import json
import sys

def read_file(filename):
    with open(filename) as f:
        for line in f:
            yield json.loads(line)

def file_details_from_acr_filename(filename):
    parts = filename.split('_')
    assert len(parts) == 6
    return {
        'upc': parts[0],
        'cd': parts[1],
        'track_id': parts[2],
        'tuid': parts[3],
        'isrc': parts[4],
        'identifier_timestamp': int(parts[5])
    }

def file_details_to_dd_filename(details):
    return f"{details['upc']}_{details['cd']}_{details['track_id']}"

def main():
    input_filename = sys.argv[1]
    output_filename = sys.argv[2]

    tuid_to_latest_delivery = {}

    # Find the latest delivery time for each tuid
    for input in read_file(input_filename):
        for asset in input['dup-files']:
            details = file_details_from_acr_filename(asset['id'])

            current_timestamp = tuid_to_latest_delivery.get(details['tuid'])
            if current_timestamp is not None:
                if current_timestamp > details['identifier_timestamp']:
                    continue
                assert current_timestamp != details['identifier_timestamp']

            tuid_to_latest_delivery[details['tuid']] = details['identifier_timestamp']

    # Write the file out with only the latest deliveries, and with DD-style filenames
    with open(output_filename, 'w') as output_file:
        for input in read_file(input_filename):
            output = {
                'acr_id': input['acr_id'],
                'assets': [],
            }
            for asset in input['dup-files']:
                details = file_details_from_acr_filename(asset['id'])
                if tuid_to_latest_delivery[details['tuid']] != details['identifier_timestamp']:
                    continue
                output['assets'].append({
                    'filename': file_details_to_dd_filename(details),
                    'tuid': details['tuid'],
                    'md5': asset['md5'],
                })
            output_file.write(json.dumps(output) + '\n')


if __name__ == "__main__":
    main()