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

using namespace std;

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

// Mock function to replace std::time()
uint32_t getMockTime() {
    return mock_timestamp;
}

// Override the global time function in AlertManager
void setMockTime(uint32_t time) {
    mock_timestamp = time;
}

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

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

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

// Test checkAltitudeAlert - Normal Input
TEST_F(AlertManagerTest, testCheckAltitudeAlertNormalInput) {
    // Given: Altitude within normal range
    float altitude = 80.0f;
    uint32_t timestamp = getMockTime();

    // When: Check altitude alert
    alert_manager.checkAltitudeAlert(altitude, timestamp);

    // Then: No alert should be triggered
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

// Test checkAltitudeAlert - Upper Threshold Exceeded
TEST_F(AlertManagerTest, testCheckAltitudeAlertUpperThresholdExceeded) {
    // Given: Altitude exceeds upper threshold
    float altitude = 101.0f; // Above default 100.0f
    uint32_t timestamp = getMockTime();

    // When: Check altitude alert
    alert_manager.checkAltitudeAlert(altitude, timestamp);

    // Then: Upper altitude alert should be active
    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 checkAltitudeAlert - Lower Threshold Exceeded
TEST_F(AlertManagerTest, testCheckAltitudeAlertLowerThresholdExceeded) {
    // Given: Altitude below lower threshold
    float altitude = -51.0f; // Below default -50.0f
    uint32_t timestamp = getMockTime();

    // When: Check altitude alert
    alert_manager.checkAltitudeAlert(altitude, timestamp);

    // Then: Lower altitude alert should be active
    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 checkAltitudeAlert - Recovery from Upper Threshold
TEST_F(AlertManagerTest, testCheckAltitudeAlertRecoveryFromUpperThreshold) {
    // Given: Initially exceed upper threshold
    float altitude = 101.0f;
    uint32_t timestamp = getMockTime();
    alert_manager.checkAltitudeAlert(altitude, timestamp);

    // When: Return to normal range
    altitude = 99.0f;
    alert_manager.checkAltitudeAlert(altitude, timestamp + 1);

    // Then: Alert should be resolved
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
}

// Test checkAltitudeAlert - Recovery from Lower Threshold
TEST_F(AlertManagerTest, testCheckAltitudeAlertRecoveryFromLowerThreshold) {
    // Given: Initially below lower threshold
    float altitude = -51.0f;
    uint32_t timestamp = getMockTime();
    alert_manager.checkAltitudeAlert(altitude, timestamp);

    // When: Return to normal range
    altitude = -49.0f;
    alert_manager.checkAltitudeAlert(altitude, timestamp + 1);

    // Then: Alert should be resolved
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
}

// Test setAltitudeThresholds - Valid Thresholds
TEST_F(AlertManagerTest, testSetAltitudeThresholdsValidThresholds) {
    // Given: Valid upper and lower thresholds
    float upper = 150.0f;
    float lower = -100.0f;

    // When: Set thresholds
    alert_manager.setAltitudeThresholds(upper, lower);

    // Then: Thresholds should be updated
    EXPECT_EQ(alert_manager.getAltitudeThresholds().first, upper);
    EXPECT_EQ(alert_manager.getAltitudeThresholds().second, lower);
}

// Test setAltitudeThresholds - Invalid Thresholds (upper <= lower)
TEST_F(AlertManagerTest, testSetAltitudeThresholdsInvalidThresholds) {
    // Given: Invalid thresholds
    float upper = 50.0f;
    float lower = 100.0f;

    // When: Set thresholds
    alert_manager.setAltitudeThresholds(upper, lower);

    // Then: Should not update and print error
    EXPECT_EQ(alert_manager.getAltitudeThresholds().first, 100.0f);
    EXPECT_EQ(alert_manager.getAltitudeThresholds().second, -50.0f);
}

// Test triggerSensorFailure - Normal Trigger
TEST_F(AlertManagerTest, testTriggerSensorFailureNormalTrigger) {
    // Given: Timestamp
    uint32_t timestamp = getMockTime();

    // When: Trigger sensor failure
    alert_manager.triggerSensorFailure(timestamp);

    // Then: Sensor failure alert should be active
    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].status, AlertStatus::ACTIVE);
    EXPECT_EQ(active_alerts[0].description, "传感器故障");
}

// Test triggerLowBattery - Normal Trigger
TEST_F(AlertManagerTest, testTriggerLowBatteryNormalTrigger) {
    // Given: Timestamp and battery level
    uint32_t timestamp = getMockTime();
    float battery_level = 15.0f;

    // When: Trigger low battery
    alert_manager.triggerLowBattery(timestamp, battery_level);

