#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 getTimestamp function
uint32_t getTimestamp() {
    return mock_timestamp;
}

// Override the global getTimestamp to use mock
extern "C" uint32_t getTimestamp() {
    return mock_timestamp;
}

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

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

    void TearDown() override {
        // Clear any remaining alerts
        alert_manager.resetAllAlerts();
    }
};

// Test case: AlertManager 构造函数初始化默认阈值
TEST_F(AlertManagerTest, testAlertManagerConstructor) {
    EXPECT_FLOAT_EQ(alert_manager.getUpperThreshold(), 100.0f);
    EXPECT_FLOAT_EQ(alert_manager.getLowerThreshold(), -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, testAlertManagerDestructor) {
    // Destructor should not cause any observable side effects
    // Simply verify no crash occurs
    // This is implicitly tested by the test framework
    EXPECT_TRUE(true);
}

// Test case: initialize 输出初始化信息
TEST_F(AlertManagerTest, testInitializeOutput) {
    // Capture output
    std::ostringstream buffer;
    std::streambuf* old = std::cout.rdbuf(buffer.rdbuf());
    alert_manager.initialize();
    std::cout.rdbuf(old);

    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) {
    alert_manager.checkAltitudeAlert(50.0f, mock_timestamp);
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

// Test case: checkAltitudeAlert 触发上限预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertUpperThreshold) {
    alert_manager.checkAltitudeAlert(101.0f, 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);
    EXPECT_EQ(active_alerts[0].trigger_time, mock_timestamp);
}

// Test case: checkAltitudeAlert 触发下限预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertLowerThreshold) {
    alert_manager.checkAltitudeAlert(-51.0f, 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);
    EXPECT_EQ(active_alerts[0].trigger_time, mock_timestamp);
}

// Test case: checkAltitudeAlert 高度恢复正常解除预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertRecovery) {
    // Trigger upper threshold
    alert_manager.checkAltitudeAlert(101.0f, mock_timestamp);
    EXPECT_TRUE(alert_manager.hasActiveAlerts());

    // Return to normal
    alert_manager.checkAltitudeAlert(99.0f, mock_timestamp + 1);
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

// Test case: setAltitudeThresholds 合法阈值设置
TEST_F(AlertManagerTest, testSetAltitudeThresholdsValid) {
    alert_manager.setAltitudeThresholds(200.0f, -100.0f);
    EXPECT_FLOAT_EQ(alert_manager.getUpperThreshold(), 200.0f);
    EXPECT_FLOAT_EQ(alert_manager.getLowerThreshold(), -100.0f);
}

// Test case: setAltitudeThresholds 非法阈值设置（上界 <= 下界）
TEST_F(AlertManagerTest, testSetAltitudeThresholdsInvalid) {
    std::ostringstream buffer;
    std::streambuf* old = std::cerr.rdbuf(buffer.rdbuf());
    alert_manager.setAltitudeThresholds(50.0f, 100.0f);
    std::cerr.rdbuf(old);

    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);
    EXPECT_FLOAT_EQ(alert_manager.getUpperThreshold(), 100.0f); // Should remain unchanged
    EXPECT_FLOAT_EQ(alert_manager.getLowerThreshold(), -50.0f);
}

// Test case: triggerSensorFailure 触发传感器故障预警
TEST_F(AlertManagerTest, testTriggerSensorFailure) {
    alert_manager.triggerSensorFailure(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].status, AlertStatus::ACTIVE);
    EXPECT_EQ(active_alerts[0].trigger_time, mock_timestamp);
    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(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_EQ(active_alerts[0].status, AlertStatus::ACTIVE);
    EXPECT_EQ(active_alerts[0].trigger_time, mock_timestamp);
    EXPECT_EQ(active_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);
    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].status, AlertStatus::ACTIVE);
    EXPECT_EQ(active_alerts[0].trigger_time, mock_timestamp);
    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) {
    // Trigger multiple alerts
    alert_manager.triggerSensorFailure(mock_timestamp);
    alert_manager.triggerLowBattery(mock_timestamp + 1, 10.0f);
    alert_manager.triggerCommunicationError(mock_timestamp + 2);

    alert_manager.acknowledgeAllAlerts(mock_timestamp + 3);

    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_TRUE(active_alerts.empty());

    // Check that all were acknowledged
    auto alerts = alert_manager.getAlertHistory(10);
    EXPECT_EQ(alerts.size(), 3);
    for (const auto& alert : alerts) {
        EXPECT_EQ(alert.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 active_alerts = alert_manager.getActiveAlerts();
    EXPECT_TRUE(active_alerts.empty());

    auto history = alert_manager.getAlertHistory(10);
    EXPECT_EQ(history.size(), 1);
    EXPECT_EQ(history[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);

