High-Level Design (HLD) for Offline Snake Game Feature in an E-Commerce App

1. Title and Overview

This document presents the High-Level Design (HLD) for an Offline Snake Game in an Android e-commerce app. This feature ensures user engagement when the internet connection is lost by launching a classic Snake Game. The game is dismissed once the internet connection is restored, and the user resumes shopping.

2. Functional Requirements

• Detect internet disconnection while the user is browsing.
• Seamlessly transition to an offline Snake Game.
• Allow the user to interact with and play the game.
• Automatically close the game when internet connectivity is restored.
• Resume the user’s previous shopping session without data loss.

3. Non-Functional Requirements

• Performance: The game should run smoothly without lag.
• Scalability: This should work across multiple Android devices with minimal resource usage.
• Battery Efficiency: The game should consume minimal power.
• Security: No user data should be collected or transmitted.
• Usability: The transition between the app and the game should be seamless.

4. System Architecture

Component Diagram

5. Design Components

1. Network Manager

Detects internet connectivity and notifies other components.

class NetworkManager(context: Context) {
    private val connectivityManager =
        context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager

    fun isInternetAvailable(): Boolean {
        val network = connectivityManager.activeNetwork ?: return false
        val capabilities = connectivityManager.getNetworkCapabilities(network) ?: return false
        return capabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
    }
}

2. Snake Game UI

It uses Jetpack Compose for rendering.

@Composable
fun SnakeGameScreen(viewModel: SnakeGameViewModel) {
    val gameState by viewModel.gameState.collectAsState()
    
    Box(modifier = Modifier.fillMaxSize()) {
        SnakeGameCanvas(gameState)
    }
}

3. ViewModel for Snake Game

Handles game state and listens for network changes.

class SnakeGameViewModel(private val networkManager: NetworkManager) : ViewModel() {
    private val _gameState = MutableStateFlow(GameState())
    val gameState: StateFlow<GameState> = _gameState

    init {
        viewModelScope.launch {
            while (!networkManager.isInternetAvailable()) {
                _gameState.value = _gameState.value.update()
                delay(100) // Game frame rate
            }
        }
    }
}

4. Room Database (Optional)

Stores game state for persistence.

@Entity
data class SnakeGameState(
    @PrimaryKey val id: Int = 1,
    val score: Int,
    val snakePosition: String // Serialized position data
)

6. Data Flow

7. Error Handling

• If the game crashes, fall back to the main shopping interface.
• If the app cannot detect internet status, retry using exponential backoff.
• If the game fails to load, show a simple offline message instead.

8. Security Considerations

• No sensitive user data is stored or transmitted.
• The feature operates entirely offline, ensuring data privacy.
• Securely handles network status changes to avoid exploits.

9. Technology Stack

• Android SDK (Kotlin, Jetpack Compose) — UI development.
• MVVM Architecture — Ensures separation of concerns.
• Room Database — Optional offline game state storage.
• Coroutines & Flow — Handles asynchronous updates.
• Connectivity Manager — Monitors network changes.

10. Challenges and Mitigation

Challenge 1: Ensuring Smooth Transition

• Mitigation: Use animated transitions to prevent a jarring user experience.

Challenge 2: Managing Resource Consumption

• Mitigation: Optimize rendering and use background thread processing.

Challenge 3: Handling Frequent Network Fluctuations

• Mitigation: Introduce a threshold delay before switching to the game.

11. Monitoring and Metrics

• User Engagement: Track how long users interact with the game.
• Crash Reports: Monitor app stability with Firebase Crashlytics.
• Battery Usage: Measure power consumption and optimize accordingly.
• Network Recovery Timing: Analyze average downtime duration.

12. Conclusion

The Offline Snake Game enhances user experience by keeping users engaged when internet connectivity is lost. By leveraging Jetpack Compose, MVVM, and Coroutines, we ensure a scalable, high-performance, and user-friendly implementation.