import asyncio
import logging
from collections import defaultdict

import websockets
from fastapi import WebSocket, WebSocketDisconnect, Depends, HTTPException, status

from app.chat.exceptions import UseWSException, MessageNotFoundException, MessageAlreadyPinnedException
from app.exceptions import IncorrectDataException
from app.chat.exceptions import UserDontHavePermissionException
from app.services import message_service, auth_service
from app.utils.unit_of_work import UnitOfWork
from app.chat.router import router
from app.chat.shemas import SSendMessage, SDeleteMessage, SEditMessage, SPinMessage, SUnpinMessage, Responses
from app.dependencies import get_current_user_ws, get_token, get_subprotocol_ws, get_verificated_user
from app.users.schemas import SUser


class ConnectionManager:
	def __init__(self):
		self.active_connections: dict[int, list[WebSocket]] = defaultdict(list)
		self.message_methods = {
			"send": self._send,
			"delete": self._delete,
			"edit": self._edit,
			"pin": self._pin,
			"unpin": self._unpin,
		}

	async def connect(self, chat_id: int, websocket: WebSocket, subprotocol: str | None = None) -> None:
		await websocket.accept(subprotocol=subprotocol)
		self.active_connections[chat_id].append(websocket)

	async def disconnect(
		self,
		chat_id: int,
		websocket: WebSocket,
		code_and_reason: tuple[int, str] | None = None,
	) -> None:
		self.active_connections[chat_id].remove(websocket)
		if code_and_reason:
			await websocket.close(code=code_and_reason[0], reason=code_and_reason[1])

	async def broadcast(self, uow: UnitOfWork, user_id: int, chat_id: int, message: dict) -> None:
		try:
			new_message = await self.message_methods[message["flag"]](uow, user_id, chat_id, message)
			for websocket in self.active_connections[chat_id]:
				await websocket.send_json(new_message)
			await polling_manager.send(chat_id, new_message)
		except (MessageNotFoundException, MessageAlreadyPinnedException):
			pass
		except KeyError:
			raise IncorrectDataException

	@staticmethod
	async def _send(uow: UnitOfWork, user_id: int, chat_id: int, message: dict) -> dict:
		message = SSendMessage.model_validate(message)

		new_message = await message_service.send_message(
			uow=uow,
			user_id=user_id,
			chat_id=chat_id,
			message=message,
		)
		new_message = new_message.model_dump()
		new_message["id"] = str(new_message["id"])
		new_message["answer_id"] = str(new_message["answer_id"]) if new_message["answer_id"] else None
		new_message["created_at"] = new_message["created_at"].isoformat()
		new_message["flag"] = "send"
		return new_message

	@staticmethod
	async def _delete(uow: UnitOfWork, user_id: int, _: int, message: dict) -> dict:
		message = SDeleteMessage.model_validate(message)

		if message.user_id != user_id:
			raise UserDontHavePermissionException

		await message_service.delete_message(uow=uow, message_id=message.id)
		new_message = {"id": str(message.id), "flag": "delete"}
		return new_message

	@staticmethod
	async def _edit(uow: UnitOfWork, user_id: int, _: int, message: dict) -> dict:
		message = SEditMessage.model_validate(message)

		if message.user_id != user_id:
			raise UserDontHavePermissionException

		await message_service.edit_message(
			uow=uow,
			message_id=message.id,
			new_message=message.new_message,
			new_image_url=message.new_image_url,
		)
		new_message = {
			"flag": "edit",
			"id": str(message.id),
			"new_message": message.new_message,
			"new_image_url": message.new_image_url,
		}
		return new_message

	@staticmethod
	async def _pin(uow: UnitOfWork, _: int, chat_id: int, message: dict) -> dict:
		message = SPinMessage.model_validate(message)
		pinned_message = await message_service.pin_message(
			uow=uow,
			chat_id=chat_id,
			user_id=message.user_id,
			message_id=message.id,
		)
		new_message = pinned_message.model_dump()
		new_message["id"] = str(new_message["id"])
		new_message["answer_id"] = str(new_message["answer_id"]) if new_message["answer_id"] else None
		new_message["created_at"] = new_message["created_at"].isoformat()
		new_message["flag"] = "pin"
		return new_message

	@staticmethod
	async def _unpin(uow: UnitOfWork, _: int, chat_id: int, message: dict) -> dict:
		message = SUnpinMessage.model_validate(message)
		await message_service.unpin_message(uow=uow, chat_id=chat_id, message_id=message.id)
		new_message = {"flag": "unpin", "id": str(message.id)}
		return new_message


manager = ConnectionManager()


@router.websocket(
	"/ws/{chat_id}",
)
async def websocket_endpoint(
	chat_id: int,
	websocket: WebSocket,
	user: SUser = Depends(get_current_user_ws),
	subprotocol: str = Depends(get_subprotocol_ws),
	uow=Depends(UnitOfWork),
):
	try:
		await auth_service.check_verificated_user(uow=uow, user_id=user.id)
		await auth_service.validate_user_access_to_chat(uow=uow, user_id=user.id, chat_id=chat_id)
		await manager.connect(chat_id, websocket, subprotocol)
		while True:
			data = await websocket.receive_json()

			await manager.broadcast(uow=uow, user_id=user.id, chat_id=chat_id, message=data)
	except WebSocketDisconnect:
		await manager.disconnect(chat_id, websocket)
	except HTTPException as e:
		code = status.WS_1011_INTERNAL_ERROR if e.status_code == 500 else status.WS_1003_UNSUPPORTED_DATA

		reason = e.detail
		code_and_reason = (code, reason)
		await manager.disconnect(chat_id=chat_id, websocket=websocket, code_and_reason=code_and_reason)
	except Exception as e:
		logging.warning(e)
		code_and_reason = (status.WS_1011_INTERNAL_ERROR, "Internal Server Error")
		await manager.disconnect(chat_id=chat_id, websocket=websocket, code_and_reason=code_and_reason)


