import sys
import binascii
import os
import ctypes
import struct

if(len(sys.argv) is not 3):
    sys.exit('usage: mainRenamer.py "pathToFile\\fileName.bin" newTitleId')

fileIn = sys.argv[1]
newTitleId = struct.pack("<Q",int(sys.argv[2],16))

base = os.path.splitext(fileIn)[0]
fileOut =  base+".tmp"


readBytes = int(0)
aci0Off = -0xFFFFF

metaString = ""
aciString = ""
with open(fileIn, "rb") as f:
    with open(fileOut, "wb") as n:
        chunk = 1
        while True:
            if chunk:
                if readBytes == 0:
                    chunk = f.read(4)
                    n.write(chunk)
                    readBytes += 4
                    metaString = chunk.decode("utf-8")
                elif readBytes == 0x70:
                    chunk = f.read(4)
                    n.write(chunk)
                    readBytes += 4
                    aci0Off = struct.unpack("<l", chunk)[0]
                elif readBytes == aci0Off:
                    chunk = f.read(4)
                    n.write(chunk)
                    readBytes += 4
                    aciString = chunk.decode("utf-8")
                elif readBytes == (aci0Off + 0x10):
                    chunk = f.read(8)
                    print("old Title Id: "+ hex(struct.unpack("<Q", chunk)[0]).rstrip("L").lstrip("0x").upper())
                    print("new Title Id: "+ hex(struct.unpack("<Q", newTitleId)[0]).rstrip("L").lstrip("0x").upper())
                    readBytes += 8
                    n.write(newTitleId)
                else:
                    chunk = f.read(1)
                    readBytes += 1
                    if chunk:
                        n.write(chunk)
                #print(readBytes)
            else:
                break
        n.close()
    f.close()

if not (metaString == "META" and aciString == "ACI0"):
    print("Error Wrong File Format")
else:
    os.rename(fileIn, base+".npdm.bak")
    os.rename(fileOut, base+".npdm")
    print("New TitleId written")