Implement XEP-0425 Moderated Message Retraction

Monal/Classes/DataLayer.h

@@ -215,7 +215,8 @@ extern NSString* const kMessageTypeFiletransfer;
 -(void) deleteMessageHistoryLocally:(NSNumber*) messageNo;
 -(void) updateMessageHistory:(NSNumber*) messageNo withText:(NSString*) newText;
 -(NSNumber* _Nullable) getLMCHistoryIDForMessageId:(NSString*) messageid from:(NSString*) from actualFrom:(NSString* _Nullable) actualFrom participantJid:(NSString* _Nullable) participantJid andAccount:(NSNumber*) accountNo;
--(NSNumber* _Nullable) getRetractionHistoryIDForMessageId:(NSString* _Nullable) messageid from:(NSString*) from actualFrom:(NSString* _Nullable) actualFrom participantJid:(NSString* _Nullable) participantJid andAccount:(NSNumber*) accountNo;
+-(NSNumber* _Nullable) getRetractionHistoryIDForMessageId:(NSString*) messageid from:(NSString*) from actualFrom:(NSString* _Nullable) actualFrom participantJid:(NSString* _Nullable) participantJid andAccount:(NSNumber*) accountNo;
+-(NSNumber* _Nullable) getRetractionHistoryIDForModeratedStanzaId:(NSString*) stanzaId from:(NSString*) from andAccount:(NSNumber*) accountNo;
 
 -(NSDate* _Nullable) returnTimestampForQuote:(NSNumber*) historyID;
 -(BOOL) checkLMCEligible:(NSNumber*) historyID encrypted:(BOOL) encrypted historyBaseID:(NSNumber* _Nullable) historyBaseID;

Monal/Classes/DataLayer.m

@@ -1524,7 +1524,7 @@ -(NSNumber* _Nullable) getLMCHistoryIDForMessageId:(NSString*) messageid from:(N
     }];
 }
 
--(NSNumber* _Nullable) getRetractionHistoryIDForMessageId:(NSString* _Nullable) messageid from:(NSString*) from actualFrom:(NSString* _Nullable) actualFrom participantJid:(NSString* _Nullable) participantJid andAccount:(NSNumber*) accountNo
+-(NSNumber* _Nullable) getRetractionHistoryIDForMessageId:(NSString*) messageid from:(NSString*) from actualFrom:(NSString* _Nullable) actualFrom participantJid:(NSString* _Nullable) participantJid andAccount:(NSNumber*) accountNo
 {
     return [self.db idReadTransaction:^{
         return [self.db executeScalar:@"SELECT M.message_history_id FROM message_history AS M INNER JOIN account AS A ON M.account_id=A.account_id INNER JOIN buddylist AS B on M.buddy_name = B.buddy_name AND M.account_id = B.account_id WHERE M.account_id=? AND ( \
@@ -1534,6 +1534,15 @@ -(NSNumber* _Nullable) getRetractionHistoryIDForMessageId:(NSString* _Nullable)
     }];
 }
 
+-(NSNumber* _Nullable) getRetractionHistoryIDForModeratedStanzaId:(NSString*) stanzaId from:(NSString*) from andAccount:(NSNumber*) accountNo
+{
+    return [self.db idReadTransaction:^{
+        return [self.db executeScalar:@"SELECT M.message_history_id FROM message_history AS M INNER JOIN account AS A ON M.account_id=A.account_id INNER JOIN buddylist AS B on M.buddy_name = B.buddy_name AND M.account_id = B.account_id \
+            WHERE M.account_id=? AND B.Muc=1 AND M.stanzaid=? AND M.buddy_name=?;"
+            andArguments:@[accountNo, stanzaId, from]];
+    }];
+}
+
 -(NSDate* _Nullable) returnTimestampForQuote:(NSNumber*) historyID
 {
     return [self.db idReadTransaction:^{

Monal/Classes/MLIQProcessor.m

@@ -727,6 +727,33 @@ +(BOOL) processRosterWithAccount:(xmpp*) account andIqNode:(XMPPIQ*) iqNode
                                                         userInfo:@{@"versionInfo": newSoftwareVersionInfo}];
 $$
 