@router.post(
	"/ws/{chat_id}",
	responses={
		status.HTTP_401_UNAUTHORIZED: {
			"model": Responses.STokenMissingException,
			"description": "Токен отсутствует"
		},
		status.HTTP_403_FORBIDDEN: {
			"model": Responses.SNotAuthenticated,
			"description": "Not authenticated"
		},
		status.HTTP_404_NOT_FOUND: {
			"model": Responses.SUserNotFoundException,
			"description": "Юзер не найден"
		},
		status.HTTP_409_CONFLICT: {
			"model": Responses.SUserMustConfirmEmailException,
			"description": "Сначала подтвердите почту"
		},
		status.HTTP_500_INTERNAL_SERVER_ERROR: {
			"model": Responses.SBlackPhoenixException,
			"description": "Внутренняя ошибка сервера"
		},
	},
)
async def chat_ws(
	chat_id: int,
	token: str = Depends(get_token),
):
	raise UseWSException  # noqa
	url = f"ws://localhost:8000/api/chat/ws/{chat_id}"
	async with websockets.connect(url, extra_headers={"Authorization": f"Bearer {token}"}) as websocket:
		print(await websocket.recv())


class PollingManager:
	def __init__(self):
		self.waiters: dict[int, list[asyncio.Future]] = defaultdict(list)
		self.messages: dict[int, list[dict]] = defaultdict(list)

	async def poll(self, chat_id: int) -> dict:
		future = asyncio.Future()
		self.waiters[chat_id].append(future)
		try:
			await future
			message = self.messages[chat_id][0]
			return message
		except asyncio.CancelledError:
			self.waiters[chat_id].remove(future)
			raise HTTPException(status_code=status.HTTP_408_REQUEST_TIMEOUT, detail="Client disconnected")

	async def prepare(
		self,
		uow: UnitOfWork,
		user_id: int,
		chat_id: int,
		message: SSendMessage | SDeleteMessage | SEditMessage | SPinMessage | SUnpinMessage,
	) -> None:
		message = message.model_dump()
		await manager.broadcast(uow=uow, user_id=user_id, chat_id=chat_id, message=message)

		await self.send(chat_id=chat_id, message=message)

	async def send(
		self,
		chat_id: int,
		message: dict,
	) -> None:
		self.messages[chat_id].append(message)
		while self.waiters[chat_id]:
			waiter = self.waiters[chat_id].pop(0)
			if not waiter.done():
				waiter.set_result(None)
		await asyncio.sleep(0)
		self.messages[chat_id].pop(0)


polling_manager = PollingManager()


@router.get(
	"/poll/{chat_id}",
	status_code=status.HTTP_200_OK,
	response_model=None,
	responses={
		status.HTTP_401_UNAUTHORIZED: {
			"model": Responses.STokenMissingException,
			"description": "Токен отсутствует"
		},
		status.HTTP_403_FORBIDDEN: {
			"model": Responses.SNotAuthenticated,
			"description": "Not authenticated"
		},
		status.HTTP_404_NOT_FOUND: {
			"model": Responses.SUserNotFoundException,
			"description": "Юзер не найден"
		},
		status.HTTP_409_CONFLICT: {
			"model": Responses.SUserMustConfirmEmailException,
			"description": "Сначала подтвердите почту"
		},
		status.HTTP_500_INTERNAL_SERVER_ERROR: {
			"model": Responses.SBlackPhoenixException,
			"description": "Внутренняя ошибка сервера"
		},
	},
)
async def poll(chat_id: int, user: SUser = Depends(get_verificated_user), uow=Depends(UnitOfWork)):
	await auth_service.validate_user_access_to_chat(uow=uow, user_id=user.id, chat_id=chat_id)
	return await polling_manager.poll(chat_id)


@router.post(
	"/send/{chat_id}",
	status_code=status.HTTP_201_CREATED,
	response_model=None,
	responses={
		status.HTTP_401_UNAUTHORIZED: {
			"model": Responses.STokenMissingException,
			"description": "Токен отсутствует"
		},
		status.HTTP_403_FORBIDDEN: {
			"model": Responses.SNotAuthenticated,
			"description": "Not authenticated"
		},
		status.HTTP_404_NOT_FOUND: {
			"model": Responses.SUserNotFoundException,
			"description": "Юзер не найден"
		},
		status.HTTP_409_CONFLICT: {
			"model": Responses.SUserMustConfirmEmailException,
			"description": "Сначала подтвердите почту"
		},
		status.HTTP_500_INTERNAL_SERVER_ERROR: {
			"model": Responses.SBlackPhoenixException,
			"description": "Внутренняя ошибка сервера"
		},
	},
)
async def send(
	chat_id: int,
	message: SSendMessage | SDeleteMessage | SEditMessage | SPinMessage | SUnpinMessage,
	user: SUser = Depends(get_verificated_user),
	uow=Depends(UnitOfWork),
):
	await auth_service.validate_user_access_to_chat(uow=uow, user_id=user.id, chat_id=chat_id)
	await polling_manager.prepare(uow=uow, user_id=user.id, chat_id=chat_id, message=message)