Adapt message requests to support invite flow.

app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationActivity.java

@@ -153,6 +153,8 @@ import org.thoughtcrime.securesms.groups.GroupChangeFailedException;
 import org.thoughtcrime.securesms.groups.GroupInsufficientRightsException;
 import org.thoughtcrime.securesms.groups.GroupManager;
 import org.thoughtcrime.securesms.groups.GroupNotAMemberException;
+import org.thoughtcrime.securesms.groups.ui.GroupChangeFailureReason;
+import org.thoughtcrime.securesms.groups.ui.GroupErrors;
 import org.thoughtcrime.securesms.groups.ui.LeaveGroupDialog;
 import org.thoughtcrime.securesms.groups.ui.managegroup.ManageGroupActivity;
 import org.thoughtcrime.securesms.groups.ui.pendingmemberinvites.PendingMemberInvitesActivity;
@@ -2190,6 +2192,10 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
     return getRecipient() != null && getRecipient().isPushGroup();
   }
 
+  private boolean isPushGroupV1Conversation() {
+    return getRecipient() != null && getRecipient().isPushV1Group();
+  }
+
   private boolean isSmsForced() {
     return sendButton.isManualSelection() && sendButton.getSelectedTransport().isSms();
   }
@@ -2825,7 +2831,7 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
 
   @Override
   public void onMessageRequest(@NonNull MessageRequestViewModel viewModel) {
-    messageRequestBottomView.setAcceptOnClickListener(v -> viewModel.onAccept());
+    messageRequestBottomView.setAcceptOnClickListener(v -> viewModel.onAccept(this::showGroupChangeErrorToast));
     messageRequestBottomView.setDeleteOnClickListener(v -> onMessageRequestDeleteClicked(viewModel));
     messageRequestBottomView.setBlockOnClickListener(v -> onMessageRequestBlockClicked(viewModel));
     messageRequestBottomView.setUnblockOnClickListener(v -> onMessageRequestUnblockClicked(viewModel));
@@ -2844,6 +2850,10 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
     });
   }
 
+  private void showGroupChangeErrorToast(@NonNull GroupChangeFailureReason e) {
+    Toast.makeText(this, GroupErrors.getUserDisplayMessage(e), Toast.LENGTH_LONG).show();
+  }
+
   @Override
   public void handleReaction(@NonNull View maskTarget,
                              @NonNull MessageRecord messageRecord,
@@ -3005,9 +3015,12 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
   }
 
   private void presentMessageRequestDisplayState(@NonNull MessageRequestViewModel.DisplayState displayState) {
-    if (getIntent().hasExtra(TEXT_EXTRA) || getIntent().hasExtra(MEDIA_EXTRA) || getIntent().hasExtra(STICKER_EXTRA) || (isPushGroupConversation() && !isActiveGroup())) {
+    if (getIntent().hasExtra(TEXT_EXTRA) || getIntent().hasExtra(MEDIA_EXTRA) || getIntent().hasExtra(STICKER_EXTRA)) {
       Log.d(TAG, "[presentMessageRequestDisplayState] Have extra, so ignoring provided state.");
       messageRequestBottomView.setVisibility(View.GONE);
+    } else if (isPushGroupV1Conversation() && !isActiveGroup()) {
+      Log.d(TAG, "[presentMessageRequestDisplayState] Inactive push group V1, so ignoring provided state.");
+      messageRequestBottomView.setVisibility(View.GONE);
     } else {
       Log.d(TAG, "[presentMessageRequestDisplayState] " + displayState);
       switch (displayState) {

app/src/main/java/org/thoughtcrime/securesms/database/GroupDatabase.java

@@ -496,6 +496,11 @@ public final class GroupDatabase extends Database {
     }
   }
 
