Prefill refund dialog

src/main/java/org/example/petshopdesktop/api/dto/sale/SaleItemResponse.java

@@ -51,4 +51,11 @@ public class SaleItemResponse {
     public void setUnitPrice(BigDecimal unitPrice) {
         this.unitPrice = unitPrice;
     }
+
+    public BigDecimal getLineTotal() {
+        if (unitPrice == null || quantity == null) {
+            return BigDecimal.ZERO;
+        }
+        return unitPrice.multiply(BigDecimal.valueOf(quantity));
+    }
 }

src/main/java/org/example/petshopdesktop/controllers/SaleController.java

@@ -371,6 +371,7 @@ public class SaleController {
 
     private void openRefundDialog() {
         try {
+            SaleLineItem selectedSale = tvSales.getSelectionModel().getSelectedItem();
             FXMLLoader loader = new FXMLLoader(getClass().getResource(
                 "/org/example/petshopdesktop/dialogviews/refund-dialog-view.fxml"));
             Stage dialog = new Stage();
@@ -378,6 +379,10 @@ public class SaleController {
             dialog.initModality(Modality.APPLICATION_MODAL);
             dialog.setTitle("Process Refund");
             dialog.setScene(new Scene(loader.load()));
+            if (selectedSale != null) {
+                loader.<org.example.petshopdesktop.controllers.dialogcontrollers.RefundDialogController>getController()
+                    .prefillSale((long) selectedSale.getSaleId());
+            }
             dialog.setResizable(false);
             dialog.showAndWait();
 

src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/RefundDialogController.java

@@ -114,6 +114,18 @@ public class RefundDialogController {
 
     @FXML
     void btnLoadSaleClicked(ActionEvent event) {
+        loadSale();
+    }
+
+    public void prefillSale(Long saleId) {
+        if (saleId == null) {
+            return;
+        }
+        txtSaleId.setText(String.valueOf(saleId));
+        loadSale();
+    }
+
+    private void loadSale() {
         String saleIdText = txtSaleId.getText().trim();
         if (saleIdText.isEmpty()) {
             showError("Load Sale", "Enter a transaction ID.");