refactoring to a proper MVVM

TODO.md

@@ -0,0 +1,75 @@
+# LocalChat (lchat) - Improvement Plan
+
+## Phase 1: Architecture Foundation
+
+### 1.1 MVVM with ViewModels and Repository Pattern ✅
+- [x] Create ViewModels for each screen (LobbyViewModel, ChatViewModel)
+- [x] Extract business logic from Fragments to ViewModels
+- [x] Create Repository layer for data operations
+- [x] Implement proper state management with LiveData/StateFlow
+- [x] Add ViewModelFactory if needed
+
+### 1.2 Dependency Injection with Hilt
+- [ ] Add Hilt dependencies
+- [ ] Set up Hilt modules for WifiAwareManager
+- [ ] Convert singletons to proper DI
+- [ ] Inject ViewModels using Hilt
+
+## Phase 2: Core UX Improvements
+
+### 2.1 Connection Status Management
+- [ ] Add connection state to ViewModels
+- [ ] Create UI indicator for connection status
+- [ ] Show real-time connection state changes
+- [ ] Add connection error messages
+
+### 2.2 User List Feature
+- [ ] Track connected users in Repository
+- [ ] Add UI to display active users
+- [ ] Handle user join/leave events
+- [ ] Show user count in chat header
+
+## Phase 3: Data Persistence
+
+### 3.1 Room Database Setup
+- [ ] Add Room dependencies
+- [ ] Create Message and User entities
+- [ ] Implement DAOs for data access
+- [ ] Create database migrations
+
+### 3.2 Message Persistence
+- [ ] Store messages in Room database
+- [ ] Load message history on app restart
+- [ ] Implement message sync logic
+- [ ] Add message timestamps
+
+## Phase 4: Reliability Improvements
+
+### 4.1 Reconnection Handling
+- [ ] Detect connection drops
+- [ ] Implement exponential backoff retry
+- [ ] Preserve message queue during disconnection
+- [ ] Auto-reconnect when network available
+
+### 4.2 Network State Monitoring
+- [ ] Monitor WiFi state changes
+- [ ] Handle app lifecycle properly
+- [ ] Save and restore connection state
+
+## Phase 5: Advanced Features
+
+### 5.1 Background Service
+- [ ] Create foreground service for persistent connection
+- [ ] Handle Doze mode and battery optimization
+- [ ] Add notification for active chat
+- [ ] Implement proper service lifecycle
+
+### 5.2 Additional Features
+- [ ] Message delivery status
+- [ ] Typing indicators
+- [ ] File/image sharing support
+- [ ] Message encryption improvements
+
+## Current Status
+- 🚀 Starting with Phase 1.1 - MVVM Architecture
+- Target: Create a maintainable, testable architecture

app/src/main/java/com/mattintech/lchat/data/Message.kt

@@ -2,9 +2,9 @@ package com.mattintech.lchat.data
 
 data class Message(
     val id: String,
-    val senderId: String,
+    val userId: String,
-    val senderName: String,
+    val userName: String,
     val content: String,
     val timestamp: Long,
-    val isLocal: Boolean = false
+    val isOwnMessage: Boolean = false
 )

app/src/main/java/com/mattintech/lchat/network/WifiAwareManagerSingleton.kt

@@ -1,20 +0,0 @@
-package com.mattintech.lchat.network
-
-import android.content.Context
-
-object WifiAwareManagerSingleton {
-    private var instance: WifiAwareManager? = null
-    
-    fun getInstance(context: Context): WifiAwareManager {
-        if (instance == null) {
-            instance = WifiAwareManager(context.applicationContext)
-            instance!!.initialize()
-        }
-        return instance!!
-    }
-    
-    fun reset() {
-        instance?.stop()
-        instance = null
-    }
-}

