Introduce more sharing states

briar-android/src/main/java/org/briarproject/briar/android/contactselection/SelectableContactHolder.java

@@ -13,7 +13,9 @@ import androidx.annotation.UiThread;
 
 import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
-import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.INVITED;
+import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.ERROR;
+import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.INVITE_RECEIVED;
+import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.INVITE_SENT;
 import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.NOT_SUPPORTED;
 import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.SHARING;
 
@@ -35,10 +37,14 @@ class SelectableContactHolder
 			@StringRes int strRes;
 			if (item.getSharingStatus() == SHARING) {
 				strRes = R.string.forum_invitation_already_sharing;
-			} else if (item.getSharingStatus() == INVITED) {
+			} else if (item.getSharingStatus() == INVITE_SENT) {
 				strRes = R.string.forum_invitation_already_invited;
+			} else if (item.getSharingStatus() == INVITE_RECEIVED) {
+				strRes = R.string.forum_invitation_invite_received;
 			} else if (item.getSharingStatus() == NOT_SUPPORTED) {
 				strRes = R.string.forum_invitation_not_supported;
+			} else if (item.getSharingStatus() == ERROR) {
+				strRes = R.string.forum_invitation_error;
 			} else throw new AssertionError("Unhandled SharingStatus");
 			info.setText(strRes);
 			info.setVisibility(VISIBLE);

briar-android/src/main/res/values/strings.xml

@@ -461,8 +461,10 @@
 	<string name="forum_declined_toast">Invitation declined</string>
 	<string name="shared_by_format">Shared by %s</string>
 	<string name="forum_invitation_already_sharing">Already sharing</string>
-	<string name="forum_invitation_already_invited">Already invited</string>
+	<string name="forum_invitation_already_invited">Invitation already sent</string>
+	<string name="forum_invitation_invite_received">Invitation already received</string>
 	<string name="forum_invitation_not_supported">Not supported by this contact</string>
+	<string name="forum_invitation_error">Error. This is a bug and not your fault</string>
 	<string name="forum_invitation_response_accepted_sent">You accepted the forum invitation from %s.</string>
 	<string name="forum_invitation_response_declined_sent">You declined the forum invitation from %s.</string>
 	<string name="forum_invitation_response_declined_auto">The forum invitation from %s was automatically declined.</string>

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

@@ -84,6 +84,8 @@ public interface GroupInvitationManager extends ConversationClient {
 	 * and {@link PrivateGroup} identified by the given {@link GroupId}.
 	 * This indicates whether the {@link PrivateGroup} can be shared
 	 * with the contact.
+	 *
+	 * @throws ProtocolStateException if {@link PrivateGroup} was already left.
 	 */
 	SharingStatus getSharingStatus(Contact c, GroupId g) throws DbException;
 }

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

@@ -5,6 +5,7 @@ import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.sync.GroupId;
+import org.briarproject.briar.api.client.ProtocolStateException;
 import org.briarproject.briar.api.client.SessionId;
 import org.briarproject.briar.api.conversation.ConversationManager.ConversationClient;
 import org.briarproject.nullsafety.NotNullByDefault;
@@ -24,10 +25,14 @@ public interface SharingManager<S extends Shareable>
 		SHAREABLE,
 		/**
 		 * The {@link Shareable} can not be shared with the requested contact,
-		 * because of an ongoing sharing session.
+		 * because the contact was already invited.
-		 * In most cases, this means that the contact was already invited.
 		 */
-		INVITED,
+		INVITE_SENT,
+		/**
+		 * The {@link Shareable} can not be shared with the requested contact,
+		 * because the contact has already invited us.
+		 */
+		INVITE_RECEIVED,
 		/**
 		 * The {@link Shareable} can not be shared with the requested contact,
 		 * because it is already being shared.
@@ -38,7 +43,11 @@ public interface SharingManager<S extends Shareable>
 		 * because it is not supported by that contact.
 		 * This could be a missing or outdated client.
 		 */
-		NOT_SUPPORTED
+		NOT_SUPPORTED,
+		/**
+		 * The sharing session has encountered an error.
+		 */
+		ERROR
 	}
 
