Show decrypted notification bodies and authenticated sender avatars.

Wait for E2EE cleartext before building tray text, and post Android notifications natively so dynamic avatars fetched with secure media auth can appear as large icons.

android/app/src/main/java/com/paarrot/app/MatrixSyncService.kt

@@ -10,6 +10,7 @@ import android.content.Context
 import android.content.Intent
 import android.net.Uri
 import android.os.Build
+import android.util.Base64
 import android.util.Log
 import android.graphics.Bitmap
 import android.graphics.BitmapFactory
@@ -220,9 +221,10 @@ class MatrixSyncService : Service() {
                 val inlineImage: Bitmap? = if (
                     (msgtype == "m.image" || msgtype == "m.sticker") && !content.has("file")
                 ) {
-                    content.optString("url").takeIf { it.startsWith("mxc://") }
-                        ?.let { mxcToDownloadUrl(it, homeserver) }
-                        ?.let { downloadBitmap(it, token) }
+                    content.optString("url").takeIf { it.startsWith("mxc://") }?.let { mxc ->
+                        mxcToDownloadUrls(mxc, homeserver)
+                            .firstNotNullOfOrNull { downloadBitmap(it, token) }
+                    }
                 } else null
 
                 showMessageNotification(
@@ -404,9 +406,7 @@ class MatrixSyncService : Service() {
                 conn.disconnect()
             }
             displayNameCache[mxid] = displayName
-            val avatar = avatarMxc
-                ?.let { mxcToThumbnailUrl(it, homeserver, size = 96) }
-                ?.let { downloadBitmap(it, token) }
+            val avatar = avatarMxc?.let { downloadAvatarBitmap(it, homeserver, token, size = 96) }
             avatarCache[mxid] = avatar
             UserProfile(displayName, avatar)
         } catch (e: Exception) {
@@ -417,24 +417,47 @@ class MatrixSyncService : Service() {
         }
     }
 
-    private fun mxcToThumbnailUrl(mxcUrl: String, homeserver: String, size: Int): String? {
+    private fun mxcToThumbnailUrls(mxcUrl: String, homeserver: String, size: Int): List<String> {
         val withoutScheme = mxcUrl.removePrefix("mxc://")
         val slash = withoutScheme.indexOf('/')
-        if (slash < 0) return null
+        if (slash < 0) return emptyList()
         val serverName = withoutScheme.substring(0, slash)
         val mediaId = withoutScheme.substring(slash + 1)
-        return "$homeserver/_matrix/media/v3/thumbnail/$serverName/$mediaId?width=$size&height=$size&method=crop"
+        val query = "width=$size&height=$size&method=crop"
+        // Prefer MSC3916 authenticated media, fall back to legacy media repo.
+        return listOf(
+            "$homeserver/_matrix/client/v1/media/thumbnail/$serverName/$mediaId?$query",
+            "$homeserver/_matrix/media/v3/thumbnail/$serverName/$mediaId?$query",
+        )
     }
 
-    private fun mxcToDownloadUrl(mxcUrl: String, homeserver: String): String? {
+    private fun mxcToDownloadUrls(mxcUrl: String, homeserver: String): List<String> {
         val withoutScheme = mxcUrl.removePrefix("mxc://")
         val slash = withoutScheme.indexOf('/')
-        if (slash < 0) return null
+        if (slash < 0) return emptyList()
         val serverName = withoutScheme.substring(0, slash)
         val mediaId = withoutScheme.substring(slash + 1)
-        return "$homeserver/_matrix/media/v3/download/$serverName/$mediaId"
+        return listOf(
+            "$homeserver/_matrix/client/v1/media/download/$serverName/$mediaId",
+            "$homeserver/_matrix/media/v3/download/$serverName/$mediaId",
+        )
     }
 
+    private fun downloadAvatarBitmap(
+        mxcUrl: String,
+        homeserver: String,
+        token: String,
+        size: Int,
+    ): Bitmap? {
+        for (url in mxcToThumbnailUrls(mxcUrl, homeserver, size)) {
+            downloadBitmap(url, token)?.let { return it }
+        }
+        return null
+    }
+
+    private fun mxcToDownloadUrl(mxcUrl: String, homeserver: String): String? =
+        mxcToDownloadUrls(mxcUrl, homeserver).firstOrNull()
+
     private fun downloadBitmap(urlString: String, token: String): Bitmap? {
         return try {
             val conn = URL(urlString).openConnection() as HttpURLConnection
@@ -505,11 +528,7 @@ class MatrixSyncService : Service() {
         }
     }
 
