Unify all private message responses in one PrivateResponse class

This also adds `Shareable`s to invitation response
which is a precondition for #561

briar-android/src/main/java/org/briarproject/briar/android/blog/BlogControllerImpl.java

@@ -25,7 +25,7 @@ import org.briarproject.briar.api.blog.BlogManager;
 import org.briarproject.briar.api.blog.BlogSharingManager;
 import org.briarproject.briar.api.blog.event.BlogInvitationResponseReceivedEvent;
 import org.briarproject.briar.api.blog.event.BlogPostAddedEvent;
-import org.briarproject.briar.api.sharing.InvitationResponse;
+import org.briarproject.briar.api.messaging.PrivateResponse;
 import org.briarproject.briar.api.sharing.event.ContactLeftShareableEvent;
 
 import java.util.ArrayList;
@@ -107,8 +107,8 @@ class BlogControllerImpl extends BaseControllerImpl
 		} else if (e instanceof BlogInvitationResponseReceivedEvent) {
 			BlogInvitationResponseReceivedEvent b =
 					(BlogInvitationResponseReceivedEvent) e;
-			InvitationResponse r = b.getResponse();
-			if (r.getShareableId().equals(groupId) && r.wasAccepted()) {
+			PrivateResponse<Blog> r = b.getResponse();
+			if (r.getObject().getId().equals(groupId) && r.wasAccepted()) {
 				LOG.info("Blog invitation accepted");
 				onBlogInvitationAccepted(b.getContactId());
 			}

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListFragment.java

@@ -44,8 +44,8 @@ import org.briarproject.briar.api.introduction.event.IntroductionResponseReceive
 import org.briarproject.briar.api.messaging.ConversationManager;
 import org.briarproject.briar.api.messaging.PrivateMessageHeader;
 import org.briarproject.briar.api.messaging.PrivateRequest;
+import org.briarproject.briar.api.messaging.PrivateResponse;
 import org.briarproject.briar.api.messaging.event.PrivateMessageReceivedEvent;
-import org.briarproject.briar.api.sharing.InvitationResponse;
 import org.briarproject.briar.api.sharing.event.InvitationRequestReceivedEvent;
 import org.briarproject.briar.api.sharing.event.InvitationResponseReceivedEvent;
 
@@ -277,7 +277,7 @@ public class ContactListFragment extends BaseFragment implements EventListener {
 			LOG.info("Invitation response received, updating item");
 			InvitationResponseReceivedEvent m =
 					(InvitationResponseReceivedEvent) e;
-			InvitationResponse ir = m.getResponse();
+			PrivateResponse ir = m.getResponse();
 			updateItem(m.getContactId(), ir);
 		}
 	}

briar-android/src/main/java/org/briarproject/briar/android/contact/ConversationActivity.java

@@ -71,9 +71,9 @@ import org.briarproject.briar.api.messaging.PrivateMessage;
 import org.briarproject.briar.api.messaging.PrivateMessageFactory;
 import org.briarproject.briar.api.messaging.PrivateMessageHeader;
 import org.briarproject.briar.api.messaging.PrivateRequest;
+import org.briarproject.briar.api.messaging.PrivateResponse;
 import org.briarproject.briar.api.messaging.event.PrivateMessageReceivedEvent;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationManager;
-import org.briarproject.briar.api.sharing.InvitationResponse;
 import org.briarproject.briar.api.sharing.event.InvitationRequestReceivedEvent;
 import org.briarproject.briar.api.sharing.event.InvitationResponseReceivedEvent;
 import org.thoughtcrime.securesms.components.util.FutureTaskListener;
@@ -424,7 +424,7 @@ public class ConversationActivity extends BriarActivity
 				item = ConversationItem
 						.from(this, contactName, (PrivateRequest) i);
 			} else {
-				InvitationResponse r = (InvitationResponse) i;
+				PrivateResponse r = (PrivateResponse) i;
 				item = ConversationItem.from(this, contactName, r);
 			}
 			items.add(item);
@@ -507,16 +507,16 @@ public class ConversationActivity extends BriarActivity
 					(IntroductionRequestReceivedEvent) e;
 			if (event.getContactId().equals(contactId)) {
 				LOG.info("Introduction request received, adding...");
-				IntroductionRequest ir = event.getIntroductionRequest();
-				handleIntroductionRequest(ir);
+				PrivateRequest ir = event.getIntroductionRequest();
+				handlePrivateRequest(ir);
 			}
 		} else if (e instanceof IntroductionResponseReceivedEvent) {
 			IntroductionResponseReceivedEvent event =
 					(IntroductionResponseReceivedEvent) e;
 			if (event.getContactId().equals(contactId)) {
 				LOG.info("Introduction response received, adding...");
-				IntroductionResponse ir = event.getIntroductionResponse();
-				handleIntroductionResponse(ir);
+				PrivateResponse ir = event.getIntroductionResponse();
+				handlePrivateResponse(ir);
 			}
 		} else if (e instanceof InvitationRequestReceivedEvent) {
 			InvitationRequestReceivedEvent event =
@@ -524,15 +524,15 @@ public class ConversationActivity extends BriarActivity
 			if (event.getContactId().equals(contactId)) {
 				LOG.info("Invitation received, adding...");
 				PrivateRequest ir = event.getRequest();
-				handleInvitationRequest(ir);
+				handlePrivateRequest(ir);
 			}
 		} else if (e instanceof InvitationResponseReceivedEvent) {
 			InvitationResponseReceivedEvent event =
 					(InvitationResponseReceivedEvent) e;
 			if (event.getContactId().equals(contactId)) {
 				LOG.info("Invitation response received, adding...");
-				InvitationResponse ir = event.getResponse();
-				handleInvitationResponse(ir);
+				PrivateResponse ir = event.getResponse();
+				handlePrivateResponse(ir);
 			}
 		}
 	}
@@ -546,7 +546,7 @@ public class ConversationActivity extends BriarActivity
 		});
 	}
 
-	private void handleIntroductionRequest(IntroductionRequest m) {
+	private void handlePrivateRequest(PrivateRequest m) {
 		getContactNameTask().addListener(new FutureTaskListener<String>() {
 			@Override
 			public void onSuccess(String contactName) {
@@ -565,7 +565,7 @@ public class ConversationActivity extends BriarActivity
 		});
 	}
 
-	private void handleIntroductionResponse(IntroductionResponse m) {
+	private void handlePrivateResponse(PrivateResponse m) {
 		getContactNameTask().addListener(new FutureTaskListener<String>() {
 			@Override
 			public void onSuccess(String contactName) {
@@ -584,46 +584,8 @@ public class ConversationActivity extends BriarActivity
 		});
 	}
 
-	private void handleInvitationRequest(PrivateRequest m) {
-		getContactNameTask().addListener(new FutureTaskListener<String>() {
-			@Override
-			public void onSuccess(String contactName) {
-				runOnUiThreadUnlessDestroyed(() -> {
-					ConversationItem item = ConversationItem
-							.from(ConversationActivity.this, contactName, m);
-					addConversationItem(item);
-				});
-			}
-
-			@Override
-			public void onFailure(Throwable exception) {
-				runOnUiThreadUnlessDestroyed(
-						() -> handleDbException((DbException) exception));
-			}
-		});
-	}
-
-	private void handleInvitationResponse(InvitationResponse m) {
-		getContactNameTask().addListener(new FutureTaskListener<String>() {
-			@Override
-			public void onSuccess(String contactName) {
-				runOnUiThreadUnlessDestroyed(() -> {
-					ConversationItem item = ConversationItem
-							.from(ConversationActivity.this, contactName, m);
-					addConversationItem(item);
-				});
-			}
-
-			@Override
-			public void onFailure(Throwable exception) {
-				runOnUiThreadUnlessDestroyed(
-						() -> handleDbException((DbException) exception));
-			}
-		});
-	}
-
-	private void markMessages(Collection<MessageId> messageIds,
-			boolean sent, boolean seen) {
+	private void markMessages(Collection<MessageId> messageIds, boolean sent,
+			boolean seen) {
 		runOnUiThreadUnlessDestroyed(() -> {
 			adapter.incrementRevision();
 			Set<MessageId> messages = new HashSet<>(messageIds);

briar-android/src/main/java/org/briarproject/briar/android/contact/ConversationItem.java

