composeApp/src/androidMain/kotlin/su/reya/coop/App.kt

@@ -6,14 +6,11 @@ import android.os.Build
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.BackHandler
 import androidx.compose.foundation.isSystemInDarkTheme
-import androidx.compose.foundation.layout.Box
-import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
 import androidx.compose.material3.MaterialExpressiveTheme
 import androidx.compose.material3.MotionScheme
 import androidx.compose.material3.SnackbarHostState
-import androidx.compose.material3.Text
 import androidx.compose.material3.Typography
 import androidx.compose.material3.darkColorScheme
 import androidx.compose.material3.dynamicDarkColorScheme
@@ -27,8 +24,6 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.runtime.staticCompositionLocalOf
-import androidx.compose.ui.Alignment
-import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.core.util.Consumer
 import androidx.lifecycle.ViewModel
@@ -235,34 +230,26 @@ fun App(
                         NewIdentityScreen(accountViewModel)
                     }
                     entry<Screen.Chat> { key ->
-                        val initialRoom = remember(key.id) { chatRepository.getChatRoom(key.id) }
-                        
-                        if (initialRoom != null) {
-                            val factory = remember(initialRoom) {
-                                object : ViewModelProvider.Factory {
-                                    override fun <T : ViewModel> create(modelClass: Class<T>): T {
-                                        return ChatScreenViewModel(
-                                            initialRoom,
-                                            key.screening,
-                                            accountRepository,
-                                            chatRepository
-                                        ) as T
-                                    }
+                        val factory = remember(key) {
+                            object : ViewModelProvider.Factory {
+                                override fun <T : ViewModel> create(modelClass: Class<T>): T {
+                                    @Suppress("UNCHECKED_CAST")
+                                    return ChatScreenViewModel(
+                                        key.id,
+                                        key.screening,
+                                        accountRepository,
+                                        chatRepository
+                                    ) as T
                                 }
                             }
-                            ChatScreen(
-                                viewModel<ChatScreenViewModel>(
-                                    key = key.id.toString(),
-                                    factory = factory
-                                ),
-                                accountViewModel
-                            )
-                        } else {
-                            // Handle the rare case where the room isn't in DB (e.g., invalid deep link)
-                            Box(Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
-                                Text("Room not found")
-                            }
                         }
+                        ChatScreen(
+                            viewModel<ChatScreenViewModel>(
+                                key = key.id.toString(),
+                                factory = factory
+                            ),
+                            accountViewModel
+                        )
                     }
                     entry<Screen.NewChat> {
                         NewChatScreen(accountViewModel, chatViewModel)

composeApp/src/androidMain/kotlin/su/reya/coop/screens/chat/ChatScreen.kt

@@ -94,11 +94,12 @@ import rust.nostr.sdk.UnsignedEvent
 import su.reya.coop.LocalNavigator
 import su.reya.coop.LocalProfileCache
 import su.reya.coop.LocalSnackbarHostState
+import su.reya.coop.Room
 import su.reya.coop.RoomUiState
 import su.reya.coop.Screen
-import su.reya.coop.flow
 import su.reya.coop.formatAsGroup
 import su.reya.coop.shared.Avatar
+import su.reya.coop.uiStateFlow
 import su.reya.coop.viewmodel.AccountViewModel
 import su.reya.coop.viewmodel.ChatScreenViewModel
 
@@ -117,11 +118,25 @@ fun ChatScreen(
     val scope = rememberCoroutineScope()
     val listState = rememberLazyListState()
 
+    val id = viewModel.id
     val currentUser by viewModel.currentUser.collectAsStateWithLifecycle()
-    val pubkey = currentUser?.publicKey
+    val chatRooms by viewModel.chatRooms.collectAsStateWithLifecycle()
+    val room by remember(id) { derivedStateOf { chatRooms.firstOrNull { it.id == id } } }
 
-    val room by viewModel.room.collectAsStateWithLifecycle()
-    val roomState by room.flow(profileCache, pubkey).collectAsStateWithLifecycle(RoomUiState())
+    // Show empty screen
+    if (room == null) {
+        Box(
+            modifier = Modifier.fillMaxSize(),
+            contentAlignment = Alignment.Center
+        ) {
+            Text(
+                text = "Something went wrong.",
+                style = MaterialTheme.typography.titleMediumEmphasized,
+                color = MaterialTheme.colorScheme.onSurface
+            )
+        }
+        return
+    }
 
     val loading = viewModel.loading
     val newOtherMessages = viewModel.newOtherMessages
@@ -131,6 +146,9 @@ fun ChatScreen(
     val groupedMessages =
         remember { derivedStateOf { messages.groupBy { it.createdAt().formatAsGroup() } } }
 
