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

// 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 AlertManager
namespace {
    uint32_t get_current_timestamp() {
        return get_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: 构造函数初始化默认阈值和容器
TEST_F(AlertManagerTest, testAlertManagerConstructor) {
    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: 析构函数自动清理资源
TEST_F(AlertManagerTest, testAlertManagerDestructor) {
    // Destructor is implicitly tested by scope cleanup
    // No explicit assertion needed as it's a simple cleanup
    EXPECT_TRUE(true); // Placeholder to ensure test passes
}

// Test case: initialize 输出默认阈值信息
TEST_F(AlertManagerTest, testInitializeOutput) {
    // Capture output using a mock stream
    std::ostringstream buffer;
    std::streambuf* orig = std::cout.rdbuf();
    std::cout.rdbuf(buffer.rdbuf());

    alert_manager.initialize();

    std::cout.rdbuf(orig);

    std::string output = buffer.str();
    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"), std::string::npos);
    EXPECT_NE(output.find("下限=-50米"), std::string::npos);
}

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

// Test case: checkAltitudeAlert 触发高度上限预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertUpperThreshold) {
    float altitude = 101.0f;
    alert_manager.checkAltitudeAlert(altitude, get_mock_timestamp());
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    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 触发高度下限预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertLowerThreshold) {
    float altitude = -51.0f;
    alert_manager.checkAltitudeAlert(altitude, get_mock_timestamp());
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    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 高度恢复正常解除预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertResolution) {
    float high_altitude = 101.0f;
    float normal_altitude = 99.0f;

    alert_manager.checkAltitudeAlert(high_altitude, get_mock_timestamp());
    EXPECT_TRUE(alert_manager.hasActiveAlerts());

    alert_manager.checkAltitudeAlert(normal_altitude, get_mock_timestamp());
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

// Test case: setAltitudeThresholds 合法阈值设置成功
TEST_F(AlertManagerTest, testSetAltitudeThresholdsValid) {
    alert_manager.setAltitudeThresholds(150.0f, -100.0f);
    auto thresholds = alert_manager.getAltitudeThresholds();
    EXPECT_FLOAT_EQ(thresholds.first, 150.0f);
    EXPECT_FLOAT_EQ(thresholds.second, -100.0f);
}

// Test case: setAltitudeThresholds 非法阈值（上界 <= 下界）
TEST_F(AlertManagerTest, testSetAltitudeThresholdsInvalid) {
    std::ostringstream buffer;
    std::streambuf* orig = std::cerr.rdbuf();
    std::cerr.rdbuf(buffer.rdbuf());

    alert_manager.setAltitudeThresholds(50.0f, 100.0f);

    std::cerr.rdbuf(orig);
    std::string error_output = buffer.str();
    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());
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    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) {
    float battery_level = 15.0f;
    alert_manager.triggerLowBattery(get_mock_timestamp(), battery_level);
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 1);
    EXPECT_EQ(active_alerts[0].type, AlertType::LOW_BATTERY);
    EXPECT_EQ(active_alerts[0].description, "低电量警告：当前电量15%");
}

// Test case: triggerCommunicationError 触发通信错误预警
TEST_F(AlertManagerTest, testTriggerCommunicationError) {
    alert_manager.triggerCommunicationError(get_mock_timestamp());
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    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);

    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    EXPECT_TRUE(alert_manager.hasUnacknowledgedAlerts());

    alert_manager.acknowledgeAllAlerts(get_mock_timestamp());

    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 2);
    EXPECT_EQ(active_alerts[0].status, AlertStatus::ACKNOWLEDGED);
    EXPECT_EQ(active_alerts[1].status, AlertStatus::ACKNOWLEDGED);
}

// Test case: acknowledgeAlert 确认指定类型预警
TEST_F(AlertManagerTest, testAcknowledgeAlert) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    EXPECT_TRUE(alert_manager.hasActiveAlerts());

    alert_manager.acknowledgeAlert(AlertType::SENSOR_FAILURE, get_mock_timestamp());

    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 1);
    EXPECT_EQ(active_alerts[0].status, AlertStatus::ACKNOWLEDGED);
}

// Test case: acknowledgeAlert 无效类型不处理
TEST_F(AlertManagerTest, testAcknowledgeAlertInvalidType) {
    alert_manager.acknowledgeAlert(AlertType::NONE, get_mock_timestamp());
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

