import asyncio
from enum import IntEnum
import json
import sys
import threading
from typing import Optional, Coroutine, Any, Callable
import zlib
import aiohttp
import websockets

from .utils import EventEmitter
from .utils.rest import RESTClient
from .intents import Intents, get_number
from .user import User

class GatewayEvents(IntEnum):
    DISPATCH           = 0
    HEARTBEAT          = 1
    IDENTIFY           = 2
    PRESENCE           = 3
    VOICE_STATE        = 4
    VOICE_PING         = 5
    RESUME             = 6
    RECONNECT          = 7
    REQUEST_MEMBERS    = 8
    INVALIDATE_SESSION = 9
    HELLO              = 10
    HEARTBEAT_ACK      = 11
    GUILD_SYNC         = 12

class Client:
    _token: str

    @property
    async def user(self):
        data = await self.rest_client.get('/users/@me')
        return User(data)

    def __init__(self, intents: list[Intents]):
        self.gateway = None
        self.loop = asyncio.get_event_loop()
        self.code: int = get_number(intents)
        self.event_emitter = EventEmitter()
        self.buffer = bytearray()
        self.inflator = zlib.decompressobj()
        self.heartbeat_interval: int = None
        self.ready: bool = False
        self.rest_client = RESTClient(self._token, aiohttp.ClientSession(headers={
            "Authorization": f"Bot {self._token}",
            "User-Agent": "DiscordBot (https://github.com/mounderfod/discobra 0.0.1)"
        }))

    async def connect(self):
        async with websockets.connect("wss://gateway.discord.gg/?v=10&encoding=json") as gateway:
            self.gateway = gateway
            threading.Thread(target=self.loop.run_forever).start()
            while True:
                await self.poll_event()
    
    async def send(self, data: dict):
        """
        Send data to the gateway.
        """
        await self.gateway.send(json.dumps(data))
    
    async def recv(self, msg):
        """
        Receive data from the gateway.
        """
        if type(msg) is bytes:
            self.buffer.extend(msg)
            if len(msg) < 4 or msg[-4:] != b'\x00\x00\xff\xff':
                return

            msg = self.inflator.decompress(self.buffer)
            msg.decode('utf-8')
            self.buffer = bytearray()
        msg = json.loads(msg)
        opcode = msg['op']
        data = msg['d']
        sequence = msg['s']

        if opcode != GatewayEvents.DISPATCH.value:
            if opcode == GatewayEvents.RECONNECT.value:
                return await self.close()

            if opcode == GatewayEvents.HELLO.value:
                self.heartbeat_interval = data['heartbeat_interval']
                asyncio.run_coroutine_threadsafe(self.heartbeat(self.heartbeat_interval), self.loop)
                return await self.identify()

            if opcode == GatewayEvents.HEARTBEAT_ACK.value:
                return await self.heartbeat(self.heartbeat_interval)
            
            if opcode == GatewayEvents.HEARTBEAT.value:
                return await self.heartbeat(self.heartbeat_interval)

        event = msg['t']

        if event == 'READY':
            print(data)

        self.event_emitter.emit('on_' + event.lower())


    async def close(self):
        """
        Close the client.
        """
        self.loop.stop()
        await self.gateway.close()

    async def poll_event(self):
        msg = await self.gateway.recv()
        await self.recv(msg)
    

    async def heartbeat(self, interval: int):
        await asyncio.sleep(interval / 1000)
        heartbeat = {
            "op": 1,
            "d": None
        }
        await self.gateway.send(json.dumps(heartbeat))

    async def identify(self):
        """
        Identify the client.
        """
        identify = {
            "op": GatewayEvents.IDENTIFY,
            "d": {
                "token": self._token,
                "intents": self.code,
                "properties": {
                    "os": sys.platform,
                    "browser": "discobra",
                    "device": "discobra"
                }
            }
        }
        await self.gateway.send(json.dumps(identify))

    def event(self, coro: Optional[Callable[..., Coroutine[Any, Any, Any]]]=None, /) -> Optional[Callable[..., Coroutine[Any, Any, Any]]]:
        """
        Registers a coroutine to be called when an event is emitted.
        """
        if not asyncio.iscoroutinefunction(coro):
            raise TypeError('event registered must be a coroutine function')
        self.event_emitter.add_listener(coro.__name__, coro)
        return coro

    def run(self, token: str):
        """
        Run the client.
        """
        self._token = token
        asyncio.run(self.connect())