    // Then: Low battery alert should be active
    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].status, AlertStatus::ACTIVE);
    EXPECT_EQ(active_alerts[0].description, "低电量警告：当前电量15%") << "Description mismatch";
}

// Test triggerCommunicationError - Normal Trigger
TEST_F(AlertManagerTest, testTriggerCommunicationErrorNormalTrigger) {
    // Given: Timestamp
    uint32_t timestamp = getMockTime();

    // When: Trigger communication error
    alert_manager.triggerCommunicationError(timestamp);

    // Then: Communication error alert should be active
    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].status, AlertStatus::ACTIVE);
    EXPECT_EQ(active_alerts[0].description, "通信错误");
}

// Test acknowledgeAllAlerts - Acknowledge All Active Alerts
TEST_F(AlertManagerTest, testAcknowledgeAllAlertsAcknowledgeAllActiveAlerts) {
    // Given: Multiple active alerts
    uint32_t timestamp = getMockTime();
    alert_manager.triggerSensorFailure(timestamp);
    alert_manager.triggerLowBattery(timestamp + 1, 10.0f);

    // When: Acknowledge all alerts
    alert_manager.acknowledgeAllAlerts(timestamp + 2);

    // Then: All alerts should be acknowledged
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 0);
}

// Test acknowledgeAlert - Acknowledge Specific Alert
TEST_F(AlertManagerTest, testAcknowledgeAlertAcknowledgeSpecificAlert) {
    // Given: One active alert
    uint32_t timestamp = getMockTime();
    alert_manager.triggerSensorFailure(timestamp);

    // When: Acknowledge specific alert
    alert_manager.acknowledgeAlert(AlertType::SENSOR_FAILURE, timestamp + 1);

    // Then: Alert should be acknowledged
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 0);
}

// Test acknowledgeAlert - Try to Acknowledge Non-Existing Alert
TEST_F(AlertManagerTest, testAcknowledgeAlertTryToAcknowledgeNonExistingAlert) {
    // Given: No existing alert
    uint32_t timestamp = getMockTime();

    // When: Acknowledge non-existing alert
    alert_manager.acknowledgeAlert(AlertType::ALTITUDE_UPPER, timestamp);

    // Then: No change in state
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
}

// Test resetAlert - Reset Existing Alert
TEST_F(AlertManagerTest, testResetAlertResetExistingAlert) {
    // Given: An active alert
    uint32_t timestamp = getMockTime();
    alert_manager.triggerSensorFailure(timestamp);

    // When: Reset the alert
    alert_manager.resetAlert(AlertType::SENSOR_FAILURE);

    // Then: Alert should be gone
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 0);
}

// Test resetAlert - Reset Non-Existing Alert
TEST_F(AlertManagerTest, testResetAlertResetNonExistingAlert) {
    // Given: No existing alert
    // When: Reset non-existing alert
    alert_manager.resetAlert(AlertType::ALTITUDE_UPPER);

    // Then: No effect
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
}

// Test resetAllAlerts - Reset All Alerts
TEST_F(AlertManagerTest, testResetAllAlertsResetAllAlerts) {
    // Given: Multiple active alerts
    uint32_t timestamp = getMockTime();
    alert_manager.triggerSensorFailure(timestamp);
    alert_manager.triggerLowBattery(timestamp + 1, 10.0f);

    // When: Reset all alerts
    alert_manager.resetAllAlerts();

    // Then: All alerts should be cleared
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 0);
}

// Test hasActiveAlerts - No Active Alerts
TEST_F(AlertManagerTest, testHasActiveAlertsNoActiveAlerts) {
    // Given: No active alerts
    // When: Check for active alerts
    bool result = alert_manager.hasActiveAlerts();

    // Then: Should return false
    EXPECT_FALSE(result);
}

// Test hasActiveAlerts - With Active Alerts
TEST_F(AlertManagerTest, testHasActiveAlertsWithActiveAlerts) {
    // Given: One active alert
    uint32_t timestamp = getMockTime();
    alert_manager.triggerSensorFailure(timestamp);

    // When: Check for active alerts
    bool result = alert_manager.hasActiveAlerts();

    // Then: Should return true
    EXPECT_TRUE(result);
}

// Test hasUnacknowledgedAlerts - No Unacknowledged Alerts
TEST_F(AlertManagerTest, testHasUnacknowledgedAlertsNoUnacknowledgedAlerts) {
    // Given: No unacknowledged alerts
    // When: Check for unacknowledged alerts
    bool result = alert_manager.hasUnacknowledgedAlerts();

