio=('aac', 'ape', 'asf', 'f4a', 'f4b', 'm4b', 'm4p', 'm4r', 'oga', 'ogx', 'spx', 'vorbis', 'wma', 'weba'),
    thumbnails=('jpg', 'png', 'webp'),
    storyboards=('mhtml', ),
    subtitles=('srt', 'vtt', 'ass', 'lrc'),
    manifests=('f4f', 'f4m', 'm3u8', 'smil', 'mpd'),
)
MEDIA_EXTENSIONS.video += MEDIA_EXTENSIONS.common_video
MEDIA_EXTENSIONS.audio += MEDIA_EXTENSIONS.common_audio

KNOWN_EXTENSIONS = (*MEDIA_EXTENSIONS.video, *MEDIA_EXTENSIONS.audio, *MEDIA_EXTENSIONS.manifests)


class RetryManager:
    """Usage:
        for retry in RetryManager(...):
            try:
                ...
            except SomeException as err:
                retry.error = err
                continue
    """
    attempt, _error = 0, None

    def __init__(self, _retries, _error_callback, **kwargs):
        self.retries = _retries or 0
        self.error_callback = functools.partial(_error_callback, **kwargs)

    def _should_retry(self):
        return self._error is not NO_DEFAULT and self.attempt <= self.retries

    @property
    def error(self):
        if self._error is NO_DEFAULT:
            return None
        return self._error

    @error.setter
    def error(self, value):
        self._error = value

    def __iter__(self):
        while self._should_retry():
            self.error = NO_DEFAULT
            self.attempt += 1
            yield self
            if self.error:
                self.error_callback(self.error, self.attempt, self.retries)

    @staticmethod
    def report_retry(e, count, retries, *, sleep_func, info, warn, error=None, suffix=None):
        """Utility function for reporting retries"""
        if count > retries:
            if error:
                return error(f'{e}. Giving up after {count - 1} retries') if count > 1 else error(str(e))
            raise e

        if not count:
            return warn(e)
        elif isinstance(e, ExtractorError):
            e = remove_end(str_or_none(e.cause) or e.orig_msg, '.')
        warn(f'{e}. Retrying{format_field(suffix, None, " %s")} ({count}/{retries})...')

        delay = float_or_none(sleep_func(n=count - 1)) if callable(sleep_func) else sleep_func
        if delay:
            info(f'Sleeping {delay:.2f} seconds ...')
            time.sleep(delay)


def make_archive_id(ie, video_id):
    ie_key = ie if isinstance(ie, str) else ie.ie_key()
    return f'{ie_key.lower()} {video_id}'


def truncate_string(s, left, right=0):
    assert left > 3 and right >= 0
    if s is None or len(s) <= left + right:
        return s
    return f'{s[:left-3]}...{s[-right:] if right else ""}'


def orderedSet_from_options(options, alias_dict, *, use_regex=False, start=None):
    assert 'all' in alias_dict, '"all" alias is required'
    requested = list(start or [])
    for val in options:
        discard = val.startswith('-')
        if discard:
            val = val[1:]

        if val in alias_dict:
            val = alias_dict[val] if not discard else [
                i[1:] if i.startswith('-') else f'-{i}' for i in alias_dict[val]]
            # NB: Do not allow regex in aliases for performance
            requested = orderedSet_from_options(val, alias_dict, start=requested)
            continue

        current = (filter(re.compile(val, re.I).fullmatch, alias_dict['all']) if use_regex
                   else [val] if val in alias_dict['all'] else None)
        if current is None:
            raise ValueError(val)

        if discard:
            for item in current:
                while item in requested:
                    requested.remove(item)
        else:
            requested.extend(current)

    return orderedSet(requested)


class FormatSorter:
    regex = r' *((?P<reverse>\+)?(?P<field>[a-zA-Z0-9_]+)((?P<separator>[~:])(?P<limit>.*?))?)? *$'

