Building a Real-Time Chat App with Stream's Android SDK, Jetpack Compose, and Offline AI Agents

dependencies {
    // Stream Chat SDK
    implementation "io.getstream:stream-chat-android:5.0.0"

    // Jetpack Compose
    implementation "androidx.compose.ui:ui:1.5.0"
    implementation "androidx.compose.material3:material3:1.1.0"
    implementation "androidx.lifecycle:lifecycle-viewmodel-compose:2.6.2"

    // TensorFlow Lite for offline AI
    implementation "org.tensorflow:tensorflow-lite:2.14.0"
    implementation "org.tensorflow:tensorflow-lite-support:0.4.0"

    // Coroutines
    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.7.3"
}

<uses-permission android:name="android.permission.INTERNET" />

class ChatApplication : Application() {
    override fun onCreate() {
        super.onCreate()
        val apiKey = "YOUR_STREAM_API_KEY"
        val chatClient = ChatClient.Builder(apiKey, this).build()
        // Set the chat client as a singleton or use dependency injection
        ChatClient.setInstance(chatClient)
    }
}

<application
    android:name=".ChatApplication"
    ... >
    ...
</application>

@Composable
fun ChatScreen(
    channelId: String,
    viewModel: ChatViewModel = viewModel()
) {
    val messages by viewModel.messages.collectAsStateWithLifecycle()
    val connectionState by viewModel.connectionState.collectAsStateWithLifecycle()

    Column(modifier = Modifier.fillMaxSize()) {
        when (connectionState) {
            ConnectionState.CONNECTED -> {
                MessageList(
                    messages = messages,
                    modifier = Modifier.weight(1f)
                )
                MessageInput(
                    onSendMessage = { text ->
                        viewModel.sendMessage(text)
                    },
                    modifier = Modifier.fillMaxWidth()
                )
            }
            else -> {
                CircularProgressIndicator(modifier = Modifier.align(Alignment.CenterHorizontally))
            }
        }
    }
}

@Composable
fun MessageList(
    messages: List<Message>,
    modifier: Modifier = Modifier
) {
    LazyColumn(
        modifier = modifier.padding(8.dp),
        reverseLayout = true
    ) {
        items(messages) { message ->
            MessageItem(message = message)
        }
    }
}

@Composable
fun MessageItem(message: Message) {
    val isCurrentUser = message.user.id == ChatClient.getCurrentUser()?.id
    val backgroundColor = if (isCurrentUser) Color.Blue else Color.Gray
    val textColor = if (isCurrentUser) Color.White else Color.Black

    Row(
        modifier = Modifier
            .fillMaxWidth()
            .padding(vertical = 4.dp),
        horizontalArrangement = if (isCurrentUser) Arrangement.End else Arrangement.Start
    ) {
        Surface(
            color = backgroundColor,
            shape = RoundedCornerShape(8.dp)
        ) {
            Text(
                text = message.text,
                color = textColor,
                modifier = Modifier.padding(12.dp)
            )
        }
    }
}

class ChatViewModel(
    private val chatClient: ChatClient = ChatClient.instance()
) : ViewModel() {
    private val _messages = MutableStateFlow<List<Message>>(emptyList())
    val messages: StateFlow<List<Message>> = _messages.asStateFlow()

    private val _connectionState = MutableStateFlow<ConnectionState>(ConnectionState.INITIAL)
    val connectionState: StateFlow<ConnectionState> = _connectionState.asStateFlow()

    init {
        connectToChannel()
    }

    private fun connectToChannel() {
        viewModelScope.launch {
            val channel = chatClient.channel("messaging", "general")
            channel.watch().await()
            _connectionState.value = ConnectionState.CONNECTED
            channel.messages.collect { messageList ->
                _messages.value = messageList
            }
        }
    }

    fun sendMessage(text: String) {
        viewModelScope.launch {
            val channel = chatClient.channel("messaging", "general")
            channel.sendMessage(Message(text = text)).await()
        }
    }
}

class AiAgent(context: Context) {
    private val interpreter: Interpreter
    private val tokenizer: Tokenizer

    init {
        // Load the TensorFlow Lite model
        val model = FileUtil.loadMappedFile(context, "ai_model.tflite")
        interpreter = Interpreter(model)
        tokenizer = Tokenizer(context)
    }

    fun generateResponse(input: String): String {
        val tokens = tokenizer.encode(input)
        val output = Array(1) { FloatArray(100) }
        interpreter.run(tokens, output)
        return tokenizer.decode(output[0])
    }
}

class ChatViewModel(
    private val chatClient: ChatClient = ChatClient.instance(),
    private val aiAgent: AiAgent = AiAgent.get()
) : ViewModel() {
    // ... existing code ...

    fun sendMessage(text: String) {
        viewModelScope.launch {
            val channel = chatClient.channel("messaging", "general")
            channel.sendMessage(Message(text = text)).await()

            // Check if network is available
            if (!isNetworkAvailable()) {
                val aiResponse = aiAgent.generateResponse(text)
                channel.sendMessage(Message(text = aiResponse)).await()
            }
        }
    }

    private fun isNetworkAvailable(): Boolean {
        val connectivityManager = getApplication<Application>().getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
        val network = connectivityManager.activeNetwork ?: return false
        val capabilities = connectivityManager.getNetworkCapabilities(network) ?: return false
        return capabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
    }
}