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

// Mock time function for deterministic testing
uint32_t mock_timestamp = 1000;
uint32_t get_mock_timestamp() { return mock_timestamp; }

// Override the global timestamp getter in alert_manager.cpp
extern "C" 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 = 1000;
        alert_manager.initialize();
    }

    void TearDown() override {
        alert_manager.resetAllAlerts();
    }
};

// Test case: AlertManager 构造函数初始化默认阈值和清空容器
TEST_F(AlertManagerTest, testAlertManagerConstructor) {
    EXPECT_FLOAT_EQ(alert_manager.getUpperThreshold(), 100.0f);
    EXPECT_FLOAT_EQ(alert_manager.getLowerThreshold(), -50.0f);
    EXPECT_TRUE(alert_manager.alerts_.empty());
    EXPECT_TRUE(alert_manager.alert_history_.empty());
}

// Test case: AlertManager 析构函数无特殊逻辑
TEST_F(AlertManagerTest, testAlertManagerDestructor) {
    // No specific behavior to assert, just ensure no crash
    // This is a placeholder for completeness
    EXPECT_NO_FATAL_FAILURE({});
}

// Test case: initialize 输出初始化信息并显示阈值
TEST_F(AlertManagerTest, testInitialize) {
    // Since output is printed, we can't directly verify it
    // But we can confirm that initialization logic runs without error
    EXPECT_NO_FATAL_FAILURE(alert_manager.initialize());
}

// Test case: checkAltitudeAlert 正常高度不触发预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertNormal) {
    const float altitude = 50.0f;
    mock_timestamp = 1000;
    alert_manager.checkAltitudeAlert(altitude, mock_timestamp);
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

// Test case: checkAltitudeAlert 高度超过上限触发预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertUpperThreshold) {
    const float altitude = 101.0f;
    mock_timestamp = 1000;
    alert_manager.checkAltitudeAlert(altitude, 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);
}

// Test case: checkAltitudeAlert 高度低于下限触发预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertLowerThreshold) {
    const float altitude = -51.0f;
    mock_timestamp = 1000;
    alert_manager.checkAltitudeAlert(altitude, 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);
}

// Test case: checkAltitudeAlert 高度恢复后解除预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertResolution) {
    // Trigger upper threshold
    alert_manager.checkAltitudeAlert(101.0f, 1000);
    EXPECT_TRUE(alert_manager.hasActiveAlerts());

    // Return to normal
    alert_manager.checkAltitudeAlert(99.0f, 1001);
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

// Test case: setAltitudeThresholds 合法输入更新阈值
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 非法输入（上限 <= 下限）应输出错误
TEST_F(AlertManagerTest, testSetAltitudeThresholdsInvalid) {
    EXPECT_DEATH_IF_SUPPORTED(alert_manager.setAltitudeThresholds(50.0f, 100.0f), "");
}

// Test case: triggerSensorFailure 触发传感器故障预警
TEST_F(AlertManagerTest, testTriggerSensorFailure) {
    mock_timestamp = 1000;
    alert_manager.triggerSensorFailure(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);
}

// Test case: triggerLowBattery 触发低电量预警并包含电量值
TEST_F(AlertManagerTest, testTriggerLowBattery) {
    mock_timestamp = 1000;
    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_TRUE(active_alerts[0].description.find("15.5") != std::string::npos);
}

// Test case: triggerCommunicationError 触发通信错误预警
TEST_F(AlertManagerTest, testTriggerCommunicationError) {
    mock_timestamp = 1000;
    alert_manager.triggerCommunicationError(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);
}

// Test case: acknowledgeAllAlerts 确认所有活动预警
TEST_F(AlertManagerTest, testAcknowledgeAllAlerts) {
    mock_timestamp = 1000;
    alert_manager.triggerSensorFailure(mock_timestamp);
    alert_manager.triggerLowBattery(mock_timestamp, 10.0f);
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    EXPECT_TRUE(alert_manager.hasUnacknowledgedAlerts());

    alert_manager.acknowledgeAllAlerts(mock_timestamp);
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    auto active_alerts = alert_manager.getActiveAlerts();
    for (const auto& alert : active_alerts) {
        EXPECT_EQ(alert.status, AlertStatus::ACKNOWLEDGED);
    }
}

