btxt exporter for "Metroid Dread"

btxt.py

#!/usr/bin/python3
# -*- coding: UTF-8 -*-

import os
import re
import struct
import sys

def export_btxt(bin):
  magic = bin[0x00 : 0x04]
  assert magic == b'BTXT'
  _, __ = struct.unpack("<2H", bin[0x04: 0x08])
  assert _ == 1 and __ == 10
  keys = []
  values = []
  pos = 0x08
  while pos < len(bin):
    key = ""
    c = bin[pos]
    while c:
      key += chr(c)
      pos += 1
      c = bin[pos]
    keys.append(key)
    value = ""
    pos += 1
    c, = struct.unpack("<H", bin[pos : pos + 2])
    while c:
      value += chr(c)
      pos += 2
      c, = struct.unpack("<H", bin[pos : pos + 2])
    pos += 2
    values.append(value)
  data = dict(zip(keys, values))
  return data

def parse_path(path, root = ""):
  path = path.replace("\\", "/")
  root = root.replace("\\", "/")
  if path.startswith(root):
    path = path[len(root) : ]
  path = re.sub(r"^(\.*/)+", "", path)
  return path

if __name__ == "__main__":
  args = sys.argv
  if len(args) > 1:
    root = args[1]
  else:
    root = "./"
  if len(args) > 2:
    export = args[2]
  else:
    export = "../export.txt"
  ext = ".txt"
  w = os.walk(root)
  g = open(export, "w", -1, "utf-8")
  for root, dirs, files in w:
    for file in files:
      if file.endswith(ext):
        path = os.path.join(root, file)
        with open(path, "rb") as f:
          txts = export_btxt(f.read())
        g.write(f"{parse_path(path, root)}\n")
        for k, v in txts.items():
          v = v.replace("\\", "\\\\").replace("\t", "\\t").replace("\n", "\\n")
          g.write(f"{k}\t{v}\n")
        g.flush()
  g.close()