    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_TRUE(active_alerts.empty());

    auto history = alert_manager.getAlertHistory(10);
    EXPECT_EQ(history.size(), 1);
    EXPECT_EQ(history[0].status, AlertStatus::RESOLVED);
}

// 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_TRUE(alert_manager.getActiveAlerts().empty());
    EXPECT_TRUE(alert_manager.getAlertHistory(10).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());

    alert_manager.resetAlert(AlertType::SENSOR_FAILURE);
    EXPECT_FALSE(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.acknowledgeAlert(AlertType::SENSOR_FAILURE, mock_timestamp + 1);
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
}

// Test case: getActiveAlerts 获取活动预警列表
TEST_F(AlertManagerTest, testGetActiveAlerts) {
    alert_manager.triggerSensorFailure(mock_timestamp);
    alert_manager.triggerLowBattery(mock_timestamp + 1, 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 获取历史记录（最大数量限制）
TEST_F(AlertManagerTest, testGetAlertHistoryMaxCount) {
    // Add more than MAX_HISTORY alerts
    for (int i = 0; i < 15; ++i) {
        alert_manager.triggerSensorFailure(mock_timestamp + i);
    }

    auto history = alert_manager.getAlertHistory(10);
    EXPECT_EQ(history.size(), 10);
    EXPECT_EQ(history[0].trigger_time, mock_timestamp + 5);
    EXPECT_EQ(history[9].trigger_time, mock_timestamp + 14);
}

// Test case: getStatusDescription 生成系统状态描述
TEST_F(AlertManagerTest, testGetStatusDescription) {
    alert_manager.triggerSensorFailure(mock_timestamp);
    alert_manager.triggerLowBattery(mock_timestamp + 1, 10.0f);

    std::string status_desc = alert_manager.getStatusDescription();
    EXPECT_NE(status_desc.find("有2个活动预警"), std::string::npos);
    EXPECT_NE(status_desc.find("传感器故障"), std::string::npos);
    EXPECT_NE(status_desc.find("低电量警告"), std::string::npos);
}

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

// Test case: addToHistory 添加历史记录并保持最大数量限制
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 = 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, mock_timestamp + 1);
    EXPECT_EQ(history[max_history - 1].trigger_time, mock_timestamp + max_history);
}

// Test case: triggerAlert 内部方法触发预警
TEST_F(AlertManagerTest, testTriggerAlertInternal) {
    alert_manager.triggerAlert(AlertType::ALTITUDE_UPPER, 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, testUpdateAlertStatusAcknowledged) {
    alert_manager.triggerSensorFailure(mock_timestamp);
    alert_manager.updateAlertStatus(AlertType::SENSOR_FAILURE, AlertStatus::ACKNOWLEDGED, mock_timestamp + 1);

    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_TRUE(active_alerts.empty());

    auto history = alert_manager.getAlertHistory(10);
    EXPECT_EQ(history.size(), 1);
    EXPECT_EQ(history[0].status, AlertStatus::ACKNOWLEDGED);
}

// Test case: updateAlertStatus 更新预警状态为已解决
TEST_F(AlertManagerTest, testUpdateAlertStatusResolved) {
    alert_manager.triggerSensorFailure(mock_timestamp);
    alert_manager.updateAlertStatus(AlertType::SENSOR_FAILURE, AlertStatus::RESOLVED, mock_timestamp + 1);

    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_TRUE(active_alerts.empty());

    auto history = alert_manager.getAlertHistory(10);
    EXPECT_EQ(history.size(), 1);
    EXPECT_EQ(history[0].status, AlertStatus::RESOLVED);
}

// 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::SENSOR_FAILURE), "传感器故障");
    EXPECT_EQ(alert_manager.getAlertTypeName(AlertType::NONE), "无");
}

// 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::ACKNOWLEDGED), "已确认");
    EXPECT_EQ(alert_manager.getAlertStatusName(AlertStatus::RESOLVED), "已解决");
}

// Test case: getUpperThreshold 获取上限阈值
TEST_F(AlertManagerTest, testGetUpperThreshold) {
    EXPECT_FLOAT_EQ(alert_manager.getUpperThreshold(), 100.0f);
    alert_manager.setAltitudeThresholds(200.0f, -100.0f);
    EXPECT_FLOAT_EQ(alert_manager.getUpperThreshold(), 200.0f);
}

// Test case: getLowerThreshold 获取下限阈值
TEST_F(AlertManagerTest, testGetLowerThreshold) {
    EXPECT_FLOAT_EQ(alert_manager.getLowerThreshold(), -50.0f);
    alert_manager.setAltitudeThresholds(200.0f, -100.0f);
    EXPECT_FLOAT_EQ(alert_manager.getLowerThreshold(), -100.0f);
}