Merge pull request #3573 from vitorpamplona/claude/concord-image-display-ou01vs

Support NIP-92 imeta attachments in chat messages

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/types/Chat.kt

@@ -41,8 +41,10 @@ import com.vitorpamplona.amethyst.ui.note.elements.DisplayUncitedHashtags
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
 import com.vitorpamplona.amethyst.ui.theme.StdVertSpacer
 import com.vitorpamplona.amethyst.ui.theme.placeholderText
+import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.tags.hashtags.hasHashtags
 import com.vitorpamplona.quartz.nip10Notes.BaseNoteEvent
+import com.vitorpamplona.quartz.nip92IMeta.imetas
 
 @Composable
 fun RenderChat(
@@ -58,6 +60,13 @@ fun RenderChat(
 ) {
     val noteEvent = note.event ?: return
     val eventContent = remember(noteEvent) { noteEvent.content }
+    // Content actually handed to the media renderer. The shared renderer only shows media whose URL
+    // appears in the text, but some NIP-C7/Concord clients (e.g. Ditto/Soapbox Armada) attach an
+    // image purely as a NIP-92 `imeta` tag and leave the content empty. Append any imeta URL missing
+    // from the content so those attachments render — symmetric to ChannelChat.imageMessage, which
+    // appends the URL on send. Encrypted-blob key/nonce are already registered by URL, so the shared
+    // pipeline fetches and decrypts them transparently.
+    val displayContent = remember(noteEvent) { appendMissingImetaUrls(noteEvent) }
 
     // A boosted note inside a zap/nutzap/onchain activity card is always shown as a
     // compact 2-line preview, even when the logged-in user is only a zap-split
@@ -101,7 +110,7 @@ fun RenderChat(
                 remember(note) { note.event?.tags?.toImmutableListOfLists() ?: EmptyTagList }
 
             TranslatableRichTextViewer(
-                content = eventContent,
+                content = displayContent,
                 canPreview = canPreview && !makeItShort,
                 quotesLeft = quotesLeft,
                 modifier = Modifier.fillMaxWidth(),
@@ -120,3 +129,16 @@ fun RenderChat(
         }
     }
 }
+
+/**
+ * Returns [event]'s content with every NIP-92 `imeta` URL that is not already present appended on its
+ * own line, so an attachment carried only as an `imeta` tag (empty/incomplete content) still renders.
+ * Returns the original content unchanged when every imeta URL is already inline (the common case), so
+ * normal messages are untouched.
+ */
+private fun appendMissingImetaUrls(event: Event): String {
+    val content = event.content
+    val missing = event.imetas().map { it.url }.filter { it.isNotBlank() && !content.contains(it) }
+    if (missing.isEmpty()) return content
+    return (listOf(content) + missing).filter { it.isNotBlank() }.joinToString("\n")
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/concord/ConcordChannelScreen.kt

@@ -566,5 +566,6 @@ private fun SuccessfulUploads.toConcordImeta(): IMetaTag? {
         blurhash = result.fileHeader.blurHash?.blurhash,
         cipher = cipher,
         originalHash = result.hashBeforeEncryption,
+        thumbhash = result.fileHeader.thumbHash?.thumbhash,
     )
 }

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/concord/cord03Channels/ChannelChat.kt

@@ -35,7 +35,9 @@ import com.vitorpamplona.quartz.nip25Reactions.ReactionEvent
 import com.vitorpamplona.quartz.nip59Giftwrap.rumors.RumorAssembler
 import com.vitorpamplona.quartz.nip92IMeta.IMetaTag
 import com.vitorpamplona.quartz.nip92IMeta.IMetaTagBuilder
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.OriginalHashTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.ThumbhashTag
 import com.vitorpamplona.quartz.nipC7Chats.ChatEvent
 import com.vitorpamplona.quartz.utils.ciphers.AESGCM
 
@@ -198,7 +200,9 @@ object ChannelChat {
      * Builds the encrypted-image `imeta` tag Armada's `ChatComposer` emits with `encryptAttachments`:
      * `url` (ciphertext blob), `m` (plaintext mime), `dim`, `blurhash`, plus `encryption-algorithm`
      * (`aes-gcm`), `decryption-key`, `decryption-nonce` (hex), and `ox` (the *plaintext* SHA-256 for
-     * integrity). Deliberately omits `x` (a ciphertext hash) to match Armada exactly.
+     * integrity). Deliberately omits `x` (a ciphertext hash) to match Armada exactly. When a
+     * [thumbhash] is available it is added as an extra (additive, ignored by clients that don't read
+     * it) so receivers can paint a placeholder while the blob decrypts.
      */
     fun encryptedImageImeta(
         url: String,
@@ -207,12 +211,14 @@ object ChannelChat {
         blurhash: String?,
         cipher: AESGCM,
         originalHash: String?,
+        thumbhash: String? = null,
     ): IMetaTag =
         IMetaTagBuilder(url)
             .apply {
                 mimeType?.let { add("m", it) }
                 dim?.let { add("dim", it) }
-                blurhash?.let { add("blurhash", it) }
+                blurhash?.let { add(BlurhashTag.TAG_NAME, it) }
+                thumbhash?.let { add(ThumbhashTag.TAG_NAME, it) }
                 add(EncryptionAlgo.TAG_NAME, cipher.name())
                 add(EncryptionKey.TAG_NAME, cipher.keyBytes.toHexKey())
                 add(EncryptionNonce.TAG_NAME, cipher.nonce.toHexKey())

quartz/src/commonTest/kotlin/com/vitorpamplona/quartz/concord/cord03Channels/ChannelChatEndToEndTest.kt

@@ -135,6 +135,7 @@ class ChannelChatEndToEndTest {
                 blurhash = "LKO2",
                 cipher = cipher,
                 originalHash = ox,
+                thumbhash = "abc123",
             )
         val msg = ChannelChat.imageMessage(author, channelIdHex, 0L, "look", listOf(imeta), createdAt = 5L)
 
@@ -148,6 +149,9 @@ class ChannelChatEndToEndTest {
         assertTrue(imetaTag.contains("url $url"))
         assertTrue(imetaTag.contains("m image/jpeg"))
         assertTrue(imetaTag.contains("dim 800x600"))
+        assertTrue(imetaTag.contains("blurhash LKO2"))
+        // Thumbhash rides as an additive imeta field so receivers can paint a placeholder.
+        assertTrue(imetaTag.contains("thumbhash abc123"))
         assertTrue(imetaTag.contains("encryption-algorithm aes-gcm"))
         assertTrue(imetaTag.contains("decryption-key ${ByteArray(32) { 0x11 }.toHexKey()}"))
         assertTrue(imetaTag.contains("decryption-nonce ${ByteArray(16) { 0x22 }.toHexKey()}"))