    default = ('hidden', 'aud_or_vid', 'hasvid', 'ie_pref', 'lang', 'quality',
               'res', 'fps', 'hdr:12', 'vcodec:vp9.2', 'channels', 'acodec',
               'size', 'br', 'asr', 'proto', 'ext', 'hasaud', 'source', 'id')  # These must not be aliases
    ytdl_default = ('hasaud', 'lang', 'quality', 'tbr', 'filesize', 'vbr',
                    'height', 'width', 'proto', 'vext', 'abr', 'aext',
                    'fps', 'fs_approx', 'source', 'id')

    settings = {
        'vcodec': {'type': 'ordered', 'regex': True,
                   'order': ['av0?1', 'vp0?9.2', 'vp0?9', '[hx]265|he?vc?', '[hx]264|avc', 'vp0?8', 'mp4v|h263', 'theora', '', None, 'none']},
        'acodec': {'type': 'ordered', 'regex': True,
                   'order': ['[af]lac', 'wav|aiff', 'opus', 'vorbis|ogg', 'aac', 'mp?4a?', 'mp3', 'ac-?4', 'e-?a?c-?3', 'ac-?3', 'dts', '', None, 'none']},
        'hdr': {'type': 'ordered', 'regex': True, 'field': 'dynamic_range',
                'order': ['dv', '(hdr)?12', r'(hdr)?10\+', '(hdr)?10', 'hlg', '', 'sdr', None]},
        'proto': {'type': 'ordered', 'regex': True, 'field': 'protocol',
                  'order': ['(ht|f)tps', '(ht|f)tp$', 'm3u8.*', '.*dash', 'websocket_frag', 'rtmpe?', '', 'mms|rtsp', 'ws|websocket', 'f4']},
        'vext': {'type': 'ordered', 'field': 'video_ext',
                 'order': ('mp4', 'mov', 'webm', 'flv', '', 'none'),
                 'order_free': ('webm', 'mp4', 'mov', 'flv', '', 'none')},
        'aext': {'type': 'ordered', 'regex': True, 'field': 'audio_ext',
                 'order': ('m4a', 'aac', 'mp3', 'ogg', 'opus', 'web[am]', '', 'none'),
                 'order_free': ('ogg', 'opus', 'web[am]', 'mp3', 'm4a', 'aac', '', 'none')},
        'hidden': {'visible': False, 'forced': True, 'type': 'extractor', 'max': -1000},
        'aud_or_vid': {'visible': False, 'forced': True, 'type': 'multiple',
                       'field': ('vcodec', 'acodec'),
                       'function': lambda it: int(any(v != 'none' for v in it))},
        'ie_pref': {'priority': True, 'type': 'extractor'},
        'hasvid': {'priority': True, 'field': 'vcodec', 'type': 'boolean', 'not_in_list': ('none',)},
        'hasaud': {'field': 'acodec', 'type': 'boolean', 'not_in_list': ('none',)},
        'lang': {'convert': 'float', 'field': 'language_preference', 'default': -1},
        'quality': {'convert': 'float', 'default': -1},
        'filesize': {'convert': 'bytes'},
        'fs_approx': {'convert': 'bytes', 'field': 'filesize_approx'},
        'id': {'convert': 'string', 'field': 'format_id'},
        'height': {'convert': 'float_none'},
        'width': {'convert': 'float_none'},
        'fps': {'convert': 'float_none'},
        'channels': {'convert': 'float_none', 'field': 'audio_channels'},
        'tbr': {'convert': 'float_none'},
        'vbr': {'convert': 'float_none'},
        'abr': {'convert': 'float_none'},
        'asr': {'convert': 'float_none'},
        'source': {'convert': 'float', 'field': 'source_preference', 'default': -1},

