#include <gtest/gtest.h>
#include "alert_manager.hpp"
#include <sstream>
#include <iostream>

// 辅助类：用于捕获标准输出和标准错误输出
class StreamCapture {
public:
    StreamCapture() : old_cout_(std::cout.rdbuf()), old_cerr_(std::cerr.rdbuf()) {
        std::cout.rdbuf(ss_cout_.rdbuf());
        std::cerr.rdbuf(ss_cerr_.rdbuf());
    }
    
    ~StreamCapture() {
        std::cout.rdbuf(old_cout_);
        std::cerr.rdbuf(old_cerr_);
    }
    
    std::string getCout() const { return ss_cout_.str(); }
    std::string getCerr() const { return ss_cerr_.str(); }
    
private:
    std::stringstream ss_cout_;
    std::stringstream ss_cerr_;
    std::streambuf* old_cout_;
    std::streambuf* old_cerr_;
};

// 测试夹具：为每个测试用例创建独立的 AlertManager 实例
class AlertManagerTest : public ::testing::Test {
protected:
    void SetUp() override {
        manager.initialize();
    }
    
    void TearDown() override {
        manager.resetAllAlerts();
    }
    
    AlertManager manager;
};

// ==================== checkAltitudeAlert 测试 ====================

// 正常输入测试：高度在阈值范围内，不应触发任何预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertNormalRange) {
    StreamCapture capture;
    
    // 默认阈值：上限100.0，下限-50.0
    // 测试正常高度 50.0
    manager.checkAltitudeAlert(50.0f, 1000);
    
    EXPECT_FALSE(manager.hasActiveAlerts());
    EXPECT_FALSE(manager.hasUnacknowledgedAlerts());
    
    // 测试接近上限但未超过
    manager.checkAltitudeAlert(99.9f, 1001);
    EXPECT_FALSE(manager.hasActiveAlerts());
    
    // 测试接近下限但未低于
    manager.checkAltitudeAlert(-49.9f, 1002);
    EXPECT_FALSE(manager.hasActiveAlerts());
}

// 边界值测试：高度刚好等于阈值，不应触发预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertAtThreshold) {
    StreamCapture capture;
    
    // 测试高度等于上限
    manager.checkAltitudeAlert(100.0f, 2000);
    EXPECT_FALSE(manager.hasActiveAlerts());
    
    // 测试高度等于下限
    manager.checkAltitudeAlert(-50.0f, 2001);
    EXPECT_FALSE(manager.hasActiveAlerts());
}

// 边界值测试：高度超过上限，应触发 ALTITUDE_UPPER 预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertExceedsUpper) {
    StreamCapture capture;
    
    // 高度超过上限
    manager.checkAltitudeAlert(150.0f, 3000);
    
    EXPECT_TRUE(manager.hasActiveAlerts());
    EXPECT_TRUE(manager.hasUnacknowledgedAlerts());
    
    auto activeAlerts = manager.getActiveAlerts();
    ASSERT_EQ(1, activeAlerts.size());
    EXPECT_EQ(AlertType::ALTITUDE_UPPER, activeAlerts[0].type);
    EXPECT_EQ(AlertStatus::ACTIVE, activeAlerts[0].status);
    EXPECT_EQ(3000, activeAlerts[0].trigger_time);
    
    // 验证输出包含预警信息
    std::string coutOutput = capture.getCout();
    EXPECT_NE(std::string::npos, coutOutput.find("高度上限预警"));
    EXPECT_NE(std::string::npos, coutOutput.find("150"));
}

// 边界值测试：高度低于下限，应触发 ALTITUDE_LOWER 预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertBelowLower) {
    StreamCapture capture;
    
    // 高度低于下限
    manager.checkAltitudeAlert(-100.0f, 4000);
    
    EXPECT_TRUE(manager.hasActiveAlerts());
    EXPECT_TRUE(manager.hasUnacknowledgedAlerts());
    
    auto activeAlerts = manager.getActiveAlerts();
    ASSERT_EQ(1, activeAlerts.size());
    EXPECT_EQ(AlertType::ALTITUDE_LOWER, activeAlerts[0].type);
    EXPECT_EQ(AlertStatus::ACTIVE, activeAlerts[0].status);
    EXPECT_EQ(4000, activeAlerts[0].trigger_time);
    