    // Then: Should return false
    EXPECT_FALSE(result);
}

// Test hasUnacknowledgedAlerts - With Unacknowledged Alerts
TEST_F(AlertManagerTest, testHasUnacknowledgedAlertsWithUnacknowledgedAlerts) {
    // Given: One active alert
    uint32_t timestamp = getMockTime();
    alert_manager.triggerSensorFailure(timestamp);

    // When: Check for unacknowledged alerts
    bool result = alert_manager.hasUnacknowledgedAlerts();

    // Then: Should return true
    EXPECT_TRUE(result);
}

// Test getActiveAlerts - Empty List
TEST_F(AlertManagerTest, testGetActiveAlertsEmptyList) {
    // Given: No active alerts
    // When: Get active alerts
    auto alerts = alert_manager.getActiveAlerts();

    // Then: Should return empty vector
    EXPECT_EQ(alerts.size(), 0);
}

// Test getActiveAlerts - With Active Alerts
TEST_F(AlertManagerTest, testGetActiveAlertsWithActiveAlerts) {
    // Given: One active alert
    uint32_t timestamp = getMockTime();
    alert_manager.triggerSensorFailure(timestamp);

    // When: Get active alerts
    auto alerts = alert_manager.getActiveAlerts();

    // Then: Should return one alert
    EXPECT_EQ(alerts.size(), 1);
    EXPECT_EQ(alerts[0].type, AlertType::SENSOR_FAILURE);
    EXPECT_EQ(alerts[0].status, AlertStatus::ACTIVE);
}

// Test getAlertHistory - Max Count Greater Than History Size
TEST_F(AlertManagerTest, testGetAlertHistoryMaxCountGreaterThanHistorySize) {
    // Given: Add multiple alerts
    uint32_t timestamp = getMockTime();
    alert_manager.triggerSensorFailure(timestamp);
    alert_manager.triggerLowBattery(timestamp + 1, 10.0f);
    alert_manager.triggerCommunicationError(timestamp + 2);

    // When: Get history with max count larger than size
    auto history = alert_manager.getAlertHistory(10);

    // Then: Should return all history entries
    EXPECT_EQ(history.size(), 3);
}

// Test getAlertHistory - Max Count Less Than History Size
TEST_F(AlertManagerTest, testGetAlertHistoryMaxCountLessThanHistorySize) {
    // Given: Add more alerts than max count
    uint32_t timestamp = getMockTime();
    alert_manager.triggerSensorFailure(timestamp);
    alert_manager.triggerLowBattery(timestamp + 1, 10.0f);
    alert_manager.triggerCommunicationError(timestamp + 2);

    // When: Get history with smaller max count
    auto history = alert_manager.getAlertHistory(2);

    // Then: Should return only last 2 entries
    EXPECT_EQ(history.size(), 2);
    EXPECT_EQ(history[0].type, AlertType::LOW_BATTERY);
    EXPECT_EQ(history[1].type, AlertType::COMMUNICATION_ERROR);
}

// Test getAlertHistory - Empty History
TEST_F(AlertManagerTest, testGetAlertHistoryEmptyHistory) {
    // Given: No history entries
    // When: Get history
    auto history = alert_manager.getAlertHistory(5);

    // Then: Should return empty vector
    EXPECT_EQ(history.size(), 0);
}

// Test getStatusDescription - No Active Alerts
TEST_F(AlertManagerTest, testGetStatusDescriptionNoActiveAlerts) {
    // Given: No active alerts
    // When: Get status description
    string description = alert_manager.getStatusDescription();

    // Then: Should indicate system is normal
    EXPECT_EQ(description, "系统状态：正常");
}

// Test getStatusDescription - With Active Alerts
TEST_F(AlertManagerTest, testGetStatusDescriptionWithActiveAlerts) {
    // Given: One active alert
    uint32_t timestamp = getMockTime();
    alert_manager.triggerSensorFailure(timestamp);

    // When: Get status description
    string description = alert_manager.getStatusDescription();

    // Then: Should include alert details
    EXPECT_NE(description.find("系统状态：有1个活动预警"), string::npos);
    EXPECT_NE(description.find("传感器故障"), string::npos);
}

// Test clearHistory - Clear All History
TEST_F(AlertManagerTest, testClearHistoryClearAllHistory) {
    // Given: Add some history entries
    uint32_t timestamp = getMockTime();
    alert_manager.triggerSensorFailure(timestamp);
    alert_manager.triggerLowBattery(timestamp + 1, 10.0f);

    // When: Clear history
    alert_manager.clearHistory();

    // Then: History should be empty
    EXPECT_EQ(alert_manager.getAlertHistory(10).size(), 0);
}

