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

// Mock for time to ensure deterministic tests
static uint32_t mock_timestamp = 1640995200; // 2022-01-01 00:00:00 UTC

class MockTime { 
public:
    static uint32_t getTimestamp() { return mock_timestamp; }
    static void setTimestamp(uint32_t t) { mock_timestamp = t; }
};

// Helper function to compare AlertInfo
bool operator==(const AlertInfo& a, const AlertInfo& b) {
    return a.type == b.type &&
           a.status == b.status &&
           a.trigger_time == b.trigger_time &&
           a.acknowledge_time == b.acknowledge_time &&
           a.resolve_time == b.resolve_time &&
           a.description == b.description;
}

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

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

    void TearDown() override {
        manager.clearHistory();
    }
};

TEST_F(AlertManagerTest, testAlertManagerDefaultInitialization) {
    EXPECT_FLOAT_EQ(manager.getAltitudeThresholds().first, 100.0f);
    EXPECT_FLOAT_EQ(manager.getAltitudeThresholds().second, -50.0f);
    EXPECT_TRUE(manager.getActiveAlerts().empty());
    EXPECT_TRUE(manager.getAlertHistory(10).empty());
}

TEST_F(AlertManagerTest, testInitialize) {
    // No direct output assertion, but verify initialization logic
    // This is tested implicitly via constructor
    EXPECT_NO_FATAL_FAILURE(manager.initialize());
}

TEST_F(AlertManagerTest, testCheckAltitudeAlertNormal) {
    mock_timestamp = 1640995200;
    manager.checkAltitudeAlert(105.0f, mock_timestamp);
    auto alerts = manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].type, AlertType::ALTITUDE_UPPER);
    EXPECT_EQ(alerts[0].status, AlertStatus::ACTIVE);
    EXPECT_EQ(alerts[0].trigger_time, mock_timestamp);
}

TEST_F(AlertManagerTest, testCheckAltitudeAlertBelowLower) {
    mock_timestamp = 1640995200;
    manager.checkAltitudeAlert(-55.0f, mock_timestamp);
    auto alerts = manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].type, AlertType::ALTITUDE_LOWER);
    EXPECT_EQ(alerts[0].status, AlertStatus::ACTIVE);
}

TEST_F(AlertManagerTest, testCheckAltitudeAlertResetWhenNormal) {
    mock_timestamp = 1640995200;
    manager.checkAltitudeAlert(105.0f, mock_timestamp); // Trigger upper
    mock_timestamp = 1640995201;
    manager.checkAltitudeAlert(90.0f, mock_timestamp); // Reset
    auto alerts = manager.getActiveAlerts();
    EXPECT_TRUE(alerts.empty());
}

TEST_F(AlertManagerTest, testSetAltitudeThresholdsValid) {
    manager.setAltitudeThresholds(200.0f, -100.0f);
    auto thresholds = manager.getAltitudeThresholds();
    EXPECT_FLOAT_EQ(thresholds.first, 200.0f);
    EXPECT_FLOAT_EQ(thresholds.second, -100.0f);
}

TEST_F(AlertManagerTest, testSetAltitudeThresholdsInvalid) {
    EXPECT_NO_FATAL_FAILURE(manager.setAltitudeThresholds(50.0f, 100.0f));
    // Should print error, but no crash
    EXPECT_FLOAT_EQ(manager.getAltitudeThresholds().first, 100.0f);
    EXPECT_FLOAT_EQ(manager.getAltitudeThresholds().second, -50.0f);
}

TEST_F(AlertManagerTest, testTriggerSensorFailure) {
    mock_timestamp = 1640995200;
    manager.triggerSensorFailure(mock_timestamp);
    auto alerts = manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].type, AlertType::SENSOR_FAILURE);
    EXPECT_EQ(alerts[0].status, AlertStatus::ACTIVE);
    EXPECT_EQ(alerts[0].trigger_time, mock_timestamp);
}

TEST_F(AlertManagerTest, testTriggerLowBattery) {
    mock_timestamp = 1640995200;
    manager.triggerLowBattery(mock_timestamp, 15.0f);
    auto alerts = manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].type, AlertType::LOW_BATTERY);
    EXPECT_EQ(alerts[0].status, AlertStatus::ACTIVE);
    EXPECT_NE(alerts[0].description.find("15.0%"), std::string::npos);
}

TEST_F(AlertManagerTest, testTriggerCommunicationError) {
    mock_timestamp = 1640995200;
    manager.triggerCommunicationError(mock_timestamp);
    auto alerts = manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].type, AlertType::COMMUNICATION_ERROR);
    EXPECT_EQ(alerts[0].status, AlertStatus::ACTIVE);
}

TEST_F(AlertManagerTest, testAcknowledgeAllAlerts) {
    mock_timestamp = 1640995200;
    manager.triggerSensorFailure(mock_timestamp);
    manager.triggerLowBattery(mock_timestamp + 1, 10.0f);
    mock_timestamp = 1640995202;
    manager.acknowledgeAllAlerts(mock_timestamp);
    auto alerts = manager.getActiveAlerts();
    EXPECT_TRUE(alerts.empty());
    EXPECT_EQ(alerts.size(), 0);
}

TEST_F(AlertManagerTest, testAcknowledgeAlert) {
    mock_timestamp = 1640995200;
    manager.triggerSensorFailure(mock_timestamp);
    mock_timestamp = 1640995201;
    manager.acknowledgeAlert(AlertType::SENSOR_FAILURE, mock_timestamp);
    auto alerts = manager.getActiveAlerts();
    EXPECT_TRUE(alerts.empty());
}

