#!/usr/bin/env python3

from argparse import ArgumentParser, FileType
from struct import pack, unpack

import json
import re

def str_array2json(input, output):
	if input.endswith(".bin"):
		# str_array.binからJSONへ
		with open(input, "rb") as f:
			offsets = []
			while True:
				offset, = unpack("<I", f.read(4))
				if offset == 0:
					break
				offsets.append(offset)

			strings = []
			for offset in offsets:
				f.seek(offset)
				bstr = f.read(256)
				strings.append(bstr[:bstr.find(b"\0")].decode("utf8"))

			with open(output, "w") as out:
				json.dump(strings, out, indent="\t", ensure_ascii=False)
	else:
		# JSONからstr_array.binへ
		with open(input, "r") as f, open(output, "wb") as out:
			strings = json.loads(re.sub("//.*", "", f.read(), flags=re.MULTILINE))

			cur_ofs = (len(strings) + 1) * 4
			for string in strings:
				out.write(pack("<I", cur_ofs))
				cur_ofs += len(string.encode("utf8")) + 1
			out.write(pack("<I", 0))

			for string in strings:
				out.write(string.encode("utf8") + b"\0")

if __name__ == "__main__":
	parser = ArgumentParser(description="Project DIVA fのstr_array.binをJSONに変換")
	parser.add_argument("input", type=str)
	parser.add_argument("output", type=str)

	args = parser.parse_args()

	str_array2json(args.input, args.output)