from datetime import datetime, timezone, timedelta

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

from app.core.database import get_db
from app.core.security import get_current_user
from app.models.user import User
from app.models.playlist import Playlist
from app.models.track import Track
from app.models.recommendation import Recommendation

router = APIRouter(prefix="/admin", tags=["admin"])

ADMIN_EMAILS = ["chris.ryan@deepcutsai.com"]


@router.get("/stats")
async def get_stats(
    user: User = Depends(get_current_user),
    db: AsyncSession = Depends(get_db),
):
    if user.email not in ADMIN_EMAILS:
        raise HTTPException(status_code=403, detail="Admin only")

    now = datetime.now(timezone.utc)
    today = now.replace(hour=0, minute=0, second=0, microsecond=0)
    week_ago = now - timedelta(days=7)
    month_ago = now - timedelta(days=30)

    # User stats
    total_users = (await db.execute(select(func.count(User.id)))).scalar() or 0
    pro_users = (await db.execute(select(func.count(User.id)).where(User.is_pro == True))).scalar() or 0

    # Playlist stats
    total_playlists = (await db.execute(select(func.count(Playlist.id)))).scalar() or 0
    total_tracks = (await db.execute(select(func.count(Track.id)))).scalar() or 0

    # Recommendation stats
    total_recs = (await db.execute(select(func.count(Recommendation.id)))).scalar() or 0
    recs_today = (await db.execute(
        select(func.count(Recommendation.id)).where(Recommendation.created_at >= today)
    )).scalar() or 0
    recs_this_week = (await db.execute(
        select(func.count(Recommendation.id)).where(Recommendation.created_at >= week_ago)
    )).scalar() or 0
    recs_this_month = (await db.execute(
        select(func.count(Recommendation.id)).where(Recommendation.created_at >= month_ago)
    )).scalar() or 0

    saved_recs = (await db.execute(
        select(func.count(Recommendation.id)).where(Recommendation.saved == True)
    )).scalar() or 0
    disliked_recs = (await db.execute(
        select(func.count(Recommendation.id)).where(Recommendation.disliked == True)
    )).scalar() or 0

    # Per-user breakdown
    user_stats_result = await db.execute(
        select(
            User.id, User.name, User.email, User.is_pro, User.created_at,
            func.count(Recommendation.id).label("rec_count"),
        )
        .outerjoin(Recommendation, Recommendation.user_id == User.id)
        .group_by(User.id)
        .order_by(User.id)
    )
    user_breakdown = [
        {
            "id": row.id,
            "name": row.name,
            "email": row.email,
            "is_pro": row.is_pro,
            "created_at": row.created_at.isoformat() if row.created_at else None,
            "recommendation_count": row.rec_count,
        }
        for row in user_stats_result.all()
    ]

    return {
        "users": {
            "total": total_users,
            "pro": pro_users,
            "free": total_users - pro_users,
        },
        "playlists": {
            "total": total_playlists,
            "total_tracks": total_tracks,
        },
        "recommendations": {
            "total": total_recs,
            "today": recs_today,
            "this_week": recs_this_week,
            "this_month": recs_this_month,
            "saved": saved_recs,
            "disliked": disliked_recs,
        },
        "user_breakdown": user_breakdown,
    }