+    val roomState by (room as Room).uiStateFlow(profileCache, currentUser?.publicKey)
+        .collectAsStateWithLifecycle(RoomUiState())
+
     var text by remember { mutableStateOf("") }
     var selectedMessage by remember { mutableStateOf<Pair<MessageModel, Rect>?>(null) }
     var replyingTo by remember { mutableStateOf<MessageModel?>(null) }
@@ -175,7 +193,9 @@ fun ChatScreen(
         }
     }
 
-    Box(modifier = Modifier.fillMaxSize()) {
+    Box(
+        modifier = Modifier.fillMaxSize()
+    ) {
         Scaffold(
             modifier = Modifier.blur(blurAmount),
             contentWindowInsets = ScaffoldDefaults.contentWindowInsets.union(WindowInsets.ime),
@@ -187,7 +207,7 @@ fun ChatScreen(
                         Row(
                             verticalAlignment = Alignment.CenterVertically,
                             modifier = Modifier.clickable {
-                                room.members.firstOrNull()?.let { pubkey ->
+                                room?.members?.firstOrNull()?.let { pubkey ->
                                     navigator.navigate(Screen.Profile(pubkey.toBech32()))
                                 }
                             }
@@ -245,7 +265,7 @@ fun ChatScreen(
                             .padding(bottom = innerPadding.calculateBottomPadding())
                     ) {
                         if (requireScreening) {
-                            ScreenerCard(accountViewModel, room)
+                            room?.let { ScreenerCard(accountViewModel, it) }
                         }
 
                         when (messages.isNotEmpty()) {
@@ -263,7 +283,8 @@ fun ChatScreen(
                                             items = messagesInGroup,
                                             key = { it.ensureId().id()?.toHex()!! }
                                         ) { event ->
-                                            val model = rememberMessageModel(event, pubkey)
+                                            val model =
+                                                rememberMessageModel(event, currentUser?.publicKey)
 
                                             val replyPreview =
                                                 remember(model.replyEventIds, messages.size) {
@@ -277,9 +298,7 @@ fun ChatScreen(
                                                 modifier = Modifier.fillMaxWidth(),
                                                 verticalArrangement = Arrangement.spacedBy(2.dp)
                                             ) {
-                                                replyPreview?.let {
-                                                    ReplyPreview(it, model.isMine)
-                                                }
+                                                replyPreview?.let { ReplyPreview(it, model.isMine) }
                                                 ChatMessage(
                                                     model = model,
                                                     modifier = Modifier.graphicsLayer {

shared/src/commonMain/kotlin/su/reya/coop/Room.kt

@@ -71,7 +71,7 @@ data class RoomUiState(
     val isGroup: Boolean = false
 )
 
-fun Room.flow(
+fun Room.uiStateFlow(
     profileCache: ProfileCache,
     currentUser: PublicKey? = null
 ): Flow<RoomUiState> {

shared/src/commonMain/kotlin/su/reya/coop/viewmodel/ChatScreenViewModel.kt

@@ -7,40 +7,30 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.setValue
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
-import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
-import kotlinx.coroutines.flow.map
-import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
 import rust.nostr.sdk.EventId
 import rust.nostr.sdk.UnsignedEvent
+import su.reya.coop.Profile
 import su.reya.coop.Room
 import su.reya.coop.repository.AccountRepository
 import su.reya.coop.repository.ChatRepository
 import su.reya.coop.roomId
 
 class ChatScreenViewModel(
-    initialRoom: Room,
+    val id: Long,
     screening: Boolean,
     accountRepository: AccountRepository,
     private val chatRepository: ChatRepository,
 ) : ViewModel(), ErrorHost by chatRepository {
+    val currentUser: StateFlow<Profile?> = accountRepository.currentUserProfile
+    val chatRooms: StateFlow<List<Room>> = chatRepository.chatRooms
+
     var loading by mutableStateOf(true)
     var newOtherMessages by mutableIntStateOf(0)
     var requireScreening by mutableStateOf(screening)
     val messages = mutableStateListOf<UnsignedEvent>()
 
-    val currentUser = accountRepository.currentUserProfile
-    val id = initialRoom.id
-    
-    val room: StateFlow<Room> = chatRepository.chatRooms
-        .map { rooms -> rooms.find { it.id == id } ?: initialRoom }
-        .stateIn(
-            scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5000),
-            initialValue = initialRoom
-        )
-
     init {
         loadMessages()
         connect()