#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 the time function
uint32_t get_mock_timestamp() {
    return mock_timestamp;
}

// Override the global time function in alert_manager.cpp
extern "C" 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, testAlertManagerConstructorDefaultThresholds) {
    EXPECT_FLOAT_EQ(alert_manager.getAltitudeThresholds().first, 100.0f);
    EXPECT_FLOAT_EQ(alert_manager.getAltitudeThresholds().second, -50.0f);
    EXPECT_TRUE(alert_manager.getActiveAlerts().empty());
    EXPECT_TRUE(alert_manager.getAlertHistory(10).empty());
}

// Test case: AlertManager 析构函数无副作用
TEST_F(AlertManagerTest, testAlertManagerDestructorNoSideEffects) {
    // Destructor should not throw or cause undefined behavior
    // Simply verify it can be called without issues
    AlertManager temp_manager;
    // No assertion needed as destructor is trivial
}

// Test case: initialize 输出初始化信息
TEST_F(AlertManagerTest, testInitializeOutputInfo) {
    // 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 高度正常时无预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertNormalHeight) {
    alert_manager.checkAltitudeAlert(50.0f, get_mock_timestamp());
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

// Test case: checkAltitudeAlert 超过上限触发预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertUpperThresholdTrigger) {
    alert_manager.checkAltitudeAlert(101.0f, get_mock_timestamp());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 1);
    EXPECT_EQ(active_alerts[0].type, AlertType::ALTITUDE_UPPER);
    EXPECT_EQ(active_alerts[0].status, AlertStatus::ACTIVE);
}

// Test case: checkAltitudeAlert 低于下限触发预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertLowerThresholdTrigger) {
    alert_manager.checkAltitudeAlert(-51.0f, get_mock_timestamp());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 1);
    EXPECT_EQ(active_alerts[0].type, AlertType::ALTITUDE_LOWER);
    EXPECT_EQ(active_alerts[0].status, AlertStatus::ACTIVE);
}

// Test case: checkAltitudeAlert 上限恢复正常解除预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertUpperThresholdResolve) {
    alert_manager.checkAltitudeAlert(101.0f, get_mock_timestamp());
    alert_manager.checkAltitudeAlert(99.0f, get_mock_timestamp());
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

// Test case: checkAltitudeAlert 下限恢复正常解除预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertLowerThresholdResolve) {
    alert_manager.checkAltitudeAlert(-51.0f, get_mock_timestamp());
    alert_manager.checkAltitudeAlert(-49.0f, get_mock_timestamp());
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

// Test case: setAltitudeThresholds 合法输入更新阈值
TEST_F(AlertManagerTest, testSetAltitudeThresholdsValidInput) {
    alert_manager.setAltitudeThresholds(200.0f, -100.0f);
    auto thresholds = alert_manager.getAltitudeThresholds();
    EXPECT_FLOAT_EQ(thresholds.first, 200.0f);
    EXPECT_FLOAT_EQ(thresholds.second, -100.0f);
}

// Test case: setAltitudeThresholds 非法输入（上限 <= 下限）
TEST_F(AlertManagerTest, testSetAltitudeThresholdsInvalidInput) {
    // Capture stderr
    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(get_mock_timestamp());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 1);
    EXPECT_EQ(active_alerts[0].type, AlertType::SENSOR_FAILURE);
    EXPECT_EQ(active_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(get_mock_timestamp(), 15.5f);
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 1);
    EXPECT_EQ(active_alerts[0].type, AlertType::LOW_BATTERY);
    EXPECT_NE(active_alerts[0].description.find("低电量警告：当前电量15.5%"), std::string::npos);
}

// Test case: triggerCommunicationError 触发通信错误预警
TEST_F(AlertManagerTest, testTriggerCommunicationError) {
    alert_manager.triggerCommunicationError(get_mock_timestamp());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 1);
    EXPECT_EQ(active_alerts[0].type, AlertType::COMMUNICATION_ERROR);
    EXPECT_EQ(active_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(get_mock_timestamp());
    alert_manager.triggerLowBattery(get_mock_timestamp(), 10.0f);
    alert_manager.acknowledgeAllAlerts(get_mock_timestamp());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_TRUE(active_alerts.empty());
    EXPECT_TRUE(alert_manager.hasUnacknowledgedAlerts());
}

// Test case: acknowledgeAlert 确认指定类型预警
TEST_F(AlertManagerTest, testAcknowledgeAlertSpecificType) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    alert_manager.acknowledgeAlert(AlertType::SENSOR_FAILURE, get_mock_timestamp());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_TRUE(active_alerts.empty());
}