+$$class_handler(handleModerationResponse, $$ID(xmpp*, account), $$ID(XMPPIQ*, iqNode), $$ID(MLMessage*, msg))
+    [msg updateWithMessage:[[DataLayer sharedInstance] messageForHistoryID:msg.messageDBId]];       //make sure our msg is up to date
+    if([iqNode check:@"/<type=error>"])
+    {
+        DDLogError(@"Moderating message %@ returned an error: %@", msg, [iqNode findFirst:@"error"]);
+        [HelperTools postError:[NSString stringWithFormat:NSLocalizedString(@"Failed to moderate message in group/channel '%@'", @""), iqNode.fromUser] withNode:iqNode andAccount:account andIsSevere:YES];
+        return;
+    }
+
+    DDLogInfo(@"Successfully moderated message in muc: %@", msg);
+    [[DataLayer sharedInstance] deleteMessageHistory:msg.messageDBId];
+
+    //update ui
+    DDLogInfo(@"Sending out kMonalDeletedMessageNotice notification for historyId %@", msg.messageDBId);
+    [[MLNotificationQueue currentQueue] postNotificationName:kMonalDeletedMessageNotice object:account userInfo:@{
+        @"message": msg,
+        @"historyId": msg.messageDBId,
+        @"contact": msg.contact,
+    }];
+
+    //update unread count in active chats list
+    [msg.contact updateUnreadCount];
+    [[MLNotificationQueue currentQueue] postNotificationName:kMonalContactRefresh object:account userInfo:@{
+        @"contact": msg.contact,
+    }];
+$$
+
 +(void) respondWithErrorTo:(XMPPIQ*) iqNode onAccount:(xmpp*) account
 {
     XMPPIQ* errorIq = [[XMPPIQ alloc] initAsErrorTo:iqNode];

Monal/Classes/MLMessageProcessor.m

@@ -440,8 +440,16 @@ +(MLMessage* _Nullable) processMessage:(XMPPMessage*) messageNode andOuterMessag
     if([messageNode check:@"{urn:xmpp:message-retract:1}retract"])
     {
         NSString* idToRetract = [messageNode findFirst:@"{urn:xmpp:message-retract:1}retract@id"];
-        //this checks if this message is from the same jid as the message it tries to retract (e.g. inbound can only retract inbound and outbound only outbound)
-        NSNumber* historyIdToRetract = [[DataLayer sharedInstance] getRetractionHistoryIDForMessageId:idToRetract from:messageNode.fromUser actualFrom:actualFrom participantJid:participantJid andAccount:account.accountNo];
+        NSNumber* historyIdToRetract = nil;
+        if(possiblyUnknownContact.isGroup && [[account.mucProcessor getRoomFeaturesForMuc:possiblyUnknownContact.contactJid] containsObject:@"urn:xmpp:message-moderate:1"] && [messageNode findFirst:@"{urn:xmpp:message-retract:1}retract/{urn:xmpp:message-moderate:1}moderated"])
+        {
+            historyIdToRetract = [[DataLayer sharedInstance] getRetractionHistoryIDForModeratedStanzaId:idToRetract from:messageNode.fromUser andAccount:account.accountNo];
+        }
+        else
+        {
+            //this checks for all spelled out in the business rules of XEP-0424
+            historyIdToRetract = [[DataLayer sharedInstance] getRetractionHistoryIDForMessageId:idToRetract from:messageNode.fromUser actualFrom:actualFrom participantJid:participantJid andAccount:account.accountNo];
+        }
 
         if(historyIdToRetract != nil)
         {

Monal/Classes/chatViewController.m

@@ -2483,17 +2483,26 @@ -(UISwipeActionsConfiguration*) tableView:(UITableView*) tableView trailingSwipe
     quoteAction.image = [[[UIImage systemImageNamed:@"quote.bubble.fill"] imageWithHorizontallyFlippedOrientation] imageWithTintColor:UIColor.whiteColor renderingMode:UIImageRenderingModeAutomatic];
 
     UIContextualAction* retractAction = [UIContextualAction contextualActionWithStyle:UIContextualActionStyleDestructive title:NSLocalizedString(@"Retract", @"Chat msg action") handler:^(UIContextualAction* action, UIView* sourceView, void (^completionHandler)(BOOL actionPerformed)) {
-        [self.xmppAccount retractMessage:message];
-        [[DataLayer sharedInstance] deleteMessageHistory:message.messageDBId];
-        [message updateWithMessage:[[[DataLayer sharedInstance] messagesForHistoryIDs:@[message.messageDBId]] firstObject]];
+        //only delete directly if we sent that message, try to moderate otherwise
+        if(!message.inbound)
+        {
+            [self.xmppAccount retractMessage:message];
+            [[DataLayer sharedInstance] deleteMessageHistory:message.messageDBId];
+            [message updateWithMessage:[[[DataLayer sharedInstance] messagesForHistoryIDs:@[message.messageDBId]] firstObject]];
 
-        //update table entry
-        [self->_messageTable beginUpdates];
-        [self->_messageTable reloadRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationNone];
-        [self->_messageTable endUpdates];
-
-        //update active chats if necessary
-        [[MLNotificationQueue currentQueue] postNotificationName:kMonalContactRefresh object:self.xmppAccount userInfo:@{@"contact": self.contact}];
+            //update table entry
+            [self->_messageTable beginUpdates];
+            [self->_messageTable reloadRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationNone];
+            [self->_messageTable endUpdates];
+
+            //update active chats if necessary
+            [[MLNotificationQueue currentQueue] postNotificationName:kMonalContactRefresh object:self.xmppAccount userInfo:@{@"contact": self.contact}];
+        }
+        else
+        {
+            //hardcode reason for now (change this when rewriting chatui using swiftui)
+            [self.xmppAccount moderateMessage:message withReason:@"This message contains inappropriate content for this forum."];
+        }
 
         return completionHandler(YES);
     }];
@@ -2510,7 +2519,7 @@ -(UISwipeActionsConfiguration*) tableView:(UITableView*) tableView trailingSwipe
 
