import asyncio
import os

from fastapi import FastAPI
from fastapi.responses import HTMLResponse
from fastapi.websockets import WebSocket, WebSocketDisconnect
from jinja2 import Environment, FileSystemLoader

import config


class ConnectionManager:
    connections: list[WebSocket]

    class StateError(Exception):
        pass

    def __init__(
            self,
    ):
        self.connections = []

    async def connect(
            self,
            websocket: WebSocket,
    ):
        await websocket.accept()
        self.connections.append(websocket)

    def disconnect(
            self,
            websocket: WebSocket,
    ):
        self.connections.remove(websocket)

    async def broadcast(
            self,
            data: dict,
    ):
        for connection in self.connections:
            asyncio.ensure_future(connection.send_json(data))


connection_manager = ConnectionManager()


app = FastAPI(
    title=config.Main.app_name,
)

env = Environment(
    loader=FileSystemLoader(
        searchpath=os.path.join(
            config.Main.cwd,
            'templates',
        ),
    ),
    enable_async=True,
)
env.globals['app_name'] = config.Main.app_name


@app.get(
    path='/',
)
async def _():
    template = env.get_template('main.jinja2')
    return HTMLResponse(
        content=await template.render_async(
            title='Дашборд',
        ),
    )


@app.websocket(
    path='/ws',
)
async def _(
        websocket: WebSocket,
):
    await connection_manager.connect(websocket)
    try:
        while True:
            await connection_manager.broadcast(await websocket.receive_json())
    except WebSocketDisconnect:
        connection_manager.disconnect(websocket)