"""异常检测模块：ANOMALY_WINDOW × 6 算法多路跑 + 容错。"""

import logging
from typing import Any

logger = logging.getLogger(__name__)

ALL_ALGOS = ["ksigma", "iqr", "grubbs", "shesd", "lof", "sample_ad_model"]


def run_anomaly_window(conn, stable: str, algo: str) -> list[tuple[int, int]]:
    """执行单算法 ANOMALY_WINDOW。

    Args:
        conn: TDConnection 实例
        stable: supertable 名称（不含 ds_ 前缀）
        algo: 算法名

    Returns:
        [(start_ts_ms, end_ts_ms), ...] 异常窗口列表

    Raises:
        ValueError: 算法不支持
        Exception: SQL 执行失败（透传）
    """
    if algo not in ALL_ALGOS:
        raise ValueError(f"不支持的算法: {algo}，可选: {ALL_ALGOS}")

    sql = (
        f"SELECT _WSTART, _WEND "
        f"FROM (SELECT ts, `value` AS v FROM ds_{stable}) "
        f"ANOMALY_WINDOW(v, 'algo={algo}')"
    )

    rows = conn.execute(sql)

    windows = []
    for row in rows:
        if row[0] is not None and row[1] is not None:
            windows.append((int(row[0]), int(row[1])))
    return windows


def detect_all_algos(conn, stable: str, algos: list[str] | None = None) -> dict[str, Any]:
    """依次执行所有指定算法，独立容错。

    Args:
        conn: TDConnection 实例
        stable: supertable 名称
        algos: 算法列表，默认 ALL_ALGOS

    Returns:
        {algo_name: {"windows": [...], "error": None | str}, ...}
    """
    algos = algos or ALL_ALGOS
    results: dict[str, Any] = {}

    for algo in algos:
        logger.info("running ANOMALY_WINDOW algo=%s stable=%s", algo, stable)
        try:
            if algo == "sample_ad_model":
                # 检查模型文件
                import os
                model_path = os.path.join("data", "models", "sample_ad_model")
                if not os.path.exists(model_path):
                    results[algo] = {"windows": [], "error": "model file not found"}
                    logger.warning("sample_ad_model skip: model file not found at %s", model_path)
                    continue

            windows = run_anomaly_window(conn, stable, algo)
            results[algo] = {"windows": windows, "error": None}
            logger.info("algo=%s: %d windows found", algo, len(windows))
        except Exception as e:
            results[algo] = {"windows": [], "error": str(e)}
            logger.warning("algo=%s failed (non-fatal): %s", algo, e)

    return results