import argparse
import os
from os import path
from sys import stderr

from tbxi.lowlevel import MAGIC
from tbxi.prcldump import dump


parser = argparse.ArgumentParser(description='''
    Dump a MacOS parcel blob (magic number 0x7072636C 'prcl') to a
    plain-text Parcelfile and several decompressed binaries. This output
    can be rebuilt using the Parcel Compiler (prclc). Usually parcel
    blobs are found embedded inside a file called "Mac OS ROM", although
    the Blue Box uses them in isolation. As a convenience this utility
    will search for the magic number inside any input file (with a
    warning).
''')

parser.add_argument('source', nargs=1, help='file to be decompiled')

meg = parser.add_mutually_exclusive_group()
meg.add_argument('-d', metavar='dest-dir', help='output directory (Parcelfile will be created within)')
meg.add_argument('-f', metavar='dest-file', help='output file (binaries will go in parent directory)')

args = parser.parse_args()

with open(args.source[0], 'rb') as f:
    binary = f.read()

if not binary.startswith(MAGIC):
    try:
        offset = binary.index(MAGIC)
    except ValueError:
        print('Not a parcels file', file=stderr)
        exit(1)
    else:
        print('Warning: parcel blob wrapped at offset 0x%x' % offset)
        binary = binary[offset:]

if args.f:
    dest_file = path.abspath(args.f)
    dest_dir = path.dirname(dest_file)
elif args.d:
    dest_dir = path.abspath(args.d)
    dest_file = path.join(dest_dir, 'Parcelfile')
else:
    dest_dir = path.abspath(args.source[0].rstrip(path.sep) + '-dump')
    dest_file = path.join(dest_dir, 'Parcelfile')

os.makedirs(dest_dir, exist_ok=True)

dump(binary, dest_file, dest_dir)