app/src/main/java/com/mattintech/lchat/repository/ChatRepository.kt

@@ -0,0 +1,111 @@
+package com.mattintech.lchat.repository
+
+import android.content.Context
+import com.mattintech.lchat.data.Message
+import com.mattintech.lchat.network.WifiAwareManager
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import java.util.UUID
+
+class ChatRepository private constructor(context: Context) {
+    
+    companion object {
+        @Volatile
+        private var INSTANCE: ChatRepository? = null
+        
+        fun getInstance(context: Context): ChatRepository {
+            return INSTANCE ?: synchronized(this) {
+                INSTANCE ?: ChatRepository(context.applicationContext).also { INSTANCE = it }
+            }
+        }
+    }
+    
+    private val wifiAwareManager = WifiAwareManager(context)
+    
+    private val _messages = MutableStateFlow<List<Message>>(emptyList())
+    val messages: StateFlow<List<Message>> = _messages.asStateFlow()
+    
+    private val _connectionState = MutableStateFlow<ConnectionState>(ConnectionState.Disconnected)
+    val connectionState: StateFlow<ConnectionState> = _connectionState.asStateFlow()
+    
+    private val _connectedUsers = MutableStateFlow<List<String>>(emptyList())
+    val connectedUsers: StateFlow<List<String>> = _connectedUsers.asStateFlow()
+    
+    private var messageCallback: ((String, String, String) -> Unit)? = null
+    private var connectionCallback: ((String, Boolean) -> Unit)? = null
+    
+    init {
+        wifiAwareManager.initialize()
+        setupWifiAwareCallbacks()
+    }
+    
+    private fun setupWifiAwareCallbacks() {
+        wifiAwareManager.setMessageCallback { userId, userName, content ->
+            val message = Message(
+                id = UUID.randomUUID().toString(),
+                userId = userId,
+                userName = userName,
+                content = content,
+                timestamp = System.currentTimeMillis(),
+                isOwnMessage = false
+            )
+            addMessage(message)
+            messageCallback?.invoke(userId, userName, content)
+        }
+    }
+    
+    fun startHostMode(roomName: String) {
+        wifiAwareManager.startHostMode(roomName)
+        _connectionState.value = ConnectionState.Hosting(roomName)
+    }
+    
+    fun startClientMode() {
+        wifiAwareManager.startClientMode()
+        _connectionState.value = ConnectionState.Searching
+    }
+    
+    fun sendMessage(userId: String, userName: String, content: String) {
+        val message = Message(
+            id = UUID.randomUUID().toString(),
+            userId = userId,
+            userName = userName,
+            content = content,
+            timestamp = System.currentTimeMillis(),
+            isOwnMessage = true
+        )
+        addMessage(message)
+        wifiAwareManager.sendMessage(userId, userName, content)
+    }
+    
+    private fun addMessage(message: Message) {
+        _messages.value = _messages.value + message
+    }
+    
+    fun clearMessages() {
+        _messages.value = emptyList()
+    }
+    
+    fun setMessageCallback(callback: (String, String, String) -> Unit) {
+        messageCallback = callback
+    }
+    
+    fun setConnectionCallback(callback: (String, Boolean) -> Unit) {
+        connectionCallback = callback
+        wifiAwareManager.setConnectionCallback(callback)
+    }
+    
+    fun stop() {
+        wifiAwareManager.stop()
+        _connectionState.value = ConnectionState.Disconnected
+        _connectedUsers.value = emptyList()
+    }
+    
+    sealed class ConnectionState {
+        object Disconnected : ConnectionState()
+        object Searching : ConnectionState()
+        data class Hosting(val roomName: String) : ConnectionState()
+        data class Connected(val roomName: String) : ConnectionState()
+        data class Error(val message: String) : ConnectionState()
+    }
+}

app/src/main/java/com/mattintech/lchat/ui/ChatFragment.kt

@@ -6,15 +6,16 @@ import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import androidx.fragment.app.Fragment
+import androidx.lifecycle.ViewModelProvider
+import androidx.lifecycle.lifecycleScope
 import androidx.navigation.fragment.navArgs
 import androidx.recyclerview.widget.LinearLayoutManager
-import com.mattintech.lchat.data.Message
 import com.mattintech.lchat.databinding.FragmentChatBinding
-import com.mattintech.lchat.network.WifiAwareManager
-import com.mattintech.lchat.network.WifiAwareManagerSingleton
 import com.mattintech.lchat.ui.adapters.MessageAdapter
 import com.mattintech.lchat.utils.LOG_PREFIX
-import java.util.UUID
+import com.mattintech.lchat.viewmodel.ChatViewModel
+import com.mattintech.lchat.viewmodel.ViewModelFactory
+import kotlinx.coroutines.launch
 
 class ChatFragment : Fragment() {
     
@@ -26,10 +27,8 @@ class ChatFragment : Fragment() {
     private val binding get() = _binding!!
     