-    private fun channelIdForKind(kind: String): String = when (kind) {
-        "direct" -> CHANNEL_DIRECTS
-        "space" -> CHANNEL_SPACES
-        else -> CHANNEL_HOME
-    }
+    private fun channelIdForKind(kind: String): String = channelIdForKindStatic(kind)
 
     private fun showMessageNotification(
         nm: NotificationManager,
@@ -520,72 +539,20 @@ class MatrixSyncService : Service() {
         inlineImage: Bitmap? = null,
         groupInfo: NotificationGroupInfo,
     ) {
-        val launchIntent = packageManager.getLaunchIntentForPackage(packageName)
-            ?: Intent(this, MainActivity::class.java)
-        val roomNotifId = notificationIdForRoom(roomId)
-        val pi = PendingIntent.getActivity(
-            this, roomNotifId, launchIntent,
-            PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE,
-        )
-
         val isDm = groupInfo.kind == "direct"
         val title = if (isDm) sender else groupInfo.roomName.ifBlank { sender }
         val text = if (isDm) body else "$sender: $body"
-        val channelId = channelIdForKind(groupInfo.kind)
-
-        val builder = NotificationCompat.Builder(this, channelId)
-            .setSmallIcon(R.drawable.ic_stat_paarrot)
-            .setContentTitle(title)
-            .setContentText(text)
-            .setAutoCancel(true)
-            .setContentIntent(pi)
-            .setPriority(NotificationCompat.PRIORITY_HIGH)
-            .setCategory(NotificationCompat.CATEGORY_MESSAGE)
-            .setGroup(groupInfo.groupId)
-            .setOnlyAlertOnce(true)
-            .setSubText(groupInfo.groupName)
-
-        builder.extras.putString(EXTRA_ROOM_ID, roomId)
-        builder.extras.putString(EXTRA_GROUP_ID, groupInfo.groupId)
-
-        if (largeIcon != null) builder.setLargeIcon(largeIcon)
-
-        if (inlineImage != null) {
-            builder.setStyle(
-                NotificationCompat.BigPictureStyle()
-                    .bigPicture(inlineImage)
-                    .bigLargeIcon(null as Bitmap?)
-            )
-        } else {
-            builder.setStyle(
-                NotificationCompat.BigTextStyle()
-                    .bigText(text)
-                    .setSummaryText(groupInfo.groupName)
-            )
-        }
-
-        // Stable per-room id replaces the previous tray entry instead of stacking.
-        nm.notify(roomNotifId, builder.build())
-
-        // Nest under Direct messages / Space name / Home in the notification shade.
-        val summaryId = notificationIdForGroupSummary(groupInfo.groupId)
-        val summary = NotificationCompat.Builder(this, channelId)
-            .setSmallIcon(R.drawable.ic_stat_paarrot)
-            .setContentTitle(groupInfo.groupName)
-            .setContentText("New messages")
-            .setAutoCancel(true)
-            .setContentIntent(pi)
-            .setPriority(NotificationCompat.PRIORITY_HIGH)
-            .setCategory(NotificationCompat.CATEGORY_MESSAGE)
-            .setGroup(groupInfo.groupId)
-            .setGroupSummary(true)
-            .setStyle(
-                NotificationCompat.InboxStyle()
-                    .setBigContentTitle(groupInfo.groupName)
-                    .setSummaryText(groupInfo.groupName)
-            )
-        summary.extras.putString(EXTRA_GROUP_ID, groupInfo.groupId)
-        nm.notify(summaryId, summary.build())
+        postMessageNotification(
+            this,
+            roomId = roomId,
+            title = title,
+            body = text,
+            groupId = groupInfo.groupId,
+            groupName = groupInfo.groupName,
+            kind = groupInfo.kind,
+            largeIcon = largeIcon,
+            inlineImage = inlineImage,
+        )
     }
 
     private fun buildStatusNotification(): Notification {
@@ -620,28 +587,7 @@ class MatrixSyncService : Service() {
     }
 