// Test case: acknowledgeAlert 确认指定类型预警
TEST_F(AlertManagerTest, testAcknowledgeAlert) {
    mock_timestamp = 1000;
    alert_manager.triggerSensorFailure(mock_timestamp);
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    EXPECT_TRUE(alert_manager.hasUnacknowledgedAlerts());

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

// Test case: resetAlert 重置指定类型的预警
TEST_F(AlertManagerTest, testResetAlert) {
    mock_timestamp = 1000;
    alert_manager.triggerSensorFailure(mock_timestamp);
    EXPECT_TRUE(alert_manager.hasActiveAlerts());

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

// Test case: resetAllAlerts 清除所有活动预警并重置状态
TEST_F(AlertManagerTest, testResetAllAlerts) {
    mock_timestamp = 1000;
    alert_manager.triggerSensorFailure(mock_timestamp);
    alert_manager.triggerLowBattery(mock_timestamp, 10.0f);
    EXPECT_TRUE(alert_manager.hasActiveAlerts());

    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, testHasActiveAlerts) {
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    mock_timestamp = 1000;
    alert_manager.triggerSensorFailure(mock_timestamp);
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
}

// Test case: hasUnacknowledgedAlerts 检查是否存在未确认的活动预警
TEST_F(AlertManagerTest, testHasUnacknowledgedAlerts) {
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
    mock_timestamp = 1000;
    alert_manager.triggerSensorFailure(mock_timestamp);
    EXPECT_TRUE(alert_manager.hasUnacknowledgedAlerts());
    alert_manager.acknowledgeAllAlerts(mock_timestamp);
    EXPECT_FALSE(alert_manager.hasUnacknowledgedAlerts());
}

// Test case: getActiveAlerts 返回当前所有活动预警信息列表
TEST_F(AlertManagerTest, testGetActiveAlerts) {
    mock_timestamp = 1000;
    alert_manager.triggerSensorFailure(mock_timestamp);
    alert_manager.triggerLowBattery(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 获取最近的预警历史记录
TEST_F(AlertManagerTest, testGetAlertHistoryMaxCount) {
    mock_timestamp = 1000;
    for (int i = 0; i < 5; ++i) {
        alert_manager.triggerSensorFailure(mock_timestamp + i);
    }
    auto history = alert_manager.getAlertHistory(3);
    EXPECT_EQ(history.size(), 3);
    EXPECT_EQ(history[0].type, AlertType::SENSOR_FAILURE);
    EXPECT_EQ(history[2].trigger_time, 1002);
}

// Test case: getStatusDescription 生成系统状态描述
TEST_F(AlertManagerTest, testGetStatusDescription) {
    mock_timestamp = 1000;
    alert_manager.triggerSensorFailure(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) {
    mock_timestamp = 1000;
    alert_manager.triggerSensorFailure(mock_timestamp);
    EXPECT_FALSE(alert_manager.alert_history_.empty());
    alert_manager.clearHistory();
    EXPECT_TRUE(alert_manager.alert_history_.empty());
}

// Test case: addToHistory 添加预警到历史记录，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 + 2; ++i) {
        AlertInfo alert;
        alert.type = AlertType::SENSOR_FAILURE;
        alert.status = AlertStatus::ACTIVE;
        alert.trigger_time = 1000 + i;
        alert.description = "test";
        alert_manager.addToHistory(alert);
    }
    EXPECT_EQ(alert_manager.alert_history_.size(), MAX_HISTORY);
    EXPECT_EQ(alert_manager.alert_history_[0].trigger_time, 1002);
    EXPECT_EQ(alert_manager.alert_history_[MAX_HISTORY - 1].trigger_time, 1004);
}