+  @WorkerThread
+  public boolean isPendingMember(@NonNull GroupId.Push groupId, @NonNull Recipient recipient) {
+    return getGroup(groupId).transform(g -> g.isPendingMember(recipient)).or(false);
+  }
+
   private static String serializeV2GroupMembers(@NonNull Context context, @NonNull DecryptedGroup decryptedGroup) {
     List<RecipientId> groupMembers  = new ArrayList<>(decryptedGroup.getMembersCount());
 
@@ -707,6 +712,17 @@ public final class GroupDatabase extends Database {
         return id.isV1() ? GroupAccessControl.ALL_MEMBERS : GroupAccessControl.ONLY_ADMINS;
       }
     }
+
+    boolean isPendingMember(@NonNull Recipient recipient) {
+      if (isV2Group()) {
+        Optional<UUID> uuid = recipient.getUuid();
+        if (uuid.isPresent()) {
+          return DecryptedGroupUtil.findPendingByUuid(requireV2GroupProperties().getDecryptedGroup().getPendingMembersList(), uuid.get())
+                                   .isPresent();
+        }
+      }
+      return false;
+    }
   }
 
   public static class V2GroupProperties {

app/src/main/java/org/thoughtcrime/securesms/database/ThreadDatabase.java

@@ -31,6 +31,7 @@ import com.fasterxml.jackson.annotation.JsonProperty;
 
 import net.sqlcipher.database.SQLiteDatabase;
 
+import org.signal.storageservice.protos.groups.local.DecryptedGroup;
 import org.thoughtcrime.securesms.contactshare.Contact;
 import org.thoughtcrime.securesms.contactshare.ContactUtil;
 import org.thoughtcrime.securesms.database.MessagingDatabase.MarkedMessageInfo;
@@ -51,6 +52,7 @@ import org.thoughtcrime.securesms.util.TextSecurePreferences;
 import org.thoughtcrime.securesms.util.Util;
 import org.whispersystems.libsignal.util.Pair;
 import org.whispersystems.libsignal.util.guava.Optional;
+import org.whispersystems.signalservice.api.groupsv2.DecryptedGroupUtil;
 
 import java.io.Closeable;
 import java.io.IOException;
@@ -61,6 +63,7 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.UUID;
 
 public class ThreadDatabase extends Database {
 
@@ -761,12 +764,21 @@ public class ThreadDatabase extends Database {
     RecipientId threadRecipientId      = getRecipientIdForThreadId(record.getThreadId());
 
     if (!messageRequestAccepted && threadRecipientId != null) {
-      boolean isPushGroup = Recipient.resolved(threadRecipientId).isPushGroup();
+      Recipient resolved = Recipient.resolved(threadRecipientId);
-      if (isPushGroup) {
+      if (resolved.isPushGroup()) {
-        RecipientId recipientId = DatabaseFactory.getMmsSmsDatabase(context).getGroupAddedBy(record.getThreadId());
+        if (resolved.isPushV2Group()) {
+          DecryptedGroup decryptedGroup = DatabaseFactory.getGroupDatabase(context).requireGroup(resolved.requireGroupId().requireV2()).requireV2GroupProperties().getDecryptedGroup();
+          Optional<UUID> inviter        = DecryptedGroupUtil.findInviter(decryptedGroup.getPendingMembersList(), Recipient.self().getUuid().get());
 
-        if (recipientId != null) {
+          RecipientId recipientId = inviter.isPresent() ? RecipientId.from(inviter.get(), null) : RecipientId.UNKNOWN;
-          return Extra.forGroupMessageRequest(recipientId);
+
+          return Extra.forGroupV2invite(recipientId);
+        } else {
+          RecipientId recipientId = DatabaseFactory.getMmsSmsDatabase(context).getGroupAddedBy(record.getThreadId());
+
+          if (recipientId != null) {
+            return Extra.forGroupMessageRequest(recipientId);
+          }
         }
       }
 
