import sys, os, struct, re, csv

re_name = re.compile(r"(.*);([0-9]+)")
block_size = 2352

def readSectorForm1(f, lba, count):
    f.seek(lba * block_size)
    data = ""
    for i in xrange(count):
	block = f.read(block_size)
	data += block[24:2048+24]
	del block
	
    return data

def readDir( f, path, dir_pos, dir_size, parent):
    dir = readSectorForm1(f, dir_pos, (dir_size + 2047) / 2048)
    list = []
    pos = 0
    while pos < len(dir):
	(entry_size, file_pos, file_len, attr, name_len) = struct.unpack_from("<BxIxxxxIxxxxxxxxxxxBxxxxxxB", dir, pos)
	if entry_size > 0:
	    hidden = (attr & 1) != 0
	    subdir = (attr & 2) != 0

	    if file_pos != dir_pos and file_pos != parent:
		name = dir[pos+33:pos+33+name_len]
		if not subdir:
		    pat = re_name.match(name)
		    if pat:
			name = pat.group(1)

		file_path = os.path.join(path, name)
		if subdir:
		    list.extend( readDir(f, file_path, file_pos, file_len, dir_pos) )
		else:
		    list.append( (file_path, file_pos, file_len) )
	    
	    pos += entry_size
	else:
	    pos = (pos + 2047) & ~2047

    del dir
    return list

def readFileTable(f):
    fileTable = readSectorForm1( f, 24, 16 )
    index = 0
    fileCount = 0
    dirCount = 0
    dirIndex = 0
    movies = False
    list = []
    while True:
	startSector = struct.unpack_from("<I", fileTable, index * 7 + 0)[0] & 0xFFFFFF
	if startSector == 0xFFFFFF:
	    break
	fileSize = struct.unpack_from("<i", fileTable, index * 7 + 3)[0]
	if fileSize < 0:
	    fileCount = 0
	    dirIndex = dirCount
	    movies = dirCount == 0
	    dirCount += 1
	elif fileSize > 0:
	    file_path = os.path.join("dir%i" % dirIndex, "file%i.bin" % fileCount)
	    list.append( (file_path, startSector, fileSize, movies) )
	    fileCount += 1
	index += 1
    return list

def main(*argv):
    for arg in argv:
	f = open(arg, "rb")
	
	# identify the disk
	volume_descriptor = readSectorForm1( f, 16, 1 )
	(system_identifier, volume_identifier) = struct.unpack_from("<32s32s", volume_descriptor, 8)
	system_identifier = system_identifier.strip()
	if system_identifier != "PLAYSTATION":
	    print "Not a playstation image: \"%s\"" % system_identifier
	    f.close()
	    return
	volume_identifier = volume_identifier.strip()
	if volume_identifier != "XENOGEARS":
	    print "Not a Xenogears image: \"%s\"" % volume_identifier
	    f.close()
	    return
	
	# read the filesystem
	(root_pos,) = struct.unpack_from("<I", volume_descriptor, 156 + 2)
	(root_len,) = struct.unpack_from("<I", volume_descriptor, 156 + 10)
	list = readDir( f, "", root_pos, root_len, root_pos)

	# find if we're disk 1 or disk 2
	disk = None
	for file in list:
	    if file[0] == 'SLUS_006.64':
		disk = 1
		break
	    elif file[0] == 'SLUS_006.69':
		disk = 2
		break
	if disk is None:
	    print "Failed to find executable"
	    print "Please post this to the tech-related forum on http://forums.qhimm.com/"
	    print list
	    f.close()
	    return
    
	# export normal files
	if True:
	    for (name, startSector, fileSize)  in list:
		blocks = (fileSize + 2047) / 2048
		data = readSectorForm1(f, startSector, blocks)
		
		path = os.path.join("disk%i" % disk, name)
		dirname = os.path.dirname(path)
		if not os.path.exists(dirname):
		    os.makedirs(dirname)
		
		d = open(path, "wb")
		d.write(data[:fileSize])
		d.close()
		del data

	# export directory table
	if False:
	    c = open("xenogears_iso%i.csv" % disk, "wt")
	    w = csv.writer(c)
	    w.writerows(list)
	    c.close()

	# get hidden file table
	list = readFileTable(f)

	# export hidden files
	if True:
	    for (name, startSector, fileSize, movieFlag) in list:
		if movieFlag:
		    blocks = (fileSize + 2335) / 2336
		    f.seek(startSector * block_size)
		    data = f.read(blocks * block_size)
		else:
		    blocks = (fileSize + 2047) / 2048
		    data = readSectorForm1(f, startSector, blocks)
		
		path = os.path.join("disk%i" % disk, name)
		dirname = os.path.dirname(path)
		if not os.path.exists(dirname):
		    os.makedirs(dirname)
		
		d = open(path, "wb")
		d.write(data[:fileSize])
		d.close()
		del data

	# export file table
	if False:
	    c = open("xenogears_table%i.csv" % disk, "wt")
	    w = csv.writer(c)
	    w.writerows(list)
	    c.close()
	    
	f.close()

if __name__ == "__main__":
    main(*sys.argv[1:])