 	/**
@@ -106,6 +115,8 @@ public interface SharingManager<S extends Shareable>
 	 * and {@link Shareable} identified by the given {@link GroupId}.
 	 * This indicates whether the {@link Shareable} can be shared
 	 * with the contact.
+	 *
+	 * @throws ProtocolStateException if {@link Shareable} was already left.
 	 */
 	SharingStatus getSharingStatus(GroupId g, Contact c) throws DbException;
 
@@ -114,6 +125,8 @@ public interface SharingManager<S extends Shareable>
 	 * and {@link Shareable} identified by the given {@link GroupId}.
 	 * This indicates whether the {@link Shareable} can be shared
 	 * with the contact.
+	 *
+	 * @throws ProtocolStateException if {@link Shareable} was already left.
 	 */
 	SharingStatus getSharingStatus(Transaction txn, GroupId g, Contact c)
 			throws DbException;

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

@@ -26,6 +26,7 @@ import org.briarproject.bramble.api.versioning.ClientVersioningManager;
 import org.briarproject.bramble.api.versioning.ClientVersioningManager.ClientVersioningHook;
 import org.briarproject.briar.api.autodelete.event.ConversationMessagesDeletedEvent;
 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.conversation.ConversationMessageHeader;
 import org.briarproject.briar.api.conversation.DeletionResult;
@@ -57,6 +58,9 @@ import javax.inject.Inject;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
 import static org.briarproject.bramble.api.sync.validation.IncomingMessageHook.DeliveryAction.ACCEPT_DO_NOT_SHARE;
 import static org.briarproject.briar.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
+import static org.briarproject.briar.privategroup.invitation.CreatorState.DISSOLVED;
+import static org.briarproject.briar.privategroup.invitation.CreatorState.ERROR;
+import static org.briarproject.briar.privategroup.invitation.CreatorState.INVITED;
 import static org.briarproject.briar.privategroup.invitation.CreatorState.JOINED;
 import static org.briarproject.briar.privategroup.invitation.CreatorState.START;
 import static org.briarproject.briar.privategroup.invitation.MessageType.ABORT;
@@ -533,8 +537,14 @@ class GroupInvitationManagerImpl extends ConversationClientImpl
 					.parseCreatorSession(contactGroupId, ss.bdfSession);
 			CreatorState state = session.getState();
 			if (state == START) return SharingStatus.SHAREABLE;
+			if (state == INVITED) return SharingStatus.INVITE_RECEIVED;
 			if (state == JOINED) return SharingStatus.SHARING;
-			return SharingStatus.INVITED;
+			// The creator can also be a LEFT state, after re-adding a contact
+			// and re-creating the session with #recreateSession()
+			if (state == CreatorState.LEFT) return SharingStatus.SHARING;
+			if (state == DISSOLVED) throw new ProtocolStateException();
+			if (state == ERROR) return SharingStatus.ERROR;
+			throw new AssertionError("Unhandled state: " + state.name());
 		} catch (FormatException e) {
 			throw new DbException(e);
 		} finally {

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

@@ -26,6 +26,7 @@ import org.briarproject.bramble.api.versioning.ClientVersioningManager;
 import org.briarproject.bramble.api.versioning.ClientVersioningManager.ClientVersioningHook;
 import org.briarproject.briar.api.autodelete.event.ConversationMessagesDeletedEvent;
 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.conversation.ConversationMessageHeader;
 import org.briarproject.briar.api.conversation.ConversationRequest;
@@ -58,7 +59,11 @@ import static org.briarproject.briar.sharing.MessageType.DECLINE;
 import static org.briarproject.briar.sharing.MessageType.INVITE;
 import static org.briarproject.briar.sharing.MessageType.LEAVE;
 import static org.briarproject.briar.sharing.State.LOCAL_INVITED;
+import static org.briarproject.briar.sharing.State.LOCAL_LEFT;
+import static org.briarproject.briar.sharing.State.REMOTE_HANGING;
+import static org.briarproject.briar.sharing.State.REMOTE_INVITED;
 import static org.briarproject.briar.sharing.State.SHARING;
+import static org.briarproject.briar.sharing.State.START;
 
