"""detection 模块测试（mock TDengine execute 返回预设窗口）。"""

from unittest.mock import MagicMock
import pytest
from ts_anomaly_td.detection import run_anomaly_window, detect_all_algos, ALL_ALGOS


def make_mock_conn(rows=None):
    """构造 mock TDConnection，execute 返回预设行。"""
    conn = MagicMock()
    conn.execute.return_value = rows or []
    return conn


def test_run_anomaly_window_returns_windows():
    """正常返回两个异常窗口。"""
    conn = make_mock_conn([
        (1000000, 2000000),
        (3000000, 4000000),
    ])
    windows = run_anomaly_window(conn, "finance_001", "ksigma")
    assert windows == [(1000000, 2000000), (3000000, 4000000)]


def test_run_anomaly_window_empty():
    """无异常窗口时返回空列表。"""
    conn = make_mock_conn([])
    windows = run_anomaly_window(conn, "finance_001", "iqr")
    assert windows == []


def test_run_anomaly_window_invalid_algo():
    """不支持的算法抛 ValueError。"""
    conn = make_mock_conn()
    with pytest.raises(ValueError, match="不支持的算法"):
        run_anomaly_window(conn, "test", "nonexistent")


def test_run_anomaly_window_sql_error():
    """SQL 执行失败传播异常。"""
    conn = make_mock_conn()
    conn.execute.side_effect = Exception("TDengine error")

    with pytest.raises(Exception, match="TDengine error"):
        run_anomaly_window(conn, "test", "ksigma")


def test_detect_all_algos_independent_fault_tolerance():
    """单个算法失败不影响其他算法。"""
    conn = MagicMock()

    def side_effect(sql):
        if "iqr" in sql:
            raise Exception("iqr failed")
        return [(1000, 2000)]

    conn.execute.side_effect = side_effect

    results = detect_all_algos(conn, "test")

    # 所有 6 个算法都在结果中
    assert set(results.keys()) == set(ALL_ALGOS)

    # iqr 记录了 error
    assert results["iqr"]["error"] == "iqr failed"
    assert results["iqr"]["windows"] == []

    # 其他算法正常
    for algo in ALL_ALGOS:
        if algo != "iqr":
            assert results[algo]["error"] is None
            assert len(results[algo]["windows"]) == 1


def test_detect_all_algos_custom_algo_list():
    """指定算法子集。"""
    conn = make_mock_conn([(1000, 2000)])
    results = detect_all_algos(conn, "test", algos=["ksigma", "iqr"])
    assert set(results.keys()) == {"ksigma", "iqr"}