import asyncio
from typing import AsyncGenerator
from quart import Quart, render_template, websocket
import logging

logger = logging.getLogger(__name__)


app = Quart(__name__)
connections = set()

@app.route("/")
async def index():
    return await render_template("index.html")

@app.route("/api")
async def json():
    return {"hello": "world"}


async def _send() -> None:
    connection = asyncio.Queue()
    connections.add(connection)

    try:
        while True:
            message = await connection.get()
            await websocket.send(message)
    finally:
        connections.remove(connection)

async def _receive() -> None:
    while True:
        message = await websocket.receive()
        for connection in connections:
            await connection.put(message)

@app.websocket("/ws")
async def ws() -> None:
    producer = asyncio.create_task(_send())
    consumer = asyncio.create_task(_receive())
    await asyncio.gather(producer, consumer)

    #await websocket.send_json({"hello": "world"})



class WebUI(object):
    """The Web interface."""

    def __init__(self):
        self.shutdown_event = asyncio.Event()
        self.task = None
        app.config["PROPAGATE_EXCEPTIONS"] = True
        pass

    def run_task(self):
        return app.run_task(port=5000, debug=True, shutdown_trigger=self.shutdown_event.wait)

    async def stop(self):
        self.shutdown_event.set()
        self.task.cancel() # or close?