@@ -903,6 +915,7 @@ public class ThreadDatabase extends Database {
     @JsonProperty private final boolean isAlbum;
     @JsonProperty private final boolean isRemoteDelete;
     @JsonProperty private final boolean isMessageRequestAccepted;
+    @JsonProperty private final boolean isGv2Invite;
     @JsonProperty private final String  groupAddedBy;
 
     public Extra(@JsonProperty("isRevealable") boolean isRevealable,
@@ -910,6 +923,7 @@ public class ThreadDatabase extends Database {
                  @JsonProperty("isAlbum") boolean isAlbum,
                  @JsonProperty("isRemoteDelete") boolean isRemoteDelete,
                  @JsonProperty("isMessageRequestAccepted") boolean isMessageRequestAccepted,
+                 @JsonProperty("isGv2Invite") boolean isGv2Invite,
                  @JsonProperty("groupAddedBy") String groupAddedBy)
     {
       this.isRevealable             = isRevealable;
@@ -917,31 +931,36 @@ public class ThreadDatabase extends Database {
       this.isAlbum                  = isAlbum;
       this.isRemoteDelete           = isRemoteDelete;
       this.isMessageRequestAccepted = isMessageRequestAccepted;
+      this.isGv2Invite              = isGv2Invite;
       this.groupAddedBy             = groupAddedBy;
     }
 
     public static @NonNull Extra forViewOnce() {
-      return new Extra(true, false, false, false, true, null);
+      return new Extra(true, false, false, false, true, false, null);
     }
 
     public static @NonNull Extra forSticker() {
-      return new Extra(false, true, false, false, true, null);
+      return new Extra(false, true, false, false, true, false, null);
     }
 
     public static @NonNull Extra forAlbum() {
-      return new Extra(false, false, true, false, true, null);
+      return new Extra(false, false, true, false, true, false, null);
     }
 
     public static @NonNull Extra forRemoteDelete() {
-      return new Extra(false, false, false, true, true, null);
+      return new Extra(false, false, false, true, true, false, null);
     }
 
     public static @NonNull Extra forMessageRequest() {
-      return new Extra(false, false, false, false, false, null);
+      return new Extra(false, false, false, false, false, false, null);
     }
 
     public static @NonNull Extra forGroupMessageRequest(RecipientId recipientId) {
-      return new Extra(false, false, false, false, false, recipientId.serialize());
+      return new Extra(false, false, false, false, false, false, recipientId.serialize());
+    }
+
+    public static @NonNull Extra forGroupV2invite(RecipientId recipientId) {
+      return new Extra(false, false, false, false, false, true, recipientId.serialize());
     }
 
     public boolean isViewOnce() {
@@ -964,6 +983,10 @@ public class ThreadDatabase extends Database {
       return isMessageRequestAccepted;
     }
 
+    public boolean isGv2Invite() {
+      return isGv2Invite;
+    }
+
     public @Nullable String getGroupAddedBy() {
       return groupAddedBy;
     }

app/src/main/java/org/thoughtcrime/securesms/database/model/ThreadRecord.java

@@ -19,13 +19,14 @@ package org.thoughtcrime.securesms.database.model;
 
 import android.content.Context;
 import android.net.Uri;
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
 import android.text.Spannable;
 import android.text.SpannableString;
 import android.text.TextUtils;
 import android.text.style.StyleSpan;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
 import org.thoughtcrime.securesms.R;
 import org.thoughtcrime.securesms.database.MmsSmsColumns;
 import org.thoughtcrime.securesms.database.SmsDatabase;
@@ -79,7 +80,9 @@ public class ThreadRecord extends DisplayRecord {
   @Override
   public SpannableString getDisplayBody(@NonNull Context context) {
     if (getGroupAddedBy() != null) {
-      return emphasisAdded(context.getString(R.string.ThreadRecord_s_added_you_to_the_group, Recipient.live(getGroupAddedBy()).get().getDisplayName(context)));
+      return emphasisAdded(context.getString(isGv2Invite() ? R.string.ThreadRecord_s_invited_you_to_the_group
+                                                           : R.string.ThreadRecord_s_added_you_to_the_group,
+                           Recipient.live(getGroupAddedBy()).get().getDisplayName(context)));
     } else if (!isMessageRequestAccepted()) {
       return emphasisAdded(context.getString(R.string.ThreadRecord_message_request));
     } else if (isGroupUpdate()) {
@@ -194,6 +197,10 @@ public class ThreadRecord extends DisplayRecord {
     else                                                  return null;
   }
 
