#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 getMockTimestamp() { return mock_timestamp; }

// Override the global timestamp getter in alert_manager.cpp
extern "C" uint32_t getTimestamp() { return getMockTimestamp(); }

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

    void SetUp() override {
        mock_timestamp = 1000;
        alert_manager.initialize();
    }

    void advanceTime(uint32_t seconds) {
        mock_timestamp += seconds;
    }
};

// Test case: AlertManager 构造函数初始化默认阈值
TEST_F(AlertManagerTest, testAlertManagerConstructorNormalInput) {
    EXPECT_FLOAT_EQ(alert_manager.getAltitudeThresholds().first, 100.0f);
    EXPECT_FLOAT_EQ(alert_manager.getAltitudeThresholds().second, -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, testAlertManagerDestructorNoSideEffect) {
    // Destructor has no logic, just verify it's callable
    AlertManager temp_manager;
    EXPECT_NO_THROW({});
}

// Test case: initialize 输出正确信息
TEST_F(AlertManagerTest, testInitializeOutputCorrectInfo) {
    std::stringstream buffer;
    std::streambuf* old_cout = std::cout.rdbuf(buffer.rdbuf());
    alert_manager.initialize();
    std::cout.rdbuf(old_cout);

    EXPECT_NE(buffer.str().find("预警管理器初始化完成。"), std::string::npos);
    EXPECT_NE(buffer.str().find("默认预警阈值：上限=100米，下限=-50米"), std::string::npos);
}

// Test case: checkAltitudeAlert 触发上限预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertTriggerUpper) {
    alert_manager.checkAltitudeAlert(105.0f, getMockTimestamp());
    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 恢复正常状态
TEST_F(AlertManagerTest, testCheckAltitudeAlertResolveUpper) {
    alert_manager.checkAltitudeAlert(105.0f, getMockTimestamp());
    alert_manager.checkAltitudeAlert(95.0f, getMockTimestamp());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_TRUE(active_alerts.empty());
}

// Test case: checkAltitudeAlert 触发下限预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertTriggerLower) {
    alert_manager.checkAltitudeAlert(-55.0f, getMockTimestamp());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 1);
    EXPECT_EQ(active_alerts[0].type, AlertType::ALTITUDE_LOWER);
}

// Test case: setAltitudeThresholds 合法输入更新阈值
TEST_F(AlertManagerTest, testSetAltitudeThresholdsValidInput) {
    alert_manager.setAltitudeThresholds(200.0f, -100.0f);
    auto thresholds = alert_manager.getAltitudeThresholds();
    EXPECT_FLOAT_EQ(thresholds.first, 200.0f);
    EXPECT_FLOAT_EQ(thresholds.second, -100.0f);
}

// Test case: setAltitudeThresholds 非法输入输出错误提示
TEST_F(AlertManagerTest, testSetAltitudeThresholdsInvalidInput) {
    std::stringstream buffer;
    std::streambuf* old_cerr = std::cerr.rdbuf(buffer.rdbuf());
    alert_manager.setAltitudeThresholds(50.0f, 100.0f);
    std::cerr.rdbuf(old_cerr);
    EXPECT_NE(buffer.str().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(getMockTimestamp());
    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
TEST_F(AlertManagerTest, testTriggerLowBattery) {
    alert_manager.triggerLowBattery(getMockTimestamp(), 15.0f);
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(active_alerts.size(), 1);
    EXPECT_EQ(active_alerts[0].type, AlertType::LOW_BATTERY);
    EXPECT_NE(active_alerts[0].description.find("低电量警告：当前电量15%"), std::string::npos);
}

// Test case: triggerCommunicationError 触发通信错误预警
TEST_F(AlertManagerTest, testTriggerCommunicationError) {
    alert_manager.triggerCommunicationError(getMockTimestamp());
    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) {
    alert_manager.triggerSensorFailure(getMockTimestamp());
    alert_manager.triggerLowBattery(getMockTimestamp(), 10.0f);
    alert_manager.acknowledgeAllAlerts(getMockTimestamp());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_TRUE(active_alerts.empty());
    EXPECT_TRUE(alert_manager.hasUnacknowledgedAlerts());
}

// Test case: acknowledgeAlert 确认指定类型预警
TEST_F(AlertManagerTest, testAcknowledgeAlert) {
    alert_manager.triggerSensorFailure(getMockTimestamp());
    alert_manager.acknowledgeAlert(AlertType::SENSOR_FAILURE, getMockTimestamp());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_TRUE(active_alerts.empty());
}

