#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import json
import logging
from ipaddress import IPv4Address

import uvicorn
from fastapi import FastAPI, status
from fastapi.security import OAuth2PasswordBearer
from starlette.websockets import WebSocketDisconnect
from fastapi import Body, Header, Response, WebSocket as FastAPIWebSocket

from nonebot.log import logger
from nonebot.config import Env, Config
from nonebot.utils import DataclassEncoder
from nonebot.adapters.cqhttp import Bot as CQBot
from nonebot.drivers import BaseDriver, BaseWebSocket
from nonebot.typing import Optional, Callable, overrides


class Driver(BaseDriver):

    def __init__(self, env: Env, config: Config):
        super().__init__(env, config)

        self._server_app = FastAPI(
            debug=config.debug,
            openapi_url=None,
            docs_url=None,
            redoc_url=None,
        )

        self._server_app.post("/{adapter}/")(self._handle_http)
        self._server_app.post("/{adapter}/http")(self._handle_http)
        self._server_app.websocket("/{adapter}/ws")(self._handle_ws_reverse)
        self._server_app.websocket("/{adapter}/ws/")(self._handle_ws_reverse)

    @property
    @overrides(BaseDriver)
    def server_app(self) -> FastAPI:
        return self._server_app

    @property
    @overrides(BaseDriver)
    def asgi(self):
        return self._server_app

    @property
    @overrides(BaseDriver)
    def logger(self) -> logging.Logger:
        return logging.getLogger("fastapi")

    @overrides(BaseDriver)
    def on_startup(self, func: Callable) -> Callable:
        return self.server_app.on_event("startup")(func)

    @overrides(BaseDriver)
    def on_shutdown(self, func: Callable) -> Callable:
        return self.server_app.on_event("shutdown")(func)

    @overrides(BaseDriver)
    def run(self,
            host: Optional[IPv4Address] = None,
            port: Optional[int] = None,
            *,
            app: Optional[str] = None,
            **kwargs):
        LOGGING_CONFIG = {
            "version": 1,
            "disable_existing_loggers": False,
            "formatters": {
                "default": {
                    "()": "logging.Formatter",
                    "fmt": "[%(asctime)s %(name)s] %(levelname)s: %(message)s",
                },
            },
            "handlers": {
                "default": {
                    "formatter": "default",
                    "class": "logging.StreamHandler",
                    "stream": "ext://sys.stdout",
                },
            },
            "loggers": {
                "uvicorn.error": {
                    "handlers": ["default"],
                    "level": "INFO"
                },
                "uvicorn.access": {
                    "handlers": ["default"],
                    "level": "INFO",
                },
            },
        }
        uvicorn.run(app or self.server_app,
                    host=host or str(self.config.host),
                    port=port or self.config.port,
                    reload=app and self.config.debug,
                    debug=self.config.debug,
                    log_config=LOGGING_CONFIG,
                    **kwargs)

    @overrides(BaseDriver)
    async def _handle_http(self,
                           adapter: str,
                           response: Response,
                           data: dict = Body(...),
                           x_self_id: int = Header(None),
                           access_token: str = OAuth2PasswordBearer(
                               "/", auto_error=False)):
        # TODO: Check authorization

        # Create Bot Object
        if adapter == "cqhttp":
            bot = CQBot("http", self.config, x_self_id)
        else:
            response.status_code = status.HTTP_404_NOT_FOUND
            return {"status": 404, "message": "adapter not found"}

        await bot.handle_message(data)
        return {"status": 200, "message": "success"}

    @overrides(BaseDriver)
    async def _handle_ws_reverse(self,
                                 adapter: str,
                                 websocket: FastAPIWebSocket,
                                 x_self_id: int = Header(None),
                                 access_token: str = OAuth2PasswordBearer(
                                     "/", auto_error=False)):
        websocket = WebSocket(websocket)

        # TODO: Check authorization

        # Create Bot Object
        if adapter == "coolq":
            bot = CQBot("websocket",
                        self.config,
                        x_self_id,
                        websocket=websocket)
        else:
            await websocket.close(code=status.WS_1003_UNSUPPORTED_DATA)
            return

        await websocket.accept()
        self._clients[x_self_id] = bot

        while not websocket.closed:
            data = await websocket.receive()

            if not data:
                continue

            await bot.handle_message(data)

        del self._clients[x_self_id]


class WebSocket(BaseWebSocket):

    def __init__(self, websocket: FastAPIWebSocket):
        super().__init__(websocket)
        self._closed = None

    @property
    @overrides(BaseWebSocket)
    def closed(self):
        return self._closed

    @overrides(BaseWebSocket)
    async def accept(self):
        await self.websocket.accept()
        self._closed = False

    @overrides(BaseWebSocket)
    async def close(self, code: int = status.WS_1000_NORMAL_CLOSURE):
        await self.websocket.close(code=code)
        self._closed = True

    @overrides(BaseWebSocket)
    async def receive(self) -> Optional[dict]:
        data = None
        try:
            data = await self.websocket.receive_json()
        except ValueError:
            logger.debug("Received an invalid json message.")
        except WebSocketDisconnect:
            self._closed = True
            logger.error("WebSocket disconnected by peer.")

        return data

    @overrides(BaseWebSocket)
    async def send(self, data: dict) -> None:
        text = json.dumps(data, cls=DataclassEncoder)
        await self.websocket.send({"type": "websocket.send", "text": text})