+  public boolean isGv2Invite() {
+    return extra != null && extra.isGv2Invite();
+  }
+
   public boolean isMessageRequestAccepted() {
     if (extra != null) return extra.isMessageRequestAccepted();
     else               return true;

app/src/main/java/org/thoughtcrime/securesms/groups/GroupManager.java

@@ -183,6 +183,8 @@ public final class GroupManager {
   {
     try (GroupManagerV2.GroupEditor editor = new GroupManagerV2(context).edit(groupId.requireV2())) {
       editor.acceptInvite();
+      DatabaseFactory.getGroupDatabase(context)
+                     .setActive(groupId, true);
     }
   }
 

app/src/main/java/org/thoughtcrime/securesms/jobs/ProfileKeySendJob.java

@@ -41,6 +41,9 @@ public class ProfileKeySendJob extends BaseJob {
   private final long              threadId;
   private final List<RecipientId> recipients;
 
+  /**
+   * Suitable for a 1:1 conversation or a GV1 group only.
+   */
   @WorkerThread
   public static ProfileKeySendJob create(@NonNull Context context, long threadId) {
     Recipient conversationRecipient = DatabaseFactory.getThreadDatabase(context).getRecipientForThreadId(threadId);
@@ -49,6 +52,10 @@ public class ProfileKeySendJob extends BaseJob {
       throw new AssertionError("We have a thread but no recipient!");
     }
 
+    if (conversationRecipient.isPushV2Group()) {
+      throw new AssertionError("Do not send profile keys directly for GV2");
+    }
+
     List<RecipientId> recipients = conversationRecipient.isGroup() ? Stream.of(conversationRecipient.getParticipants()).map(Recipient::getId).toList()
                                                                    : Stream.of(conversationRecipient.getId()).toList();
 

app/src/main/java/org/thoughtcrime/securesms/messagerequests/MessageRequestRepository.java

@@ -5,13 +5,22 @@ import android.content.Context;
 import androidx.annotation.NonNull;
 import androidx.core.util.Consumer;
 
+import org.signal.storageservice.protos.groups.local.DecryptedGroup;
 import org.thoughtcrime.securesms.database.DatabaseFactory;
 import org.thoughtcrime.securesms.database.GroupDatabase;
 import org.thoughtcrime.securesms.database.MessagingDatabase;
 import org.thoughtcrime.securesms.database.RecipientDatabase;
 import org.thoughtcrime.securesms.database.ThreadDatabase;
 import org.thoughtcrime.securesms.dependencies.ApplicationDependencies;
+import org.thoughtcrime.securesms.groups.GroupChangeBusyException;
+import org.thoughtcrime.securesms.groups.GroupChangeFailedException;
+import org.thoughtcrime.securesms.groups.GroupInsufficientRightsException;
+import org.thoughtcrime.securesms.groups.GroupManager;
+import org.thoughtcrime.securesms.groups.GroupNotAMemberException;
+import org.thoughtcrime.securesms.groups.ui.GroupChangeErrorCallback;
+import org.thoughtcrime.securesms.groups.ui.GroupChangeFailureReason;
 import org.thoughtcrime.securesms.jobs.MultiDeviceMessageRequestResponseJob;
+import org.thoughtcrime.securesms.logging.Log;
 import org.thoughtcrime.securesms.notifications.MarkReadReceiver;
 import org.thoughtcrime.securesms.notifications.MessageNotifier;
 import org.thoughtcrime.securesms.recipients.LiveRecipient;
@@ -20,14 +29,18 @@ import org.thoughtcrime.securesms.recipients.RecipientId;
 import org.thoughtcrime.securesms.recipients.RecipientUtil;
 import org.thoughtcrime.securesms.sms.MessageSender;
 import org.thoughtcrime.securesms.util.TextSecurePreferences;
+import org.thoughtcrime.securesms.util.Util;
 import org.thoughtcrime.securesms.util.concurrent.SignalExecutors;
 import org.whispersystems.libsignal.util.guava.Optional;
 
