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

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

// Mock implementation of time function
extern "C" uint32_t get_mock_timestamp() {
    return mock_timestamp;
}

// Override the original function with mock
uint32_t std::time(nullptr) {
    return mock_timestamp;
}

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

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

    void TearDown() override {
        alert_manager.resetAllAlerts();
    }
};

// Test case: AlertManager 构造函数初始化默认阈值
TEST_F(AlertManagerTest, testAlertManagerInitialization) {
    EXPECT_FLOAT_EQ(alert_manager.getAltitudeThresholds().first, 100.0f);
    EXPECT_FLOAT_EQ(alert_manager.getAltitudeThresholds().second, -50.0f);
    EXPECT_TRUE(alert_manager.alerts_.empty());
    EXPECT_TRUE(alert_manager.alert_history_.empty());
}

// Test case: AlertManager 析构函数无特殊逻辑
TEST_F(AlertManagerTest, testAlertManagerDestructor) {
    // No specific assertion needed as destructor has no logic
    // This ensures compilation and basic behavior
    EXPECT_NO_FATAL_FAILURE({ AlertManager temp; });
}

// Test case: initialize 输出初始化信息
TEST_F(AlertManagerTest, testInitializeOutput) {
    // Capture output
    testing::internal::CaptureStdout();
    alert_manager.initialize();
    std::string output = testing::internal::GetCapturedStdout();
    
    EXPECT_NE(output.find("预警管理器初始化完成。"), std::string::npos);
    EXPECT_NE(output.find("默认预警阈值：上限=100米，下限=-50米"), std::string::npos);
}

// Test case: checkAltitudeAlert 正常高度不触发预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertNormalHeight) {
    alert_manager.checkAltitudeAlert(50.0f, mock_timestamp);
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

// Test case: checkAltitudeAlert 上限超标触发预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertUpperThresholdExceeded) {
    alert_manager.checkAltitudeAlert(105.0f, mock_timestamp);
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    auto alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].type, AlertType::ALTITUDE_UPPER);
    EXPECT_EQ(alerts[0].status, AlertStatus::ACTIVE);
}

// Test case: checkAltitudeAlert 下限超标触发预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertLowerThresholdExceeded) {
    alert_manager.checkAltitudeAlert(-55.0f, mock_timestamp);
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    auto alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].type, AlertType::ALTITUDE_LOWER);
    EXPECT_EQ(alerts[0].status, AlertStatus::ACTIVE);
}

// Test case: checkAltitudeAlert 高度恢复后解除预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertResolution) {
    alert_manager.checkAltitudeAlert(105.0f, mock_timestamp); // Trigger upper
    alert_manager.checkAltitudeAlert(90.0f, mock_timestamp + 1); // Resolve
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

// Test case: setAltitudeThresholds 合法输入更新阈值
TEST_F(AlertManagerTest, testSetAltitudeThresholdsValidInput) {
    alert_manager.setAltitudeThresholds(150.0f, -80.0f);
    auto thresholds = alert_manager.getAltitudeThresholds();
    EXPECT_FLOAT_EQ(thresholds.first, 150.0f);
    EXPECT_FLOAT_EQ(thresholds.second, -80.0f);
}

// Test case: setAltitudeThresholds 非法输入（上限 <= 下限）
TEST_F(AlertManagerTest, testSetAltitudeThresholdsInvalidInput) {
    testing::internal::CaptureStderr();
    alert_manager.setAltitudeThresholds(50.0f, 100.0f);
    std::string error_output = testing::internal::GetCapturedStderr();
    EXPECT_NE(error_output.find("错误：上限阈值必须大于下限阈值。"), std::string::npos);
}

// Test case: triggerSensorFailure 触发传感器故障预警
TEST_F(AlertManagerTest, testTriggerSensorFailure) {
    alert_manager.triggerSensorFailure(mock_timestamp);
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    auto alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].type, AlertType::SENSOR_FAILURE);
    EXPECT_EQ(alerts[0].description, "传感器故障");
}

// Test case: triggerLowBattery 触发低电量预警
TEST_F(AlertManagerTest, testTriggerLowBattery) {
    alert_manager.triggerLowBattery(mock_timestamp, 15.5f);
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    auto alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].type, AlertType::LOW_BATTERY);
    EXPECT_EQ(alerts[0].description, "低电量警告：当前电量15.5%" );
}

// Test case: triggerCommunicationError 触发通信错误预警
TEST_F(AlertManagerTest, testTriggerCommunicationError) {
    alert_manager.triggerCommunicationError(mock_timestamp);
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    auto alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].type, AlertType::COMMUNICATION_ERROR);
    EXPECT_EQ(alerts[0].description, "通信错误");
}

// Test case: acknowledgeAllAlerts 确认所有活动预警
TEST_F(AlertManagerTest, testAcknowledgeAllAlerts) {
    alert_manager.triggerSensorFailure(mock_timestamp);
    alert_manager.triggerLowBattery(mock_timestamp + 1, 10.0f);
    alert_manager.acknowledgeAllAlerts(mock_timestamp + 2);
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
    auto alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 2);
    EXPECT_EQ(alerts[0].status, AlertStatus::ACKNOWLEDGED);
    EXPECT_EQ(alerts[1].status, AlertStatus::ACKNOWLEDGED);
}

// Test case: acknowledgeAlert 确认指定类型预警
TEST_F(AlertManagerTest, testAcknowledgeAlert) {
    alert_manager.triggerSensorFailure(mock_timestamp);
    alert_manager.acknowledgeAlert(AlertType::SENSOR_FAILURE, mock_timestamp + 1);
    auto alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].status, AlertStatus::ACKNOWLEDGED);
}

