feat: Add endpoint and service logic to clear all messages within a conversation.

src/messages/messages.service.ts

@@ -615,6 +615,49 @@ export class MessagesService {
     };
   }
 
+  /**
+   * Clear all messages in a conversation (keep the conversation itself)
+   */
+  async clearChat(conversationId: string, userId: string) {
+    const conversation = await this.prisma.conversation.findUnique({
+      where: { id: conversationId },
+      include: {
+        agentProfile: {
+          select: { userId: true },
+        },
+      },
+    });
+
+    if (!conversation) {
+      throw new NotFoundException('Conversation not found');
+    }
+
+    const isUser = conversation.userId === userId;
+    const isAgent = conversation.agentProfile.userId === userId;
+
+    if (!isUser && !isAgent) {
+      throw new ForbiddenException('You are not part of this conversation');
+    }
+
+    // Delete all messages
+    await this.prisma.message.deleteMany({
+      where: { conversationId },
+    });
+
+    // Reset conversation preview
+    await this.prisma.conversation.update({
+      where: { id: conversationId },
+      data: {
+        lastMessageAt: null,
+        lastMessageText: null,
+        userUnreadCount: 0,
+        agentUnreadCount: 0,
+      },
+    });
+
+    return null;
+  }
+
   /**
    * Delete a conversation and all its messages
    */