 @NotNullByDefault
 abstract class SharingManagerImpl<S extends Shareable>
@@ -468,7 +473,8 @@ abstract class SharingManagerImpl<S extends Shareable>
 	}
 
 	@Override
-	public SharingStatus getSharingStatus(GroupId g, Contact c) throws DbException {
+	public SharingStatus getSharingStatus(GroupId g, Contact c)
+			throws DbException {
 		Transaction txn = db.startTransaction(true);
 		try {
 			SharingStatus sharingStatus = getSharingStatus(txn, g, c);
@@ -495,9 +501,14 @@ abstract class SharingManagerImpl<S extends Shareable>
 			// If the session's in the right state, the contact can be invited
 			Session session =
 					sessionParser.parseSession(contactGroupId, ss.bdfSession);
-			if (session.getState().canInvite()) return SharingStatus.SHAREABLE;
+			State state = session.getState();
-			if (session.getState().isSharing()) return SharingStatus.SHARING;
+			if (state == START) return SharingStatus.SHAREABLE;
-			return SharingStatus.INVITED;
+			if (state == LOCAL_INVITED) return SharingStatus.INVITE_RECEIVED;
+			if (state == REMOTE_INVITED) return SharingStatus.INVITE_SENT;
+			if (state == SHARING) return SharingStatus.SHARING;
+			if (state == LOCAL_LEFT || state == REMOTE_HANGING)
+				throw new ProtocolStateException();
+			throw new AssertionError("Unhandled state: " + state.name());
 		} catch (FormatException e) {
 			throw new DbException(e);
 		}

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

@@ -46,14 +46,6 @@ enum State {
 		return visibility;
 	}
 
-	public boolean canInvite() {
-		return this == START;
-	}
-
-	public boolean isSharing() {
-		return this == SHARING;
-	}
-
 	public boolean isAwaitingResponse() {
 		return this == LOCAL_INVITED || this == REMOTE_INVITED;
 	}

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

@@ -29,7 +29,7 @@ import javax.annotation.Nullable;
 
 import static java.util.Collections.emptySet;
 import static org.briarproject.briar.api.autodelete.AutoDeleteConstants.MIN_AUTO_DELETE_TIMER_MS;
-import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.INVITED;
+import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.INVITE_RECEIVED;
 import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.SHAREABLE;
 import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.SHARING;
 import static org.briarproject.briar.test.BriarTestUtils.assertGroupCount;
@@ -322,7 +322,7 @@ public class GroupInvitationIntegrationTest
 		sendInvitation(c0.getClock().currentTimeMillis(), null);
 
 		// invitation is not allowed before the first hasn't been answered
-		assertEquals(INVITED, groupInvitationManager0
+		assertEquals(INVITE_RECEIVED, groupInvitationManager0
 				.getSharingStatus(contact1From0, privateGroup.getId()));
 
 		// deliver invitation and response
@@ -740,7 +740,7 @@ public class GroupInvitationIntegrationTest
 		addDefaultContacts();
 
 		// creator can still not invite again
-		assertEquals(INVITED, groupInvitationManager0
+		assertEquals(SHARING, groupInvitationManager0
 				.getSharingStatus(contact1From0, privateGroup.getId()));
 
