#!/usr/bin/env python3

import os
import subprocess

"""
mkgamezips - Creates the ucode/gamezips.bin from ucode/game.bin

game.bin is the compiled game code from ld. This game code is split into
4KB chunks. Each chunk is individually zipped.

The format of the gamezips binary is:
* Array of offsets to each zip, where each offset is 4 bytes and relative to the
  start of the gamezips segment.
* After the array of offsets comes the data it points to. Each data consists of:
    * 2 bytes of probable garbage data (set to 0x0000 by this script)
    * Zip data (starting with 0x1173001000)
    * Optional single byte to align it to the next 2 byte boundary. The added
      byte is probable garbage data (set to 0x00 by this script).
"""
def main():
    zips = get_zips()

    fd = open('build/ntsc-final/ucode/gamezips.bin', 'wb')
    pos = len(zips) * 4 + 4

    # Write pointer array
    for zip in zips:
        fd.write(pos.to_bytes(4, byteorder='big'))
        pos += 2 + len(zip)
        if pos % 2 == 1:
            pos += 1

    # Last pointer points to end
    fd.write(pos.to_bytes(4, byteorder='big'))

    # Write data
    for index, zip in enumerate(zips):
        if pos % 2 == 1:
            fd.write(b'\x00')
            pos += 1

        fd.write(b'\x00\x00')
        fd.write(zip)
        pos += len(zip)

    fd.close()

def get_filecontents(filename):
    fd = open(filename, 'rb')
    binary = fd.read()
    fd.close()
    return binary

def get_zips():
    binary = get_filecontents('build/ntsc-final/ucode/game.bin')
    parts = [binary[i:i+0x1000] for i in range(0, len(binary), 0x1000)]
    return [zip(part) for part in parts]

def zip(binary):
    fd = open('build/part.bin', 'wb')
    fd.write(binary)
    fd.close()

    zipped = subprocess.check_output(['tools/rarezip', 'build/part.bin'])
    os.remove('build/part.bin')
    return zipped

main()