Recover stale Android chat ids

android/app/build.gradle.kts

@@ -22,8 +22,8 @@ android {
         applicationId = "xyz.kusoft.qmax"
         minSdk = 26
         targetSdk = 36
-        versionCode = 47
-        versionName = "0.1.46"
+        versionCode = 48
+        versionName = "0.1.47"
 
         buildConfigField("String", "QMAX_DEFAULT_SERVER_URL", "\"https://qmax.kusoft.xyz\"")
         buildConfigField("String", "QMAX_DEFAULT_PAIRING_CODE", "\"qmax-MxRq4h2HQBEIFs6k\"")

android/app/src/main/java/xyz/kusoft/qmax/ui/QMaxViewModel.kt

@@ -20,6 +20,7 @@ import xyz.kusoft.qmax.core.model.MaxBridgeStatusDto
 import xyz.kusoft.qmax.core.model.MessageDeletedDto
 import xyz.kusoft.qmax.core.model.MessageDto
 import xyz.kusoft.qmax.core.model.QMaxSession
+import xyz.kusoft.qmax.core.network.QMaxHttpException
 import xyz.kusoft.qmax.core.realtime.QMaxRealtimeClient
 import java.io.File
 
@@ -378,9 +379,16 @@ class QMaxViewModel(private val repository: QMaxRepository) : ViewModel() {
         if (cached.isNotEmpty() && state.value.selectedChat?.id == chat.id && state.value.messages.isEmpty()) {
             state.value = state.value.copy(messages = cached)
         }
-        val fresh = withTimeout(MessageSyncTimeoutMs) {
+        val fresh = try {
+            withTimeout(MessageSyncTimeoutMs) {
                 repository.messages(session, chat.id)
             }
+        } catch (error: QMaxHttpException) {
+            if (error.code == 404 && recoverMissingChat(session, chat)) {
+                return@launchLoading
+            }
+            throw error
+        }
         if (state.value.selectedChat?.id == chat.id) {
             val selected = state.value.selectedChat?.copy(unreadCount = 0)
             selected?.let(::rememberChatRead)
@@ -393,6 +401,61 @@ class QMaxViewModel(private val repository: QMaxRepository) : ViewModel() {
         }
     }
 
+    private suspend fun recoverMissingChat(session: QMaxSession, staleChat: ChatDto): Boolean {
+        val freshChats = runCatching {
+            withTimeout(ChatListTimeoutMs) {
+                repository.chats(session)
+            }
+        }.getOrElse {
+            return false
+        }
+
+        val orderedFresh = normalizeChats(freshChats)
+        val replacement = findReplacementChat(staleChat, orderedFresh)
+        if (replacement == null) {
+            state.value = state.value.copy(
+                selectedChat = null,
+                chats = orderedFresh,
+                messages = emptyList(),
+                error = null
+            )
+            repository.cacheChats(session, orderedFresh)
+            return true
+        }
+
+        val openedChat = replacement.copy(unreadCount = 0)
+        rememberChatRead(openedChat)
+        val chats = normalizeChats(
+            orderedFresh.map { chat ->
+                if (chat.id == openedChat.id) chat.copy(unreadCount = 0) else chat
+            },
+            selectedChatId = openedChat.id
+        )
+        state.value = state.value.copy(
+            selectedChat = openedChat,
+            chats = chats,
+            messages = emptyList(),
+            chatPresenceText = null,
+            error = null
+        )
+        repository.cacheChats(session, chats)
+        syncChatRead(openedChat.id)
+        realtime.joinChat(openedChat.id)
+
+        val freshMessages = withTimeout(MessageSyncTimeoutMs) {
+            repository.messages(session, openedChat.id)
+        }
+        if (state.value.selectedChat?.id == openedChat.id) {
+            state.value = state.value.copy(
+                selectedChat = state.value.selectedChat?.copy(unreadCount = 0),
+                chats = normalizeChats(state.value.chats, selectedChatId = openedChat.id),
+                messages = freshMessages
+            )
+            persistCurrentChats()
+        }
+        return true
+    }
+
     fun sendMessage() = sendComposer(emptyList())
 
     fun sendComposer(attachmentUris: List<Uri>, onSuccess: () -> Unit = {}) = launchLoading(false) {
@@ -731,6 +794,33 @@ class QMaxViewModel(private val repository: QMaxRepository) : ViewModel() {
         }
     }
 
+    private fun findReplacementChat(staleChat: ChatDto, freshChats: List<ChatDto>): ChatDto? {
+        staleChat.externalId?.takeIf { it.isNotBlank() }?.let { externalId ->
+            freshChats.firstOrNull { it.externalId == externalId }?.let { return it }
+        }
+
+        val titleMatches = freshChats.filter { it.title.equals(staleChat.title, ignoreCase = true) }
+        if (titleMatches.size == 1) {
+            return titleMatches.first()
+        }
+
+        val staleAvatar = staleChat.avatarUrl.orEmpty()
+        if (staleAvatar.isNotBlank()) {
+            titleMatches.firstOrNull { it.avatarUrl.orEmpty() == staleAvatar }?.let { return it }
+            val staleFingerprint = avatarFingerprint(staleAvatar)
+            titleMatches.firstOrNull { avatarFingerprint(it.avatarUrl.orEmpty()) == staleFingerprint }?.let { return it }
+        }
+
+        return null
+    }
+
+    private fun avatarFingerprint(value: String): String {
+        if (value.isBlank()) return ""
+        return runCatching {
+            android.net.Uri.parse(value).getQueryParameter("r")
+        }.getOrNull()?.takeIf { it.isNotBlank() } ?: value
+    }
+
     private suspend fun refreshPresence(chatId: String) {
         val session = state.value.session ?: return
         val presence = runCatching {