+import java.io.IOException;
 import java.util.List;
 import java.util.concurrent.Executor;
 
 final class MessageRequestRepository {
 
+  private static final String TAG = Log.tag(MessageRequestRepository.class);
+
   private final Context  context;
   private final Executor executor;
 
@@ -48,14 +61,24 @@ final class MessageRequestRepository {
       GroupDatabase groupDatabase = DatabaseFactory.getGroupDatabase(context);
       Optional<GroupDatabase.GroupRecord> groupRecord = groupDatabase.getGroup(recipientId);
       onMemberCountLoaded.accept(groupRecord.transform(record -> {
+        if (record.isV2Group()) {
+          DecryptedGroup decryptedGroup = record.requireV2GroupProperties().getDecryptedGroup();
+          return new GroupMemberCount(decryptedGroup.getMembersCount(), decryptedGroup.getPendingMembersCount());
+        } else {
           return new GroupMemberCount(record.getMembers().size(), 0);
+        }
       }).or(GroupMemberCount.ZERO));
     });
   }
 
   void getMessageRequestState(@NonNull Recipient recipient, long threadId, @NonNull Consumer<MessageRequestState> state) {
     executor.execute(() -> {
-      if (!RecipientUtil.isMessageRequestAccepted(context, threadId)) {
+      if (recipient.isPushV2Group()) {
+        boolean pendingMember = DatabaseFactory.getGroupDatabase(context)
+                                               .isPendingMember(recipient.requireGroupId().requireV2(), Recipient.self());
+        state.accept(pendingMember ? MessageRequestState.UNACCEPTED
+                                   : MessageRequestState.ACCEPTED);
+      } else if (!RecipientUtil.isMessageRequestAccepted(context, threadId)) {
         state.accept(MessageRequestState.UNACCEPTED);
       } else if (RecipientUtil.isPreMessageRequestThread(context, threadId) && !RecipientUtil.isLegacyProfileSharingAccepted(recipient)) {
         state.accept(MessageRequestState.LEGACY);
@@ -65,23 +88,46 @@ final class MessageRequestRepository {
     });
   }
 
-  void acceptMessageRequest(@NonNull LiveRecipient liveRecipient, long threadId, @NonNull Runnable onMessageRequestAccepted) {
+  void acceptMessageRequest(@NonNull LiveRecipient liveRecipient,
+                            long threadId,
+                            @NonNull Runnable onMessageRequestAccepted,
+                            @NonNull GroupChangeErrorCallback mainThreadError)
+  {
+    GroupChangeErrorCallback error = e -> Util.runOnMain(() -> mainThreadError.onError(e));
     executor.execute(()-> {
-      RecipientDatabase recipientDatabase = DatabaseFactory.getRecipientDatabase(context);
+      if (liveRecipient.get().isPushV2Group()) {
-      recipientDatabase.setProfileSharing(liveRecipient.getId(), true);
+        try {
-      liveRecipient.refresh();
+          Log.i(TAG, "GV2 accepting invite");
+          GroupManager.acceptInvite(context, liveRecipient.get().requireGroupId().requireV2());
 