@@ -17,9 +17,9 @@ import org.briarproject.briar.api.introduction.IntroductionRequest;
 import org.briarproject.briar.api.introduction.IntroductionResponse;
 import org.briarproject.briar.api.messaging.PrivateMessageHeader;
 import org.briarproject.briar.api.messaging.PrivateRequest;
+import org.briarproject.briar.api.messaging.PrivateResponse;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationRequest;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationResponse;
-import org.briarproject.briar.api.sharing.InvitationResponse;
 import org.briarproject.briar.api.sharing.Shareable;
 
 import javax.annotation.Nullable;
@@ -87,46 +87,6 @@ abstract class ConversationItem {
 		}
 	}
 
-	static ConversationItem from(Context ctx, String contactName,
-			IntroductionResponse ir) {
-		if (ir.isLocal()) {
-			String text;
-			if (ir.wasAccepted()) {
-				text = ctx.getString(
-						R.string.introduction_response_accepted_sent,
-						ir.getName());
-				text += "\n\n" + ctx.getString(
-						R.string.introduction_response_accepted_sent_info,
-						ir.getName());
-			} else {
-				text = ctx.getString(
-						R.string.introduction_response_declined_sent,
-						ir.getName());
-			}
-			return new ConversationNoticeOutItem(ir.getId(), ir.getGroupId(),
-					text, null, ir.getTimestamp(), ir.isSent(), ir.isSeen());
-		} else {
-			String text;
-			if (ir.wasAccepted()) {
-				text = ctx.getString(
-						R.string.introduction_response_accepted_received,
-						contactName, ir.getName());
-			} else {
-				if (ir.isIntroducer()) {
-					text = ctx.getString(
-							R.string.introduction_response_declined_received,
-							contactName, ir.getName());
-				} else {
-					text = ctx.getString(
-							R.string.introduction_response_declined_received_by_introducee,
-							contactName, ir.getName());
-				}
-			}
-			return new ConversationNoticeInItem(ir.getId(), ir.getGroupId(),
-					text, null, ir.getTimestamp(), ir.isRead());
-		}
-	}
-
 	static ConversationItem from(Context ctx, String contactName,
 			PrivateRequest ir) {
 		if (ir.isLocal()) {
@@ -196,7 +156,44 @@ abstract class ConversationItem {
 	}
 
 	static ConversationItem from(Context ctx, String contactName,
-			InvitationResponse ir) {
+			IntroductionResponse ir) {
+		if (ir.isLocal()) {
+			String text;
+			if (ir.wasAccepted()) {
+				text = ctx.getString(
+						R.string.introduction_response_accepted_sent,
+						ir.getObject().getName());
+				text += "\n\n" + ctx.getString(
+						R.string.introduction_response_accepted_sent_info,
+						ir.getObject().getName());
+			} else {
+				text = ctx.getString(
+						R.string.introduction_response_declined_sent,
+						ir.getObject().getName());
+			}
+			return new ConversationNoticeOutItem(ir.getId(), ir.getGroupId(),
+					text, null, ir.getTimestamp(), ir.isSent(), ir.isSeen());
+		} else {
+			@StringRes int res;
+			if (ir.wasAccepted()) {
+				res = R.string.introduction_response_accepted_received;
+			} else {
+				if (ir.getObject().isIntroducer()) {
+					res = R.string.introduction_response_declined_received;
+				} else {
+					res =
+							R.string.introduction_response_declined_received_by_introducee;
+				}
+			}
+			String text =
+					ctx.getString(res, contactName, ir.getObject().getName());
+			return new ConversationNoticeInItem(ir.getId(), ir.getGroupId(),
+					text, null, ir.getTimestamp(), ir.isRead());
+		}
+	}
+
+	static ConversationItem from(Context ctx, String contactName,
+			PrivateResponse ir) {
 		@StringRes int res;
 		if (ir.isLocal()) {
 			if (ir.wasAccepted()) {
@@ -208,7 +205,7 @@ abstract class ConversationItem {
 					res = R.string.groups_invitations_response_accepted_sent;
 				} else {
 					throw new IllegalArgumentException(
-							"Unknown InvitationResponse");
+							"Unknown PrivateResponse");
 				}
 			} else {
 				if (ir instanceof ForumInvitationResponse) {
@@ -219,7 +216,7 @@ abstract class ConversationItem {
 					res = R.string.groups_invitations_response_declined_sent;
 				} else {
 					throw new IllegalArgumentException(
-							"Unknown InvitationResponse");
+							"Unknown PrivateResponse");
 				}
 			}
 			String text = ctx.getString(res, contactName);
@@ -235,7 +232,7 @@ abstract class ConversationItem {
 					res = R.string.groups_invitations_response_accepted_received;
 				} else {
 					throw new IllegalArgumentException(
-							"Unknown InvitationResponse");
+							"Unknown PrivateResponse");
 				}
 			} else {
 					if (ir instanceof ForumInvitationResponse) {
@@ -246,7 +243,7 @@ abstract class ConversationItem {
 						res = R.string.groups_invitations_response_declined_received;
 					} else {
 						throw new IllegalArgumentException(
-								"Unknown InvitationResponse");
+								"Unknown PrivateResponse");
 					}
 			}
 			String text = ctx.getString(res, contactName);
@@ -261,14 +258,12 @@ abstract class ConversationItem {
 	 * PrivateMessageHeader.
 	 **/
 	static ConversationItem from(Context ctx, PrivateMessageHeader h) {
-		if(h instanceof IntroductionRequest) {
-			return from(ctx, "", (IntroductionRequest) h);
-		} else if(h instanceof IntroductionResponse) {
+		if(h instanceof IntroductionResponse) {
 			return from(ctx, "", (IntroductionResponse) h);
 		} else if(h instanceof PrivateRequest) {
 			return from(ctx, "", (PrivateRequest) h);
-		} else if(h instanceof InvitationResponse) {
-			return from(ctx, "", (InvitationResponse) h);
+		} else if(h instanceof PrivateResponse) {
+			return from(ctx, "", (PrivateResponse) h);
 		} else {
 			return from(h);
 		}

briar-android/src/main/java/org/briarproject/briar/android/forum/ForumControllerImpl.java

@@ -86,7 +86,7 @@ class ForumControllerImpl extends
 					(ForumInvitationResponseReceivedEvent) e;
 			ForumInvitationResponse r =
 					(ForumInvitationResponse) f.getResponse();
-			if (r.getShareableId().equals(getGroupId()) && r.wasAccepted()) {
+			if (r.getObject().getId().equals(getGroupId()) && r.wasAccepted()) {
 				LOG.info("Forum invitation was accepted");
 				onForumInvitationAccepted(f.getContactId());
 			}

briar-android/src/main/java/org/briarproject/briar/android/privategroup/conversation/GroupControllerImpl.java

@@ -101,7 +101,7 @@ class GroupControllerImpl extends
 					(GroupInvitationResponseReceivedEvent) e;
 			GroupInvitationResponse r =
 					(GroupInvitationResponse) g.getResponse();
-			if (getGroupId().equals(r.getShareableId()) && r.wasAccepted()) {
+			if (getGroupId().equals(r.getObject().getId()) && r.wasAccepted()) {
 				listener.runOnUiThreadUnlessDestroyed(
 						() -> listener.onInvitationAccepted(g.getContactId()));
 			}

briar-api/src/main/java/org/briarproject/briar/api/blog/BlogInvitationResponse.java

@@ -4,15 +4,15 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.api.client.SessionId;
-import org.briarproject.briar.api.sharing.InvitationResponse;
+import org.briarproject.briar.api.messaging.PrivateResponse;
 
 @NotNullByDefault
-public class BlogInvitationResponse extends InvitationResponse {
+public class BlogInvitationResponse extends PrivateResponse<Blog> {
 
 	public BlogInvitationResponse(MessageId id, GroupId groupId, long time,
 			boolean local, boolean sent, boolean seen, boolean read,
-			SessionId sessionId, GroupId blogId, boolean accept) {
-		super(id, groupId, time, local, sent, seen, read, sessionId, blogId,
+			SessionId sessionId, Blog blog, boolean accept) {
+		super(id, groupId, time, local, sent, seen, read, sessionId, blog,
 				accept);
 	}
 

briar-api/src/main/java/org/briarproject/briar/api/blog/event/BlogInvitationResponseReceivedEvent.java

