#!/usr/bin/env python3

HELP = '''GreggyBits: (un)pack resources in the Macintosh System file (7.1)

Algorithm by Greg Mariott <http://www.greggybits.com>
Reimplemented by Maxim Poliakovski and Elliot Nunn

Use the 'rfx' wrapper command to access resources inside a file'''

def debug_round_trip(filename, packed):
    print(filename.split('/')[-1], end=' ')

    unpacked = unpack(packed)
    repacked = pack(unpacked)

    if packed == repacked:
        print('good', end=' ')
    elif packed[17] != repacked[17]:
        print('WRONGMODE', repacked[17], 'not', packed[17], end=' ')
        if pack_with_flags(unpacked, packed[17]) == packed:
            print('(correct when mode is forced)', end=' ')
    elif packed[:14] == repacked[:14] and packed[16:] == repacked[16:]:
        print('sloppy', hex(struct.unpack_from('>H', repacked, 14)[0]), 'not', hex(struct.unpack_from('>H', packed, 14)[0]), end=' ')
    else:
        print('other', end=' ')

    print()

if __name__ == '__main__':
    # Some cheeky debug code for testing... rfx greggybits --debug System//
    from macresources.greggybits import pack, pack_with_flags, unpack
    import struct
    import sys

    import argparse

    parser = argparse.ArgumentParser(
        description=HELP, formatter_class=argparse.RawTextHelpFormatter,
    )
    parser.prog = '[rfx] ' + parser.prog

    parser.add_argument('path', nargs='+', metavar='file', action='store', help='Resource data')
    parser.add_argument('-x', dest='do_compress', action='store_false', help='extract (default: compress)')
    parser.add_argument('--debug', action='store_true', help='attempt to round-trip resources')

    args = parser.parse_args()

    for el in args.path:
        from macresources.greggybits import pack, unpack

        with open(el, 'r+b') as f:
            already_compressed = (f.read(4) == b'\xA8\x9Fer')
            if already_compressed == args.do_compress: continue

            f.seek(0)
            data = f.read()

            try:
                if args.do_compress:
                    data = pack(data)
                    if args.debug: debug_round_trip(el, data)
                else:
                    if args.debug: debug_round_trip(el, data)
                    data = unpack(data)

                f.seek(0)
                f.write(data)
                f.truncate()
            except ValueError:
                raise
                print('some kind of error')