"""Oracle ADB price_history CRUD."""

from __future__ import annotations

import os
from contextlib import contextmanager
from typing import Generator, Optional

import oracledb

_pool: Optional[oracledb.ConnectionPool] = None


def _get_pool() -> oracledb.ConnectionPool:
    global _pool
    if _pool is None:
        kwargs: dict = dict(
            user=os.environ["ORACLE_USER"],
            password=os.environ["ORACLE_PASSWORD"],
            dsn=os.environ["ORACLE_DSN"],
            min=1,
            max=3,
            increment=1,
        )
        wallet = os.environ.get("ORACLE_WALLET")
        if wallet:
            kwargs["config_dir"] = wallet
        _pool = oracledb.create_pool(**kwargs)
    return _pool


@contextmanager
def _conn() -> Generator[oracledb.Connection, None, None]:
    pool = _get_pool()
    conn = pool.acquire()
    try:
        yield conn
        conn.commit()
    except Exception:
        conn.rollback()
        raise
    finally:
        pool.release(conn)


def insert_prices(ticker_prices: dict[str, float]) -> None:
    """여러 종목의 현재가를 한 번에 저장."""
    if not ticker_prices:
        return
    rows = [(ticker, price) for ticker, price in ticker_prices.items()]
    sql = "INSERT INTO price_history (ticker, price) VALUES (:1, :2)"
    with _conn() as conn:
        conn.cursor().executemany(sql, rows)


def get_price_n_hours_ago(ticker: str, hours: float) -> Optional[float]:
    """N시간 전 가장 가까운 가격 반환. 데이터 없으면 None."""
    sql = """
        SELECT price FROM price_history
         WHERE ticker = :ticker
           AND recorded_at BETWEEN
               SYSTIMESTAMP - INTERVAL ':h' HOUR - INTERVAL '10' MINUTE
               AND SYSTIMESTAMP - INTERVAL ':h' HOUR + INTERVAL '10' MINUTE
         ORDER BY ABS(CAST(recorded_at AS DATE) -
                      CAST(SYSTIMESTAMP - INTERVAL ':h' HOUR AS DATE))
         FETCH FIRST 1 ROWS ONLY
    """
    # Oracle INTERVAL bind param 미지원으로 직접 포맷
    h = int(hours)
    sql = f"""
        SELECT price FROM price_history
         WHERE ticker = :ticker
           AND recorded_at BETWEEN
               SYSTIMESTAMP - ({h}/24) - (10/1440)
               AND SYSTIMESTAMP - ({h}/24) + (10/1440)
         ORDER BY ABS(CAST(recorded_at AS DATE) -
                      CAST(SYSTIMESTAMP - ({h}/24) AS DATE))
         FETCH FIRST 1 ROWS ONLY
    """
    with _conn() as conn:
        cursor = conn.cursor()
        cursor.execute(sql, {"ticker": ticker})
        row = cursor.fetchone()
    return float(row[0]) if row else None


def cleanup_old_prices(keep_hours: int = 48) -> None:
    """N시간 이상 오래된 데이터 삭제 (DB 용량 관리)."""
    sql = f"DELETE FROM price_history WHERE recorded_at < SYSTIMESTAMP - ({keep_hours}/24)"
    with _conn() as conn:
        conn.cursor().execute(sql)