symuid/symuid-import-cmus

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import datetime as dt
import os
import re
import symuid
# import symuid.library.cmus
import sys

FILE_PREFIX = b'CTC'
VERSION_LENGTH = 1
SUPPORTED_VERSION = b'\x0c'
LINE_SEPARATOR = b'\xff' * 56
COLUMN_SEPARATOR = b'\x00'
# always big endian, see cache_init()
FLAGS_BYTEORDER = 'big'
FLAGS_LENGTH = 4
FLAG_64_BIT = 0x01

def symuid_import_cmus(cache_path):
    with open(os.path.expanduser(cache_path), 'rb') as c:
        # see cache.c cache_init()
        assert c.read(len(FILE_PREFIX)) == FILE_PREFIX
        cache_version = c.read(VERSION_LENGTH)
        assert cache_version == SUPPORTED_VERSION, cache_version
        flags = int.from_bytes(c.read(FLAGS_LENGTH), byteorder=FLAGS_BYTEORDER)
        # only support 64-bit flag
        assert flags & ~FLAG_64_BIT == 0, flags
        cache_data = [l.split(COLUMN_SEPARATOR)
                      for l in c.read().split(LINE_SEPARATOR)]
    for track_data in cache_data[1:]:
        track_path, codec, codec_profile = track_data[0:3]
        if not os.path.exists(track_path):
            sys.stderr.write('{!r}: not found\n'.format(track_path))
        else:
            print(track_path)


def _init_argparser():
    import argparse
    argparser = argparse.ArgumentParser(description=None)
    argparser.add_argument(
        'cache_path',
        nargs='?',
        default='~/.config/cmus/cache',
        help='(default: %(default)r)',
    )
    return argparser


def main(argv):
    argparser = _init_argparser()
    args = argparser.parse_args(argv[1:])
    symuid_import_cmus(**vars(args))
    return 0

if __name__ == "__main__":
    sys.exit(main(sys.argv))