TEST_F(AlertManagerTest, testResetAlert) {
    mock_timestamp = 1640995200;
    manager.triggerSensorFailure(mock_timestamp);
    manager.resetAlert(AlertType::SENSOR_FAILURE);
    auto alerts = manager.getActiveAlerts();
    EXPECT_TRUE(alerts.empty());
}

TEST_F(AlertManagerTest, testResetAllAlerts) {
    mock_timestamp = 1640995200;
    manager.triggerSensorFailure(mock_timestamp);
    manager.triggerLowBattery(mock_timestamp + 1, 10.0f);
    manager.resetAllAlerts();
    auto alerts = manager.getActiveAlerts();
    EXPECT_TRUE(alerts.empty());
}

TEST_F(AlertManagerTest, testHasActiveAlerts) {
    EXPECT_FALSE(manager.hasActiveAlerts());
    mock_timestamp = 1640995200;
    manager.triggerSensorFailure(mock_timestamp);
    EXPECT_TRUE(manager.hasActiveAlerts());
}

TEST_F(AlertManagerTest, testHasUnacknowledgedAlerts) {
    EXPECT_FALSE(manager.hasUnacknowledgedAlerts());
    mock_timestamp = 1640995200;
    manager.triggerSensorFailure(mock_timestamp);
    EXPECT_TRUE(manager.hasUnacknowledgedAlerts());
    manager.acknowledgeAllAlerts(mock_timestamp + 1);
    EXPECT_FALSE(manager.hasUnacknowledgedAlerts());
}

TEST_F(AlertManagerTest, testGetActiveAlerts) {
    mock_timestamp = 1640995200;
    manager.triggerSensorFailure(mock_timestamp);
    auto alerts = manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].type, AlertType::SENSOR_FAILURE);
}

TEST_F(AlertManagerTest, testGetAlertHistoryMaxCount) {
    mock_timestamp = 1640995200;
    for (int i = 0; i < 15; ++i) {
        manager.triggerSensorFailure(mock_timestamp + i);
    }
    auto history = manager.getAlertHistory(10);
    EXPECT_EQ(history.size(), 10);
}

TEST_F(AlertManagerTest, testGetStatusDescriptionNoAlerts) {
    std::string desc = manager.getStatusDescription();
    EXPECT_EQ(desc, "系统状态：正常");
}

TEST_F(AlertManagerTest, testGetStatusDescriptionWithAlerts) {
    mock_timestamp = 1640995200;
    manager.triggerSensorFailure(mock_timestamp);
    std::string desc = manager.getStatusDescription();
    EXPECT_NE(desc.find("有1个活动预警"), std::string::npos);
    EXPECT_NE(desc.find("传感器故障"), std::string::npos);
}

TEST_F(AlertManagerTest, testClearHistory) {
    mock_timestamp = 1640995200;
    manager.triggerSensorFailure(mock_timestamp);
    manager.clearHistory();
    EXPECT_TRUE(manager.getAlertHistory(10).empty());
}

TEST_F(AlertManagerTest, testAddToHistoryLimit) {
    mock_timestamp = 1640995200;
    for (int i = 0; i < 100; ++i) {
        manager.triggerSensorFailure(mock_timestamp + i);
    }
    auto history = manager.getAlertHistory(10);
    EXPECT_EQ(history.size(), 10);
}

TEST_F(AlertManagerTest, testTriggerAlert) {
    mock_timestamp = 1640995200;
    manager.triggerAlert(AlertType::SENSOR_FAILURE, mock_timestamp, "Test alert");
    auto alerts = manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].description, "Test alert");
}

TEST_F(AlertManagerTest, testUpdateAlertStatusAcknowledged) {
    mock_timestamp = 1640995200;
    manager.triggerSensorFailure(mock_timestamp);
    mock_timestamp = 1640995201;
    manager.updateAlertStatus(AlertType::SENSOR_FAILURE, AlertStatus::ACKNOWLEDGED, mock_timestamp);
    auto alerts = manager.getActiveAlerts();
    EXPECT_TRUE(alerts.empty());
}

TEST_F(AlertManagerTest, testUpdateAlertStatusResolved) {
    mock_timestamp = 1640995200;
    manager.triggerSensorFailure(mock_timestamp);
    mock_timestamp = 1640995201;
    manager.updateAlertStatus(AlertType::SENSOR_FAILURE, AlertStatus::RESOLVED, mock_timestamp);
    auto alerts = manager.getActiveAlerts();
    EXPECT_TRUE(alerts.empty());
}

TEST_F(AlertManagerTest, testGetAlertTypeName) {
    EXPECT_EQ(manager.getAlertTypeName(AlertType::ALTITUDE_UPPER), "高度上限预警");
    EXPECT_EQ(manager.getAlertTypeName(AlertType::NONE), "无");
    EXPECT_EQ(manager.getAlertTypeName(static_cast<AlertType>(99)), "未知预警");
}

TEST_F(AlertManagerTest, testGetAlertStatusName) {
    EXPECT_EQ(manager.getAlertStatusName(AlertStatus::ACTIVE), "预警中");
    EXPECT_EQ(manager.getAlertStatusName(AlertStatus::INACTIVE), "未激活");
    EXPECT_EQ(manager.getAlertStatusName(static_cast<AlertStatus>(99)), "未知状态");
}

TEST_F(AlertManagerTest, testDestructorDoesNotCrash) {
    // Verify destructor doesn't throw or crash
    EXPECT_NO_FATAL_FAILURE({
        AlertManager* mgr = new AlertManager();
        delete mgr;
    });
}