Switch over to new link preview system

src/org/thoughtcrime/securesms/loki/LokiPublicChatPoller.kt

@@ -103,7 +103,8 @@ class LokiPublicChatPoller(private val context: Context, private val group: Loki
             } else {
                 null
             }
-            val attachments = message.attachments.map { attachment ->
+            val attachments = message.attachments.mapNotNull { attachment ->
+                if (attachment.kind != LokiPublicChatMessage.Attachment.Kind.Attachment) { return@mapNotNull null }
                 SignalServiceAttachmentPointer(
                     attachment.serverID,
                     attachment.contentType,
@@ -117,8 +118,25 @@ class LokiPublicChatPoller(private val context: Context, private val group: Loki
                     Optional.fromNullable(attachment.caption),
                     attachment.url)
             }
+            val linkPreview = message.attachments.firstOrNull { it.kind == LokiPublicChatMessage.Attachment.Kind.LinkPreview }
+            val signalLinkPreviews = mutableListOf<SignalServiceDataMessage.Preview>()
+            if (linkPreview != null) {
+                val attachment = SignalServiceAttachmentPointer(
+                        linkPreview.serverID,
+                        linkPreview.contentType,
+                        ByteArray(0),
+                        Optional.of(linkPreview.size),
+                        Optional.absent(),
+                        linkPreview.width, linkPreview.height,
+                        Optional.absent(),
+                        Optional.of(linkPreview.fileName),
+                        false,
+                        Optional.fromNullable(linkPreview.caption),
+                        linkPreview.url)
+                signalLinkPreviews.add(SignalServiceDataMessage.Preview(linkPreview.linkPreviewURL!!, linkPreview.linkPreviewTitle!!, Optional.of(attachment)))
+            }
             val body = if (message.body == message.timestamp.toString()) "" else message.body // Workaround for the fact that the back-end doesn't accept messages without a body
-            val serviceDataMessage = SignalServiceDataMessage(message.timestamp, serviceGroup, attachments, body, false, 0, false, null, false, quote, null, null, null)
+            val serviceDataMessage = SignalServiceDataMessage(message.timestamp, serviceGroup, attachments, body, false, 0, false, null, false, quote, null, signalLinkPreviews, null)
             val serviceContent = SignalServiceContent(serviceDataMessage, message.hexEncodedPublicKey, SignalServiceAddress.DEFAULT_DEVICE_ID, message.timestamp, false)
             val senderDisplayName = "${message.displayName} (...${message.hexEncodedPublicKey.takeLast(8)})"
             DatabaseFactory.getLokiUserDatabase(context).setServerDisplayName(group.id, message.hexEncodedPublicKey, senderDisplayName)