        'codec': {'type': 'combined', 'field': ('vcodec', 'acodec')},
        'br': {'type': 'combined', 'field': ('tbr', 'vbr', 'abr'), 'same_limit': True},
        'size': {'type': 'combined', 'same_limit': True, 'field': ('filesize', 'fs_approx')},
        'ext': {'type': 'combined', 'field': ('vext', 'aext')},
        'res': {'type': 'multiple', 'field': ('height', 'width'),
                'function': lambda it: (lambda l: min(l) if l else 0)(tuple(filter(None, it)))},

        # Actual field names
        'format_id': {'type': 'alias', 'field': 'id'},
        'preference': {'type': 'alias', 'field': 'ie_pref'},
        'language_preference': {'type': 'alias', 'field': 'lang'},
        'source_preference': {'type': 'alias', 'field': 'source'},
        'protocol': {'type': 'alias', 'field': 'proto'},
        'filesize_approx': {'type': 'alias', 'field': 'fs_approx'},
        'audio_channels': {'type': 'alias', 'field': 'channels'},

        # Deprecated
        'dimension': {'type': 'alias', 'field': 'res', 'deprecated': True},
        'resolution': {'type': 'alias', 'field': 'res', 'deprecated': True},
        'extension': {'type': 'alias', 'field': 'ext', 'deprecated': True},
        'bitrate': {'type': 'alias', 'field': 'br', 'deprecated': True},
        'total_bitrate': {'type': 'alias', 'field': 'tbr', 'deprecated': True},
        'video_bitrate': {'type': 'alias', 'field': 'vbr', 'deprecated': True},
        'audio_bitrate': {'type': 'alias', 'field': 'abr', 'deprecated': True},
        'framerate': {'type': 'alias', 'field': 'fps', 'deprecated': True},
        'filesize_estimate': {'type': 'alias', 'field': 'size', 'deprecated': True},
        'samplerate': {'type': 'alias', 'field': 'asr', 'deprecated': True},
        'video_ext': {'type': 'alias', 'field': 'vext', 'deprecated': True},
        'audio_ext': {'type': 'alias', 'field': 'aext', 'deprecated': True},
        'video_codec': {'type': 'alias', 'field': 'vcodec', 'deprecated': True},
        'audio_codec': {'type': 'alias', 'field': 'acodec', 'deprecated': True},
        'video': {'type': 'alias', 'field': 'hasvid', 'deprecated': True},
        'has_video': {'type': 'alias', 'field': 'hasvid', 'deprecated': True},
        'audio': {'type': 'alias', 'field': 'hasaud', 'deprecated': True},
        'has_audio': {'type': 'alias', 'field': 'hasaud', 'deprecated': True},
        'extractor': {'type': 'alias', 'field': 'ie_pref', 'deprecated': True},
        'extractor_preference': {'type': 'alias', 'field': 'ie_pref', 'deprecated': True},
    }

    def __init__(self, ydl, field_preference):
        self.ydl = ydl
        self._order = []
        self.evaluate_params(self.ydl.params, field_preference)
        if ydl.params.get('verbose'):
            self.print_verbose_info(self.ydl.write_debug)

    def _get_field_setting(self, field, key):
        if field not in self.settings:
            if key in ('forced', 'priority'):
                return False
            self.ydl.deprecated_feature(f'Using arbitrary fields ({field}) for format sorting is '
                                        'deprecated and may be removed in a future version')
            self.settings[field] = {}
        propObj = self.settings[field]
        if key not in propObj:
            type = propObj.get('type')
            if key == 'field':
                default = 'preference' if type == 'extractor' else (field,) if type in ('combined', 'multiple') else field
            elif key == 'convert':
                default = 'order' if type == 'ordered' else 'float_string' if field else 'ignore'
            else:
                default = {'type': 'field', 'visible': True, 'order': [], 'not_in_list': (None,)}.get(key, None)
            propObj[key] = default
        return propObj[key]