@@ -2,6 +2,7 @@ package org.briarproject.briar.api.blog.event;
 
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.api.blog.Blog;
 import org.briarproject.briar.api.blog.BlogInvitationResponse;
 import org.briarproject.briar.api.sharing.event.InvitationResponseReceivedEvent;
 
@@ -10,7 +11,7 @@ import javax.annotation.concurrent.Immutable;
 @Immutable
 @NotNullByDefault
 public class BlogInvitationResponseReceivedEvent
-		extends InvitationResponseReceivedEvent {
+		extends InvitationResponseReceivedEvent<Blog> {
 
 	public BlogInvitationResponseReceivedEvent(ContactId contactId,
 			BlogInvitationResponse response) {

briar-api/src/main/java/org/briarproject/briar/api/forum/ForumInvitationResponse.java

@@ -4,18 +4,18 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.api.client.SessionId;
-import org.briarproject.briar.api.sharing.InvitationResponse;
+import org.briarproject.briar.api.messaging.PrivateResponse;
 
 import javax.annotation.concurrent.Immutable;
 
 @Immutable
 @NotNullByDefault
-public class ForumInvitationResponse extends InvitationResponse {
+public class ForumInvitationResponse extends PrivateResponse<Forum> {
 
 	public ForumInvitationResponse(MessageId id, GroupId groupId, long time,
 			boolean local, boolean sent, boolean seen, boolean read,
-			SessionId sessionId, GroupId forumId, boolean accept) {
-		super(id, groupId, time, local, sent, seen, read, sessionId, forumId,
+			SessionId sessionId, Forum forum, boolean accept) {
+		super(id, groupId, time, local, sent, seen, read, sessionId, forum,
 				accept);
 	}
 

briar-api/src/main/java/org/briarproject/briar/api/introduction/IntroductionResponse.java

@@ -4,45 +4,19 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.api.client.SessionId;
-import org.briarproject.briar.api.messaging.PrivateMessageHeader;
+import org.briarproject.briar.api.messaging.PrivateResponse;
 
 import javax.annotation.concurrent.Immutable;
 
-import static org.briarproject.briar.api.introduction.Role.INTRODUCER;
-
 @Immutable
 @NotNullByDefault
-public class IntroductionResponse extends PrivateMessageHeader {
+public class IntroductionResponse extends PrivateResponse<Introduction> {
 
-	private final SessionId sessionId;
-	private final String name;
-	private final Role role;
-	private final boolean accepted;
-
-	public IntroductionResponse(SessionId sessionId, MessageId messageId,
-			GroupId groupId, Role role, long time, boolean local, boolean sent,
-			boolean seen, boolean read, String name, boolean accepted) {
-		super(messageId, groupId, time, local, sent, seen, read);
-		this.sessionId = sessionId;
-		this.name = name;
-		this.role = role;
-		this.accepted = accepted;
-	}
-
-	public SessionId getSessionId() {
-		return sessionId;
-	}
-
-	public String getName() {
-		return name;
-	}
-
-	public boolean isIntroducer() {
-		return role == INTRODUCER;
-	}
-
-	public boolean wasAccepted() {
-		return accepted;
+	public IntroductionResponse(MessageId messageId, GroupId groupId, long time,
+			boolean local, boolean sent, boolean seen, boolean read,
+			SessionId sessionId, Introduction introduction, boolean accepted) {
+		super(messageId, groupId, time, local, sent, seen, read, sessionId,
+				introduction, accepted);
 	}
 
 }

briar-api/src/main/java/org/briarproject/briar/api/messaging/PrivateResponse.java

@@ -0,0 +1,40 @@
+package org.briarproject.briar.api.messaging;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.GroupId;
+import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.briar.api.client.SessionId;
+
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+public abstract class PrivateResponse<O extends Nameable>
+		extends PrivateMessageHeader {
+
+	private final SessionId sessionId;
+	private final O object;
+	private final boolean accepted;
+
+	public PrivateResponse(MessageId id, GroupId groupId, long time,
+			boolean local, boolean sent, boolean seen, boolean read,
+			SessionId sessionId, O object, boolean accepted) {
+		super(id, groupId, time, local, sent, seen, read);
+		this.sessionId = sessionId;
+		this.object = object;
+		this.accepted = accepted;
+	}
+
+	public SessionId getSessionId() {
+		return sessionId;
+	}
+
+	public O getObject() {
+		return object;
+	}
+
+	public boolean wasAccepted() {
+		return accepted;
+	}
+
+}

briar-api/src/main/java/org/briarproject/briar/api/privategroup/event/GroupInvitationResponseReceivedEvent.java

@@ -2,7 +2,8 @@ package org.briarproject.briar.api.privategroup.event;
 
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.briar.api.sharing.InvitationResponse;
+import org.briarproject.briar.api.messaging.PrivateResponse;
+import org.briarproject.briar.api.privategroup.PrivateGroup;
 import org.briarproject.briar.api.sharing.event.InvitationResponseReceivedEvent;
 
 import javax.annotation.concurrent.Immutable;
@@ -10,10 +11,10 @@ import javax.annotation.concurrent.Immutable;
 @Immutable
 @NotNullByDefault
 public class GroupInvitationResponseReceivedEvent
-		extends InvitationResponseReceivedEvent {
+		extends InvitationResponseReceivedEvent<PrivateGroup> {
 
 	public GroupInvitationResponseReceivedEvent(ContactId contactId,
-			InvitationResponse response) {
+			PrivateResponse<PrivateGroup> response) {
 		super(contactId, response);
 	}
 }

briar-api/src/main/java/org/briarproject/briar/api/privategroup/invitation/GroupInvitationResponse.java

@@ -4,19 +4,20 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.api.client.SessionId;
-import org.briarproject.briar.api.sharing.InvitationResponse;
+import org.briarproject.briar.api.messaging.PrivateResponse;
+import org.briarproject.briar.api.privategroup.PrivateGroup;
 
 import javax.annotation.concurrent.Immutable;
 
 @Immutable
 @NotNullByDefault
-public class GroupInvitationResponse extends InvitationResponse {
+public class GroupInvitationResponse extends PrivateResponse<PrivateGroup> {
 
 	public GroupInvitationResponse(MessageId id, GroupId groupId, long time,
 			boolean local, boolean sent, boolean seen, boolean read,
-			SessionId sessionId, GroupId shareableId, boolean accept) {
+			SessionId sessionId, PrivateGroup privateGroup, boolean accept) {
 		super(id, groupId, time, local, sent, seen, read, sessionId,
-				shareableId, accept);
+				privateGroup, accept);
 	}
 
 }

briar-api/src/main/java/org/briarproject/briar/api/sharing/InvitationResponse.java

@@ -1,41 +0,0 @@
-package org.briarproject.briar.api.sharing;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.GroupId;
-import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.briar.api.client.SessionId;
-import org.briarproject.briar.api.messaging.PrivateMessageHeader;
-
-import javax.annotation.concurrent.Immutable;
-
-@Immutable
-@NotNullByDefault
-public abstract class InvitationResponse extends PrivateMessageHeader {
-
-	private final SessionId sessionId;
-	private final GroupId shareableId;
-	private final boolean accept;
-
-	public InvitationResponse(MessageId id, GroupId groupId,
-			long time, boolean local, boolean sent, boolean seen,
-			boolean read, SessionId sessionId, GroupId shareableId,
-			boolean accept) {
-		super(id, groupId, time, local, sent, seen, read);
-		this.sessionId = sessionId;
-		this.shareableId = shareableId;
-		this.accept = accept;
-	}
-
-	public SessionId getSessionId() {
-		return sessionId;
-	}
-
-	public boolean wasAccepted() {
-		return accept;
-	}
-
-	public GroupId getShareableId() {
-		return shareableId;
-	}
-
-}

briar-api/src/main/java/org/briarproject/briar/api/sharing/event/InvitationResponseReceivedEvent.java

@@ -3,19 +3,21 @@ package org.briarproject.briar.api.sharing.event;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.briar.api.sharing.InvitationResponse;
+import org.briarproject.briar.api.messaging.PrivateResponse;
+import org.briarproject.briar.api.sharing.Shareable;
 
 import javax.annotation.concurrent.Immutable;
 