     private val args: ChatFragmentArgs by navArgs()
-    private lateinit var wifiAwareManager: WifiAwareManager
+    private lateinit var viewModel: ChatViewModel
     private lateinit var messageAdapter: MessageAdapter
-    private val messages = mutableListOf<Message>()
-    private val userId = UUID.randomUUID().toString()
     
     override fun onCreateView(
         inflater: LayoutInflater,
@@ -45,8 +44,12 @@ class ChatFragment : Fragment() {
         super.onViewCreated(view, savedInstanceState)
         Log.d(TAG, "onViewCreated - room: ${args.roomName}, user: ${args.userName}, isHost: ${args.isHost}")
         
+        val factory = ViewModelFactory(requireContext())
+        viewModel = ViewModelProvider(this, factory)[ChatViewModel::class.java]
+        viewModel.initialize(args.roomName, args.userName, args.isHost)
+        
         setupUI()
-        setupWifiAware()
+        observeViewModel()
     }
     
     private fun setupUI() {
@@ -68,58 +71,35 @@ class ChatFragment : Fragment() {
         }
     }
     
-    private fun setupWifiAware() {
+    private fun observeViewModel() {
-        wifiAwareManager = WifiAwareManagerSingleton.getInstance(requireContext())
+        lifecycleScope.launch {
-        
+            viewModel.messages.collect { messages ->
-        wifiAwareManager.setMessageCallback { senderId, senderName, content ->
+                messageAdapter.submitList(messages)
-            Log.d(TAG, "Message received - from: $senderName, content: $content")
+                if (messages.isNotEmpty()) {
-            val message = Message(
+                    binding.messagesRecyclerView.smoothScrollToPosition(messages.size - 1)
-                id = UUID.randomUUID().toString(),
+                }
-                senderId = senderId,
-                senderName = senderName,
-                content = content,
-                timestamp = System.currentTimeMillis(),
-                isLocal = senderId == userId
-            )
-            
-            activity?.runOnUiThread {
-                messages.add(message)
-                messageAdapter.submitList(messages.toList())
-                binding.messagesRecyclerView.smoothScrollToPosition(messages.size - 1)
             }
         }
         
-        // No need to start host mode here - already started in LobbyFragment
+        lifecycleScope.launch {
-        Log.d(TAG, "Chat setup complete - isHost: ${args.isHost}, room: ${args.roomName}")
+            viewModel.connectionState.collect { state ->
+                Log.d(TAG, "Connection state: $state")
+                // Handle connection state changes if needed
+            }
+        }
     }
     
     private fun sendMessage() {
         val content = binding.messageInput.text?.toString()?.trim()
         if (content.isNullOrEmpty()) return
         
-        val message = Message(
+        viewModel.sendMessage(content)
-            id = UUID.randomUUID().toString(),
-            senderId = userId,
-            senderName = args.userName,
-            content = content,
-            timestamp = System.currentTimeMillis(),
-            isLocal = true
-        )
-        
-        messages.add(message)
-        messageAdapter.submitList(messages.toList())
-        binding.messagesRecyclerView.smoothScrollToPosition(messages.size - 1)
-        
-        Log.d(TAG, "Sending message: $content")
-        wifiAwareManager.sendMessage(userId, args.userName, content)
-        
         binding.messageInput.text?.clear()
     }
     
     override fun onDestroyView() {
         super.onDestroyView()
         Log.d(TAG, "onDestroyView")
-        // Don't stop WifiAwareManager here - it's shared across fragments
         _binding = null
     }
 }

app/src/main/java/com/mattintech/lchat/ui/LobbyFragment.kt

@@ -11,8 +11,10 @@ import androidx.lifecycle.ViewModelProvider
 import androidx.navigation.fragment.findNavController
 import com.mattintech.lchat.R
 import com.mattintech.lchat.databinding.FragmentLobbyBinding
-import com.mattintech.lchat.network.WifiAwareManager
+import com.mattintech.lchat.viewmodel.LobbyEvent
-import com.mattintech.lchat.network.WifiAwareManagerSingleton
+import com.mattintech.lchat.viewmodel.LobbyState
+import com.mattintech.lchat.viewmodel.LobbyViewModel
+import com.mattintech.lchat.viewmodel.ViewModelFactory
 import com.mattintech.lchat.utils.LOG_PREFIX
 
 class LobbyFragment : Fragment() {
@@ -24,7 +26,7 @@ class LobbyFragment : Fragment() {
     private var _binding: FragmentLobbyBinding? = null
     private val binding get() = _binding!!
     