    def _resolve_field_value(self, field, value, convertNone=False):
        if value is None:
            if not convertNone:
                return None
        else:
            value = value.lower()
        conversion = self._get_field_setting(field, 'convert')
        if conversion == 'ignore':
            return None
        if conversion == 'string':
            return value
        elif conversion == 'float_none':
            return float_or_none(value)
        elif conversion == 'bytes':
            return parse_bytes(value)
        elif conversion == 'order':
            order_list = (self._use_free_order and self._get_field_setting(field, 'order_free')) or self._get_field_setting(field, 'order')
            use_regex = self._get_field_setting(field, 'regex')
            list_length = len(order_list)
            empty_pos = order_list.index('') if '' in order_list else list_length + 1
            if use_regex and value is not None:
                for i, regex in enumerate(order_list):
                    if regex and re.match(regex, value):
                        return list_length - i
                return list_length - empty_pos  # not in list
            else:  # not regex or  value = None
                return list_length - (order_list.index(value) if value in order_list else empty_pos)
        else:
            if value.isnumeric():
                return float(value)
            else:
                self.settings[field]['convert'] = 'string'
                return value

    def evaluate_params(self, params, sort_extractor):
        self._use_free_order = params.get('prefer_free_formats', False)
        self._sort_user = params.get('format_sort', [])
        self._sort_extractor = sort_extractor

        def add_item(field, reverse, closest, limit_text):
            field = field.lower()
            if field in self._order:
                return
            self._order.append(field)
            limit = self._resolve_field_value(field, limit_text)
            data = {
                'reverse': reverse,
                'closest': False if limit is None else closest,
                'limit_text': limit_text,
                'limit': limit}
            if field in self.settings:
                self.settings[field].update(data)
            else:
                self.settings[field] = data

        sort_list = (
            tuple(field for field in self.default if self._get_field_setting(field, 'forced'))
            + (tuple() if params.get('format_sort_force', False)
                else tuple(field for field in self.default if self._get_field_setting(field, 'priority')))
            + tuple(self._sort_user) + tuple(sort_extractor) + self.default)

        for item in sort_list:
            match = re.match(self.regex, item)
            if match is None:
                raise ExtractorError('Invalid format sort string "%s" given by extractor' % item)
            field = match.group('field')
            if field is None:
                continue
            if self._get_field_setting(field, 'type') == 'alias':
                alias, field = field, self._get_field_setting(field, 'field')
                if self._get_field_setting(alias, 'deprecated'):
                    self.ydl.deprecated_feature(f'Format sorting alias {alias} is deprecated and may '
                                                f'be removed in a future version. Please use {field} instead')
            reverse = match.group('reverse') is not None
            closest = match.group('separator') == '~'
            limit_text = match.group('limit')

            has_limit = limit_text is not None
            has_multiple_fields = self._get_field_setting(field, 'type') == 'combined'
            has_multiple_limits = has_limit and has_multiple_fields and not self._get_field_setting(field, 'same_limit')

            fields = self._get_field_setting(field, 'field') if has_multiple_fields else (field,)
            limits = limit_text.split(':') if has_multiple_limits else (limit_text,) if has_limit else tuple()
            limit_count = len(limits)
            for (i, f) in enumerate(fields):
                add_item(f, reverse, closest,
                         limits[i] if i < limit_count
                         else limits[0] if has_limit and not has_multiple_limits
                         else None)

    def print_verbose_info(self, write_debug):
        if self._sort_user:
            write_debug('Sort order given by user: %s' % ', '.join(self._sort_user))
        if self._sort_extractor:
            write_debug('Sort order given by extractor: %s' % ', '.join(self._sort_extractor))
        write_debug('Formats sorted by: %s' % ', '.join(['%s%s%s' % (
            '+' if self._get_field_setting(field, 'reverse') else '', field,
            '%s%s(%s)' % ('~' if self._get_field_setting(field, 'closest') else ':',
                          self._get_field_setting(field, 'limit_text'),
                          self._get_field_setting(field, 'limit'))
            if self._get_field_setting(field, 'limit_text') is not None else '')
            for field in self._order if self._get_field_setting(field, 'visible')]))