 @Immutable
 @NotNullByDefault
-public abstract class InvitationResponseReceivedEvent extends Event {
+public abstract class InvitationResponseReceivedEvent<S extends Shareable>
+		extends Event {
 
 	private final ContactId contactId;
-	private final InvitationResponse response;
+	private final PrivateResponse<S> response;
 
 	public InvitationResponseReceivedEvent(ContactId contactId,
-			InvitationResponse response) {
+			PrivateResponse<S> response) {
 		this.contactId = contactId;
 		this.response = response;
 	}
@@ -24,7 +26,7 @@ public abstract class InvitationResponseReceivedEvent extends Event {
 		return contactId;
 	}
 
-	public InvitationResponse getResponse() {
+	public PrivateResponse<S> getResponse() {
 		return response;
 	}
 }

briar-core/src/main/java/org/briarproject/briar/introduction/AbstractProtocolEngine.java

@@ -20,6 +20,7 @@ import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.briar.api.client.MessageTracker;
 import org.briarproject.briar.api.client.SessionId;
+import org.briarproject.briar.api.introduction.Introduction;
 import org.briarproject.briar.api.introduction.IntroductionResponse;
 import org.briarproject.briar.api.introduction.event.IntroductionResponseReceivedEvent;
 
@@ -147,12 +148,13 @@ abstract class AbstractProtocolEngine<S extends Session>
 	void broadcastIntroductionResponseReceivedEvent(Transaction txn, Session s,
 			AuthorId sender, Author otherAuthor, AbstractIntroductionMessage m)
 			throws DbException {
+		Introduction introduction = new Introduction(otherAuthor, s.getRole());
 		AuthorId localAuthorId = identityManager.getLocalAuthor(txn).getId();
 		Contact c = contactManager.getContact(txn, sender, localAuthorId);
 		IntroductionResponse response =
-				new IntroductionResponse(s.getSessionId(), m.getMessageId(),
-						m.getGroupId(), s.getRole(), m.getTimestamp(), false,
-						false, false, false, otherAuthor.getName(),
+				new IntroductionResponse(m.getMessageId(), m.getGroupId(),
+						m.getTimestamp(), false, false, false, false,
+						s.getSessionId(), introduction,
 						m instanceof AcceptMessage);
 		IntroductionResponseReceivedEvent e =
 				new IntroductionResponseReceivedEvent(c.getId(), response);

briar-core/src/main/java/org/briarproject/briar/introduction/IntroductionManagerImpl.java

@@ -509,9 +509,10 @@ class IntroductionManagerImpl extends ConversationClientImpl
 			sessionId = session.getSessionId();
 			author = session.getRemote().author;
 		} else throw new AssertionError();
-		return new IntroductionResponse(sessionId, m, contactGroupId,
-				role, meta.getTimestamp(), meta.isLocal(), status.isSent(),
-				status.isSeen(), meta.isRead(), author.getName(), accept);
+		Introduction introduction = new Introduction(author, role);
+		return new IntroductionResponse(m, contactGroupId, meta.getTimestamp(),
+				meta.isLocal(), status.isSent(), status.isSeen(), meta.isRead(),
+				sessionId, introduction, accept);
 	}
 
 	private void removeSessionWithIntroducer(Transaction txn,

briar-core/src/main/java/org/briarproject/briar/privategroup/invitation/CreatorProtocolEngine.java

@@ -15,6 +15,7 @@ import org.briarproject.briar.api.client.MessageTracker;
 import org.briarproject.briar.api.client.ProtocolStateException;
 import org.briarproject.briar.api.client.SessionId;
 import org.briarproject.briar.api.privategroup.GroupMessageFactory;
+import org.briarproject.briar.api.privategroup.PrivateGroup;
 import org.briarproject.briar.api.privategroup.PrivateGroupFactory;
 import org.briarproject.briar.api.privategroup.PrivateGroupManager;
 import org.briarproject.briar.api.privategroup.event.GroupInvitationResponseReceivedEvent;
@@ -193,8 +194,10 @@ class CreatorProtocolEngine extends AbstractProtocolEngine<CreatorSession> {
 		setPrivateGroupVisibility(txn, s, SHARED);
 		// Broadcast an event
 		ContactId contactId = getContactId(txn, m.getContactGroupId());
+		PrivateGroup privateGroup =
+				privateGroupManager.getPrivateGroup(txn, m.getPrivateGroupId());
 		txn.attach(new GroupInvitationResponseReceivedEvent(contactId,
-				createInvitationResponse(m, contactId, true)));
+				createInvitationResponse(m, privateGroup, true)));
 		// Move to the JOINED state
 		return new CreatorSession(s.getContactGroupId(), s.getPrivateGroupId(),
 				sent.getId(), m.getId(), sent.getTimestamp(),
@@ -215,8 +218,10 @@ class CreatorProtocolEngine extends AbstractProtocolEngine<CreatorSession> {
 				m.getTimestamp(), false);
 		// Broadcast an event
 		ContactId contactId = getContactId(txn, m.getContactGroupId());
+		PrivateGroup privateGroup =
+				privateGroupManager.getPrivateGroup(txn, m.getPrivateGroupId());
 		txn.attach(new GroupInvitationResponseReceivedEvent(contactId,
-				createInvitationResponse(m, contactId, false)));
+				createInvitationResponse(m, privateGroup, false)));
 		// Move to the START state
 		return new CreatorSession(s.getContactGroupId(), s.getPrivateGroupId(),
 				s.getLastLocalMessageId(), m.getId(), s.getLocalTimestamp(),
@@ -254,10 +259,11 @@ class CreatorProtocolEngine extends AbstractProtocolEngine<CreatorSession> {
 	}
 
 	private GroupInvitationResponse createInvitationResponse(
-			GroupInvitationMessage m, ContactId c, boolean accept) {
+			GroupInvitationMessage m, PrivateGroup privateGroup,
+			boolean accept) {
 		SessionId sessionId = new SessionId(m.getPrivateGroupId().getBytes());
 		return new GroupInvitationResponse(m.getId(), m.getContactGroupId(),
 				m.getTimestamp(), false, false, true, false, sessionId,
-				m.getPrivateGroupId(), accept);
+				privateGroup, accept);
 	}
 }

briar-core/src/main/java/org/briarproject/briar/privategroup/invitation/GroupInvitationManagerImpl.java

@@ -353,7 +353,7 @@ class GroupInvitationManagerImpl extends ConversationClientImpl
 
 	private <S extends Session> S handleAction(Transaction txn,
 			LocalAction type, S session, ProtocolEngine<S> engine)
-			throws DbException, FormatException {
+			throws DbException {
 		if (type == LocalAction.INVITE) {
 			throw new IllegalArgumentException();
 		} else if (type == LocalAction.JOIN) {
@@ -392,23 +392,36 @@ class GroupInvitationManagerImpl extends ConversationClientImpl
 					.getMessageMetadataAsDictionary(txn, contactGroupId, query);
 			List<PrivateMessageHeader> messages =
 					new ArrayList<>(results.size());
+			// get invite message first and remember private groups
+			Map<SessionId, PrivateGroup> privateGroups = new HashMap<>();
 			for (Entry<MessageId, BdfDictionary> e : results.entrySet()) {
 				MessageId m = e.getKey();
 				MessageMetadata meta =
 						messageParser.parseMetadata(e.getValue());
-				MessageStatus status = db.getMessageStatus(txn, c, m);
 				MessageType type = meta.getMessageType();
-				if (type == INVITE) {
-					messages.add(parseInvitationRequest(txn, c, contactGroupId,
-							m, meta, status));
-				} else if (type == JOIN) {
-					messages.add(
-							parseInvitationResponse(c, contactGroupId, m, meta,
-									status, true));
+				if (type != INVITE) continue;
+				MessageStatus status = db.getMessageStatus(txn, c, m);
+				GroupInvitationRequest invite = parseInvitationRequest(txn,
+						contactGroupId, m, meta, status);
+				messages.add(invite);
+				privateGroups.put(invite.getSessionId(), invite.getObject());
+			}
+			for (Entry<MessageId, BdfDictionary> e : results.entrySet()) {
+				MessageId m = e.getKey();
+				MessageMetadata meta =
+						messageParser.parseMetadata(e.getValue());
+				MessageType type = meta.getMessageType();
+				if (type == INVITE) continue;
+				MessageStatus status = db.getMessageStatus(txn, c, m);
+				SessionId sessionId = getSessionId(meta.getPrivateGroupId());
+				PrivateGroup privateGroup = privateGroups.get(sessionId);
+				if (privateGroup == null) throw new AssertionError();
+				if (type == JOIN) {
+					messages.add(parseInvitationResponse(contactGroupId, m,
+							meta, status, sessionId, privateGroup, true));
 				} else if (type == LEAVE) {
-					messages.add(
-							parseInvitationResponse(c, contactGroupId, m, meta,
-									status, false));
+					messages.add(parseInvitationResponse(contactGroupId, m,
+							meta, status, sessionId, privateGroup, false));
 				}
 			}
 			return messages;
@@ -418,9 +431,8 @@ class GroupInvitationManagerImpl extends ConversationClientImpl
 	}
 
