Fix Split Bill

internal/service/order_service.go

@@ -21,6 +21,7 @@ type OrderService interface {
 	CreatePayment(ctx context.Context, req *models.CreatePaymentRequest) (*models.PaymentResponse, error)
 	RefundPayment(ctx context.Context, paymentID uuid.UUID, refundAmount float64, reason string, refundedBy uuid.UUID) error
 	SetOrderCustomer(ctx context.Context, orderID uuid.UUID, req *models.SetOrderCustomerRequest, organizationID uuid.UUID) (*models.SetOrderCustomerResponse, error)
+	SplitBill(ctx context.Context, req *models.SplitBillRequest) (*models.SplitBillResponse, error)
 }
 
 type OrderServiceImpl struct {
@@ -95,12 +96,10 @@ func (s *OrderServiceImpl) GetOrderByID(ctx context.Context, id uuid.UUID) (*mod
 }
 
 func (s *OrderServiceImpl) ListOrders(ctx context.Context, req *models.ListOrdersRequest) (*models.ListOrdersResponse, error) {
-	// Validate request
 	if err := s.validateListOrdersRequest(req); err != nil {
 		return nil, fmt.Errorf("validation error: %w", err)
 	}
 
-	// Process order listing
 	response, err := s.orderProcessor.ListOrders(ctx, req)
 	if err != nil {
 		return nil, fmt.Errorf("failed to list orders: %w", err)
@@ -384,3 +383,65 @@ func (s *OrderServiceImpl) validateSetOrderCustomerRequest(req *models.SetOrderC
 
 	return nil
 }
+
+func (s *OrderServiceImpl) SplitBill(ctx context.Context, req *models.SplitBillRequest) (*models.SplitBillResponse, error) {
+	if err := s.validateSplitBillRequest(req); err != nil {
+		return nil, fmt.Errorf("validation error: %w", err)
+	}
+
+	response, err := s.orderProcessor.SplitBill(ctx, req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to split bill: %w", err)
+	}
+
+	return response, nil
+}
+
+func (s *OrderServiceImpl) validateSplitBillRequest(req *models.SplitBillRequest) error {
+	if req == nil {
+		return fmt.Errorf("request cannot be nil")
+	}
+
+	if req.OrderID == uuid.Nil {
+		return fmt.Errorf("order ID is required")
+	}
+
+	if req.PaymentMethodID == uuid.Nil {
+		return fmt.Errorf("payment ID is required")
+	}
+
+	if req.Type != "ITEM" && req.Type != "AMOUNT" {
+		return fmt.Errorf("split type must be either ITEM or AMOUNT")
+	}
+
+	if req.Type == "ITEM" {
+		if len(req.Items) == 0 {
+			return fmt.Errorf("items are required when splitting by ITEM")
+		}
+
+		totalItemAmount := float64(0)
+		for i, item := range req.Items {
+			if item.OrderItemID == uuid.Nil {
+				return fmt.Errorf("order item ID is required for item %d", i+1)
+			}
+
+			if item.Amount <= 0 {
+				return fmt.Errorf("amount must be greater than zero for item %d", i+1)
+			}
+
+			totalItemAmount += item.Amount
+		}
+
+		if totalItemAmount <= 0 {
+			return fmt.Errorf("total item amount must be greater than zero")
+		}
+	}
+
+	if req.Type == "AMOUNT" {
+		if req.Amount <= 0 {
+			return fmt.Errorf("amount must be greater than zero when splitting by AMOUNT")
+		}
+	}
+
+	return nil
+}