     private fun ensureMessageChannels(nm: NotificationManager) {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) return
-
-        val soundUri = Uri.parse("android.resource://$packageName/${R.raw.paarrot_notification}")
-        val soundAttrs = AudioAttributes.Builder()
-            .setUsage(AudioAttributes.USAGE_NOTIFICATION)
-            .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
-            .build()
-
-        val channels = listOf(
-            Triple(CHANNEL_DIRECTS, "Direct messages", "One-to-one Matrix conversations"),
-            Triple(CHANNEL_SPACES, "Spaces", "Messages from rooms inside Spaces"),
-            Triple(CHANNEL_HOME, "Other rooms", "Rooms that are not in a Space"),
-            Triple(CHANNEL_MESSAGES, "Messages", "Legacy message channel"),
-        )
-
-        for ((id, name, description) in channels) {
-            val channel = NotificationChannel(id, name, NotificationManager.IMPORTANCE_HIGH).apply {
-                this.description = description
-                setSound(soundUri, soundAttrs)
-            }
-            nm.createNotificationChannel(channel)
-        }
+        ensureMessageChannels(this)
     }
 
     companion object {
@@ -686,6 +632,129 @@ class MatrixSyncService : Service() {
         fun notificationIdForGroupSummary(groupId: String): Int =
             notificationIdForRoom("summary:$groupId")
 
+        private fun channelIdForKindStatic(kind: String): String = when (kind) {
+            "direct" -> CHANNEL_DIRECTS
+            "space" -> CHANNEL_SPACES
+            else -> CHANNEL_HOME
+        }
+
+        fun ensureMessageChannels(context: Context) {
+            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) return
+            val nm = context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+            val soundUri = Uri.parse("android.resource://${context.packageName}/${R.raw.paarrot_notification}")
+            val soundAttrs = AudioAttributes.Builder()
+                .setUsage(AudioAttributes.USAGE_NOTIFICATION)
+                .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
+                .build()
+
+            val channels = listOf(
+                Triple(CHANNEL_DIRECTS, "Direct messages", "One-to-one Matrix conversations"),
+                Triple(CHANNEL_SPACES, "Spaces", "Messages from rooms inside Spaces"),
+                Triple(CHANNEL_HOME, "Other rooms", "Rooms that are not in a Space"),
+                Triple(CHANNEL_MESSAGES, "Messages", "Legacy message channel"),
+            )
+
+            for ((id, name, description) in channels) {
+                val channel = NotificationChannel(id, name, NotificationManager.IMPORTANCE_HIGH).apply {
+                    this.description = description
+                    setSound(soundUri, soundAttrs)
+                }
+                nm.createNotificationChannel(channel)
+            }
+        }
+
+        fun decodeBase64Bitmap(base64: String?): Bitmap? {
+            if (base64.isNullOrBlank()) return null
+            return try {
+                val raw = if (base64.contains(',')) base64.substringAfter(',') else base64
+                val bytes = Base64.decode(raw, Base64.DEFAULT)
+                BitmapFactory.decodeByteArray(bytes, 0, bytes.size)
+            } catch (e: Exception) {
+                Log.w(TAG, "Failed to decode notification icon: ${e.message}")
+                null
+            }
+        }
+
+        /**
+         * Posts a room notification (+ space/DM group summary) for both background sync
+         * and JS-driven Capacitor notifications (with optional avatar bitmap).
+         */
+        fun postMessageNotification(
+            context: Context,
+            roomId: String,
+            title: String,
+            body: String,
+            groupId: String,
+            groupName: String,
+            kind: String,
+            largeIcon: Bitmap? = null,
+            inlineImage: Bitmap? = null,
+        ) {
+            val nm = context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+            ensureMessageChannels(context)
+
+            val launchIntent = context.packageManager.getLaunchIntentForPackage(context.packageName)
+                ?: Intent(context, MainActivity::class.java)
+            val roomNotifId = notificationIdForRoom(roomId)
+            val pi = PendingIntent.getActivity(
+                context, roomNotifId, launchIntent,
+                PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE,
+            )
+
+            val channelId = channelIdForKindStatic(kind)
+            val builder = NotificationCompat.Builder(context, channelId)
+                .setSmallIcon(R.drawable.ic_stat_paarrot)
+                .setContentTitle(title)
+                .setContentText(body)
+                .setAutoCancel(true)
+                .setContentIntent(pi)
+                .setPriority(NotificationCompat.PRIORITY_HIGH)
+                .setCategory(NotificationCompat.CATEGORY_MESSAGE)
+                .setGroup(groupId)
+                .setOnlyAlertOnce(true)
+                .setSubText(groupName)
+
+            builder.extras.putString(EXTRA_ROOM_ID, roomId)
+            builder.extras.putString(EXTRA_GROUP_ID, groupId)
+
+            if (largeIcon != null) builder.setLargeIcon(largeIcon)
+
+            if (inlineImage != null) {
+                builder.setStyle(
+                    NotificationCompat.BigPictureStyle()
+                        .bigPicture(inlineImage)
+                        .bigLargeIcon(null as Bitmap?)
+                )
+            } else {
+                builder.setStyle(
+                    NotificationCompat.BigTextStyle()
+                        .bigText(body)
+                        .setSummaryText(groupName)
+                )
+            }
+
+            nm.notify(roomNotifId, builder.build())
+
+            val summaryId = notificationIdForGroupSummary(groupId)
+            val summary = NotificationCompat.Builder(context, channelId)
+                .setSmallIcon(R.drawable.ic_stat_paarrot)
+                .setContentTitle(groupName)
+                .setContentText("New messages")
+                .setAutoCancel(true)
+                .setContentIntent(pi)
+                .setPriority(NotificationCompat.PRIORITY_HIGH)
+                .setCategory(NotificationCompat.CATEGORY_MESSAGE)
+                .setGroup(groupId)
+                .setGroupSummary(true)
+                .setStyle(
+                    NotificationCompat.InboxStyle()
+                        .setBigContentTitle(groupName)
+                        .setSummaryText(groupName)
+                )
+            summary.extras.putString(EXTRA_GROUP_ID, groupId)
+            nm.notify(summaryId, summary.build())
+        }
+
         /** Cancel the tray notification posted for [roomId], if any. */
         fun clearRoomNotifications(context: Context, roomId: String) {
             if (roomId.isBlank()) return