// Test addToHistory - Add Entry
TEST_F(AlertManagerTest, testAddToHistoryAddEntry) {
    // Given: Create a new alert
    AlertInfo alert;
    alert.type = AlertType::SENSOR_FAILURE;
    alert.status = AlertStatus::ACTIVE;
    alert.trigger_time = getMockTime();
    alert.description = "Test alert";

    // When: Add to history
    alert_manager.addToHistory(alert);

    // Then: History should contain the entry
    auto history = alert_manager.getAlertHistory(1);
    EXPECT_EQ(history.size(), 1);
    EXPECT_EQ(history[0].type, AlertType::SENSOR_FAILURE);
}

// Test addToHistory - Limit History Size
TEST_F(AlertManagerTest, testAddToHistoryLimitHistorySize) {
    // Given: Add more entries than MAX_HISTORY
    const int 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 = getMockTime() + i;
        alert.description = "Test alert";
        alert_manager.addToHistory(alert);
    }

    // When: Check history size
    auto history = alert_manager.getAlertHistory(10);

    // Then: Only MAX_HISTORY entries should remain
    EXPECT_EQ(history.size(), MAX_HISTORY);
}

// Test triggerAlert - Normal Trigger
TEST_F(AlertManagerTest, testTriggerAlertNormalTrigger) {
    // Given: Valid parameters
    uint32_t timestamp = getMockTime();
    string description = "Test alert";

    // When: Trigger alert
    alert_manager.triggerAlert(AlertType::SENSOR_FAILURE, timestamp, description);

    // Then: Alert should be active
    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, description);
}

// Test updateAlertStatus - Acknowledge Alert
TEST_F(AlertManagerTest, testUpdateAlertStatusAcknowledgeAlert) {
    // Given: An active alert
    uint32_t timestamp = getMockTime();
    alert_manager.triggerSensorFailure(timestamp);

    // When: Update status to acknowledged
    alert_manager.updateAlertStatus(AlertType::SENSOR_FAILURE, AlertStatus::ACKNOWLEDGED, timestamp + 1);

    // Then: Alert should be acknowledged
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 0);
}

// Test updateAlertStatus - Resolve Alert
TEST_F(AlertManagerTest, testUpdateAlertStatusResolveAlert) {
    // Given: An active alert
    uint32_t timestamp = getMockTime();
    alert_manager.triggerSensorFailure(timestamp);

    // When: Update status to resolved
    alert_manager.updateAlertStatus(AlertType::SENSOR_FAILURE, AlertStatus::RESOLVED, timestamp + 1);

    // Then: Alert should be resolved
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 0);
}

// Test updateAlertStatus - Update Non-Existing Alert
TEST_F(AlertManagerTest, testUpdateAlertStatusUpdateNonExistingAlert) {
    // Given: No existing alert
    // When: Update non-existing alert
    alert_manager.updateAlertStatus(AlertType::SENSOR_FAILURE, AlertStatus::ACTIVE, getMockTime());

    // Then: No change
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

// Test getAlertTypeName - Valid Type
TEST_F(AlertManagerTest, testGetAlertTypeNameValidType) {
    // Given: Valid alert type
    AlertType type = AlertType::ALTITUDE_UPPER;

    // When: Get type name
    string name = alert_manager.getAlertTypeName(type);

    // Then: Should return correct name
    EXPECT_EQ(name, "高度上限预警");
}

// Test getAlertTypeName - Unknown Type
TEST_F(AlertManagerTest, testGetAlertTypeNameUnknownType) {
    // Given: Unknown alert type
    AlertType type = static_cast<AlertType>(999);

    // When: Get type name
    string name = alert_manager.getAlertTypeName(type);

    // Then: Should return "未知预警"
    EXPECT_EQ(name, "未知预警");
}

// Test getAlertStatusName - Valid Status
TEST_F(AlertManagerTest, testGetAlertStatusNameValidStatus) {
    // Given: Valid alert status
    AlertStatus status = AlertStatus::ACTIVE;

    // When: Get status name
    string name = alert_manager.getAlertStatusName(status);

    // Then: Should return correct name
    EXPECT_EQ(name, "预警中");
}

// Test getAlertStatusName - Unknown Status
TEST_F(AlertManagerTest, testGetAlertStatusNameUnknownStatus) {
    // Given: Unknown alert status
    AlertStatus status = static_cast<AlertStatus>(999);

    // When: Get status name
    string name = alert_manager.getAlertStatusName(status);

    // Then: Should return "未知状态"
    EXPECT_EQ(name, "未知状态");
}