 	private GroupInvitationRequest parseInvitationRequest(Transaction txn,
-			ContactId c, GroupId contactGroupId, MessageId m,
-			MessageMetadata meta, MessageStatus status)
-			throws DbException, FormatException {
+			GroupId contactGroupId, MessageId m, MessageMetadata meta,
+			MessageStatus status) throws DbException, FormatException {
 		SessionId sessionId = getSessionId(meta.getPrivateGroupId());
 		// Look up the invite message to get the details of the private group
 		InviteMessage invite = messageParser.getInviteMessage(txn, m);
@@ -436,15 +448,14 @@ class GroupInvitationManagerImpl extends ConversationClientImpl
 				invite.getMessage(), meta.isAvailableToAnswer(), canBeOpened);
 	}
 
-	private GroupInvitationResponse parseInvitationResponse(ContactId c,
+	private GroupInvitationResponse parseInvitationResponse(
 			GroupId contactGroupId, MessageId m, MessageMetadata meta,
-			MessageStatus status, boolean accept)
-			throws DbException, FormatException {
-		SessionId sessionId = getSessionId(meta.getPrivateGroupId());
+			MessageStatus status, SessionId sessionId,
+			PrivateGroup privateGroup, boolean accept) {
 		return new GroupInvitationResponse(m, contactGroupId,
 				meta.getTimestamp(), meta.isLocal(), status.isSent(),
-				status.isSeen(), meta.isRead(), sessionId,
-				meta.getPrivateGroupId(), accept);
+				status.isSeen(), meta.isRead(), sessionId, privateGroup,
+				accept);
 	}
 
 	@Override

briar-core/src/main/java/org/briarproject/briar/sharing/BlogInvitationFactoryImpl.java

@@ -30,10 +30,10 @@ public class BlogInvitationFactoryImpl
 	@Override
 	public BlogInvitationResponse createInvitationResponse(MessageId id,
 			GroupId contactGroupId, long time, boolean local, boolean sent,
-			boolean seen, boolean read, GroupId shareableId, boolean accept) {
-		SessionId sessionId = new SessionId(shareableId.getBytes());
-		return new BlogInvitationResponse(id, contactGroupId, time, local,
-				sent, seen, read, sessionId, shareableId, accept);
+			boolean seen, boolean read, Blog blog, boolean accept) {
+		SessionId sessionId = new SessionId(blog.getId().getBytes());
+		return new BlogInvitationResponse(id, contactGroupId, time, local, sent,
+				seen, read, sessionId, blog, accept);
 	}
 
 }

briar-core/src/main/java/org/briarproject/briar/sharing/BlogMessageParserImpl.java

@@ -30,7 +30,7 @@ class BlogMessageParserImpl extends MessageParserImpl<Blog> {
 	}
 
 	@Override
-	protected Blog createShareable(BdfList descriptor) throws FormatException {
+	public Blog createShareable(BdfList descriptor) throws FormatException {
 		// Author, RSS
 		BdfList authorList = descriptor.getList(0);
 		boolean rssFeed = descriptor.getBoolean(1);

briar-core/src/main/java/org/briarproject/briar/sharing/BlogProtocolEngineImpl.java

@@ -59,21 +59,21 @@ class BlogProtocolEngineImpl extends ProtocolEngineImpl<Blog> {
 
 	@Override
 	Event getInvitationResponseReceivedEvent(AcceptMessage m,
-			ContactId contactId) {
+			ContactId contactId, Blog shareable) {
 		BlogInvitationResponse response = invitationFactory
 				.createInvitationResponse(m.getId(), m.getContactGroupId(),
 						m.getTimestamp(), false, false, true, false,
-						m.getShareableId(), true);
+						shareable, true);
 		return new BlogInvitationResponseReceivedEvent(contactId, response);
 	}
 
 	@Override
 	Event getInvitationResponseReceivedEvent(DeclineMessage m,
-			ContactId contactId) {
+			ContactId contactId, Blog shareable) {
 		BlogInvitationResponse response = invitationFactory
 				.createInvitationResponse(m.getId(), m.getContactGroupId(),
 						m.getTimestamp(), false, false, true, false,
-						m.getShareableId(), true);
+						shareable, true);
 		return new BlogInvitationResponseReceivedEvent(contactId, response);
 	}
 

briar-core/src/main/java/org/briarproject/briar/sharing/ForumInvitationFactoryImpl.java

@@ -30,11 +30,10 @@ public class ForumInvitationFactoryImpl
 	@Override
 	public ForumInvitationResponse createInvitationResponse(MessageId id,
 			GroupId contactGroupId, long time, boolean local, boolean sent,
-			boolean seen, boolean read, GroupId shareableId,
-			boolean accept) {
-		SessionId sessionId = new SessionId(shareableId.getBytes());
+			boolean seen, boolean read, Forum forum, boolean accept) {
+		SessionId sessionId = new SessionId(forum.getId().getBytes());
 		return new ForumInvitationResponse(id, contactGroupId, time, local,
-				sent, seen, read, sessionId, shareableId, accept);
+				sent, seen, read, sessionId, forum, accept);
 	}
 
 }

briar-core/src/main/java/org/briarproject/briar/sharing/ForumMessageParserImpl.java

@@ -24,7 +24,7 @@ class ForumMessageParserImpl extends MessageParserImpl<Forum> {
 	}
 
 	@Override
-	protected Forum createShareable(BdfList descriptor) throws FormatException {
+	public Forum createShareable(BdfList descriptor) throws FormatException {
 		// Name, salt
 		String name = descriptor.getString(0);
 		byte[] salt = descriptor.getRaw(1);

briar-core/src/main/java/org/briarproject/briar/sharing/ForumProtocolEngineImpl.java

@@ -61,21 +61,21 @@ class ForumProtocolEngineImpl extends ProtocolEngineImpl<Forum> {
 
 	@Override
 	Event getInvitationResponseReceivedEvent(AcceptMessage m,
-			ContactId contactId) {
+			ContactId contactId, Forum shareable) {
 		ForumInvitationResponse response = invitationFactory
 				.createInvitationResponse(m.getId(), m.getContactGroupId(),
 						m.getTimestamp(), false, false, true, false,
-						m.getShareableId(), true);
+						shareable, true);
 		return new ForumInvitationResponseReceivedEvent(contactId, response);
 	}
 
 	@Override
 	Event getInvitationResponseReceivedEvent(DeclineMessage m,
-			ContactId contactId) {
+			ContactId contactId, Forum shareable) {
 		ForumInvitationResponse response = invitationFactory
 				.createInvitationResponse(m.getId(), m.getContactGroupId(),
 						m.getTimestamp(), false, false, true, false,
-						m.getShareableId(), true);
+						shareable, true);
 		return new ForumInvitationResponseReceivedEvent(contactId, response);
 	}
 

briar-core/src/main/java/org/briarproject/briar/sharing/InvitationFactory.java

@@ -4,10 +4,10 @@ import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.api.messaging.PrivateRequest;
-import org.briarproject.briar.api.sharing.InvitationResponse;
+import org.briarproject.briar.api.messaging.PrivateResponse;
 import org.briarproject.briar.api.sharing.Shareable;
 
-public interface InvitationFactory<S extends Shareable, I extends InvitationResponse> {
+public interface InvitationFactory<S extends Shareable, I extends PrivateResponse<S>> {
 