    // 验证输出包含预警信息
    std::string coutOutput = capture.getCout();
    EXPECT_NE(std::string::npos, coutOutput.find("高度下限预警"));
    EXPECT_NE(std::string::npos, coutOutput.find("-100"));
}

// 特殊场景测试：高度超过上限后恢复正常，预警应解除
TEST_F(AlertManagerTest, testCheckAltitudeAlertUpperResolved) {
    StreamCapture capture;
    
    // 先触发上限预警
    manager.checkAltitudeAlert(150.0f, 5000);
    EXPECT_TRUE(manager.hasActiveAlerts());
    
    // 高度恢复正常
    manager.checkAltitudeAlert(80.0f, 5001);
    
    // 预警应被解决
    EXPECT_FALSE(manager.hasActiveAlerts());
    EXPECT_FALSE(manager.hasUnacknowledgedAlerts());
    
    // 验证历史记录中存在已解决的预警
    auto history = manager.getAlertHistory(10);
    bool foundResolved = false;
    for (const auto& alert : history) {
        if (alert.type == AlertType::ALTITUDE_UPPER && 
            alert.status == AlertStatus::RESOLVED) {
            foundResolved = true;
            break;
        }
    }
    EXPECT_TRUE(foundResolved);
}

// 特殊场景测试：高度低于下限后恢复正常，预警应解除
TEST_F(AlertManagerTest, testCheckAltitudeAlertLowerResolved) {
    StreamCapture capture;
    
    // 先触发下限预警
    manager.checkAltitudeAlert(-100.0f, 6000);
    EXPECT_TRUE(manager.hasActiveAlerts());
    
    // 高度恢复正常
    manager.checkAltitudeAlert(0.0f, 6001);
    
    // 预警应被解决
    EXPECT_FALSE(manager.hasActiveAlerts());
    EXPECT_FALSE(manager.hasUnacknowledgedAlerts());
    
    // 验证历史记录
    auto history = manager.getAlertHistory(10);
    bool foundResolved = false;
    for (const auto& alert : history) {
        if (alert.type == AlertType::ALTITUDE_LOWER && 
            alert.status == AlertStatus::RESOLVED) {
            foundResolved = true;
            break;
        }
    }
    EXPECT_TRUE(foundResolved);
}

// 特殊场景测试：同时超过上下限（理论上不可能，但测试逻辑完整性）
TEST_F(AlertManagerTest, testCheckAltitudeAlertBothThresholds) {
    StreamCapture capture;
    
    // 修改阈值使上下限重叠（通过 setAltitudeThresholds 会校验，这里直接测试逻辑）
    // 注意：此测试仅验证 checkAltitudeAlert 的逻辑，不依赖阈值设置
    
    // 先触发上限预警
    manager.checkAltitudeAlert(150.0f, 7000);
    EXPECT_TRUE(manager.hasActiveAlerts());
    
    // 再触发下限预警（此时高度低于下限）
    manager.checkAltitudeAlert(-100.0f, 7001);
    
    // 应有 2 个活动预警
    auto activeAlerts = manager.getActiveAlerts();
    EXPECT_EQ(2, activeAlerts.size());
}

// 异常输入测试：高度为 NaN（如果支持）
TEST_F(AlertManagerTest, testCheckAltitudeAlertNaN) {
    StreamCapture capture;
    
    // 使用 NaN 值（如果编译器支持）
    float nanValue = std::numeric_limits<float>::quiet_NaN();
    
    // NaN 与任何值的比较结果都是 false，因此不会触发预警
    manager.checkAltitudeAlert(nanValue, 8000);
    
    // 不应触发任何预警
    EXPECT_FALSE(manager.hasActiveAlerts());
}

// 异常输入测试：高度为无穷大
TEST_F(AlertManagerTest, testCheckAltitudeAlertInfinity) {
    StreamCapture capture;
    
    float infValue = std::numeric_limits<float>::infinity();
    
