import os

from googleapiclient.discovery import build
import httplib2
httplib2.debuglevel = 4

def get_cert_files():
    return (os.environ.get('GOOGLE_API_CLIENT_CERTIFICATE'),
            os.environ.get('GOOGLE_API_CLIENT_PRIVATE_KEY'),
            None)

def getClientOptions():
    client_options = {}
    if os.environ.get('GOOGLE_API_CLIENT_CERTIFICATE') and \
       os.environ.get('GOOGLE_API_CLIENT_PRIVATE_KEY'):
        client_options['client_encrypted_cert_source'] = get_cert_files
    return client_options

def print_result(request_id, response, exception):
    if exception is not None:
        # Seems to happen for fuschia which is no longer valid
        pass
    else:
        versions = response['versions']
        if versions:
            name = versions[0].get('name')
            if name:
                product, _, platform, _, channel, _, version = name.split('/')
                print(f'The latest {channel} version of {product} on {platform} is {version}')


# Force some environment variables
os.environ['GOOGLE_API_USE_CLIENT_CERTIFICATE'] = 'true'
os.environ['GOOGLE_API_USE_MTLS_ENDPOINT'] = 'always'
os.environ['GOOGLE_API_CLIENT_CERTIFICATE'] = 'client1.pem' 
os.environ['GOOGLE_API_CLIENT_PRIVATE_KEY'] = 'client1.key'

product = 'chrome'
channel = 'stable'
httpc = httplib2.Http()
client_options = getClientOptions()
srv = build('versionhistory',
            'v1',
            http=httpc,
            client_options=client_options,
            )
results = srv.platforms().list(parent=product).execute()
platforms = [p['platformType'].lower() for p in results['platforms']]
vbatch = srv.new_batch_http_request(callback=print_result)
for platform in platforms:
    parent = f'{product}/platforms/{platform}/channels/{channel}'
    vbatch.add(srv.platforms().channels().versions().list(parent=parent,
                                                          pageSize=1))
vbatch.execute()