 	PrivateRequest<S> createInvitationRequest(boolean local, boolean sent,
 			boolean seen, boolean read, InviteMessage<S> m, ContactId c,
@@ -15,7 +15,6 @@ public interface InvitationFactory<S extends Shareable, I extends InvitationResp
 
 	I createInvitationResponse(MessageId id,
 			GroupId contactGroupId, long time, boolean local, boolean sent,
-			boolean seen, boolean read, GroupId shareableId,
-			boolean accept);
+			boolean seen, boolean read, S shareable, boolean accept);
 
 }

briar-core/src/main/java/org/briarproject/briar/sharing/MessageParser.java

@@ -22,6 +22,8 @@ interface MessageParser<S extends Shareable> {
 
 	MessageMetadata parseMetadata(BdfDictionary meta) throws FormatException;
 
+	S createShareable(BdfList descriptor) throws FormatException;
+
 	InviteMessage<S> getInviteMessage(Transaction txn, MessageId m)
 			throws DbException, FormatException;
 

briar-core/src/main/java/org/briarproject/briar/sharing/MessageParserImpl.java

@@ -94,9 +94,6 @@ abstract class MessageParserImpl<S extends Shareable>
 				m.getGroupId(), shareable, message, m.getTimestamp());
 	}
 
-	protected abstract S createShareable(BdfList descriptor)
-			throws FormatException;
-
 	@Override
 	public AcceptMessage parseAcceptMessage(Message m, BdfList body)
 			throws FormatException {

briar-core/src/main/java/org/briarproject/briar/sharing/ProtocolEngineImpl.java

@@ -113,13 +113,7 @@ abstract class ProtocolEngineImpl<S extends Shareable>
 
 	private Message sendInviteMessage(Transaction txn, Session s,
 			@Nullable String message, long timestamp) throws DbException {
-		Group g = db.getGroup(txn, s.getShareableId());
-		BdfList descriptor;
-		try {
-			descriptor = clientHelper.toList(g.getDescriptor());
-		} catch (FormatException e) {
-			throw new DbException(e); // Invalid group descriptor
-		}
+		BdfList descriptor = getDescriptor(txn, s.getShareableId());
 		long localTimestamp = Math.max(timestamp, getLocalTimestamp(s));
 		Message m = messageEncoder.encodeInviteMessage(s.getContactGroupId(),
 				localTimestamp, s.getLastLocalMessageId(), descriptor, message);
@@ -373,7 +367,8 @@ abstract class ProtocolEngineImpl<S extends Shareable>
 				m.getTimestamp(), false);
 		// Broadcast an event
 		ContactId contactId = getContactId(txn, m.getContactGroupId());
-		txn.attach(getInvitationResponseReceivedEvent(m, contactId));
+		S shareable = getShareable(txn, s.getShareableId());
+		txn.attach(getInvitationResponseReceivedEvent(m, contactId, shareable));
 		// Move to the next state
 		return new Session(nextState, s.getContactGroupId(), s.getShareableId(),
 				s.getLastLocalMessageId(), m.getId(), s.getLocalTimestamp(),
@@ -391,7 +386,7 @@ abstract class ProtocolEngineImpl<S extends Shareable>
 	}
 
 	abstract Event getInvitationResponseReceivedEvent(AcceptMessage m,
-			ContactId contactId);
+			ContactId contactId, S shareable);
 
 	@Override
 	public Session onDeclineMessage(Transaction txn, Session s,
@@ -431,7 +426,8 @@ abstract class ProtocolEngineImpl<S extends Shareable>
 		}
 		// Broadcast an event
 		ContactId contactId = getContactId(txn, m.getContactGroupId());
-		txn.attach(getInvitationResponseReceivedEvent(m, contactId));
+		S shareable = getShareable(txn, s.getShareableId());
+		txn.attach(getInvitationResponseReceivedEvent(m, contactId, shareable));
 		// Move to the next state
 		return new Session(START, s.getContactGroupId(), s.getShareableId(),
 				s.getLastLocalMessageId(), m.getId(), s.getLocalTimestamp(),
@@ -439,7 +435,7 @@ abstract class ProtocolEngineImpl<S extends Shareable>
 	}
 
 	abstract Event getInvitationResponseReceivedEvent(DeclineMessage m,
-			ContactId contactId);
+			ContactId contactId, S shareable);
 
 	@Override
 	public Session onLeaveMessage(Transaction txn, Session s,
@@ -530,6 +526,26 @@ abstract class ProtocolEngineImpl<S extends Shareable>
 				sent.getId(), null, 0, 0);
 	}
 
+	private S getShareable(Transaction txn, GroupId groupId)
+			throws DbException {
+		BdfList descriptor = getDescriptor(txn, groupId);
+		try {
+			return messageParser.createShareable(descriptor);
+		} catch (FormatException e) {
+			throw new DbException(e);
+		}
+	}
+
+	private BdfList getDescriptor(Transaction txn, GroupId groupId)
+			throws DbException {
+		Group g = db.getGroup(txn, groupId);
+		try {
+			return clientHelper.toList(g.getDescriptor());
+		} catch (FormatException e) {
+			throw new DbException(e); // Invalid group descriptor
+		}
+	}
+
 	private void markInvitesUnavailableToAnswer(Transaction txn, Session s)
 			throws DbException, FormatException {
 		GroupId shareableId = s.getShareableId();

briar-core/src/main/java/org/briarproject/briar/sharing/SharingManagerImpl.java

@@ -28,7 +28,7 @@ import org.briarproject.briar.api.client.MessageTracker;
 import org.briarproject.briar.api.client.SessionId;
 import org.briarproject.briar.api.messaging.PrivateMessageHeader;
 import org.briarproject.briar.api.messaging.PrivateRequest;
-import org.briarproject.briar.api.sharing.InvitationResponse;
+import org.briarproject.briar.api.messaging.PrivateResponse;
 import org.briarproject.briar.api.sharing.Shareable;
 import org.briarproject.briar.api.sharing.SharingInvitationItem;
 import org.briarproject.briar.api.sharing.SharingManager;
@@ -345,23 +345,35 @@ abstract class SharingManagerImpl<S extends Shareable>
 					.getMessageMetadataAsDictionary(txn, contactGroupId, query);
 			List<PrivateMessageHeader> messages =
 					new ArrayList<>(results.size());
+			// get invite messages first and remember shareables
+			Map<GroupId, S> shareables = new HashMap<>();
 			for (Entry<MessageId, BdfDictionary> e : results.entrySet()) {
 				MessageId m = e.getKey();
 				MessageMetadata meta =
 						messageParser.parseMetadata(e.getValue());
-				MessageStatus status = db.getMessageStatus(txn, c, m);
 				MessageType type = meta.getMessageType();
-				if (type == INVITE) {
-					messages.add(
-							parseInvitationRequest(txn, c, m, meta, status));
-				} else if (type == ACCEPT) {
-					messages.add(
-							parseInvitationResponse(contactGroupId, m, meta,
-									status, true));
+				if (type != INVITE) continue;
+				MessageStatus status = db.getMessageStatus(txn, c, m);
+				PrivateRequest<S> invite = parseInvitationRequest(txn, c, m,
+						meta, status);
+				messages.add(invite);
+				shareables.put(invite.getObject().getId(), invite.getObject());
+			}
+			for (Entry<MessageId, BdfDictionary> e : results.entrySet()) {
+				MessageId m = e.getKey();
+				MessageMetadata meta =
+						messageParser.parseMetadata(e.getValue());
+				MessageType type = meta.getMessageType();
+				if (type == INVITE) continue;
+				MessageStatus status = db.getMessageStatus(txn, c, m);
+				S shareable = shareables.get(meta.getShareableId());
+				if (shareable == null) throw new AssertionError();
+				if (type == ACCEPT) {
+					messages.add(parseInvitationResponse(contactGroupId, m,
+							meta, status, shareable, true));
 				} else if (type == DECLINE) {
-					messages.add(
-							parseInvitationResponse(contactGroupId, m, meta,
-									status, false));
+					messages.add(parseInvitationResponse(contactGroupId, m,
+							meta, status, shareable, false));
 				}
 			}
 			return messages;
@@ -370,7 +382,7 @@ abstract class SharingManagerImpl<S extends Shareable>
 		}
 	}
 