-      List<MessagingDatabase.MarkedMessageInfo> messageIds = DatabaseFactory.getThreadDatabase(context)
+          RecipientDatabase recipientDatabase = DatabaseFactory.getRecipientDatabase(context);
-                                                                            .setEntireThreadRead(threadId);
+          recipientDatabase.setProfileSharing(liveRecipient.getId(), true);
-      MessageNotifier.updateNotification(context);
-      MarkReadReceiver.process(context, messageIds);
 
-      if (TextSecurePreferences.isMultiDevice(context)) {
+          onMessageRequestAccepted.run();
-        ApplicationDependencies.getJobManager().add(MultiDeviceMessageRequestResponseJob.forAccept(liveRecipient.getId()));
+        } catch (GroupInsufficientRightsException e) {
+          Log.w(TAG, e);
+          error.onError(GroupChangeFailureReason.NO_RIGHTS);
+        } catch (GroupChangeBusyException | GroupChangeFailedException | GroupNotAMemberException | IOException e) {
+          Log.w(TAG, e);
+          error.onError(GroupChangeFailureReason.OTHER);
+        }
+      } else {
+        RecipientDatabase recipientDatabase = DatabaseFactory.getRecipientDatabase(context);
+        recipientDatabase.setProfileSharing(liveRecipient.getId(), true);
+
+        MessageSender.sendProfileKey(context, threadId);
+
+        List<MessagingDatabase.MarkedMessageInfo> messageIds = DatabaseFactory.getThreadDatabase(context)
+                                                                              .setEntireThreadRead(threadId);
+        MessageNotifier.updateNotification(context);
+        MarkReadReceiver.process(context, messageIds);
+
+        if (TextSecurePreferences.isMultiDevice(context)) {
+          ApplicationDependencies.getJobManager().add(MultiDeviceMessageRequestResponseJob.forAccept(liveRecipient.getId()));
+        }
+
+        onMessageRequestAccepted.run();
       }
-
-      MessageSender.sendProfileKey(context, threadId);
-      onMessageRequestAccepted.run();
     });
   }
 

app/src/main/java/org/thoughtcrime/securesms/messagerequests/MessageRequestViewModel.java

@@ -11,6 +11,7 @@ import androidx.lifecycle.Transformations;
 import androidx.lifecycle.ViewModel;
 import androidx.lifecycle.ViewModelProvider;
 
+import org.thoughtcrime.securesms.groups.ui.GroupChangeErrorCallback;
 import org.thoughtcrime.securesms.recipients.LiveRecipient;
 import org.thoughtcrime.securesms.recipients.Recipient;
 import org.thoughtcrime.securesms.recipients.RecipientForeverObserver;
@@ -89,10 +90,11 @@ public class MessageRequestViewModel extends ViewModel {
   }
 
   @MainThread
-  public void onAccept() {
+  public void onAccept(@NonNull GroupChangeErrorCallback error) {
     repository.acceptMessageRequest(liveRecipient, threadId, () -> {
       status.postValue(Status.ACCEPTED);
-    });
+    },
+    error);
   }
 
   @MainThread

app/src/main/java/org/thoughtcrime/securesms/messagerequests/MessageRequestsBottomView.java

@@ -65,7 +65,11 @@ public class MessageRequestsBottomView extends ConstraintLayout {
       blockedButtons.setVisibility(VISIBLE);
     } else {
       if (recipient.isGroup()) {
-        question.setText(HtmlCompat.fromHtml(getContext().getString(R.string.MessageRequestBottomView_do_you_want_to_join_the_group_s_they_wont_know_youve_seen_their_messages_until_you_accept, HtmlUtil.bold(recipient.getDisplayName(getContext()))), 0));
+        if (recipient.isPushV2Group()) {
+          question.setText(HtmlCompat.fromHtml(getContext().getString(R.string.MessageRequestBottomView_you_were_invited_to_join_the_group_s, HtmlUtil.bold(recipient.getDisplayName(getContext()))), 0));
+        } else {
+          question.setText(HtmlCompat.fromHtml(getContext().getString(R.string.MessageRequestBottomView_do_you_want_to_join_the_group_s_they_wont_know_youve_seen_their_messages_until_you_accept, HtmlUtil.bold(recipient.getDisplayName(getContext()))), 0));
+        }
       } else {
         question.setText(HtmlCompat.fromHtml(getContext().getString(R.string.MessageRequestBottomView_do_you_want_to_let_s_message_you_they_wont_know_youve_seen_their_messages_until_you_accept, HtmlUtil.bold(recipient.getDisplayName(getContext()))), 0));
       }