    def _calculate_field_preference_from_value(self, format, field, type, value):
        reverse = self._get_field_setting(field, 'reverse')
        closest = self._get_field_setting(field, 'closest')
        limit = self._get_field_setting(field, 'limit')

        if type == 'extractor':
            maximum = self._get_field_setting(field, 'max')
            if value is None or (maximum is not None and value >= maximum):
                value = -1
        elif type == 'boolean':
            in_list = self._get_field_setting(field, 'in_list')
            not_in_list = self._get_field_setting(field, 'not_in_list')
            value = 0 if ((in_list is None or value in in_list) and (not_in_list is None or value not in not_in_list)) else -1
        elif type == 'ordered':
            value = self._resolve_field_value(field, value, True)

        # try to convert to number
        val_num = float_or_none(value, default=self._get_field_setting(field, 'default'))
        is_num = self._get_field_setting(field, 'convert') != 'string' and val_num is not None
        if is_num:
            value = val_num

        return ((-10, 0) if value is None
                else (1, value, 0) if not is_num  # if a field has mixed strings and numbers, strings are sorted higher
                else (0, -abs(value - limit), value - limit if reverse else limit - value) if closest
                else (0, value, 0) if not reverse and (limit is None or value <= limit)
                else (0, -value, 0) if limit is None or (reverse and value == limit) or value > limit
                else (-1, value, 0))

    def _calculate_field_preference(self, format, field):
        type = self._get_field_setting(field, 'type')  # extractor, boolean, ordered, field, multiple
        get_value = lambda f: format.get(self._get_field_setting(f, 'field'))
        if type == 'multiple':
            type = 'field'  # Only 'field' is allowed in multiple for now
            actual_fields = self._get_field_setting(field, 'field')

            value = self._get_field_setting(field, 'function')(get_value(f) for f in actual_fields)
        else:
            value = get_value(field)
        return self._calculate_field_preference_from_value(format, field, type, value)

    def calculate_preference(self, format):
        # Determine missing protocol
        if not format.get('protocol'):
            format['protocol'] = determine_protocol(format)

        # Determine missing ext
        if not format.get('ext') and 'url' in format:
            format['ext'] = determine_ext(format['url'])
        if format.get('vcodec') == 'none':
            format['audio_ext'] = format['ext'] if format.get('acodec') != 'none' else 'none'
            format['video_ext'] = 'none'
        else:
            format['video_ext'] = format['ext']
            format['audio_ext'] = 'none'
        # if format.get('preference') is None and format.get('ext') in ('f4f', 'f4m'):  # Not supported?
        #    format['preference'] = -1000

        if format.get('preference') is None and format.get('ext') == 'flv' and re.match('[hx]265|he?vc?', format.get('vcodec') or ''):
            # HEVC-over-FLV is out-of-spec by FLV's original spec
            # ref. https://trac.ffmpeg.org/ticket/6389
            # ref. https://github.com/yt-dlp/yt-dlp/pull/5821
            format['preference'] = -100

        # Determine missing bitrates
        if format.get('tbr') is None:
            if format.get('vbr') is not None and format.get('abr') is not None:
                format['tbr'] = format.get('vbr', 0) + format.get('abr', 0)
        else:
            if format.get('vcodec') != 'none' and format.get('vbr') is None:
                format['vbr'] = format.get('tbr') - format.get('abr', 0)
            if format.get('acodec') != 'none' and format.get('abr') is None:
                format['abr'] = format.get('tbr') - format.get('vbr', 0)

        return tuple(self._calculate_field_preference(format, field) for field in self._order)


# Deprecated
has_certifi = bool(certifi)
has_websockets = bool(websockets)


def load_plugins(name, suffix, namespace):
    from .plugins import load_plugins
    ret = load_plugins(name, suffix)
    namespace.update(ret)
    return ret