-	private PrivateRequest parseInvitationRequest(Transaction txn,
+	private PrivateRequest<S> parseInvitationRequest(Transaction txn,
 			ContactId c, MessageId m, MessageMetadata meta,
 			MessageStatus status) throws DbException, FormatException {
 		// Look up the invite message to get the details of the private group
@@ -384,13 +396,12 @@ abstract class SharingManagerImpl<S extends Shareable>
 						meta.isAvailableToAnswer(), canBeOpened);
 	}
 
-	private InvitationResponse parseInvitationResponse(GroupId contactGroupId,
+	private PrivateResponse<S> parseInvitationResponse(GroupId contactGroupId,
 			MessageId m, MessageMetadata meta, MessageStatus status,
-			boolean accept) {
+			S shareable, boolean accept) {
 		return invitationFactory.createInvitationResponse(m, contactGroupId,
 				meta.getTimestamp(), meta.isLocal(), status.isSent(),
-				status.isSeen(), meta.isRead(), meta.getShareableId(),
-				accept);
+				status.isSeen(), meta.isRead(), shareable, accept);
 	}
 
 	@Override

briar-core/src/test/java/org/briarproject/briar/introduction/IntroductionIntegrationTest.java

@@ -159,7 +159,7 @@ public class IntroductionIntegrationTest
 		eventWaiter.await(TIMEOUT, 1);
 		assertTrue(listener0.response1Received);
 		assertEquals(introducee2.getAuthor().getName(),
-				listener0.getResponse().getName());
+				listener0.getResponse().getObject().getName());
 		assertGroupCount(messageTracker0, g1.getId(), 2, 1);
 
 		// sync second ACCEPT message
@@ -167,7 +167,7 @@ public class IntroductionIntegrationTest
 		eventWaiter.await(TIMEOUT, 1);
 		assertTrue(listener0.response2Received);
 		assertEquals(introducee1.getAuthor().getName(),
-				listener0.getResponse().getName());
+				listener0.getResponse().getObject().getName());
 		assertGroupCount(messageTracker0, g2.getId(), 2, 1);
 
 		// sync forwarded ACCEPT messages to introducees
@@ -265,7 +265,7 @@ public class IntroductionIntegrationTest
 
 		// assert that the name on the decline event is correct
 		assertEquals(introducee2.getAuthor().getName(),
-				listener0.getResponse().getName());
+				listener0.getResponse().getObject().getName());
 
 		// sync second response
 		sync2To0(1, true);
@@ -282,7 +282,7 @@ public class IntroductionIntegrationTest
 		// assert that the name on the decline event is correct
 		eventWaiter.await(TIMEOUT, 1);
 		assertEquals(introducee1.getAuthor().getName(),
-				listener2.getResponse().getName());
+				listener2.getResponse().getObject().getName());
 
 		// note how the introducer does not forward the second response,
 		// because after the first decline the protocol finished
@@ -351,7 +351,7 @@ public class IntroductionIntegrationTest
 		// assert that the name on the decline event is correct
 		eventWaiter.await(TIMEOUT, 1);
 		assertEquals(contact2From0.getAuthor().getName(),
-				listener1.getResponse().getName());
+				listener1.getResponse().getObject().getName());
 
 		assertFalse(contactManager1
 				.contactExists(author2.getId(), author1.getId()));
@@ -475,7 +475,7 @@ public class IntroductionIntegrationTest
 		// assert that the name on the decline event is correct
 		eventWaiter.await(TIMEOUT, 1);
 		assertEquals(introducee1.getAuthor().getName(),
-				listener2.getResponse().getName());
+				listener2.getResponse().getObject().getName());
 
 		// assert that introducee2 is in correct state
 		introduceeSession = getIntroduceeSession(c2);

briar-core/src/test/java/org/briarproject/briar/privategroup/invitation/CreatorProtocolEngineTest.java

@@ -310,6 +310,8 @@ public class CreatorProtocolEngineTest extends AbstractProtocolEngineTest {
 			oneOf(messageTracker)
 					.trackMessage(txn, contactGroupId, inviteTimestamp + 1,
 							false);
+			oneOf(privateGroupManager).getPrivateGroup(txn, privateGroupId);
+			will(returnValue(privateGroup));
 		}});
 		expectGetContactId();
 		expectSetPrivateGroupVisibility(SHARED);
@@ -399,6 +401,8 @@ public class CreatorProtocolEngineTest extends AbstractProtocolEngineTest {
 			oneOf(messageTracker)
 					.trackMessage(txn, contactGroupId, inviteTimestamp + 1,
 							false);
+			oneOf(privateGroupManager).getPrivateGroup(txn, privateGroupId);
+			will(returnValue(privateGroup));
 		}});
 		expectGetContactId();
 		CreatorSession newSession =

briar-core/src/test/java/org/briarproject/briar/privategroup/invitation/GroupInvitationIntegrationTest.java

@@ -2,6 +2,7 @@ package org.briarproject.briar.privategroup.invitation;
 
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.sync.Group;
+import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.test.TestDatabaseModule;
 import org.briarproject.briar.api.client.ProtocolStateException;
 import org.briarproject.briar.api.messaging.PrivateMessageHeader;
@@ -12,7 +13,6 @@ import org.briarproject.briar.api.privategroup.invitation.GroupInvitationItem;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationManager;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationRequest;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationResponse;
-import org.briarproject.briar.api.sharing.InvitationResponse;
 import org.briarproject.briar.test.BriarIntegrationTest;
 import org.briarproject.briar.test.BriarIntegrationTestComponent;
 import org.briarproject.briar.test.DaggerBriarIntegrationTestComponent;
@@ -124,7 +124,8 @@ public class GroupInvitationIntegrationTest
 		for (PrivateMessageHeader m : messages) {
 			if (m instanceof GroupInvitationResponse) {
 				foundResponse = true;
-				InvitationResponse response = (GroupInvitationResponse) m;
+				GroupInvitationResponse response = (GroupInvitationResponse) m;
+				assertEquals(privateGroup0, response.getObject());
 				assertTrue(response.isLocal());
 				assertFalse(response.wasAccepted());
 			}
@@ -140,7 +141,8 @@ public class GroupInvitationIntegrationTest
 		for (PrivateMessageHeader m : messages) {
 			if (m instanceof GroupInvitationResponse) {
 				foundResponse = true;
-				InvitationResponse response = (GroupInvitationResponse) m;
+				GroupInvitationResponse response = (GroupInvitationResponse) m;
+				assertEquals(privateGroup0, response.getObject());
 				assertFalse(response.isLocal());
 				assertFalse(response.wasAccepted());
 			}
@@ -171,24 +173,27 @@ public class GroupInvitationIntegrationTest
 		for (PrivateMessageHeader m : messages) {
 			if (m instanceof GroupInvitationResponse) {
 				foundResponse = true;
-				InvitationResponse response = (GroupInvitationResponse) m;
+				GroupInvitationResponse response = (GroupInvitationResponse) m;
+				assertEquals(privateGroup0, response.getObject());
 				assertTrue(response.wasAccepted());
 			} else {
-				assertTrue(((GroupInvitationRequest) m).doesExist());
+				GroupInvitationRequest request = (GroupInvitationRequest) m;
+				assertEquals(privateGroup0, request.getObject());
+				assertTrue(request.doesExist());
 			}
 		}
 		assertTrue(foundResponse);
 
 		sync1To0(1, true);
 
-		messages =
-				groupInvitationManager0.getMessages(contactId1From0);
+		messages = groupInvitationManager0.getMessages(contactId1From0);
 		assertEquals(2, messages.size());
 		foundResponse = false;
 		for (PrivateMessageHeader m : messages) {
 			if (m instanceof GroupInvitationResponse) {
 				foundResponse = true;
-				InvitationResponse response = (GroupInvitationResponse) m;
+				GroupInvitationResponse response = (GroupInvitationResponse) m;
+				assertEquals(privateGroup0, response.getObject());
 				assertTrue(response.wasAccepted());
 			}
 		}
@@ -432,6 +437,36 @@ public class GroupInvitationIntegrationTest
 		sync1To0(1, true);
 	}
 