app/src/main/java/org/thoughtcrime/securesms/recipients/Recipient.java

@@ -603,6 +603,11 @@ public class Recipient {
     return groupId != null && groupId.isPush();
   }
 
+  public boolean isPushV1Group() {
+    GroupId groupId = resolve().groupId;
+    return groupId != null && groupId.isV1();
+  }
+
   public boolean isPushV2Group() {
     GroupId groupId = resolve().groupId;
     return groupId != null && groupId.isV2();

app/src/main/java/org/thoughtcrime/securesms/sms/MessageSender.java

@@ -83,6 +83,9 @@ public class MessageSender {
 
   private static final String TAG = MessageSender.class.getSimpleName();
 
+  /**
+   * Suitable for a 1:1 conversation or a GV1 group only.
+   */
   @WorkerThread
   public static void sendProfileKey(final Context context, final long threadId) {
     ApplicationDependencies.getJobManager().add(ProfileKeySendJob.create(context, threadId));

app/src/main/res/values/strings.xml

@@ -774,6 +774,7 @@
     <string name="MessageRequestBottomView_unblock">Unblock</string>
     <string name="MessageRequestBottomView_do_you_want_to_let_s_message_you_they_wont_know_youve_seen_their_messages_until_you_accept">Do you want to let %1$s message you? They won\'t know you\'ve seen their messages until you accept.</string>
     <string name="MessageRequestBottomView_do_you_want_to_join_the_group_s_they_wont_know_youve_seen_their_messages_until_you_accept">Do you want to join the group %1$s? They won\'t know you\'ve seen their messages until you accept.</string>
+    <string name="MessageRequestBottomView_you_were_invited_to_join_the_group_s">You were invited to join the group %1$s. Do you want to let members of this group message you?</string>
     <string name="MessageRequestBottomView_unblock_s_to_message_and_call_each_other">Unblock %1$s to message and call each other.</string>
     <string name="MessageRequestBottomView_unblock_to_allow_group_members_to_add_you_to_this_group_again">Unblock to allow group members to add you to this group again.</string>
     <string name="MessageRequestProfileView_member_of_one_group">Member of %1$s</string>
@@ -1087,6 +1088,7 @@
     <string name="ThreadRecord_message_could_not_be_processed">Message could not be processed</string>
     <string name="ThreadRecord_message_request">Message Request</string>
     <string name="ThreadRecord_s_added_you_to_the_group">%1$s added you to the group</string>
+    <string name="ThreadRecord_s_invited_you_to_the_group">%1$s invited you to the group</string>
 
     <!-- UpdateApkReadyListener -->
     <string name="UpdateApkReadyListener_Signal_update">Signal update</string>

libsignal/service/src/main/java/org/whispersystems/signalservice/api/groupsv2/DecryptedGroupUtil.java

@@ -252,6 +252,12 @@ public final class DecryptedGroupUtil {
     return -1;
   }
 
+  public static Optional<UUID> findInviter(List<DecryptedPendingMember> pendingMembersList, UUID uuid) {
+    return Optional.fromNullable(findPendingByUuid(pendingMembersList, uuid).transform(DecryptedPendingMember::getAddedByUuid)
+                                                                            .transform(UuidUtil::fromByteStringOrNull)
+                                                                            .orNull());
+  }
+
   public static class NotAbleToApplyChangeException extends Throwable {
   }
 }