feat(conversations): expose inbox assistant

internal/service/conversation_service.go

@@ -161,6 +161,29 @@ func (s *ConversationService) GetByAccountAndDisplayIDOrID(ctx context.Context,
 	return s.repo.FindByAccountAndDisplayIDOrID(ctx, accountID, routeID)
 }
 
+// GetInboxAssistant returns the Captain assistant connected to the conversation's inbox.
+// Reference: Chatwoot enterprise ConversationsController#inbox_assistant.
+func (s *ConversationService) GetInboxAssistant(ctx context.Context, accountID, routeID uint) (*model.CaptainAssistant, error) {
+	conversation, err := s.repo.FindByAccountAndDisplayIDOrID(ctx, accountID, routeID)
+	if err != nil {
+		return nil, err
+	}
+
+	var assistant model.CaptainAssistant
+	err = s.repo.DB().WithContext(ctx).
+		Joins("JOIN captain_inboxes ON captain_inboxes.captain_assistant_id = captain_assistants.id").
+		Where("captain_inboxes.account_id = ? AND captain_inboxes.inbox_id = ? AND captain_assistants.account_id = ?", accountID, conversation.InboxID, accountID).
+		Order("captain_inboxes.id DESC").
+		First(&assistant).Error
+	if errors.Is(err, gorm.ErrRecordNotFound) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	return &assistant, nil
+}
+
 // CreateConversationRequest is the DTO for creating a conversation.
 // Reference: Chatwoot app/controllers/api/v1/accounts/conversations_controller.rb #create
 // Supports creating conversation with an initial message (like Chatwoot's ConversationBuilder).