-    private lateinit var wifiAwareManager: WifiAwareManager
+    private lateinit var viewModel: LobbyViewModel
     
     override fun onCreateView(
         inflater: LayoutInflater,
@@ -40,10 +42,11 @@ class LobbyFragment : Fragment() {
         super.onViewCreated(view, savedInstanceState)
         Log.d(TAG, "onViewCreated")
         
-        Log.d(TAG, "Getting WifiAwareManager singleton")
+        val factory = ViewModelFactory(requireContext())
-        wifiAwareManager = WifiAwareManagerSingleton.getInstance(requireContext())
+        viewModel = ViewModelProvider(this, factory)[LobbyViewModel::class.java]
         
         setupUI()
+        observeViewModel()
     }
     
     private fun setupUI() {
@@ -64,55 +67,61 @@ class LobbyFragment : Fragment() {
         }
         
         binding.actionButton.setOnClickListener {
-            val userName = binding.nameInput.text?.toString()?.trim()
+            val userName = binding.nameInput.text?.toString()?.trim() ?: ""
-            
-            if (userName.isNullOrEmpty()) {
-                Toast.makeText(context, "Please enter your name", Toast.LENGTH_SHORT).show()
-                return@setOnClickListener
-            }
             
             when (binding.modeRadioGroup.checkedRadioButtonId) {
                 R.id.hostRadio -> {
-                    val roomName = binding.roomInput.text?.toString()?.trim()
+                    val roomName = binding.roomInput.text?.toString()?.trim() ?: ""
-                    if (roomName.isNullOrEmpty()) {
+                    viewModel.startHostMode(roomName, userName)
-                        Toast.makeText(context, "Please enter a room name", Toast.LENGTH_SHORT).show()
-                        return@setOnClickListener
-                    }
-                    startHostMode(roomName, userName)
                 }
                 R.id.clientRadio -> {
-                    startClientMode(userName)
+                    viewModel.startClientMode(userName)
+                }
+            }
+        }
+    }
+    
+    private fun observeViewModel() {
+        viewModel.state.observe(viewLifecycleOwner) { state ->
+            when (state) {
+                is LobbyState.Idle -> {
+                    binding.noRoomsText.visibility = View.GONE
+                }
+                is LobbyState.Connecting -> {
+                    if (binding.modeRadioGroup.checkedRadioButtonId == R.id.clientRadio) {
+                        binding.noRoomsText.visibility = View.VISIBLE
+                        binding.noRoomsText.text = getString(R.string.connecting)
+                    }
+                }
+                is LobbyState.Connected -> {
+                    if (binding.modeRadioGroup.checkedRadioButtonId == R.id.clientRadio) {
+                        val userName = binding.nameInput.text?.toString()?.trim() ?: ""
+                        viewModel.onConnectedToRoom(state.roomName, userName)
+                    }
+                }
+                is LobbyState.Error -> {
+                    binding.noRoomsText.visibility = View.VISIBLE
+                    binding.noRoomsText.text = state.message
+                    Toast.makeText(context, state.message, Toast.LENGTH_LONG).show()
                 }
             }
         }
         
-        wifiAwareManager.setConnectionCallback { roomName, isConnected ->
+        viewModel.events.observe(viewLifecycleOwner) { event ->
-            Log.d(TAG, "Connection callback - room: $roomName, connected: $isConnected")
+            when (event) {
-            activity?.runOnUiThread {
+                is LobbyEvent.NavigateToChat -> {
-                if (isConnected && binding.modeRadioGroup.checkedRadioButtonId == R.id.clientRadio) {
+                    navigateToChat(event.roomName, event.userName, event.isHost)
-                    val userName = binding.nameInput.text?.toString()?.trim() ?: ""
+                    viewModel.clearEvent()
-                    navigateToChat(roomName, userName, false)
-                } else if (!isConnected && binding.modeRadioGroup.checkedRadioButtonId == R.id.clientRadio) {
-                    binding.noRoomsText.text = "Failed to connect to $roomName. Ensure Wi-Fi is enabled on both devices."
-                    Toast.makeText(context, "Connection failed. Check Wi-Fi is enabled.", Toast.LENGTH_LONG).show()
                 }
+                is LobbyEvent.ShowError -> {
+                    Toast.makeText(context, event.message, Toast.LENGTH_SHORT).show()
+                    viewModel.clearEvent()
+                }
+                null -> {}
             }
         }
     }
     
