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

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
extern "C" uint32_t time(nullptr) {
    return mock_timestamp;
}

// Helper function to get current timestamp
uint32_t getCurrentTimestamp() {
    return mock_timestamp;
}

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

    void SetUp() override {
        mock_timestamp = 1640995200;
        alert_manager.initialize();
    }

    void TearDown() override {
        // Reset state
        alert_manager.resetAllAlerts();
    }
};

// Test case: checkAltitudeAlert - Normal input test
TEST_F(AlertManagerTest, testCheckAltitudeAlertNormalInput) {
    // Arrange
    float altitude = 80.0f; // Within normal range
    uint32_t timestamp = getCurrentTimestamp();

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

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

// Test case: checkAltitudeAlert - Upper threshold exceeded
TEST_F(AlertManagerTest, testCheckAltitudeAlertUpperThresholdExceeded) {
    // Arrange
    float altitude = 150.0f; // Above upper threshold (100.0f)
    uint32_t timestamp = getCurrentTimestamp();

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

// Test case: checkAltitudeAlert - Lower threshold exceeded
TEST_F(AlertManagerTest, testCheckAltitudeAlertLowerThresholdExceeded) {
    // Arrange
    float altitude = -60.0f; // Below lower threshold (-50.0f)
    uint32_t timestamp = getCurrentTimestamp();

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

// Test case: checkAltitudeAlert - Recovery from upper threshold
TEST_F(AlertManagerTest, testCheckAltitudeAlertUpperThresholdRecovery) {
    // Arrange
    float altitude_above = 150.0f; // Trigger alert
    float altitude_normal = 80.0f; // Recover
    uint32_t timestamp1 = getCurrentTimestamp();
    uint32_t timestamp2 = getCurrentTimestamp() + 1;

    // Act
    alert_manager.checkAltitudeAlert(altitude_above, timestamp1);
    alert_manager.checkAltitudeAlert(altitude_normal, timestamp2);

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

// Test case: checkAltitudeAlert - Recovery from lower threshold
TEST_F(AlertManagerTest, testCheckAltitudeAlertLowerThresholdRecovery) {
    // Arrange
    float altitude_below = -60.0f; // Trigger alert
    float altitude_normal = -40.0f; // Recover
    uint32_t timestamp1 = getCurrentTimestamp();
    uint32_t timestamp2 = getCurrentTimestamp() + 1;

    // Act
    alert_manager.checkAltitudeAlert(altitude_below, timestamp1);
    alert_manager.checkAltitudeAlert(altitude_normal, timestamp2);

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

// Test case: setAltitudeThresholds - Normal input test
TEST_F(AlertManagerTest, testSetAltitudeThresholdsNormalInput) {
    // Arrange
    float upper = 200.0f;
    float lower = -100.0f;

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

    // Assert
    EXPECT_EQ(alert_manager.getAltitudeThresholds().first, upper);
    EXPECT_EQ(alert_manager.getAltitudeThresholds().second, lower);
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

// Test case: setAltitudeThresholds - Invalid input (upper <= lower)
TEST_F(AlertManagerTest, testSetAltitudeThresholdsInvalidInput) {
    // Arrange
    float upper = 50.0f;
    float lower = 100.0f;

    // Act & Assert
    EXPECT_NO_THROW(alert_manager.setAltitudeThresholds(upper, lower));
    // Note: The function prints error but does not throw exception
    // So we cannot use EXPECT_THROW here.
    // Instead, verify that thresholds were not updated
    EXPECT_EQ(alert_manager.getAltitudeThresholds().first, 100.0f); // Still default
    EXPECT_EQ(alert_manager.getAltitudeThresholds().second, -50.0f); // Still default
}

// Test case: setAltitudeThresholds - Edge case: upper == lower
TEST_F(AlertManagerTest, testSetAltitudeThresholdsEdgeCaseEqual) {
    // Arrange
    float upper = 100.0f;
    float lower = 100.0f;

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

    // Assert
    EXPECT_EQ(alert_manager.getAltitudeThresholds().first, 100.0f);
    EXPECT_EQ(alert_manager.getAltitudeThresholds().second, 100.0f);
    // But since upper <= lower, it should not be accepted
    // Verify no change in actual thresholds
    EXPECT_EQ(alert_manager.getAltitudeThresholds().first, 100.0f);
    EXPECT_EQ(alert_manager.getAltitudeThresholds().second, -50.0f);
}

// Test case: setAltitudeThresholds - Reset alerts after threshold change
TEST_F(AlertManagerTest, testSetAltitudeThresholdsResetAlerts) {
    // Arrange
    float altitude = 150.0f;
    uint32_t timestamp = getCurrentTimestamp();

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

    // Change thresholds
    float new_upper = 200.0f;
    float new_lower = -100.0f;

    // Act
    alert_manager.setAltitudeThresholds(new_upper, new_lower);

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

// Test case: checkAltitudeAlert - Multiple consecutive calls
TEST_F(AlertManagerTest, testCheckAltitudeAlertMultipleCalls) {
    // Arrange
    float altitude = 150.0f;
    uint32_t timestamp = getCurrentTimestamp();

    // Act
    alert_manager.checkAltitudeAlert(altitude, timestamp);
    alert_manager.checkAltitudeAlert(altitude, timestamp + 1);

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

// Test case: setAltitudeThresholds - Valid input with negative values
TEST_F(AlertManagerTest, testSetAltitudeThresholdsValidNegative) {
    // Arrange
    float upper = -10.0f;
    float lower = -50.0f;

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

    // Assert
    EXPECT_EQ(alert_manager.getAltitudeThresholds().first, upper);
    EXPECT_EQ(alert_manager.getAltitudeThresholds().second, lower);
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

// Test case: checkAltitudeAlert - Zero altitude
TEST_F(AlertManagerTest, testCheckAltitudeAlertZeroAltitude) {
    // Arrange
    float altitude = 0.0f;
    uint32_t timestamp = getCurrentTimestamp();

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

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

// Test case: setAltitudeThresholds - Max float values
TEST_F(AlertManagerTest, testSetAltitudeThresholdsMaxFloat) {
    // Arrange
    float upper = std::numeric_limits<float>::max();
    float lower = std::numeric_limits<float>::lowest();

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

    // Assert
    EXPECT_EQ(alert_manager.getAltitudeThresholds().first, upper);
    EXPECT_EQ(alert_manager.getAltitudeThresholds().second, lower);
    EXPECT_FALSE(alert_manager.hasActiveAlerts());
}

// Test case: checkAltitudeAlert - Altitude exactly at upper threshold
TEST_F(AlertManagerTest, testCheckAltitudeAlertAtUpperThreshold) {
    // Arrange
    float altitude = 100.0f; // Exactly equal to upper threshold
    uint32_t timestamp = getCurrentTimestamp();

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

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

// Test case: checkAltitudeAlert - Altitude exactly at lower threshold
TEST_F(AlertManagerTest, testCheckAltitudeAlertAtLowerThreshold) {
    // Arrange
    float altitude = -50.0f; // Exactly equal to lower threshold
    uint32_t timestamp = getCurrentTimestamp();

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

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