#include "gtest/gtest.h"
#include "alert_manager.hpp"
#include <memory>
#include <vector>

// Mock the time function for deterministic testing
static uint32_t mock_timestamp = 1640995200; // 2022-01-01 00:00:00 UTC

// Mock function to replace std::time
uint32_t getMockTimestamp() {
    return mock_timestamp;
}

// Override the global function in alert_manager.cpp
extern "C" uint32_t get_current_timestamp() {
    return getMockTimestamp();
}

// Test fixture for AlertManager
class AlertManagerTest : public ::testing::Test {
protected:
    AlertManager alert_manager;

    void SetUp() override {
        mock_timestamp = 1640995200;
        alert_manager.initialize();
    }

    void setMockTimestamp(uint32_t ts) {
        mock_timestamp = ts;
    }

    std::vector<AlertInfo> getActiveAlerts() {
        return alert_manager.getActiveAlerts();
    }

    bool hasActiveAlerts() const {
        return alert_manager.hasActiveAlerts();
    }
};

// Test case: checkAltitudeAlert - 正常输入测试 - 高度在阈值内
TEST_F(AlertManagerTest, testCheckAltitudeAlertNormalInputWithinThreshold) {
    // Arrange
    float altitude = 80.0f; // Within default range [-50, 100]
    setMockTimestamp(1640995200);

    // Act
    alert_manager.checkAltitudeAlert(altitude, getMockTimestamp());

    // Assert
    EXPECT_FALSE(hasActiveAlerts()) << "不应触发任何预警";
}

// Test case: checkAltitudeAlert - 正常输入测试 - 高度超过上限
TEST_F(AlertManagerTest, testCheckAltitudeAlertNormalInputAboveUpperThreshold) {
    // Arrange
    float altitude = 105.0f; // Above upper threshold (100)
    setMockTimestamp(1640995200);

    // Act
    alert_manager.checkAltitudeAlert(altitude, getMockTimestamp());

    // Assert
    EXPECT_TRUE(hasActiveAlerts()) << "应触发高度上限预警";
    auto alerts = getActiveAlerts();
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].type, AlertType::ALTITUDE_UPPER);
    EXPECT_EQ(alerts[0].status, AlertStatus::ACTIVE);
}

// Test case: checkAltitudeAlert - 正常输入测试 - 高度低于下限
TEST_F(AlertManagerTest, testCheckAltitudeAlertNormalInputBelowLowerThreshold) {
    // Arrange
    float altitude = -55.0f; // Below lower threshold (-50)
    setMockTimestamp(1640995200);

    // Act
    alert_manager.checkAltitudeAlert(altitude, getMockTimestamp());

    // Assert
    EXPECT_TRUE(hasActiveAlerts()) << "应触发高度下限预警";
    auto alerts = getActiveAlerts();
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].type, AlertType::ALTITUDE_LOWER);
    EXPECT_EQ(alerts[0].status, AlertStatus::ACTIVE);
}

// Test case: checkAltitudeAlert - 边界值测试 - 高度等于上限阈值
TEST_F(AlertManagerTest, testCheckAltitudeAlertBoundaryAtUpperThreshold) {
    // Arrange
    float altitude = 100.0f; // Equal to upper threshold
    setMockTimestamp(1640995200);

    // Act
    alert_manager.checkAltitudeAlert(altitude, getMockTimestamp());

    // Assert
    EXPECT_FALSE(hasActiveAlerts()) << "等于上限不应触发预警";
}

// Test case: checkAltitudeAlert - 边界值测试 - 高度等于下限阈值
TEST_F(AlertManagerTest, testCheckAltitudeAlertBoundaryAtLowerThreshold) {
    // Arrange
    float altitude = -50.0f; // Equal to lower threshold
    setMockTimestamp(1640995200);

    // Act
    alert_manager.checkAltitudeAlert(altitude, getMockTimestamp());

    // Assert
    EXPECT_FALSE(hasActiveAlerts()) << "等于下限不应触发预警";
}

// Test case: checkAltitudeAlert - 特殊场景测试 - 高度从超限恢复到正常
TEST_F(AlertManagerTest, testCheckAltitudeAlertSpecialScenarioRecoveryFromUpper) {
    // Arrange
    float above_threshold = 105.0f;
    float normal = 90.0f;
    setMockTimestamp(1640995200);

    // First trigger upper alert
    alert_manager.checkAltitudeAlert(above_threshold, getMockTimestamp());
    EXPECT_TRUE(hasActiveAlerts());

    // Reset timestamp and check recovery
    setMockTimestamp(1640995201);
    alert_manager.checkAltitudeAlert(normal, getMockTimestamp());

    // Assert
    EXPECT_FALSE(hasActiveAlerts()) << "恢复后应解除预警";
}

// Test case: setAltitudeThresholds - 正常输入测试 - 合法上下限设置
TEST_F(AlertManagerTest, testSetAltitudeThresholdsNormalInputValidRange) {
    // Arrange
    float upper = 150.0f;
    float lower = -100.0f;

    // Act
    alert_manager.setAltitudeThresholds(upper, lower);

    // Assert
    EXPECT_EQ(alert_manager.getUpperThreshold(), upper);
    EXPECT_EQ(alert_manager.getLowerThreshold(), lower);
    EXPECT_FALSE(hasActiveAlerts()) << "设置阈值不应触发预警";
}

// Test case: setAltitudeThresholds - 异常输入测试 - 上限不大于下限
TEST_F(AlertManagerTest, testSetAltitudeThresholdsInvalidInputUpperNotGreater) {
    // Arrange
    float upper = 50.0f;
    float lower = 50.0f;

    // Act & Assert
    EXPECT_NO_THROW(alert_manager.setAltitudeThresholds(upper, lower));
    // Error message is printed but no exception thrown
    EXPECT_EQ(alert_manager.getUpperThreshold(), 100.0f); // Should remain unchanged
    EXPECT_EQ(alert_manager.getLowerThreshold(), -50.0f);
}

// Test case: setAltitudeThresholds - 异常输入测试 - 上限小于下限
TEST_F(AlertManagerTest, testSetAltitudeThresholdsInvalidInputUpperLessThanLower) {
    // Arrange
    float upper = 50.0f;
    float lower = 75.0f;

    // Act & Assert
    EXPECT_NO_THROW(alert_manager.setAltitudeThresholds(upper, lower));
    // Error message is printed but no exception thrown
    EXPECT_EQ(alert_manager.getUpperThreshold(), 100.0f); // Should remain unchanged
    EXPECT_EQ(alert_manager.getLowerThreshold(), -50.0f);
}

// Test case: setAltitudeThresholds - 特殊场景测试 - 阈值改变后重置预警
TEST_F(AlertManagerTest, testSetAltitudeThresholdsSpecialScenarioResetAlerts) {
    // Arrange
    float altitude = 105.0f; // Exceeds original upper threshold
    setMockTimestamp(1640995200);

    // Trigger an alert
    alert_manager.checkAltitudeAlert(altitude, getMockTimestamp());
    EXPECT_TRUE(hasActiveAlerts());

    // Change thresholds to a higher value
    setMockTimestamp(1640995201);
    alert_manager.setAltitudeThresholds(200.0f, -100.0f);

    // Assert
    EXPECT_FALSE(hasActiveAlerts()) << "阈值更新后应重置相关预警";
}

// Helper method to access private members for testing
float AlertManager::getUpperThreshold() const {
    return upper_threshold_;
}

float AlertManager::getLowerThreshold() const {
    return lower_threshold_;
}