-    private fun startHostMode(roomName: String, userName: String) {
-        Log.d(TAG, "Starting host mode - room: $roomName, user: $userName")
-        wifiAwareManager.startHostMode(roomName)
-        navigateToChat(roomName, userName, true)
-    }
-    
-    private fun startClientMode(userName: String) {
-        Log.d(TAG, "Starting client mode - user: $userName")
-        binding.noRoomsText.visibility = View.VISIBLE
-        binding.noRoomsText.text = getString(R.string.connecting)
-        wifiAwareManager.startClientMode()
-    }
-    
     private fun navigateToChat(roomName: String, userName: String, isHost: Boolean) {
         Log.d(TAG, "Navigating to chat - room: $roomName, user: $userName, isHost: $isHost")
         val action = LobbyFragmentDirections.actionLobbyToChat(

app/src/main/java/com/mattintech/lchat/ui/adapters/MessageAdapter.kt

@@ -35,12 +35,12 @@ class MessageAdapter : ListAdapter<Message, MessageAdapter.MessageViewHolder>(Me
     ) : RecyclerView.ViewHolder(binding.root) {
         
         fun bind(message: Message) {
-            binding.senderName.text = message.senderName
+            binding.senderName.text = message.userName
             binding.messageContent.text = message.content
             binding.timestamp.text = timeFormat.format(Date(message.timestamp))
             
             val layoutParams = binding.messageCard.layoutParams as ConstraintLayout.LayoutParams
-            if (message.isLocal) {
+            if (message.isOwnMessage) {
                 layoutParams.startToStart = ConstraintLayout.LayoutParams.UNSET
                 layoutParams.endToEnd = ConstraintLayout.LayoutParams.PARENT_ID
                 binding.messageCard.setCardBackgroundColor(

app/src/main/java/com/mattintech/lchat/viewmodel/ChatViewModel.kt

@@ -0,0 +1,89 @@
+package com.mattintech.lchat.viewmodel
+
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.mattintech.lchat.data.Message
+import com.mattintech.lchat.repository.ChatRepository
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.stateIn
+import kotlinx.coroutines.launch
+import java.util.UUID
+
+sealed class ChatState {
+    object Connected : ChatState()
+    object Disconnected : ChatState()
+    data class Error(val message: String) : ChatState()
+}
+
+class ChatViewModel(
+    private val chatRepository: ChatRepository
+) : ViewModel() {
+    
+    private val _state = MutableLiveData<ChatState>(ChatState.Connected)
+    val state: LiveData<ChatState> = _state
+    
+    val messages: StateFlow<List<Message>> = chatRepository.messages
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5000),
+            initialValue = emptyList()
+        )
+    
+    val connectionState = chatRepository.connectionState
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5000),
+            initialValue = ChatRepository.ConnectionState.Disconnected
+        )
+    
+    val connectedUsers = chatRepository.connectedUsers
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5000),
+            initialValue = emptyList()
+        )
+    
+    private var currentUserId: String = ""
+    private var currentUserName: String = ""
+    private var currentRoomName: String = ""
+    private var isHost: Boolean = false
+    
+    fun initialize(roomName: String, userName: String, isHost: Boolean) {
+        this.currentRoomName = roomName
+        this.currentUserName = userName
+        this.isHost = isHost
+        this.currentUserId = UUID.randomUUID().toString()
+        
+        // Setup message callback if needed for additional processing
+        chatRepository.setMessageCallback { userId, userName, content ->
+            // Can add additional message processing here if needed
+        }
+    }
+    
+    fun sendMessage(content: String) {
+        if (content.isBlank()) return
+        
+        viewModelScope.launch {
+            chatRepository.sendMessage(currentUserId, currentUserName, content)
+        }
+    }
+    
+    fun getRoomInfo(): Triple<String, String, Boolean> {
+        return Triple(currentRoomName, currentUserName, isHost)
+    }
+    
+    fun disconnect() {
+        viewModelScope.launch {
+            chatRepository.stop()
+            _state.value = ChatState.Disconnected
+        }
+    }
+    
+    override fun onCleared() {
+        super.onCleared()
+        disconnect()
+    }
+}