+	@Test(expected = AssertionError.class)
+	public void testDeleteOnlyInvitationFails() throws Exception {
+		// send invitation
+		sendInvitation(clock.currentTimeMillis(), null);
+		sync0To1(1, true);
+
+		// save MessageId of invitation
+		Collection<PrivateMessageHeader> messages =
+				groupInvitationManager1.getMessages(contactId0From1);
+		assertEquals(1, messages.size());
+		MessageId inviteId = messages.iterator().next().getId();
+
+		// decline invitation
+		groupInvitationManager1
+				.respondToInvitation(contactId0From1, privateGroup0, false);
+
+		// we should have an invitation and a decline message
+		messages = groupInvitationManager1.getMessages(contactId0From1);
+		assertEquals(2, messages.size());
+
+		// delete only invitation
+		withinTransaction(db1, txn -> {
+			db1.deleteMessage(txn, inviteId);
+			db1.deleteMessageMetadata(txn, inviteId);
+		});
+
+		// This should fail
+		groupInvitationManager1.getMessages(contactId0From1);
+	}
+
 	private void sendInvitation(long timestamp, @Nullable String msg) throws
 			DbException {
 		byte[] signature = groupInvitationFactory.signInvitation(contact1From0,

briar-core/src/test/java/org/briarproject/briar/privategroup/invitation/GroupInvitationManagerImplTest.java

@@ -682,6 +682,8 @@ public class GroupInvitationManagerImplTest extends BrambleMockTestCase {
 					contactGroup.getId(), query);
 			will(returnValue(results));
 			// first message
+			oneOf(messageParser).parseMetadata(meta2);
+			will(returnValue(messageMetadata2));
 			oneOf(messageParser).parseMetadata(meta);
 			will(returnValue(messageMetadata1));
 			oneOf(db).getMessageStatus(txn, contactId, message.getId());
@@ -695,6 +697,8 @@ public class GroupInvitationManagerImplTest extends BrambleMockTestCase {
 			// second message
 			oneOf(messageParser).parseMetadata(meta2);
 			will(returnValue(messageMetadata2));
+			oneOf(messageParser).parseMetadata(meta);
+			will(returnValue(messageMetadata1));
 			oneOf(db).getMessageStatus(txn, contactId, messageId2);
 			// end transaction
 			oneOf(db).commitTransaction(txn);
@@ -709,9 +713,11 @@ public class GroupInvitationManagerImplTest extends BrambleMockTestCase {
 			if (m.getId().equals(message.getId())) {
 				assertTrue(m instanceof GroupInvitationRequest);
 				assertEquals(time1, m.getTimestamp());
+				assertEquals(pg, ((GroupInvitationRequest) m).getObject());
 			} else if (m.getId().equals(messageId2)) {
 				assertTrue(m instanceof GroupInvitationResponse);
 				assertEquals(time2, m.getTimestamp());
+				assertEquals(pg, ((GroupInvitationResponse) m).getObject());
 			} else {
 				throw new AssertionError();
 			}

briar-core/src/test/java/org/briarproject/briar/sharing/BlogSharingIntegrationTest.java

@@ -154,6 +154,7 @@ public class BlogSharingIntegrationTest
 		for (PrivateMessageHeader m : list) {
 			if (m instanceof BlogInvitationRequest) {
 				BlogInvitationRequest invitation = (BlogInvitationRequest) m;
+				assertEquals(blog2, invitation.getObject());
 				assertFalse(invitation.wasAnswered());
 				assertEquals(blog2.getAuthor().getName(),
 						invitation.getName());
@@ -161,6 +162,7 @@ public class BlogSharingIntegrationTest
 				assertEquals("Hi!", invitation.getMessage());
 			} else {
 				BlogInvitationResponse response = (BlogInvitationResponse) m;
+				assertEquals(blog2, response.getObject());
 				assertTrue(response.wasAccepted());
 				assertTrue(response.isLocal());
 			}
@@ -225,6 +227,7 @@ public class BlogSharingIntegrationTest
 		for (PrivateMessageHeader m : list) {
 			if (m instanceof BlogInvitationRequest) {
 				BlogInvitationRequest invitation = (BlogInvitationRequest) m;
+				assertEquals(rssBlog, invitation.getObject());
 				assertFalse(invitation.wasAnswered());
 				assertEquals(rssBlog.getAuthor().getName(),
 						invitation.getName());
@@ -232,6 +235,7 @@ public class BlogSharingIntegrationTest
 				assertEquals("Hi!", invitation.getMessage());
 			} else {
 				BlogInvitationResponse response = (BlogInvitationResponse) m;
+				assertEquals(rssBlog, response.getObject());
 				assertTrue(response.wasAccepted());
 				assertTrue(response.isLocal());
 			}
@@ -284,12 +288,14 @@ public class BlogSharingIntegrationTest
 		for (PrivateMessageHeader m : list) {
 			if (m instanceof BlogInvitationRequest) {
 				BlogInvitationRequest invitation = (BlogInvitationRequest) m;
+				assertEquals(blog2, invitation.getObject());
 				assertFalse(invitation.wasAnswered());
 				assertEquals(blog2.getAuthor().getName(),
 						invitation.getName());
 				assertEquals(null, invitation.getMessage());
 			} else {
 				BlogInvitationResponse response = (BlogInvitationResponse) m;
+				assertEquals(blog2, response.getObject());
 				assertFalse(response.wasAccepted());
 				assertTrue(response.isLocal());
 			}
@@ -612,7 +618,7 @@ public class BlogSharingIntegrationTest
 		}
 	}
 
-	private void listenToEvents(boolean accept) throws DbException {
+	private void listenToEvents(boolean accept) {
 		listener0 = new SharerListener();
 		c0.getEventBus().addListener(listener0);
 		listener1 = new InviteeListener(accept);

briar-core/src/test/java/org/briarproject/briar/sharing/ForumSharingIntegrationTest.java

@@ -137,15 +137,15 @@ public class ForumSharingIntegrationTest
 		// check other things are alright with the forum message
 		for (PrivateMessageHeader m : list) {
 			if (m instanceof ForumInvitationRequest) {
-				ForumInvitationRequest invitation =
-						(ForumInvitationRequest) m;
+				ForumInvitationRequest invitation = (ForumInvitationRequest) m;
 				assertFalse(invitation.wasAnswered());
 				assertEquals(forum0.getName(), invitation.getName());
+				assertEquals(forum0, invitation.getObject());
 				assertEquals("Hi!", invitation.getMessage());
 				assertTrue(invitation.doesExist());
 			} else {
-				ForumInvitationResponse response =
-						(ForumInvitationResponse) m;
+				ForumInvitationResponse response = (ForumInvitationResponse) m;
+				assertEquals(forum0, response.getObject());
 				assertTrue(response.wasAccepted());
 				assertTrue(response.isLocal());
 			}
@@ -195,12 +195,14 @@ public class ForumSharingIntegrationTest
 		for (PrivateMessageHeader m : list) {
 			if (m instanceof ForumInvitationRequest) {
 				ForumInvitationRequest invitation = (ForumInvitationRequest) m;
+				assertEquals(forum0, invitation.getObject());
 				assertFalse(invitation.wasAnswered());
 				assertEquals(forum0.getName(), invitation.getName());
 				assertEquals(null, invitation.getMessage());
 				assertFalse(invitation.doesExist());
 			} else {
 				ForumInvitationResponse response = (ForumInvitationResponse) m;
+				assertEquals(forum0, response.getObject());
 				assertFalse(response.wasAccepted());
 				assertTrue(response.isLocal());
 			}

briar-core/src/test/java/org/briarproject/briar/test/BriarIntegrationTest.java

@@ -10,6 +10,7 @@ import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.identity.AuthorFactory;
@@ -376,4 +377,21 @@ public abstract class BriarIntegrationTest<C extends BriarIntegrationTestCompone
 		assertNotNull(contactId1From2);
 		contactManager2.removeContact(contactId1From2);
 	}
+
+	@FunctionalInterface
+	protected interface TransactionScope {
+		void execute(Transaction txn) throws DbException;
+	}
+
+	protected void withinTransaction(DatabaseComponent db, TransactionScope scope)
+			throws DbException {
+		Transaction txn = db.startTransaction(false);
+		try {
+			scope.execute(txn);
+			db.commitTransaction(txn);
+		} finally {
+			db.endTransaction(txn);
+		}
+	}
+
 }