feat: Implement local file management for avatar attachments with download status checks

app/src/main/java/com/rosetta/messenger/ui/chats/components/AttachmentComponents.kt

@@ -1112,15 +1112,35 @@ fun AvatarAttachment(
     
     val timeFormat = remember { java.text.SimpleDateFormat("HH:mm", java.util.Locale.getDefault()) }
     
+    // Определяем начальный статус (как в Desktop calcDownloadStatus для AVATAR)
     LaunchedEffect(attachment.id) {
-        downloadStatus = when {
-            attachment.blob.isNotEmpty() && !isDownloadTag(attachment.preview) -> {
-                DownloadStatus.DOWNLOADED
+        withContext(Dispatchers.IO) {
+            downloadStatus = when {
+                // 1. Если blob уже есть в памяти → DOWNLOADED
+                attachment.blob.isNotEmpty() -> {
+                    Log.d(TAG, "📦 Avatar blob in memory for ${attachment.id}")
+                    DownloadStatus.DOWNLOADED
+                }
+                // 2. Если preview НЕ содержит UUID → локальный файл → DOWNLOADED
+                !isDownloadTag(attachment.preview) -> {
+                    Log.d(TAG, "📦 No download tag for avatar ${attachment.id}")
+                    DownloadStatus.DOWNLOADED
+                }
+                // 3. Есть UUID (download tag) → проверяем файловую систему
+                // Desktop: readFile(`a/${md5(attachment.id + publicKey)}`)
+                else -> {
+                    val hasLocal = AvatarFileManager.hasAvatarByAttachmentId(
+                        context, attachment.id, senderPublicKey
+                    )
+                    if (hasLocal) {
+                        Log.d(TAG, "📦 Found local avatar file for ${attachment.id}")
+                        DownloadStatus.DOWNLOADED
+                    } else {
+                        Log.d(TAG, "📥 Need to download avatar ${attachment.id}")
+                        DownloadStatus.NOT_DOWNLOADED
+                    }
+                }
             }
-            isDownloadTag(attachment.preview) -> {
-                DownloadStatus.NOT_DOWNLOADED
-            }
-            else -> DownloadStatus.DOWNLOADED
         }
         
         // Decode blurhash
@@ -1134,9 +1154,27 @@ fun AvatarAttachment(
             }
         }
         
-        if (downloadStatus == DownloadStatus.DOWNLOADED && attachment.blob.isNotEmpty()) {
+        // Загружаем аватар если статус DOWNLOADED
+        if (downloadStatus == DownloadStatus.DOWNLOADED) {
             withContext(Dispatchers.IO) {
-                avatarBitmap = base64ToBitmap(attachment.blob)
+                // 1. Сначала пробуем blob из памяти
+                if (attachment.blob.isNotEmpty()) {
+                    Log.d(TAG, "🖼️ Loading avatar from blob")
+                    avatarBitmap = base64ToBitmap(attachment.blob)
+                } else {
+                    // 2. Читаем из файловой системы (как в Desktop getBlob)
+                    Log.d(TAG, "🖼️ Loading avatar from local file")
+                    val localBlob = AvatarFileManager.readAvatarByAttachmentId(
+                        context, attachment.id, senderPublicKey
+                    )
+                    if (localBlob != null) {
+                        avatarBitmap = base64ToBitmap(localBlob)
+                        Log.d(TAG, "✅ Avatar loaded from local file")
+                    } else {
+                        Log.w(TAG, "⚠️ Failed to read local avatar file")
+                        downloadStatus = DownloadStatus.NOT_DOWNLOADED
+                    }
+                }
             }
         }
     }
@@ -1164,8 +1202,18 @@ fun AvatarAttachment(
                     if (decrypted != null) {
                         withContext(Dispatchers.IO) {
                             avatarBitmap = base64ToBitmap(decrypted)
+                            
+                            // 💾 Сохраняем в файловую систему по attachment.id (как в Desktop)
+                            // Desktop: writeFile(`a/${md5(attachment.id + publicKey)}`, encrypted)
+                            AvatarFileManager.saveAvatarByAttachmentId(
+                                context = context,
+                                base64Image = decrypted,
+                                attachmentId = attachment.id,
+                                publicKey = senderPublicKey
+                            )
+                            Log.d(TAG, "💾 Avatar saved to local file system")
                         }
-                        // Сохраняем аватар в репозиторий
+                        // Сохраняем аватар в репозиторий (для UI обновления)
                         avatarRepository?.saveAvatar(senderPublicKey, decrypted)
                         downloadStatus = DownloadStatus.DOWNLOADED
                         Log.d(TAG, "✅ Avatar downloaded and saved")