"""T4.10 智能预警 + 预测分析测试。"""

import pytest
from fastapi.testclient import TestClient

from app.services.predictor import predict_trend, detect_anomalies


class TestPredictTrend:
    """趋势预测函数测试。"""

    def test_predict_with_sufficient_data(self):
        """有足够历史数据时应返回预测。"""
        result = predict_trend([60, 62, 65, 68, 70], months_ahead=3)
        assert "predicted" in result
        assert len(result["predicted"]) == 3
        assert all(0 <= p <= 100 for p in result["predicted"])
        assert result["confidence"] > 0

    def test_predict_with_insufficient_data(self):
        """数据不足时应返回空预测。"""
        result = predict_trend([50], months_ahead=3)
        assert result["predicted"] == []
        assert result["confidence"] == 0.0

    def test_predict_stable_trend(self):
        """稳定趋势斜率应接近 0。"""
        result = predict_trend([70, 70, 70, 70], months_ahead=2)
        assert abs(result["slope"]) < 0.1

    def test_predict_upward_trend(self):
        """上升趋势斜率应为正。"""
        result = predict_trend([50, 55, 60, 65, 70], months_ahead=2)
        assert result["slope"] > 0

    def test_predict_downward_trend(self):
        """下降趋势斜率应为负。"""
        result = predict_trend([80, 75, 70, 65, 60], months_ahead=2)
        assert result["slope"] < 0


class TestDetectAnomalies:
    """异常检测函数测试。"""

    def test_detect_with_normal_data(self):
        """正常数据不应检测到异常。"""
        result = detect_anomalies([70, 71, 69, 70, 71])
        assert result == []

    def test_detect_with_anomaly(self):
        """包含异常值时应检测到。"""
        result = detect_anomalies([70, 71, 69, 70, 500], threshold=1.5)
        assert len(result) > 0
        assert 4 in result

    def test_detect_with_insufficient_data(self):
        """数据不足时应返回空。"""
        assert detect_anomalies([50, 60]) == []

    def test_detect_with_constant_data(self):
        """恒定数据不应检测到异常。"""
        assert detect_anomalies([70, 70, 70, 70]) == []


class TestForecastEndpoint:
    """预测接口测试。"""

    def test_forecast_empty(self, client: TestClient, auth_headers: dict):
        """无历史数据时应正常返回。"""
        resp = client.get("/api/v1/dashboard/forecasts", headers=auth_headers)
        assert resp.status_code == 200
        data = resp.json()["data"]
        assert "predictions" in data
        assert "trend_direction" in data
        assert "anomalies" in data

    def test_forecast_with_company_id(self, client: TestClient, auth_headers: dict, company_id: str):
        """指定企业 ID 应正常返回。"""
        resp = client.get(
            f"/api/v1/dashboard/forecasts?company_id={company_id}&months_ahead=3",
            headers=auth_headers,
        )
        assert resp.status_code == 200

    def test_forecast_invalid_months(self, client: TestClient, auth_headers: dict):
        """无效 months_ahead 应返回 422。"""
        resp = client.get("/api/v1/dashboard/forecasts?months_ahead=0", headers=auth_headers)
        assert resp.status_code == 422

    def test_forecast_no_auth(self, client: TestClient):
        """未认证应返回 401。"""
        resp = client.get("/api/v1/dashboard/forecasts")
        assert resp.status_code == 401