parse message retractions

src/androidTest/java/im/conversations/android/xmpp/TransformationTest.java

@@ -11,6 +11,7 @@ import im.conversations.android.database.ConversationsDatabase;
 import im.conversations.android.database.entity.AccountEntity;
 import im.conversations.android.database.model.MessageEmbedded;
 import im.conversations.android.database.model.Modification;
+import im.conversations.android.database.model.PartType;
 import im.conversations.android.transformer.Transformation;
 import im.conversations.android.transformer.Transformer;
 import im.conversations.android.xmpp.model.correction.Replace;
@@ -19,6 +20,7 @@ import im.conversations.android.xmpp.model.reactions.Reaction;
 import im.conversations.android.xmpp.model.reactions.Reactions;
 import im.conversations.android.xmpp.model.receipts.Received;
 import im.conversations.android.xmpp.model.reply.Reply;
+import im.conversations.android.xmpp.model.retract.Retract;
 import im.conversations.android.xmpp.model.stanza.Message;
 import java.time.Instant;
 import java.util.concurrent.ExecutionException;
@@ -430,4 +432,27 @@ public class TransformationTest {
 
         Assert.assertEquals(1L, message.states.size());
     }
+
+    @Test
+    public void messageAndRetraction() {
+        final var m1 = new Message();
+        m1.setTo(ACCOUNT);
+        m1.setFrom(REMOTE.withResource("junit"));
+        m1.setId("m1");
+        m1.addExtension(new Body("It is raining outside"));
+
+        this.transformer.transform(Transformation.of(m1, Instant.now(), REMOTE, null, null));
+
+        final var m2 = new Message();
+        m2.setTo(ACCOUNT);
+        m2.setFrom(REMOTE.withResource("junit"));
+        m2.addExtension(new Retract()).setId("m1");
+
+        this.transformer.transform(Transformation.of(m2, Instant.now(), REMOTE, null, null));
+
+        final var messages = database.messageDao().getMessages(1L);
+        final var message = Iterables.getOnlyElement(messages);
+        Assert.assertEquals(Modification.RETRACTION, message.modification);
+        Assert.assertEquals(PartType.RETRACTION, Iterables.getOnlyElement(message.contents).type);
+    }
 }

src/main/java/im/conversations/android/database/model/MessageContent.java

@@ -1,5 +1,8 @@
 package im.conversations.android.database.model;
 
+import com.google.common.collect.ImmutableList;
+import java.util.List;
+
 public class MessageContent {
 
     public final String language;
@@ -24,4 +27,7 @@ public class MessageContent {
     public static MessageContent file(final String url) {
         return new MessageContent(null, PartType.FILE, null, url);
     }
+
+    public static final List<MessageContent> RETRACTION =
+            ImmutableList.of(new MessageContent(null, PartType.RETRACTION, null, null));
 }

src/main/java/im/conversations/android/transformer/Transformation.java

@@ -18,6 +18,7 @@ import im.conversations.android.xmpp.model.muc.user.MultiUserChat;
 import im.conversations.android.xmpp.model.oob.OutOfBandData;
 import im.conversations.android.xmpp.model.reactions.Reactions;
 import im.conversations.android.xmpp.model.reply.Reply;
+import im.conversations.android.xmpp.model.retract.Retract;
 import im.conversations.android.xmpp.model.stanza.Message;
 import java.time.Instant;
 import java.util.Arrays;
@@ -38,7 +39,8 @@ public class Transformation {
                     Displayed.class,
                     Replace.class,
                     Reactions.class,
-                    Reply.class);
+                    Reply.class,
+                    Retract.class);
 
     public final Instant receivedAt;
     public final Jid to;

src/main/java/im/conversations/android/transformer/Transformer.java

@@ -21,6 +21,7 @@ import im.conversations.android.xmpp.model.muc.user.MultiUserChat;
 import im.conversations.android.xmpp.model.oob.OutOfBandData;
 import im.conversations.android.xmpp.model.reactions.Reactions;
 import im.conversations.android.xmpp.model.reply.Reply;
+import im.conversations.android.xmpp.model.retract.Retract;
 import im.conversations.android.xmpp.model.stanza.Message;
 import java.util.Arrays;
 import java.util.Collection;
@@ -74,6 +75,8 @@ public class Transformer {
         }
         final Replace messageCorrection = transformation.getExtension(Replace.class);
         final Reactions reactions = transformation.getExtension(Reactions.class);
+        final Retract retract = transformation.getExtension(Retract.class);
+        // TODO we need to remove fallbacks for reactions, retractions and potentially other things
         final List<MessageContent> contents = parseContent(transformation);
 
         final boolean identifiableSender =
@@ -85,10 +88,21 @@ public class Transformer {
                         && identifiableSender;
         final boolean isMessageCorrection =
                 Objects.nonNull(messageCorrection)
-                        && messageCorrection.getId() != null
+                        && Objects.nonNull(messageCorrection.getId())
                         && identifiableSender;
-
+        final boolean isRetraction =
-        if (contents.isEmpty()) {
+                Objects.nonNull(retract) && Objects.nonNull(retract.getId()) && identifiableSender;
+        // TODO in a way it would be more appropriate to move this into the contents.isEmpty block
+        // but for that to work we would need to properly ignore the fallback body
+        if (isRetraction) {
+            final var messageIdentifier =
+                    database.messageDao()
+                            .getOrCreateVersion(
+                                    chat, transformation, retract.getId(), Modification.RETRACTION);
+            database.messageDao()
+                    .insertMessageContent(messageIdentifier.version, MessageContent.RETRACTION);
+            return true;
+        } else if (contents.isEmpty()) {
             LOGGER.info("Received message from {} w/o contents", transformation.from);
             transformMessageState(chat, transformation);
             if (isReaction) {

src/main/java/im/conversations/android/xmpp/model/Extension.java

@@ -1,5 +1,6 @@
 package im.conversations.android.xmpp.model;
 
+import com.google.common.base.Preconditions;
 import eu.siacs.conversations.xml.Element;
 import im.conversations.android.xmpp.ExtensionFactory;
 
@@ -10,6 +11,11 @@ public class Extension extends Element {
     }
 
     public Extension(final Class<? extends Extension> clazz) {
-        this(ExtensionFactory.id(clazz));
+        this(
+                Preconditions.checkNotNull(
+                        ExtensionFactory.id(clazz),
+                        String.format(
+                                "%s does not seem to be annotated with @XmlElement",
+                                clazz.getName())));
     }
 }

src/main/java/im/conversations/android/xmpp/model/retract/Retract.java

@@ -1,10 +1,20 @@
 package im.conversations.android.xmpp.model.retract;
 
+import im.conversations.android.annotation.XmlElement;
 import im.conversations.android.xmpp.model.Extension;
 
+@XmlElement
 public class Retract extends Extension {
 
     public Retract() {
         super(Retract.class);
     }
+
+    public String getId() {
+        return this.getAttribute("id");
+    }
+
+    public void setId(final String id) {
+        this.setAttribute("id", id);
+    }
 }

src/main/java/im/conversations/android/xmpp/model/retract/Retracted.java

@@ -1,7 +1,9 @@
 package im.conversations.android.xmpp.model.retract;
 
+import im.conversations.android.annotation.XmlElement;
 import im.conversations.android.xmpp.model.Extension;
 
+@XmlElement
 public class Retracted extends Extension {
 
     public Retracted() {