import asyncio

from fastapi import APIRouter, WebSocket, WebSocketDisconnect

from app.bars.models import Timeframe

router = APIRouter()


def snapshot(runtime, tf: Timeframe) -> dict:
    return {
        "type": "snapshot",
        "tf": tf.value,
        "bars": [bar.to_dict() for bar in runtime.store.get(tf, 1000)],
        "levels": [],
        "clusters": [],
        "price": runtime.store.get(Timeframe.M1, 1)[-1].c
        if runtime.store.get(Timeframe.M1, 1)
        else None,
    }


@router.websocket("/ws")
async def websocket_endpoint(websocket: WebSocket):
    await websocket.accept()
    runtime = websocket.app.state.runtime
    queue: asyncio.Queue = asyncio.Queue(maxsize=100)
    runtime.subscribers.add(queue)
    tf = Timeframe.M1
    await websocket.send_json(snapshot(runtime, tf))

    async def receive():
        nonlocal tf
        while True:
            message = await websocket.receive_json()
            if message.get("type") == "subscribe":
                tf = Timeframe(message.get("tf", "1m"))
                await websocket.send_json(snapshot(runtime, tf))

    receiver = asyncio.create_task(receive())
    try:
        while True:
            bar = await queue.get()
            if bar.tf is tf:
                await websocket.send_json({"type": "bar", "tf": tf.value, "bar": bar.to_dict()})
    except (WebSocketDisconnect, asyncio.CancelledError):
        pass
    finally:
        receiver.cancel()
        runtime.subscribers.discard(queue)