    // 正无穷应触发上限预警
    manager.checkAltitudeAlert(infValue, 9000);
    EXPECT_TRUE(manager.hasActiveAlerts());
    
    auto activeAlerts = manager.getActiveAlerts();
    ASSERT_EQ(1, activeAlerts.size());
    EXPECT_EQ(AlertType::ALTITUDE_UPPER, activeAlerts[0].type);
}

// 异常输入测试：高度为负无穷
TEST_F(AlertManagerTest, testCheckAltitudeAlertNegativeInfinity) {
    StreamCapture capture;
    
    float negInfValue = -std::numeric_limits<float>::infinity();
    
    // 负无穷应触下限预警
    manager.checkAltitudeAlert(negInfValue, 10000);
    EXPECT_TRUE(manager.hasActiveAlerts());
    
    auto activeAlerts = manager.getActiveAlerts();
    ASSERT_EQ(1, activeAlerts.size());
    EXPECT_EQ(AlertType::ALTITUDE_LOWER, activeAlerts[0].type);
}

// 特殊场景测试：时间戳为 0
TEST_F(AlertManagerTest, testCheckAltitudeAlertTimestampZero) {
    StreamCapture capture;
    
    // 时间戳为 0 不应影响预警逻辑
    manager.checkAltitudeAlert(150.0f, 0);
    EXPECT_TRUE(manager.hasActiveAlerts());
    
    auto activeAlerts = manager.getActiveAlerts();
    ASSERT_EQ(1, activeAlerts.size());
    EXPECT_EQ(0, activeAlerts[0].trigger_time);
}

// 特殊场景测试：连续多次触发同一预警，不应重复触发
TEST_F(AlertManagerTest, testCheckAltitudeAlertDuplicateTrigger) {
    StreamCapture capture;
    
    // 第一次触发
    manager.checkAltitudeAlert(150.0f, 11000);
    EXPECT_TRUE(manager.hasActiveAlerts());
    
    // 第二次触发（高度仍然超过上限）
    manager.checkAltitudeAlert(200.0f, 11001);
    
    // 应仍只有 1 个活动预警
    auto activeAlerts = manager.getActiveAlerts();
    ASSERT_EQ(1, activeAlerts.size());
    
    // 验证历史记录中只有 1 次触发
    auto history = manager.getAlertHistory(10);
    int triggerCount = 0;
    for (const auto& alert : history) {
        if (alert.type == AlertType::ALTITUDE_UPPER && 
            alert.status == AlertStatus::ACTIVE) {
            triggerCount++;
        }
    }
    EXPECT_EQ(1, triggerCount);
}

// ==================== setAltitudeThresholds 测试 ====================

// 正常输入测试：设置有效的上下限阈值
TEST_F(AlertManagerTest, testSetAltitudeThresholdsValid) {
    StreamCapture capture;
    
    manager.setAltitudeThresholds(200.0f, -100.0f);
    
    // 验证输出
    std::string coutOutput = capture.getCout();
    EXPECT_NE(std::string::npos, coutOutput.find("预警阈值已更新"));
    EXPECT_NE(std::string::npos, coutOutput.find("200"));
    EXPECT_NE(std::string::npos, coutOutput.find("-100"));
    
    // 验证新阈值生效
    manager.checkAltitudeAlert(150.0f, 12000);
    EXPECT_FALSE(manager.hasActiveAlerts());
    
    manager.checkAltitudeAlert(250.0f, 12001);
    EXPECT_TRUE(manager.hasActiveAlerts());
}

// 边界值测试：设置上限等于下限（非法）
TEST_F(AlertManagerTest, testSetAltitudeThresholdsEqual) {
    StreamCapture capture;
    
    manager.setAltitudeThresholds(100.0f, 100.0f);
    
    // 验证错误输出
    std::string cerrOutput = capture.getCerr();
    EXPECT_NE(std::string::npos, cerrOutput.find("上限阈值必须大于下限阈值"));
    
    // 验证阈值未改变
    manager.checkAltitudeAlert(150.0f, 13000);
    EXPECT_TRUE(manager.hasActiveAlerts());
}

// 异常输入测试：设置上限小于下限（非法）
TEST_F(AlertManagerTest, testSetAltitudeThresholdsUpperLessThanLower) {
    StreamCapture capture;
    
    manager.setAltitudeThresholds(-50.0f, 100.0f);
    