android/app/src/main/java/com/paarrot/app/SyncServicePlugin.kt

@@ -19,6 +19,7 @@ import com.getcapacitor.annotation.CapacitorPlugin
  * - `getStatus()` — returns current fetch and UnifiedPush state
  * - `clearRoomNotifications({ roomId })` — dismiss native tray notifs for a room
  * - `setNotificationGroups({ rooms })` — persist space/DM grouping for tray nesting
+ * - `showNotification({ title, body, roomId, groupId, groupName, kind, largeIconBase64 })`
  */
 @CapacitorPlugin(name = "MatrixBackgroundSync")
 class SyncServicePlugin : Plugin() {
@@ -124,6 +125,34 @@ class SyncServicePlugin : Plugin() {
         call.resolve(JSObject().put("success", true))
     }
 
+    /**
+     * Shows a message notification from the JS layer (supports dynamic avatar icons).
+     * Capacitor LocalNotifications cannot load authenticated/dynamic large icons, so
+     * we post through the same native NotificationManager path as background sync.
+     */
+    @PluginMethod
+    fun showNotification(call: PluginCall) {
+        val title = call.getString("title") ?: return call.reject("title required")
+        val body = call.getString("body") ?: return call.reject("body required")
+        val roomId = call.getString("roomId") ?: return call.reject("roomId required")
+        val groupId = call.getString("groupId") ?: "paarrot_home"
+        val groupName = call.getString("groupName") ?: "Home"
+        val kind = call.getString("kind") ?: "home"
+        val largeIconBase64 = call.getString("largeIconBase64")
+
+        MatrixSyncService.postMessageNotification(
+            context = context,
+            roomId = roomId,
+            title = title,
+            body = body,
+            groupId = groupId,
+            groupName = groupName,
+            kind = kind,
+            largeIcon = MatrixSyncService.decodeBase64Bitmap(largeIconBase64),
+        )
+        call.resolve(JSObject().put("shown", true))
+    }
+
     companion object {
         const val PREFS = "sync_service_prefs"
     }