import bsdiff4
import yaml
import os
import lzma
import hashlib
import threading
import concurrent.futures
import zipfile
import sys
from typing import Tuple, Optional

import Utils
from Rom import JAP10HASH, read_rom


def get_base_rom_path(file_name: str = "") -> str:
    options = Utils.get_options()
    if not file_name:
        file_name = options["general_options"]["rom_file"]
    if not os.path.exists(file_name):
        file_name = Utils.local_path(file_name)
    return file_name

def get_base_rom_bytes(file_name: str = "") -> bytes:
    base_rom_bytes = getattr(get_base_rom_bytes, "base_rom_bytes", None)
    if not base_rom_bytes:
        file_name = get_base_rom_path(file_name)
        base_rom_bytes = bytes(read_rom(open(file_name, "rb")))

        basemd5 = hashlib.md5()
        basemd5.update(base_rom_bytes)
        if JAP10HASH != basemd5.hexdigest():
            raise Exception('Supplied Base Rom does not match known MD5 for JAP(1.0) release. '
                            'Get the correct game and version, then dump it')
        get_base_rom_bytes.base_rom_bytes = base_rom_bytes
    return base_rom_bytes


def generate_yaml(patch: bytes, metadata: Optional[dict] = None) -> bytes:
    patch = yaml.dump({"meta": metadata,
                       "patch": patch})
    return patch.encode(encoding="utf-8-sig")


def generate_patch(rom: bytes, metadata: Optional[dict] = None) -> bytes:
    if metadata is None:
        metadata = {}
    patch = bsdiff4.diff(get_base_rom_bytes(), rom)
    return generate_yaml(patch, metadata)


def create_patch_file(rom_file_to_patch: str, server: str = "") -> str:
    bytes = generate_patch(load_bytes(rom_file_to_patch),
                           {
                               "server": server})  # allow immediate connection to server in multiworld. Empty string otherwise
    target = os.path.splitext(rom_file_to_patch)[0] + ".bmbp"
    write_lzma(bytes, target)
    return target


def create_rom_file(patch_file: str) -> Tuple[dict, str]:
    data = Utils.parse_yaml(lzma.decompress(load_bytes(patch_file)).decode("utf-8-sig"))
    patched_data = bsdiff4.patch(get_base_rom_bytes(), data["patch"])
    target = os.path.splitext(patch_file)[0] + ".sfc"
    with open(target, "wb") as f:
        f.write(patched_data)
    return data["meta"], target


def update_patch_data(patch_data: bytes, server: str = "") -> bytes:
    data = Utils.parse_yaml(lzma.decompress(patch_data).decode("utf-8-sig"))
    data["meta"]["server"] = server
    bytes = generate_yaml(data["patch"], data["meta"])
    return lzma.compress(bytes)


def load_bytes(path: str) -> bytes:
    with open(path, "rb") as f:
        return f.read()


def write_lzma(data: bytes, path: str):
    with lzma.LZMAFile(path, 'wb') as f:
        f.write(data)


if __name__ == "__main__":
    host = Utils.get_public_ipv4()
    options = Utils.get_options()['server_options']
    if options['host']:
        host = options['host']

    address = f"{host}:{options['port']}"
    ziplock = threading.Lock()
    print(f"Host for patches to be created is {address}")
    with concurrent.futures.ThreadPoolExecutor() as pool:
        for rom in sys.argv:
            try:

                if rom.endswith(".sfc"):
                    print(f"Creating patch for {rom}")
                    result = pool.submit(create_patch_file, rom, address)
                    result.add_done_callback(lambda task: print(f"Created patch {task.result()}"))

                elif rom.endswith(".bmbp"):
                    print(f"Applying patch {rom}")
                    data, target = create_rom_file(rom)
                    print(f"Created rom {target}.")
                    if 'server' in data:
                        print(f"Host is {data['server']}")

                elif rom.endswith(".zip"):
                    print(f"Updating host in patch files contained in {rom}")

                    def _handle_zip_file_entry(zfinfo : zipfile.ZipInfo, server: str):
                        data = zfr.read(zfinfo)
                        if zfinfo.filename.endswith(".bmbp"):
                            data = update_patch_data(data, server)
                        with ziplock:
                            zfw.writestr(zfinfo, data)
                        return zfinfo.filename


                    futures = []
                    with zipfile.ZipFile(rom, "r") as zfr:
                        updated_zip = os.path.splitext(rom)[0] + "_updated.zip"
                        with zipfile.ZipFile(updated_zip, "w", compression=zipfile.ZIP_DEFLATED, compresslevel=9) as zfw:
                            for zfname in zfr.namelist():
                                futures.append(pool.submit(_handle_zip_file_entry, zfr.getinfo(zfname), address))
                            for future in futures:
                                print(f"File {future.result()} added to {os.path.split(updated_zip)[1]}")

            except:
                import traceback
                traceback.print_exc()
                input("Press enter to close.")