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

// Test case: resetAllAlerts 清除所有活动预警
TEST_F(AlertManagerTest, testResetAllAlertsClearAll) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    alert_manager.triggerLowBattery(get_mock_timestamp(), 10.0f);
    alert_manager.resetAllAlerts();
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_TRUE(alert_manager.getAlertHistory(10).size() >= 2);
}

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

// Test case: hasActiveAlerts 检查存在活动预警
TEST_F(AlertManagerTest, testHasActiveAlertsWhenAlertsExist) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
}

// Test case: hasUnacknowledgedAlerts 检查未确认预警
TEST_F(AlertManagerTest, testHasUnacknowledgedAlertsWhenActive) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    EXPECT_TRUE(alert_manager.hasUnacknowledgedAlerts());
}

// Test case: hasUnacknowledgedAlerts 检查已确认预警
TEST_F(AlertManagerTest, testHasUnacknowledgedAlertsWhenAcknowledged) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    alert_manager.acknowledgeAlert(AlertType::SENSOR_FAILURE, get_mock_timestamp());
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
}

// Test case: getActiveAlerts 返回活动预警列表
TEST_F(AlertManagerTest, testGetActiveAlertsReturnsCorrectList) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    alert_manager.triggerLowBattery(get_mock_timestamp(), 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) {
    // Add multiple alerts
    for (int i = 0; i < 5; ++i) {
        alert_manager.triggerSensorFailure(get_mock_timestamp() + i);
    }
    auto history = alert_manager.getAlertHistory(3);
    EXPECT_EQ(history.size(), 3);
    EXPECT_EQ(history[0].trigger_time, get_mock_timestamp() + 4);
}

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

// Test case: getStatusDescription 生成系统正常状态描述
TEST_F(AlertManagerTest, testGetStatusDescriptionNormalState) {
    std::string status = alert_manager.getStatusDescription();
    EXPECT_EQ(status, "系统状态：正常");
}

// Test case: clearHistory 清空历史记录
TEST_F(AlertManagerTest, testClearHistoryClearsAll) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    alert_manager.clearHistory();
    EXPECT_TRUE(alert_manager.getAlertHistory(10).empty());
}

// Test case: addToHistory 添加预警到历史记录并限制数量
TEST_F(AlertManagerTest, testAddToHistoryLimitSize) {
    const size_t max_history = 5;
    // Simulate adding more than max_history entries
    for (int i = 0; i < max_history + 2; ++i) {
        AlertInfo alert;
        alert.type = AlertType::SENSOR_FAILURE;
        alert.status = AlertStatus::ACTIVE;
        alert.trigger_time = get_mock_timestamp() + i;
        alert.description = "Test alert";
        alert_manager.addToHistory(alert);
    }
    auto history = alert_manager.getAlertHistory(max_history);
    EXPECT_EQ(history.size(), max_history);
    EXPECT_EQ(history[0].trigger_time, get_mock_timestamp() + max_history + 1);
}

// Test case: triggerAlert 内部方法触发新预警
TEST_F(AlertManagerTest, testTriggerAlertInternalMethod) {
    alert_manager.triggerAlert(AlertType::ALTITUDE_UPPER, get_mock_timestamp(), "Test description");
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 1);
    EXPECT_EQ(active_alerts[0].type, AlertType::ALTITUDE_UPPER);
    EXPECT_EQ(active_alerts[0].description, "Test description");
}

// Test case: updateAlertStatus 更新预警状态为已确认
TEST_F(AlertManagerTest, testUpdateAlertStatusAcknowledge) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    alert_manager.updateAlertStatus(AlertType::SENSOR_FAILURE, AlertStatus::ACKNOWLEDGED, get_mock_timestamp());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_TRUE(active_alerts.empty());
}

// Test case: updateAlertStatus 更新预警状态为已解决
TEST_F(AlertManagerTest, testUpdateAlertStatusResolve) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    alert_manager.updateAlertStatus(AlertType::SENSOR_FAILURE, AlertStatus::RESOLVED, get_mock_timestamp());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_TRUE(active_alerts.empty());
}

// Test case: getAlertTypeName 返回正确名称
TEST_F(AlertManagerTest, testGetAlertTypeName) {
    EXPECT_EQ(AlertManager::getAlertTypeName(AlertType::ALTITUDE_UPPER), "高度上限预警");
    EXPECT_EQ(AlertManager::getAlertTypeName(AlertType::UNKNOWN), "未知预警");
}

// Test case: getAlertStatusName 返回正确状态名
TEST_F(AlertManagerTest, testGetAlertStatusName) {
    EXPECT_EQ(AlertManager::getAlertStatusName(AlertStatus::ACTIVE), "预警中");
    EXPECT_EQ(AlertManager::getAlertStatusName(AlertStatus::UNKNOWN), "未知状态");
}