# MODIFICATIONS:
# -- always extract from grimrock.dat
# -- always extract only Console.lua

import sys, zlib, binascii, struct, os

def fnv(s):
    v = 0x811c9dc5

    for c in s:
        v ^= ord(c)
        v = (v * 0x1000193) & 0xffffffff
        
    return v
        

def main():
    f = open('grimrock.dat', "rb")
    
    magic = f.read(4)
    if magic != "GRAR":
        raise Exception("DSDSSD")
        
    numentries = struct.unpack("<L", f.read(4))[0]
    
    dir = {}
    for i in xrange(numentries):
        hash, offset, packedsize, unpackedsize = struct.unpack("<LLLL", f.read(16))
        
        if hash in dir:
            raise Exception("DSDSSSDDS")
            
        dir[hash] = (offset, packedsize, unpackedsize)
    
    
    filename = 'Console.lua'

    hash = fnv(filename)
    
    if hash in dir:
	offset, packedsize, unpackedsize = dir[hash]
	print "found", filename
	
	f.seek(offset)
	
	if packedsize != 0:
	    foo = struct.unpack("<L", f.read(4))[0]

	    zblock = f.read(packedsize-4)
	    block = zlib.decompress(zblock)
	else:
	    block = f.read(unpackedsize)

	if not os.path.isfile(filename):
	    print "Modifying file..."

	    # The max lines configuration, because 10 is lame.
	    if block[71:81] == 'maxLines\x03\x0a':
	        block = block[:80] + '\x2a' + block[81:]
	    else:
	        print "Couldn't find maxLines\\x03\\x0A: " + block[71:80]

	    # The first instance of *.developer.*
	    if block[405:414] == 'developer':
	        block = block[:405] + "muteMusic" + block[414:]
	    else:
	        print "Can't find .developer. to modify: " + block[405:414]

	    # The special character used to open the console; many
	    # US keyboards lack the one they used.
	    if block[1985] == '\xa7':
	        block = block[:1985] + '~' + block[1986:]
	    else:
	        print "The special character wasn't \\xA7, so not modifying it."

	    # The second instance of *.developer.
	    if block[1992:2001] == 'developer':
	        block = block[:1992] + "muteMusic" + block[2001:]
	    else:
	        print "Can't find .developer. to modify: " + block[1990:1999]
	    open(filename, "wb").write(block)
	else:
	    print "Not overwriting existing file."
	
    else:
	print "ERRROR", filename
	exit()
main()