from __future__ import annotations

import asyncio
from contextlib import suppress
from datetime import timezone

from app.db.session import SessionLocal
from app.repositories.audio_repository import AudioRepository
from app.ws.router import manager  # используем тот же manager, что и в ws/router.py


def _iso_z(dt) -> str:
    return dt.astimezone(timezone.utc).isoformat().replace("+00:00", "Z")


async def audio_live_broadcaster(poll_interval_sec: float = 0.05) -> None:
    """
    Poll latest row and broadcast only when a NEW row appears.
    Throttling per client is handled by manager.broadcast_json().
    """
    last_time = None

    while True:
        try:
            async with SessionLocal() as db:
                repo = AudioRepository(db)
                rows = await repo.latest(1)
                if rows:
                    row = rows[0]
                    if last_time is None or row.time > last_time:
                        last_time = row.time
                        await manager.broadcast_json(
                            {
                                "time": _iso_z(row.time),
                                "rms_db": float(row.rms_db),
                                "freq_hz": int(row.frequency_hz),
                            }
                        )
        except Exception:
            # не даём таске умереть при временных проблемах БД
            pass

        await asyncio.sleep(poll_interval_sec)