from __future__ import annotations

import logging
from typing import TYPE_CHECKING, Tuple

if TYPE_CHECKING:
    from sampy.server import Server


class Game:
    @staticmethod
    async def on_packet(server: Server, packet: bytes, addr: Tuple[str, int]) -> bool:
        packet = Obfuscation.deobfuscate(server, packet)

        # TODO
        return False


class Obfuscation:
    # Found @ addr 0x004C88E0 in windows server executable
    LOOKUP_TABLE = bytes.fromhex(
        """
        b46207e59daf63dde3d0ccfedcdb6b2e6a40ab47c9d153d52091a50e4adf1889
        fd6f2512b713770065366d49ec572aa9115ffa7895a4bd1ed97944cdde81eb09
        3ef6eeda7fa31aa72da6adc14693d21b9caad74e4b4d4cf3b834c0ca88f494cb
        04393082d673b0bf2201416e482ca875b10aae9f278010cef02928850d05f735
        bbbc1506f56071031fea5a33928de7905be9cf9ed35ded311c0b5216510f86c5
        689b210c8b4287ff4fbec8e8c7d47ae0552f8a8eba9837e4b238a1b632833a7b
        843c61fb8c143d433b1dc3a296b3f8c4f2262bd87cfc232466ef6964505459f1
        a074acc67db5e6e2c27e67175ee1b93f6c700899455676f99a9719725c028f58
        """
    )

    # I think this used to be zlib compression, but has been swapped out with obfuscation instead
    @staticmethod
    def deobfuscate(server: Server, packet: bytes) -> bytes:
        checksum, data = packet[0], bytearray(packet[1:])

        data = Obfuscation.xor_every_other_byte(
            Obfuscation.get_port_xor_key(server), data
        )
        data = bytes(Obfuscation.LOOKUP_TABLE[b] for b in packet)

        if checksum != Obfuscation.calc_checksum(data):
            logging.error("Checksum failed!")
            raise Exception("Checksum fail")

        return bytes(data)

    @staticmethod
    def obfuscate(server: Server, packet: bytes) -> bytes:
        data = bytes(Obfuscation.LOOKUP_TABLE.index(b) for b in packet)
        data = Obfuscation.xor_every_other_byte(
            Obfuscation.get_port_xor_key(server), data
        )

        checksum = Obfuscation.calc_checksum(data)
        return bytes([checksum]) + data

    @staticmethod
    def xor_every_other_byte(xor: int, packet: bytearray) -> bytearray:
        for i in range(1, len(packet), 2):
            packet[i] ^= xor
        return packet

    @staticmethod
    def calc_checksum(packet: bytearray) -> int:
        checksum = 0
        for byte in packet:
            checksum ^= byte & 0xAA
        return checksum

    @staticmethod
    def get_port_xor_key(server: Server) -> int:
        return (server.config.port ^ 0xCCCC) & 0xFF