"""당일 trade_history — 프로세스 공유 RAM + TTL.

check_buy·포트가드가 같은 표를 나눠 씀. SELECT 연타·공유 DB 락 대기 완화.
TTL 만료 또는 invalidate 시에만 DB 재조회 (DB 쓰기 아님).
"""
from __future__ import annotations

import threading
import time
from typing import Any, Dict, List, Optional, Tuple

_LOCK = threading.Lock()
_DAY: str = ""
_ROWS: List[Dict] = []
_TS: float = 0.0


def _ttl_sec() -> float:
    try:
        from .env import get_env_float
        return float(get_env_float("TODAY_TRADES_CACHE_TTL_SEC", 1.0) or 1.0)
    except Exception:
        return 1.0


def invalidate_today_trades_cache() -> None:
    """매수 체결 직후 등 — 다음 get 이 DB 재조회."""
    global _DAY, _ROWS, _TS
    with _LOCK:
        _DAY = ""
        _ROWS = []
        _TS = 0.0


def get_today_trades_cached(
    db: Any,
    today: Optional[str] = None,
) -> Tuple[List[Dict], bool, float]:
    """Returns: (rows, from_cache, db_ms).

    from_cache=True 이면 DB 미호출.
    """
    global _DAY, _ROWS, _TS
    from datetime import datetime as dt

    day = str(today or dt.now().strftime("%Y%m%d"))
    ttl = _ttl_sec()
    now = time.time()
    with _LOCK:
        if _DAY == day and (ttl <= 0 or (now - _TS) < ttl):
            return list(_ROWS), True, 0.0

    t0 = time.perf_counter()
    try:
        rows = list(db.get_trades_by_date(day) or [])
    except Exception:
        rows = []
    db_ms = (time.perf_counter() - t0) * 1000.0

    with _LOCK:
        _DAY = day
        _ROWS = rows
        _TS = time.time()
        return list(rows), False, db_ms