import argparse
import datetime
import json
import os
import re
import sys

CDM_MAJOR = 19
CDM_MINOR = 0

def get_build_id(args):
    with args.version_txt as file:
        return file.read().strip()


def hdr(args):
    output = f'''\
#ifndef {args.guard}
#define {args.guard}

#define WV_ANDROID_BUILD_ID "{get_build_id(args)}"

#endif  // {args.guard}'''
    print(output)


def apex_manifest(args):
    rc = get_build_id(args)
    m = re.match(r'[A-Z0-9]{4}\.(?P<build_date>\d{6})\.', rc)
    if m:
        v = int(f'{CDM_MAJOR}{CDM_MINOR}{m["build_date"]}')
    else:
        v = 1

    out = dict(name=args.name, version=v, requireNativeLibs=['liboemcrypto.so'])
    print(json.dumps(out))


if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='Widevine Android genrule utility')
    parser.set_defaults(func=lambda _: parser.print_help())
    subparsers = parser.add_subparsers(help='Available subcommands')

    hdr_description = 'Generate build id C++ header (stdout)'
    parser_hdr = subparsers.add_parser('build_id_header', help=hdr_description)
    parser_hdr.add_argument('--guard', type=str,
                            default='WVCDM_WV_ANDROID_BUILD_ID_H_',
                            help='Include guard')
    parser_hdr.add_argument('version_txt', type=argparse.FileType('r'),
                            nargs='?',
                            default=sys.stdin,
                            help='version.txt file')
    parser_hdr.set_defaults(func=hdr)

    apex_description = 'Generate APEX manifest json (stdout)'
    parser_apex = subparsers.add_parser('apex_manifest', help=apex_description)
    parser_apex.add_argument('--name', help='apex name',
                             default='com.google.android.widevine')
    parser_apex.add_argument('version_txt', type=argparse.FileType('r'),
                             nargs='?',
                             default=sys.stdin,
                             help='version.txt file')
    parser_apex.set_defaults(func=apex_manifest)

    # Parse the arguments and call the appropriate function
    args = parser.parse_args()
    args.func(args)