Converts Luigi's Mansion Dark Moon NLOC (translation) files to NLOCT (a custom easy-to-edit format I invented) and back. I should make this easier to use...

nloc.py

# 10/29/16
# NLOC haxxor script


# ~~~~~~~~~~
# NLOC: Next level LOCalization? Localizable text strings.
#     Probably does, since if you get a hash ID wrong, it defaults to
#     "missing loc string". Which certainly looks like "localized" in
#     that context.
# 00-03    "NLOC"
# 04-07    1... always? (TODO: check if it is.)
# 08-0B    Looks like a hash of the language name or ID, in some way.
#          (considering it's the same in both english.data's but different in dutch.data)
# 0C-0F    Number of strings
# String info table:
#     00-03    String offset, relative to the end of this table
#     04-07    Some sort of hash/ID. Entries are sorted by this.
#              Consistent across languages for equivalent strings.
# Then UTF-16 (UCS-2?) null-terminated text strings.
# Strings appear to be in whatever order NLG decided to put them in:
#     similar strings are grouped together in locally logical order.


import struct


NLOCTS_IN = [
    'nlocts/ukenglish.nloct',
    'patches.nloct',
]
DICT_IN  = 'ukenglish.dict'

NLOC_OUT = 'ukenglish_modified.data'
DICT_OUT = 'ukenglish_modified.dict'


def nlgHashFunction(data):
    """
    Reverse-engineered from the binary. `data` must be a bytes object.
    This function has some interesting properties:
    - case-insensitive
    - insensitive to leading whitespace (but not trailing whitespace)
    """
    h = -1

    for c in data:
        if (c - 65) & 0xFFFFFFFF <= 0x19:
            c |= 0x20

        h = (h * 33 + c) & 0xFFFFFFFF

    return h


def strToHash(s):
    return nlgHashFunction(s.encode('latin-1'))


def keyAndLine(line):
    if line.startswith('"'):
        # Hash a string
        strEnd = line.index('"', 1)
        s = line[1:strEnd]
        return strToHash(s), line[strEnd+1:].lstrip()
    return int(line.split(' ')[0], 16), line[line.index(' ')+1:].lstrip()


nlocKeyRepo = None
def hashToStr(h):
    global nlocKeyRepo
    if nlocKeyRepo is None:
        # Load it
        try:
            with open('nlocKeyRepo.txt', 'r', encoding='utf-8') as f:
                keys = f.read().splitlines()
        except Exception:
            print('Could not open nlocKeyRepo.txt. This file is used to '
                  'list strings that can be used in place of key hash '
                  'values where possible.')
        nlocKeyRepo = {}
        for k in keys:
            nlocKeyRepo[strToHash(k)] = k
    if h in nlocKeyRepo:
        return '"%s"' % nlocKeyRepo[h]
    else:
        return hex(h).upper()[2:]


def generateNLOC(nloct):
    """
    Convert nloct to nloc.
    To apply multiple NLOCTs as patches, simply append the patches to
    the original!
    """
    langId = 0
    blockcomment = False
    strs = {}
    for line in nloct.splitlines():
        # Allow ### to start/end block-comments a la Coffeescript
        if line.startswith('###'):
            blockcomment = not blockcomment
            continue
        if blockcomment: continue

        if line.startswith('#') or not line: continue

        if line.lower().startswith('langid:'):
            # Language ID line; this is handled entirely differently
            langIdStr = line[len('langid:'):]
            if langIdStr.startswith('"'):
                langId = strToHash(langIdStr[1:-1])
            else:
                langId = int(langIdStr, 16)
            continue

        idHash, msg = keyAndLine(line)

        strs[idHash] = msg

    if len(strs) < 1935:
        print('WARNING: The NLOC being generated only contains %d strings, '
            'whereas retail LMDM NLOCs should have at least 1935!' % len(strs))
    elif len(strs) > 1935:
        print('WARNING: Your NLOC has more than 1935 strings! (%d)'
              % len(strs))
    if langId == 0:
        print('WARNING: Language ID was not set.')

    newNlocHeader = bytearray()
    newNlocContents = bytearray()
    newNlocHeader.extend(struct.pack('<4s3I', b'NLOC', 1, langId, len(strs)))
    # Code RE suggests that the second value there is compared against
    # a literal value 1, and fails if it's different.
    for id in sorted(strs):
        newNlocHeader.extend(struct.pack('<II', id, len(newNlocContents) // 2))
        newNlocContents.extend(strs[id].encode('utf-16-le') + b'\0\0')
    return bytes(newNlocHeader + newNlocContents)


def readNLOC(data, *, endian='<'):
    """
    Convert an NLOC file to NLOCT.
    """
    endianName = 'le' if endian == '<' else 'be'
    output = []

    langId, strCount = struct.unpack_from(endian + 'II', data, 8)
    output.append('langid:' + hashToStr(langId))

    fullStr = data[0x14 + 8 * strCount:].decode('utf-16-' + endianName)

    for i in range(strCount):
        sId, sStart = struct.unpack_from(endian + 'II', data, 0x14 + 8 * i)
        s = fullStr[sStart:fullStr.index('\x00', sStart + 1)]
        output.append(hashToStr(sId) + '    ' + s)

    return '\n'.join(output)


def main():
    """
    Main function to convert NLOC/NLOCT
    """

    # Read the NLOCTs
    nlocts = []
    for n in NLOCTS_IN:
        with open(n, 'r', encoding='utf-8') as f:
            nlocts.append(f.read())

    # Generate the NLOC
    nloc = generateNLOC('\n'.join(nlocts))

    # Generate the new .data
    data = struct.pack('<4I', 0x12027020, len(nloc), 0, 0) + nloc + b'\0\0'
    with open(NLOC_OUT, 'wb') as f:
        f.write(data)

    # Update the .dict horrifically hackily (sorry)
    with open(DICT_IN, 'rb') as f:
        dict = bytearray(f.read())
    dict[0x68:0x6C] = struct.pack('<I', len(data) - 16)
    dict[0x74:0x78] = struct.pack('<I', len(data))
    dict[0x84:0x88] = struct.pack('<I', len(data))
    with open(DICT_OUT, 'wb') as f:
        f.write(dict)

main()