         //update active chats if necessary
         [[MLNotificationQueue currentQueue] postNotificationName:kMonalContactRefresh object:self.xmppAccount userInfo:@{@"contact": self.contact}];
-
+        
         return completionHandler(YES);
     }];
     localDeleteAction.backgroundColor = UIColor.systemYellowColor;
@@ -2538,8 +2547,8 @@ -(UISwipeActionsConfiguration*) tableView:(UITableView*) tableView trailingSwipe
             LMCEditAction,
             retractAction,
         ]];
-    //only allow retraction for outgoing messages
-    else if(!message.inbound)
+    //only allow retraction for outgoing messages or if we are the moderator of that muc
+    else if(!message.inbound || (self.contact.isGroup && [[[DataLayer sharedInstance] getOwnRoleInGroupOrChannel:self.contact] isEqualToString:@"moderator"] && [[self.xmppAccount.mucProcessor getRoomFeaturesForMuc:self.contact.contactJid] containsObject:@"urn:xmpp:message-moderate:1"]))
         return [UISwipeActionsConfiguration configurationWithActions:@[
             quoteAction,
             copyAction,

Monal/Classes/xmpp.h

@@ -123,6 +123,7 @@ typedef void (^monal_iq_handler_t)(XMPPIQ* _Nullable);
  send a message to a contact with xmpp id
  */
 -(void) retractMessage:(MLMessage*) msg;
+-(void) moderateMessage:(MLMessage*) msg withReason:(NSString*) reason;
 -(void) sendMessage:(NSString*) message toContact:(MLContact*) contact isEncrypted:(BOOL) encrypt isUpload:(BOOL) isUpload andMessageId:(NSString*) messageId;
 -(void) sendMessage:(NSString*) message toContact:(MLContact*) contact isEncrypted:(BOOL) encrypt isUpload:(BOOL) isUpload andMessageId:(NSString*) messageId withLMCId:(NSString* _Nullable) LMCId;
 -(void) sendChatState:(BOOL) isTyping toContact:(nonnull MLContact*) contact;

Monal/Classes/xmpp.m

@@ -3317,6 +3317,20 @@ -(void) retractMessage:(MLMessage*) msg
     [self send:messageNode];
 }
 
+-(void) moderateMessage:(MLMessage*) msg withReason:(NSString*) reason
+{
+    MLAssert(msg.isMuc, @"Moderated message must be in a muc!");
+
+    XMPPIQ* iqNode = [[XMPPIQ alloc] initWithType:kiqSetType to:msg.buddyName];
+    [iqNode addChildNode:[[MLXMLNode alloc] initWithElement:@"moderate" andNamespace:@"urn:xmpp:message-moderate:1" withAttributes:@{
+        @"id": msg.stanzaId,
+    } andChildren:@[
+        [[MLXMLNode alloc] initWithElement:@"retract" andNamespace:@"urn:xmpp:message-retract:1"],
+        [[MLXMLNode alloc] initWithElement:@"reason" andData:reason],
+    ] andData:nil]];
+    [self sendIq:iqNode withHandler:$newHandler(MLIQProcessor, handleModerationResponse, $ID(msg))];
+}
+
 -(void) addEME:(NSString*) encryptionNamesapce withName:(NSString* _Nullable) name toMessageNode:(XMPPMessage*) messageNode
 {
     if(name)

monal.doap

@@ -654,10 +654,19 @@
         <xmpp:xep rdf:resource="https://xmpp.org/extensions/xep-0424.html" />
         <xmpp:status>complete</xmpp:status>
         <xmpp:since>6.3</xmpp:since>
-        <xmpp:version>0.4.0</xmpp:version>
+        <xmpp:version>0.4.1</xmpp:version>
         <xmpp:note>XEP-0424: Message Retraction</xmpp:note>
       </xmpp:SupportedXep>
     </implements>
+    <implements>
+      <xmpp:SupportedXep>
+        <xmpp:xep rdf:resource="https://xmpp.org/extensions/xep-0425.html" />
+        <xmpp:status>complete</xmpp:status>
+        <xmpp:since>6.3</xmpp:since>
+        <xmpp:version>0.3.0</xmpp:version>
+        <xmpp:note>XEP-0425: Moderated Message Retraction</xmpp:note>
+      </xmpp:SupportedXep>
+    </implements>
     <implements>
       <xmpp:SupportedXep>
         <xmpp:xep rdf:resource="https://xmpp.org/extensions/xep-0440.html" />