from datetime import datetime, timedelta, timezone

from fastapi import APIRouter, Depends
from sqlalchemy import func, select, text
from sqlalchemy.ext.asyncio import AsyncSession

from haunt_fm.db import get_session
from haunt_fm.models.track import (
    ListenEvent,
    Playlist,
    TasteProfile,
    Track,
    TrackEmbedding,
)
from haunt_fm.config import settings
from haunt_fm.services.embedding import is_model_loaded
from haunt_fm.services.embedding_worker import is_running as is_worker_running
from haunt_fm.services.embedding_worker import last_processed as worker_last_processed

router = APIRouter(prefix="/api")


@router.get("/status")
async def status(session: AsyncSession = Depends(get_session)):
    # DB connectivity
    try:
        await session.execute(text("SELECT 1"))
        db_connected = True
    except Exception:
        db_connected = False

    if not db_connected:
        return {"healthy": False, "db_connected": False}

    now = datetime.now(timezone.utc)
    day_ago = now - timedelta(days=1)

    # Listen events
    total_events = (await session.execute(select(func.count(ListenEvent.id)))).scalar() or 0
    events_24h = (
        await session.execute(
            select(func.count(ListenEvent.id)).where(ListenEvent.listened_at >= day_ago)
        )
    ).scalar() or 0
    latest_event = (
        await session.execute(select(func.max(ListenEvent.listened_at)))
    ).scalar()

    # Tracks
    total_tracks = (await session.execute(select(func.count(Track.id)))).scalar() or 0
    from_history = (
        await session.execute(
            select(func.count(func.distinct(ListenEvent.track_id)))
        )
    ).scalar() or 0
    from_discovery = total_tracks - from_history

    # Embeddings
    def _embedding_count(status_val: str):
        return select(func.count(Track.id)).where(Track.embedding_status == status_val)

    emb_done = (await session.execute(_embedding_count("done"))).scalar() or 0
    emb_pending = (await session.execute(_embedding_count("pending"))).scalar() or 0
    emb_failed = (await session.execute(_embedding_count("failed"))).scalar() or 0
    emb_no_preview = (await session.execute(_embedding_count("no_preview"))).scalar() or 0

    # Taste profile
    taste = (await session.execute(select(TasteProfile).where(TasteProfile.name == "default"))).scalar()

    # Playlists
    total_playlists = (await session.execute(select(func.count(Playlist.id)))).scalar() or 0
    last_playlist = (await session.execute(select(func.max(Playlist.created_at)))).scalar()

    return {
        "healthy": db_connected,
        "db_connected": db_connected,
        "clap_model_loaded": is_model_loaded(),
        "pipeline": {
            "listen_events": {
                "total": total_events,
                "last_24h": events_24h,
                "latest": latest_event.isoformat() if latest_event else None,
            },
            "tracks": {
                "total": total_tracks,
                "from_history": from_history,
                "from_discovery": from_discovery,
            },
            "embeddings": {
                "done": emb_done,
                "pending": emb_pending,
                "failed": emb_failed,
                "no_preview": emb_no_preview,
                "worker_running": is_worker_running(),
                "worker_last_processed": worker_last_processed().isoformat() if worker_last_processed() else None,
            },
            "taste_profile": {
                "exists": taste is not None,
                "track_count": taste.track_count if taste else 0,
                "updated_at": taste.updated_at.isoformat() if taste else None,
            },
            "playlists": {
                "total_generated": total_playlists,
                "last_generated": last_playlist.isoformat() if last_playlist else None,
            },
        },
        "dependencies": {
            "lastfm_api": "configured" if settings.lastfm_api_key else "not_configured",
            "itunes_api": "ok",  # no auth needed
            "ha_reachable": bool(settings.ha_token),
            "music_assistant_reachable": bool(settings.ha_token),
        },
    }