arcadeutils/splitrom

#! /usr/bin/env python3
import argparse
import os
import sys

from arcadeutils.binary import ByteUtil


def main() -> int:
    parser = argparse.ArgumentParser("ROM manipulation utilities.")
    subparsers = parser.add_subparsers(
        dest="action",
        help="Action to perform.",
    )

    byteswap = subparsers.add_parser(
        "byteswap",
        help="Swap every byte pair of a 16bit rom.",
    )
    byteswap.add_argument(
        "old",
        metavar="OLD",
        type=str,
        help="Old rom file to byteswap.",
    )
    byteswap.add_argument(
        "new",
        metavar="NEW",
        type=str,
        help="New rom file to write after byteswapping.",
    )

    wordswap = subparsers.add_parser(
        "wordswap",
        help="Swap every 32bit value in a 32bit rom.",
    )
    wordswap.add_argument(
        "old",
        metavar="OLD",
        type=str,
        help="Old rom file to wordswap.",
    )
    wordswap.add_argument(
        "new",
        metavar="NEW",
        type=str,
        help="New rom file to write after wordswapping.",
    )

    combine8 = subparsers.add_parser(
        "combine8",
        help="Combine two 8bit roms to one 16bit rom.",
    )
    combine8.add_argument(
        "upper",
        metavar="UPPER",
        type=str,
        help="Upper half of rom file.",
    )
    combine8.add_argument(
        "lower",
        metavar="LOWER",
        type=str,
        help="Lower half of rom file.",
    )
    combine8.add_argument(
        "combined",
        metavar="COMBINED",
        type=str,
        help="Combined output file.",
    )

    combine16 = subparsers.add_parser(
        "combine16",
        help="Combine two 16bit roms to one 32bit rom.",
    )
    combine16.add_argument(
        "upper",
        metavar="UPPER",
        type=str,
        help="Upper half of rom file.",
    )
    combine16.add_argument(
        "lower",
        metavar="LOWER",
        type=str,
        help="Lower half of rom file.",
    )
    combine16.add_argument(
        "combined",
        metavar="COMBINED",
        type=str,
        help="Combined output file.",
    )

    split8 = subparsers.add_parser(
        "split8",
        help="Split one 16bit rom to two 8bit roms.",
    )
    split8.add_argument(
        "combined",
        metavar="COMBINED",
        type=str,
        help="Combined input file.",
    )
    split8.add_argument(
        "upper",
        metavar="UPPER",
        type=str,
        help="Upper half output rom file.",
    )
    split8.add_argument(
        "lower",
        metavar="LOWER",
        type=str,
        help="Lower half output rom file.",
    )

    split16 = subparsers.add_parser(
        "split16",
        help="Split one 32bit rom to two 16bit roms.",
    )
    split16.add_argument(
        "combined",
        metavar="COMBINED",
        type=str,
        help="Combined input file.",
    )
    split16.add_argument(
        "upper",
        metavar="UPPER",
        type=str,
        help="Upper half output rom file.",
    )
    split16.add_argument(
        "lower",
        metavar="LOWER",
        type=str,
        help="Lower half output rom file.",
    )

    args = parser.parse_args()
    if args.action == "combine8":
        with open(args.upper, "rb") as fp:
            upper = fp.read()
        with open(args.lower, "rb") as fp:
            lower = fp.read()
        with open(args.combined, "wb") as fp:
            fp.write(ByteUtil.combine8bithalves(upper, lower))
    elif args.action == "combine16":
        with open(args.upper, "rb") as fp:
            upper = fp.read()
        with open(args.lower, "rb") as fp:
            lower = fp.read()
        with open(args.combined, "wb") as fp:
            fp.write(ByteUtil.combine16bithalves(upper, lower))
    elif args.action == "split8":
        with open(args.combined, "rb") as fp:
            combined = fp.read()
        upper, lower = ByteUtil.split8bithalves(combined)
        with open(args.lower, "wb") as fp:
            fp.write(lower)
        with open(args.upper, "wb") as fp:
            fp.write(upper)
    elif args.action == "split16":
        with open(args.combined, "rb") as fp:
            combined = fp.read()
        upper, lower = ByteUtil.split16bithalves(combined)
        with open(args.lower, "wb") as fp:
            fp.write(lower)
        with open(args.upper, "wb") as fp:
            fp.write(upper)
    elif args.action == "byteswap":
        with open(args.old, "rb") as fp:
            old = fp.read()
        with open(args.new, "wb") as fp:
            fp.write(ByteUtil.byteswap(old))
    elif args.action == "wordswap":
        with open(args.old, "rb") as fp:
            old = fp.read()
        with open(args.new, "wb") as fp:
            fp.write(ByteUtil.wordswap(old))
    else:
        print(f"Please specify a valid command!{os.linesep}", file=sys.stderr)
        parser.print_help()
        return 1

    return 0


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