 		// finally invitee can remove group without issues

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

@@ -25,6 +25,7 @@ import org.briarproject.bramble.test.DbExpectations;
 import org.briarproject.bramble.test.TestUtils;
 import org.briarproject.briar.api.client.MessageTracker;
 import org.briarproject.briar.api.client.SessionId;
+import org.briarproject.briar.api.client.ProtocolStateException;
 import org.briarproject.briar.api.conversation.ConversationMessageHeader;
 import org.briarproject.briar.api.privategroup.PrivateGroup;
 import org.briarproject.briar.api.privategroup.PrivateGroupFactory;
@@ -62,7 +63,8 @@ import static org.briarproject.briar.api.privategroup.PrivateGroupConstants.GROU
 import static org.briarproject.briar.api.privategroup.PrivateGroupConstants.MAX_GROUP_NAME_LENGTH;
 import static org.briarproject.briar.api.privategroup.invitation.GroupInvitationManager.CLIENT_ID;
 import static org.briarproject.briar.api.privategroup.invitation.GroupInvitationManager.MAJOR_VERSION;
-import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.INVITED;
+import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.ERROR;
+import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.INVITE_RECEIVED;
 import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.SHAREABLE;
 import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.SHARING;
 import static org.briarproject.briar.privategroup.invitation.MessageType.ABORT;
@@ -880,15 +882,20 @@ public class GroupInvitationManagerImplTest extends BrambleMockTestCase {
 	@Test
 	public void testIsNotInvitationAllowed() throws Exception {
 		expectIsInvitationAllowed(CreatorState.DISSOLVED);
-		assertEquals(INVITED, groupInvitationManager
+		try {
-				.getSharingStatus(contact, privateGroup.getId()));
+			groupInvitationManager
+					.getSharingStatus(contact, privateGroup.getId());
+			fail();
+		} catch (ProtocolStateException e) {
+			// expected
+		}
 
 		expectIsInvitationAllowed(CreatorState.ERROR);
-		assertEquals(INVITED, groupInvitationManager
+		assertEquals(ERROR, groupInvitationManager
 				.getSharingStatus(contact, privateGroup.getId()));
 
 		expectIsInvitationAllowed(CreatorState.INVITED);
-		assertEquals(INVITED, groupInvitationManager
+		assertEquals(INVITE_RECEIVED, groupInvitationManager
 				.getSharingStatus(contact, privateGroup.getId()));
 
 		expectIsInvitationAllowed(CreatorState.JOINED);
@@ -896,7 +903,7 @@ public class GroupInvitationManagerImplTest extends BrambleMockTestCase {
 				.getSharingStatus(contact, privateGroup.getId()));
 
 		expectIsInvitationAllowed(CreatorState.LEFT);
-		assertEquals(INVITED, groupInvitationManager
+		assertEquals(SHARING, groupInvitationManager
 				.getSharingStatus(contact, privateGroup.getId()));
 	}
 

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

@@ -13,6 +13,7 @@ import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.test.TestDatabaseConfigModule;
+import org.briarproject.briar.api.client.ProtocolStateException;
 import org.briarproject.briar.api.conversation.ConversationMessageHeader;
 import org.briarproject.briar.api.conversation.ConversationResponse;
 import org.briarproject.briar.api.conversation.DeletionResult;
@@ -43,11 +44,11 @@ import javax.annotation.Nullable;
 
 import static java.util.Collections.emptySet;
 import static junit.framework.Assert.assertNotNull;
+import static junit.framework.TestCase.fail;
 import static org.briarproject.bramble.util.StringUtils.getRandomString;
 import static org.briarproject.briar.api.autodelete.AutoDeleteConstants.MIN_AUTO_DELETE_TIMER_MS;
 import static org.briarproject.briar.api.forum.ForumSharingManager.CLIENT_ID;
 import static org.briarproject.briar.api.forum.ForumSharingManager.MAJOR_VERSION;
-import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.INVITED;
 import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.SHAREABLE;
 import static org.briarproject.briar.api.sharing.SharingManager.SharingStatus.SHARING;
 import static org.briarproject.briar.test.BriarTestUtils.assertGroupCount;
@@ -349,8 +350,12 @@ public class ForumSharingIntegrationTest
 		assertEquals(SHAREABLE, forumSharingManager0
 				.getSharingStatus(forum.getId(), contact1From0));
 		// invitee that left can not yet share again
-		assertEquals(INVITED, forumSharingManager1
+		try {
-				.getSharingStatus(forum.getId(), contact0From1));
+			forumSharingManager1.getSharingStatus(forum.getId(), contact0From1);
+			fail();
+		} catch (ProtocolStateException e) {
+			// expected
+		}
 
 		// sharer responds with leave message
 		sync0To1(1, true);