// Test case: resetAlert 重置指定类型预警
TEST_F(AlertManagerTest, testResetAlert) {
    alert_manager.triggerSensorFailure(mock_timestamp);
    alert_manager.resetAlert(AlertType::SENSOR_FAILURE);
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_FALSE(alert_manager.alerts_.count(AlertType::SENSOR_FAILURE));
}

// Test case: resetAllAlerts 重置所有预警
TEST_F(AlertManagerTest, testResetAllAlerts) {
    alert_manager.triggerSensorFailure(mock_timestamp);
    alert_manager.triggerLowBattery(mock_timestamp + 1, 10.0f);
    alert_manager.resetAllAlerts();
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_TRUE(alert_manager.alerts_.empty());
}

// Test case: hasActiveAlerts 检查是否存在活动预警
TEST_F(AlertManagerTest, testHasActiveAlerts) {
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    alert_manager.triggerSensorFailure(mock_timestamp);
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
}

// Test case: hasUnacknowledgedAlerts 检查是否存在未确认预警
TEST_F(AlertManagerTest, testHasUnacknowledgedAlerts) {
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
    alert_manager.triggerSensorFailure(mock_timestamp);
    EXPECT_TRUE(alert_manager.hasUnacknowledgedAlerts());
    alert_manager.acknowledgeAllAlerts(mock_timestamp + 1);
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
}

// Test case: getActiveAlerts 返回活动预警列表
TEST_F(AlertManagerTest, testGetActiveAlerts) {
    alert_manager.triggerSensorFailure(mock_timestamp);
    alert_manager.triggerLowBattery(mock_timestamp + 1, 10.0f);
    auto alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 2);
    EXPECT_EQ(alerts[0].type, AlertType::SENSOR_FAILURE);
    EXPECT_EQ(alerts[1].type, AlertType::LOW_BATTERY);
}

// Test case: getAlertHistory 获取最近历史记录
TEST_F(AlertManagerTest, testGetAlertHistoryMaxCount) {
    for (int i = 0; i < 5; ++i) {
        alert_manager.triggerSensorFailure(mock_timestamp + i);
    }
    auto history = alert_manager.getAlertHistory(3);
    EXPECT_EQ(history.size(), 3);
    EXPECT_EQ(history[0].trigger_time, mock_timestamp + 2);
    EXPECT_EQ(history[2].trigger_time, mock_timestamp + 4);
}

// Test case: getStatusDescription 生成系统状态描述
TEST_F(AlertManagerTest, testGetStatusDescription) {
    alert_manager.triggerSensorFailure(mock_timestamp);
    std::string status_desc = alert_manager.getStatusDescription();
    EXPECT_NE(status_desc.find("系统状态：有1个活动预警"), std::string::npos);
    EXPECT_NE(status_desc.find("传感器故障"), std::string::npos);
}

// Test case: clearHistory 清空历史记录
TEST_F(AlertManagerTest, testClearHistory) {
    for (int i = 0; i < 5; ++i) {
        alert_manager.triggerSensorFailure(mock_timestamp + i);
    }
    alert_manager.clearHistory();
    EXPECT_TRUE(alert_manager.alert_history_.empty());
}

// Test case: addToHistory 添加预警到历史记录并限制数量
TEST_F(AlertManagerTest, testAddToHistoryLimit) {
    const size_t MAX_HISTORY = 10;
    for (int i = 0; i < MAX_HISTORY + 1; ++i) {
        alert_manager.triggerSensorFailure(mock_timestamp + i);
    }
    EXPECT_EQ(alert_manager.alert_history_.size(), MAX_HISTORY);
    EXPECT_EQ(alert_manager.alert_history_[0].trigger_time, mock_timestamp + 1);
    EXPECT_EQ(alert_manager.alert_history_[MAX_HISTORY - 1].trigger_time, mock_timestamp + MAX_HISTORY);
}

// Test case: triggerAlert 触发新预警并添加到历史
TEST_F(AlertManagerTest, testTriggerAlert) {
    alert_manager.triggerAlert(AlertType::ALTITUDE_UPPER, mock_timestamp, "测试预警");
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    auto alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].description, "测试预警");
    EXPECT_EQ(alert_manager.alert_history_.size(), 1);
}

// Test case: updateAlertStatus 更新预警状态并反馈
TEST_F(AlertManagerTest, testUpdateAlertStatus) {
    alert_manager.triggerSensorFailure(mock_timestamp);
    alert_manager.updateAlertStatus(AlertType::SENSOR_FAILURE, AlertStatus::ACKNOWLEDGED, mock_timestamp + 1);
    auto alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].status, AlertStatus::ACKNOWLEDGED);
}

// Test case: getAlertTypeName 转换预警类型名称
TEST_F(AlertManagerTest, testGetAlertTypeName) {
    EXPECT_EQ(alert_manager.getAlertTypeName(AlertType::ALTITUDE_UPPER), "高度上限预警");
    EXPECT_EQ(alert_manager.getAlertTypeName(AlertType::UNKNOWN), "未知预警");
}

// Test case: getAlertStatusName 转换预警状态名称
TEST_F(AlertManagerTest, testGetAlertStatusName) {
    EXPECT_EQ(alert_manager.getAlertStatusName(AlertStatus::ACTIVE), "预警中");
    EXPECT_EQ(alert_manager.getAlertStatusName(AlertStatus::UNKNOWN), "未知状态");
}