#include "gtest/gtest.h"
#include "alert_manager.hpp"
#include <memory>

using namespace std;

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

// Override the timestamp getter for testing
uint32_t get_mock_timestamp() {
    return mock_timestamp;
}

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

    void SetUp() override {
        // Reset to default thresholds
        alert_manager.setAltitudeThresholds(100.0f, -50.0f);
        mock_timestamp = 1640995200;
    }

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

// Test case: 正常输入测试 - 检查高度在正常范围内时不应触发预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertNormalRange) {
    // Arrange
    float altitude = 50.0f; // Within normal range
    uint32_t timestamp = get_mock_timestamp();

    // Act
    alert_manager.checkAltitudeAlert(altitude, timestamp);

    // Assert
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_EQ(alert_manager.getActiveAlerts().size(), 0);
}

// Test case: 边界值测试 - 高度等于上限阈值时不应触发预警（严格大于才触发）
TEST_F(AlertManagerTest, testCheckAltitudeAlertUpperBoundary) {
    // Arrange
    float altitude = 100.0f; // Equal to upper threshold
    uint32_t timestamp = get_mock_timestamp();

    // Act
    alert_manager.checkAltitudeAlert(altitude, timestamp);

    // Assert
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_EQ(alert_manager.getActiveAlerts().size(), 0);
}

// Test case: 边界值测试 - 高度略高于上限阈值时应触发预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertAboveUpperThreshold) {
    // Arrange
    float altitude = 100.1f; // Slightly above upper threshold
    uint32_t timestamp = get_mock_timestamp();

    // Act
    alert_manager.checkAltitudeAlert(altitude, timestamp);

    // Assert
    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 case: 边界值测试 - 高度等于下限阈值时不应触发预警（严格小于才触发）
TEST_F(AlertManagerTest, testCheckAltitudeAlertLowerBoundary) {
    // Arrange
    float altitude = -50.0f; // Equal to lower threshold
    uint32_t timestamp = get_mock_timestamp();

    // Act
    alert_manager.checkAltitudeAlert(altitude, timestamp);

    // Assert
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_EQ(alert_manager.getActiveAlerts().size(), 0);
}

// Test case: 边界值测试 - 高度略低于下限阈值时应触发预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertBelowLowerThreshold) {
    // Arrange
    float altitude = -50.1f; // Slightly below lower threshold
    uint32_t timestamp = get_mock_timestamp();

    // Act
    alert_manager.checkAltitudeAlert(altitude, timestamp);

    // Assert
    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 case: 特殊场景测试 - 高度从超限恢复到正常范围时应解除预警
TEST_F(AlertManagerTest, testCheckAltitudeAlertResolution) {
    // Arrange
    float altitude_above = 100.1f; // Trigger alert
    float altitude_normal = 50.0f;  // Resolve alert
    uint32_t timestamp1 = get_mock_timestamp();
    uint32_t timestamp2 = get_mock_timestamp() + 1;

    // Act - trigger upper alert
    alert_manager.checkAltitudeAlert(altitude_above, timestamp1);
    EXPECT_TRUE(alert_manager.hasActiveAlerts());

    // Act - resolve alert
    alert_manager.checkAltitudeAlert(altitude_normal, timestamp2);

    // Assert
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_EQ(alert_manager.getActiveAlerts().size(), 0);
}

// Test case: 异常输入测试 - 设置非法阈值（上界不大于下界）
TEST_F(AlertManagerTest, testSetAltitudeThresholdsInvalidInput) {
    // Arrange
    float upper = 50.0f;
    float lower = 100.0f;

    // Act & Assert
    EXPECT_NO_THROW(alert_manager.setAltitudeThresholds(upper, lower));
    // The function should print error message but not crash
    // We can't directly capture stderr in gtest, so we rely on no exception
    EXPECT_EQ(alert_manager.getAltitudeThresholds().first, 100.0f); // Should remain unchanged
    EXPECT_EQ(alert_manager.getAltitudeThresholds().second, -50.0f);
}

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

    // Act
    alert_manager.setAltitudeThresholds(upper, lower);

    // Assert
    auto thresholds = alert_manager.getAltitudeThresholds();
    EXPECT_FLOAT_EQ(thresholds.first, upper);
    EXPECT_FLOAT_EQ(thresholds.second, lower);
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

// Test case: 特殊场景测试 - 设置新阈值后，原有预警应被重置
TEST_F(AlertManagerTest, testSetAltitudeThresholdsResetAlerts) {
    // Arrange
    float altitude = 150.0f; // Above initial upper threshold
    uint32_t timestamp = get_mock_timestamp();

    // Trigger an alert first
    alert_manager.checkAltitudeAlert(altitude, timestamp);
    EXPECT_TRUE(alert_manager.hasActiveAlerts());

    // Act - change thresholds
    alert_manager.setAltitudeThresholds(200.0f, -100.0f);

    // Assert
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_EQ(alert_manager.getActiveAlerts().size(), 0);
}

// Test case: 特殊场景测试 - 多次调用 checkAltitudeAlert 应正确处理状态切换
TEST_F(AlertManagerTest, testCheckAltitudeAlertStateTransition) {
    // Arrange
    float altitude_high = 100.1f;
    float altitude_low = -50.1f;
    float altitude_normal = 50.0f;
    uint32_t timestamp1 = get_mock_timestamp();
    uint32_t timestamp2 = get_mock_timestamp() + 1;
    uint32_t timestamp3 = get_mock_timestamp() + 2;

    // Act - trigger both alerts
    alert_manager.checkAltitudeAlert(altitude_high, timestamp1);
    alert_manager.checkAltitudeAlert(altitude_low, timestamp2);
    EXPECT_TRUE(alert_manager.hasActiveAlerts());
    EXPECT_EQ(alert_manager.getActiveAlerts().size(), 2);

    // Act - restore to normal
    alert_manager.checkAltitudeAlert(altitude_normal, timestamp3);

    // Assert
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
    EXPECT_EQ(alert_manager.getActiveAlerts().size(), 0);
}