"""모델 성능 메트릭 API."""
from __future__ import annotations

from datetime import date, timedelta

from fastapi import APIRouter, HTTPException, Query
from sqlalchemy import text

from app.db.connection import get_engine

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


@router.get("/{code}")
def code_metrics(
    code: str,
    window_days: int = Query(default=30, ge=1, le=365),
) -> dict:
    """code 의 최근 window_days 윈도우 prediction_outcomes 집계."""
    eng = get_engine()
    end = date.today()
    start = end - timedelta(days=window_days)
    with eng.connect() as conn:
        sym = conn.execute(
            text("SELECT code, name FROM symbols WHERE code = :c"),
            {"c": code},
        ).first()
        if not sym:
            raise HTTPException(status_code=404, detail=f"unknown code: {code}")
        rows = conn.execute(
            text(
                """
                SELECT model, horizon,
                       COUNT(*) AS n,
                       AVG(CASE WHEN direction_hit THEN 1.0 ELSE 0.0 END) AS hit_rate,
                       AVG(abs_error) AS mae
                  FROM prediction_outcomes
                 WHERE code = :c AND resolved_at >= :s
                 GROUP BY model, horizon
                 ORDER BY model, horizon
                """
            ),
            {"c": code, "s": start},
        ).all()

    return {
        "code": sym[0],
        "name": sym[1],
        "window_days": window_days,
        "range": {"from": str(start), "to": str(end)},
        "by_model_horizon": [
            {
                "model": r[0],
                "horizon": int(r[1]),
                "n": int(r[2]),
                "hit_rate": float(r[3]) if r[3] is not None else None,
                "mae": float(r[4]) if r[4] is not None else None,
            }
            for r in rows
        ],
    }


@router.get("")
def overall_metrics(
    window_days: int = Query(default=30, ge=1, le=365),
) -> dict:
    """전체 시드 종목 누적 메트릭."""
    eng = get_engine()
    end = date.today()
    start = end - timedelta(days=window_days)
    with eng.connect() as conn:
        rows = conn.execute(
            text(
                """
                SELECT po.model, po.horizon,
                       COUNT(*) AS n,
                       AVG(CASE WHEN po.direction_hit THEN 1.0 ELSE 0.0 END) AS hit_rate,
                       AVG(po.abs_error) AS mae
                  FROM prediction_outcomes po
                 WHERE po.resolved_at >= :s
                 GROUP BY po.model, po.horizon
                 ORDER BY po.model, po.horizon
                """
            ),
            {"s": start},
        ).all()
    return {
        "window_days": window_days,
        "range": {"from": str(start), "to": str(end)},
        "by_model_horizon": [
            {
                "model": r[0],
                "horizon": int(r[1]),
                "n": int(r[2]),
                "hit_rate": float(r[3]) if r[3] is not None else None,
                "mae": float(r[4]) if r[4] is not None else None,
            }
            for r in rows
        ],
    }