import hashlib
import os
import struct
import argparse
import hashlib

import decompress_sd0
from bitstream import c_bool, c_int, c_ubyte, c_uint, ReadStream

args = {}


class PKExtractor:
    def load(self, path: str, output: str) -> None:
        self.records = {}

        filenames = {}

        for filename in ("trunk.txt", "hotfix.txt"):
            filenames.update(self._load_filehashes(
                os.path.join(path, "versions", filename)))
        print("Loaded hashes")
        pks = []
        for dir, _, files in os.walk(os.path.join(path, "client/res/pack")):
            for file in files:
                if file.endswith(".pk"):
                    pks.append(os.path.join(dir, file))

        for pk in pks:
            self._load_pk(pk, filenames)

        for filename in sorted(self.records.keys()):
            print(filename)
            self._save_path(output, filename)

    def _load_filehashes(self, path: str):
        filenames = {}
        with open(path) as file:
            for line in file.read().splitlines()[3:]:
                values = line.split(",")
                filenames[values[2]] = values[0]
        return filenames

    def _load_pki(self, path: str):
        # unused, alternate way to get the list of pks
        with open(path, "rb") as file:
            stream = ReadStream(file.read())

        assert stream.read(c_uint) == 3
        pack_files = []
        for _ in range(stream.read(c_uint)):
            pack_files.append(stream.read(
                bytes, length_type=c_uint).decode("latin1"))

        for _ in range(stream.read(c_uint)):
            stream.skip_read(20)

        assert stream.all_read()
        return pack_files

    def _load_pk(self, path: str, filenames) -> None:
        with open(path, "rb") as file:
            assert file.read(7) == b"ndpk\x01\xff\x00"
            file.seek(-8, 2)
            number_of_records_address = struct.unpack("I", file.read(4))[0]
            unknown = struct.unpack("I", file.read(4))[0]
            if unknown != 0:
                print(unknown, path)
            file.seek(number_of_records_address)
            data = ReadStream(file.read()[:-8])

        number_of_records = data.read(c_uint)
        for _ in range(number_of_records):
            pk_index = data.read(c_uint)
            unknown1 = data.read(c_int)
            unknown2 = data.read(c_int)
            original_size = data.read(c_uint)
            original_md5 = data.read(bytes, length=32).decode()
            unknown3 = data.read(c_uint)
            compressed_size = data.read(c_uint)
            compressed_md5 = data.read(bytes, length=32).decode()
            unknown4 = data.read(c_uint)
            data_position = data.read(c_uint)
            is_compressed = data.read(c_bool)
            unknown5 = data.read(c_ubyte)
            unknown6 = data.read(c_ubyte)
            unknown7 = data.read(c_ubyte)
            if original_md5 not in filenames:
                filenames[original_md5] = "unlisted/"+original_md5
            self.records[filenames[original_md5]
                         ] = path, data_position, is_compressed, original_size, original_md5, compressed_size, compressed_md5

    def extract_data(self, path: str) -> bytes:
        pk_path, data_position, is_compressed, original_size, original_md5, compressed_size, compressed_md5 = self.records[
            path]

        with open(pk_path, "rb") as file:
            file.seek(data_position)
            if is_compressed:
                data = file.read(compressed_size)
            else:
                data = file.read(original_size)
                assert file.read(5) == b"\xff\x00\x00\xdd\x00"

        if is_compressed:
            assert hashlib.md5(data).hexdigest() == compressed_md5
            data = decompress_sd0.decompress(data)

        assert hashlib.md5(data).hexdigest() == original_md5
        return data

    def _save_path(self, outdir: str, path: str) -> None:
        original_md5 = self.records[path][4]

        dir, filename = os.path.split(path)
        out = os.path.join(outdir, dir)
        os.makedirs(out, exist_ok=True)
        out_file_path = os.path.join(out, filename)

        if os.path.isfile(out_file_path):
            with open(out_file_path, "rb") as f:
                file_hash = hashlib.md5()
                while chunk := f.read(8192):
                    file_hash.update(chunk)

            if file_hash.hexdigest() == original_md5:
                print("File %s already exists with correct md5 %s" %
                      (path, original_md5))
                return

        data = self.extract_data(path)
        with open(out_file_path, "wb") as file:
            file.write(data)


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument("client_path")
    parser.add_argument("output_path")
    args = parser.parse_args()
    app = PKExtractor()
    app.load(args.client_path, args.output_path)