// Test case: resetAlert 重置指定类型预警
TEST_F(AlertManagerTest, testResetAlert) {
    alert_manager.triggerSensorFailure(getMockTimestamp());
    alert_manager.resetAlert(AlertType::SENSOR_FAILURE);
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_TRUE(active_alerts.empty());
}

// Test case: resetAllAlerts 重置所有预警
TEST_F(AlertManagerTest, testResetAllAlerts) {
    alert_manager.triggerSensorFailure(getMockTimestamp());
    alert_manager.triggerLowBattery(getMockTimestamp(), 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, testHasActiveAlertsWhenNoAlerts) {
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

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

// Test case: hasUnacknowledgedAlerts 检查未确认预警
TEST_F(AlertManagerTest, testHasUnacknowledgedAlertsWhenNoAcknowledged) {
    alert_manager.triggerSensorFailure(getMockTimestamp());
    EXPECT_TRUE(alert_manager.hasUnacknowledgedAlerts());
}

// Test case: getActiveAlerts 返回活动预警列表
TEST_F(AlertManagerTest, testGetActiveAlertsReturnsCorrectList) {
    alert_manager.triggerSensorFailure(getMockTimestamp());
    alert_manager.triggerLowBattery(getMockTimestamp(), 10.0f);
    auto alerts = alert_manager.getActiveAlerts();
    EXPECT_EQ(alerts.size(), 2);
    EXPECT_EQ(alerts[0].type, AlertType::SENSOR_FAILURE);
    EXPECT_EQ(alerts[1].type, AlertType::LOW_BATTERY);
}

// Test case: getAlertHistory 获取历史记录（最大数量限制）
TEST_F(AlertManagerTest, testGetAlertHistoryMaxCountLimit) {
    for (int i = 0; i < 5; ++i) {
        alert_manager.triggerSensorFailure(getMockTimestamp());
        advanceTime(1);
    }
    auto history = alert_manager.getAlertHistory(3);
    EXPECT_EQ(history.size(), 3);
}

// Test case: getStatusDescription 生成系统状态描述
TEST_F(AlertManagerTest, testGetStatusDescriptionWithActiveAlerts) {
    alert_manager.triggerSensorFailure(getMockTimestamp());
    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 清空历史记录
TEST_F(AlertManagerTest, testClearHistory) {
    alert_manager.triggerSensorFailure(getMockTimestamp());
    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
TEST_F(AlertManagerTest, testAddToHistoryMaintainMaxSize) {
    const size_t MAX_HISTORY = 5;
    for (int i = 0; i < MAX_HISTORY + 1; ++i) {
        alert_manager.triggerSensorFailure(getMockTimestamp());
        advanceTime(1);
    }
    auto history = alert_manager.getAlertHistory(MAX_HISTORY);
    EXPECT_EQ(history.size(), MAX_HISTORY);
}

// Test case: triggerAlert 触发新预警并添加到历史
TEST_F(AlertManagerTest, testTriggerAlertAddsToHistory) {
    alert_manager.triggerAlert(AlertType::ALTITUDE_UPPER, getMockTimestamp(), "测试预警");
    auto history = alert_manager.getAlertHistory(10);
    EXPECT_EQ(history.size(), 1);
    EXPECT_EQ(history[0].type, AlertType::ALTITUDE_UPPER);
}

// Test case: updateAlertStatus 更新状态并触发反馈
TEST_F(AlertManagerTest, testUpdateAlertStatusChangesStatus) {
    alert_manager.triggerSensorFailure(getMockTimestamp());
    alert_manager.updateAlertStatus(AlertType::SENSOR_FAILURE, AlertStatus::ACKNOWLEDGED, getMockTimestamp());
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_TRUE(active_alerts.empty());
}

// Test case: getAlertTypeName 返回正确名称
TEST_F(AlertManagerTest, testGetAlertTypeName) {
    EXPECT_EQ(alert_manager.getAlertTypeName(AlertType::ALTITUDE_UPPER), "高度上限预警");
    EXPECT_EQ(alert_manager.getAlertTypeName(AlertType::NONE), "无");
}

// Test case: getAlertStatusName 返回正确状态名
TEST_F(AlertManagerTest, testGetAlertStatusName) {
    EXPECT_EQ(alert_manager.getAlertStatusName(AlertStatus::ACTIVE), "预警中");
    EXPECT_EQ(alert_manager.getAlertStatusName(AlertStatus::RESOLVED), "已解决");
}