app/src/main/java/com/mattintech/lchat/viewmodel/LobbyViewModel.kt

@@ -0,0 +1,94 @@
+package com.mattintech.lchat.viewmodel
+
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.mattintech.lchat.repository.ChatRepository
+import kotlinx.coroutines.launch
+
+sealed class LobbyState {
+    object Idle : LobbyState()
+    object Connecting : LobbyState()
+    data class Connected(val roomName: String) : LobbyState()
+    data class Error(val message: String) : LobbyState()
+}
+
+sealed class LobbyEvent {
+    data class NavigateToChat(
+        val roomName: String,
+        val userName: String,
+        val isHost: Boolean
+    ) : LobbyEvent()
+    data class ShowError(val message: String) : LobbyEvent()
+}
+
+class LobbyViewModel(
+    private val chatRepository: ChatRepository
+) : ViewModel() {
+    
+    private val _state = MutableLiveData<LobbyState>(LobbyState.Idle)
+    val state: LiveData<LobbyState> = _state
+    
+    private val _events = MutableLiveData<LobbyEvent?>()
+    val events: LiveData<LobbyEvent?> = _events
+    
+    init {
+        setupConnectionCallback()
+    }
+    
+    private fun setupConnectionCallback() {
+        chatRepository.setConnectionCallback { roomName, isConnected ->
+            viewModelScope.launch {
+                if (isConnected) {
+                    _state.value = LobbyState.Connected(roomName)
+                } else {
+                    _state.value = LobbyState.Error("Failed to connect to $roomName. Ensure Wi-Fi is enabled on both devices.")
+                }
+            }
+        }
+    }
+    
+    fun startHostMode(roomName: String, userName: String) {
+        if (roomName.isBlank()) {
+            _events.value = LobbyEvent.ShowError("Please enter a room name")
+            return
+        }
+        
+        if (userName.isBlank()) {
+            _events.value = LobbyEvent.ShowError("Please enter your name")
+            return
+        }
+        
+        viewModelScope.launch {
+            _state.value = LobbyState.Connecting
+            chatRepository.startHostMode(roomName)
+            _events.value = LobbyEvent.NavigateToChat(roomName, userName, true)
+        }
+    }
+    
+    fun startClientMode(userName: String) {
+        if (userName.isBlank()) {
+            _events.value = LobbyEvent.ShowError("Please enter your name")
+            return
+        }
+        
+        viewModelScope.launch {
+            _state.value = LobbyState.Connecting
+            chatRepository.startClientMode()
+        }
+    }
+    
+    fun onConnectedToRoom(roomName: String, userName: String) {
+        _events.value = LobbyEvent.NavigateToChat(roomName, userName, false)
+    }
+    
+    fun clearEvent() {
+        _events.value = null
+    }
+    
+    override fun onCleared() {
+        super.onCleared()
+        // Clean up resources if needed
+    }
+}

app/src/main/java/com/mattintech/lchat/viewmodel/ViewModelFactory.kt

@@ -0,0 +1,24 @@
+package com.mattintech.lchat.viewmodel
+
+import android.content.Context
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+import com.mattintech.lchat.repository.ChatRepository
+
+class ViewModelFactory(private val context: Context) : ViewModelProvider.Factory {
+    
+    private val chatRepository by lazy { ChatRepository.getInstance(context) }
+    
+    @Suppress("UNCHECKED_CAST")
+    override fun <T : ViewModel> create(modelClass: Class<T>): T {
+        return when {
+            modelClass.isAssignableFrom(LobbyViewModel::class.java) -> {
+                LobbyViewModel(chatRepository) as T
+            }
+            modelClass.isAssignableFrom(ChatViewModel::class.java) -> {
+                ChatViewModel(chatRepository) as T
+            }
+            else -> throw IllegalArgumentException("Unknown ViewModel class: ${modelClass.name}")
+        }
+    }
+}