    // 验证错误输出
    std::string cerrOutput = capture.getCerr();
    EXPECT_NE(std::string::npos, cerrOutput.find("上限阈值必须大于下限阈值"));
    
    // 验证阈值未改变
    manager.checkAltitudeAlert(150.0f, 14000);
    EXPECT_TRUE(manager.hasActiveAlerts());
}

// 边界值测试：设置非常大的阈值范围
TEST_F(AlertManagerTest, testSetAltitudeThresholdsLargeRange) {
    StreamCapture capture;
    
    float largeUpper = 1000000.0f;
    float largeLower = -1000000.0f;
    
    manager.setAltitudeThresholds(largeUpper, largeLower);
    
    // 验证阈值设置成功
    manager.checkAltitudeAlert(500000.0f, 15000);
    EXPECT_FALSE(manager.hasActiveAlerts());
    
    manager.checkAltitudeAlert(2000000.0f, 15001);
    EXPECT_TRUE(manager.hasActiveAlerts());
}

// 边界值测试：设置非常小的阈值范围
TEST_F(AlertManagerTest, testSetAltitudeThresholdsSmallRange) {
    StreamCapture capture;
    
    float smallUpper = 0.001f;
    float smallLower = -0.001f;
    
    manager.setAltitudeThresholds(smallUpper, smallLower);
    
    // 验证阈值设置成功
    manager.checkAltitudeAlert(0.0005f, 16000);
    EXPECT_FALSE(manager.hasActiveAlerts());
    
    manager.checkAltitudeAlert(0.002f, 16001);
    EXPECT_TRUE(manager.hasActiveAlerts());
}

// 特殊场景测试：设置阈值后，原有的活动预警应被重置
TEST_F(AlertManagerTest, testSetAltitudeThresholdsResetsAlerts) {
    StreamCapture capture;
    
    // 先触发一个预警
    manager.checkAltitudeAlert(150.0f, 17000);
    EXPECT_TRUE(manager.hasActiveAlerts());
    
    // 修改阈值
    manager.setAltitudeThresholds(200.0f, -100.0f);
    
    // 原有的预警应被重置（解决）
    EXPECT_FALSE(manager.hasActiveAlerts());
    
    // 验证历史记录中存在已解决的预警
    auto history = manager.getAlertHistory(10);
    bool foundResolved = false;
    for (const auto& alert : history) {
        if (alert.type == AlertType::ALTITUDE_UPPER && 
            alert.status == AlertStatus::RESOLVED) {
            foundResolved = true;
            break;
        }
    }
    EXPECT_TRUE(foundResolved);
}

// 特殊场景测试：连续设置阈值，验证状态一致性
TEST_F(AlertManagerTest, testSetAltitudeThresholdsMultipleTimes) {
    StreamCapture capture;
    
    // 第一次设置
    manager.setAltitudeThresholds(200.0f, -100.0f);
    
    // 触发预警
    manager.checkAltitudeAlert(250.0f, 18000);
    EXPECT_TRUE(manager.hasActiveAlerts());
    
    // 第二次设置
    manager.setAltitudeThresholds(300.0f, -200.0f);
    
    // 原有预警被重置
    EXPECT_FALSE(manager.hasActiveAlerts());
    
    // 新阈值下，原来的高度不再触发预警
    manager.checkAltitudeAlert(250.0f, 18001);
    EXPECT_FALSE(manager.hasActiveAlerts());
}

// 特殊场景测试：设置阈值后立即检查高度
TEST_F(AlertManagerTest, testSetAltitudeThresholdsImmediateCheck) {
    StreamCapture capture;
    
    // 设置新阈值
    manager.setAltitudeThresholds(50.0f, -10.0f);
    
    // 立即检查高度，应触发预警
    manager.checkAltitudeAlert(60.0f, 19000);
    EXPECT_TRUE(manager.hasActiveAlerts());
    
    auto activeAlerts = manager.getActiveAlerts();
    ASSERT_EQ(1, activeAlerts.size());
    EXPECT_EQ(AlertType::ALTITUDE_UPPER, activeAlerts[0].type);
}