feat: Automatically mark messages as delivered when recipients come online or receive new messages.

src/messages/messages.gateway.ts

@@ -99,6 +99,26 @@ export class MessagesGateway implements OnGatewayConnection, OnGatewayDisconnect
       .catch((err) => {
         this.logger.warn(`Failed to update online status for ${userId}: ${err.message}`);
       });
+
+    // Mark pending SENT messages as DELIVERED now that this user is online
+    this.messagesService.markPendingMessagesAsDelivered(userId)
+      .then((results) => {
+        for (const result of results) {
+          // Notify each sender that their messages were delivered
+          const deliveredEvent = {
+            messageIds: result.messageIds,
+            conversationId: result.conversationId,
+            deliveredAt: result.deliveredAt,
+          };
+          this.sendToUser(result.senderId, 'message_delivered', deliveredEvent);
+        }
+        if (results.length > 0) {
+          this.logger.log(`Marked pending messages as delivered for ${userId} across ${results.length} conversation(s)`);
+        }
+      })
+      .catch((err) => {
+        this.logger.warn(`Failed to mark pending messages as delivered for ${userId}: ${err.message}`);
+      });
   }
 
   /**
@@ -190,6 +210,18 @@ export class MessagesGateway implements OnGatewayConnection, OnGatewayDisconnect
             ? participants.agentUserId
             : participants.userId;
           this.sendToUser(otherUserId, 'new_message', message);
+
+          // Auto-mark as DELIVERED if recipient is online
+          if (this.isUserOnline(otherUserId)) {
+            await this.messagesService.markMessageDelivered(message.id);
+            const deliveredEvent = {
+              messageId: message.id,
+              conversationId: data.conversationId,
+              deliveredAt: new Date(),
+            };
+            // Notify sender that message was delivered
+            this.sendToUser(client.userId, 'message_delivered', deliveredEvent);
+          }
         }
       } catch (participantError) {
         this.logger.warn(`Failed to get participants for direct delivery in ${data.conversationId}: ${participantError.message}`);