,merge

#!/usr/bin/env python3

import argparse
import json
import re
import sys
import yaml

# ==============================================================================
# FUNCTIONS
# ==============================================================================

# Print pretty data as pretty json
def print_json(data):
    print(json.dumps(data, indent=2))

# Raise error
def raise_type_error(left, right):
    raise TypeError(f"Unable to merge {left} {type(left)} with {right} {type(right)}")

# Merge two things together
def merge(left, right):

    # Use right value if left is empty
    if left == None:
        return right

    left_type = type(left)
    right_type = type(right)

    # Merge hashes
    if type(left) == dict:
        if type(right) != dict:
            raise_type_error(left, right)
        #print(right)
        for right_key, right_value in right.items():
            if right_key in left:
                left[right_key] = merge(left[right_key], right_value)
            else:
                left[right_key] = right_value
        return left

    # TODO: Do we need to merge lists?
    #elif left_type == list:
        #raise_type_error(left, right)

    # Overwrite left with right value
    elif left_type == right_type:
        return right

    else:
        raise_type_error(left, right)


# ==============================================================================
# MAIN
# ==============================================================================
def main():
    parser = argparse.ArgumentParser()
    parser.add_argument(
        'files',
        help='<Required> .yaml files',
        nargs='+',
        action='append',
        )
    args = parser.parse_args()
    files = args.files[0]

    #print(args.files)
    merged_data = None
    for file in files:
        data = yaml.safe_load(open(file).read())
        #print_json(data)
        merged_data = merge(merged_data, data)

    print_json(merged_data)

    return 0

if __name__ == '__main__':
  sys.exit(main())