// Test case: resetAlert 重置指定类型的预警
TEST_F(AlertManagerTest, testResetAlert) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    EXPECT_TRUE(alert_manager.hasActiveAlerts());

    alert_manager.resetAlert(AlertType::SENSOR_FAILURE);
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_TRUE(alert_manager.alerts_.empty());
}

// Test case: resetAllAlerts 重置所有活动预警
TEST_F(AlertManagerTest, testResetAllAlerts) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    alert_manager.triggerLowBattery(get_mock_timestamp(), 10.0f);

    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    EXPECT_TRUE(alert_manager.hasUnacknowledgedAlerts());

    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, testHasActiveAlertsNoAlerts) {
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

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

// Test case: hasUnacknowledgedAlerts 检查未确认的活动预警
TEST_F(AlertManagerTest, testHasUnacknowledgedAlerts) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    EXPECT_TRUE(alert_manager.hasUnacknowledgedAlerts());
}

// Test case: hasUnacknowledgedAlerts 确认后无未确认预警
TEST_F(AlertManagerTest, testHasUnacknowledgedAlertsAfterAcknowledge) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    alert_manager.acknowledgeAllAlerts(get_mock_timestamp());
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
}

// Test case: getActiveAlerts 获取所有活动预警信息
TEST_F(AlertManagerTest, testGetActiveAlerts) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    alert_manager.triggerLowBattery(get_mock_timestamp(), 10.0f);

    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 2);
    EXPECT_EQ(active_alerts[0].type, AlertType::SENSOR_FAILURE);
    EXPECT_EQ(active_alerts[1].type, AlertType::LOW_BATTERY);
}

// Test case: getAlertHistory 获取最近预警历史记录
TEST_F(AlertManagerTest, testGetAlertHistoryMaxCount) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    alert_manager.triggerLowBattery(get_mock_timestamp(), 10.0f);

    auto history = alert_manager.getAlertHistory(1);
    EXPECT_EQ(history.size(), 1);
    EXPECT_EQ(history[0].type, AlertType::LOW_BATTERY);
}

// Test case: getAlertHistory 历史记录为空时返回空向量
TEST_F(AlertManagerTest, testGetAlertHistoryEmpty) {
    auto history = alert_manager.getAlertHistory(5);
    EXPECT_TRUE(history.empty());
}

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

// Test case: getStatusDescription 包含活动预警描述
TEST_F(AlertManagerTest, testGetStatusDescriptionWithAlerts) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    std::string status_desc = alert_manager.getStatusDescription();
    EXPECT_NE(status_desc.find("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 清空预警历史记录
TEST_F(AlertManagerTest, testClearHistory) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    alert_manager.clearHistory();
    EXPECT_TRUE(alert_manager.alert_history_.empty());
}

// Test case: addToHistory 添加预警至历史记录并限制数量
TEST_F(AlertManagerTest, testAddToHistoryLimit) {
    const size_t MAX_HISTORY = 5;
    for (int i = 0; i < MAX_HISTORY + 1; ++i) {
        AlertInfo alert;
        alert.type = AlertType::SENSOR_FAILURE;
        alert.status = AlertStatus::ACTIVE;
        alert.trigger_time = static_cast<uint32_t>(get_mock_timestamp() + i);
        alert.description = "Test alert";
        alert_manager.addToHistory(alert);
    }
    EXPECT_EQ(alert_manager.alert_history_.size(), MAX_HISTORY);
}

// Test case: triggerAlert 触发新预警并添加到历史记录
TEST_F(AlertManagerTest, testTriggerAlert) {
    alert_manager.triggerAlert(AlertType::ALTITUDE_UPPER, get_mock_timestamp(), "Test description");
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    EXPECT_EQ(alert_manager.alert_history_.size(), 1);
    EXPECT_EQ(alert_manager.alert_history_[0].description, "Test description");
}

// Test case: updateAlertStatus 更新预警状态并反馈
TEST_F(AlertManagerTest, testUpdateAlertStatus) {
    alert_manager.triggerSensorFailure(get_mock_timestamp());
    auto& alert = alert_manager.alerts_[AlertType::SENSOR_FAILURE];
    EXPECT_EQ(alert.status, AlertStatus::ACTIVE);

    alert_manager.updateAlertStatus(AlertType::SENSOR_FAILURE, AlertStatus::ACKNOWLEDGED, get_mock_timestamp());
    EXPECT_EQ(alert.status, AlertStatus::ACKNOWLEDGED);
}

// Test case: getAlertTypeName 获取预警类型名称
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 获取预警状态名称
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");
}