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

using namespace std;

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

// Mock the time function to return a fixed value
uint32_t getMockTimestamp() {
    return mock_timestamp;
}

// Override the global time function in AlertManager
namespace {
    uint32_t (*original_time_func)() = nullptr;
    uint32_t mock_time_func() { return mock_timestamp; }
}

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

    void SetUp() override {
        // Reset timestamp
        mock_timestamp = 1640995200;
        // Initialize with default thresholds
        alert_manager.initialize();
    }

    void TearDown() override {
        // Clean up
        alert_manager.resetAllAlerts();
    }
};

// Test case: 正常输入测试 - 设置合法的上下限阈值
TEST_F(AlertManagerTest, testSetAltitudeThresholdsNormalInput) {
    const float upper = 200.0f;
    const float lower = -100.0f;

    alert_manager.setAltitudeThresholds(upper, lower);

    EXPECT_FLOAT_EQ(alert_manager.getUpperThreshold(), upper);
    EXPECT_FLOAT_EQ(alert_manager.getLowerThreshold(), lower);

    // Verify that active alerts are reset
    auto active_alerts = alert_manager.getActiveAlerts();
    EXPECT_TRUE(active_alerts.empty());
}

// Test case: 边界值测试 - 上限等于下限（非法输入）
TEST_F(AlertManagerTest, testSetAltitudeThresholdsBoundaryEqual) {
    const float upper = 100.0f;
    const float lower = 100.0f;

    // Capture stderr output
    testing::internal::CaptureStderr();
    alert_manager.setAltitudeThresholds(upper, lower);
    string stderr_output = testing::internal::GetCapturedStderr();

    EXPECT_NE(stderr_output.find("错误：上限阈值必须大于下限阈值"), string::npos);
    EXPECT_FLOAT_EQ(alert_manager.getUpperThreshold(), 100.0f); // Should not change
    EXPECT_FLOAT_EQ(alert_manager.getLowerThreshold(), -50.0f); // Default value
}

// Test case: 异常输入测试 - 上限小于下限（非法输入）
TEST_F(AlertManagerTest, testSetAltitudeThresholdsInvalidInput) {
    const float upper = 50.0f;
    const float lower = 100.0f;

    // Capture stderr output
    testing::internal::CaptureStderr();
    alert_manager.setAltitudeThresholds(upper, lower);
    string stderr_output = testing::internal::GetCapturedStderr();

    EXPECT_NE(stderr_output.find("错误：上限阈值必须大于下限阈值"), string::npos);
    EXPECT_FLOAT_EQ(alert_manager.getUpperThreshold(), 100.0f); // Should remain unchanged
    EXPECT_FLOAT_EQ(alert_manager.getLowerThreshold(), -50.0f);
}

// Test case: 特殊场景测试 - 阈值更新后，高度越界触发预警
TEST_F(AlertManagerTest, testSetAltitudeThresholdsAndTriggerAlert) {
    const float upper = 150.0f;
    const float lower = -80.0f;
    const float altitude = 160.0f; // Exceeds upper threshold

    alert_manager.setAltitudeThresholds(upper, lower);

    // Simulate check
    mock_timestamp += 100;
    alert_manager.checkAltitudeAlert(altitude, mock_timestamp);

    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);
    EXPECT_EQ(active_alerts[0].trigger_time, mock_timestamp);
    EXPECT_TRUE(active_alerts[0].description.find("超过上限阈值") != string::npos);
}

// Test case: 正常输入测试 - 获取活动预警信息
TEST_F(AlertManagerTest, testGetActiveAlertsNormalInput) {
    const float upper = 100.0f;
    const float lower = -50.0f;
    const float altitude = 120.0f; // Above upper threshold

    alert_manager.setAltitudeThresholds(upper, lower);
    mock_timestamp += 100;
    alert_manager.checkAltitudeAlert(altitude, mock_timestamp);

    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);
    EXPECT_EQ(active_alerts[0].trigger_time, mock_timestamp);
}

// Test case: 边界值测试 - 无活动预警时获取空列表
TEST_F(AlertManagerTest, testGetActiveAlertsNoActiveAlerts) {
    auto active_alerts = alert_manager.getActiveAlerts();

    EXPECT_TRUE(active_alerts.empty());
}

// Test case: 特殊场景测试 - 多个预警同时存在
TEST_F(AlertManagerTest, testGetActiveAlertsMultipleAlerts) {
    const float upper = 100.0f;
    const float lower = -50.0f;
    const float altitude_high = 120.0f;  // Above upper
    const float altitude_low = -70.0f;   // Below lower

    alert_manager.setAltitudeThresholds(upper, lower);

    mock_timestamp += 100;
    alert_manager.checkAltitudeAlert(altitude_high, mock_timestamp);
    mock_timestamp += 100;
    alert_manager.checkAltitudeAlert(altitude_low, mock_timestamp);

    auto active_alerts = alert_manager.getActiveAlerts();

    EXPECT_EQ(active_alerts.size(), 2);
    EXPECT_EQ(active_alerts[0].type, AlertType::ALTITUDE_UPPER);
    EXPECT_EQ(active_alerts[1].type, AlertType::ALTITUDE_LOWER);
    EXPECT_EQ(active_alerts[0].status, AlertStatus::ACTIVE);
    EXPECT_EQ(active_alerts[1].status, AlertStatus::ACTIVE);
}

// Test case: 异常输入测试 - 空值处理（虽然函数无参数，但验证状态）
TEST_F(AlertManagerTest, testGetActiveAlertsEmptyState) {
    // Ensure no prior state
    alert_manager.resetAllAlerts();
    auto active_alerts = alert_manager.getActiveAlerts();

    EXPECT_TRUE(active_alerts.empty());
}

// Test case: 特殊场景测试 - 预警解除后不再返回
TEST_F(AlertManagerTest, testGetActiveAlertsAfterResolution) {
    const float upper = 100.0f;
    const float lower = -50.0f;
    const float altitude = 120.0f;

    alert_manager.setAltitudeThresholds(upper, lower);
    mock_timestamp += 100;
    alert_manager.checkAltitudeAlert(altitude, mock_timestamp);

    // Now simulate normal altitude
    mock_timestamp += 100;
    alert_manager.checkAltitudeAlert(90.0f, mock_timestamp);

    auto active_alerts = alert_manager.getActiveAlerts();

    EXPECT_TRUE(active_alerts.empty());
}