Fixed Coupon to use in sales

android/app/src/main/java/com/example/petstoremobile/fragments/listfragments/detailfragments/SaleDetailFragment.java

@@ -201,7 +201,7 @@ public class SaleDetailFragment extends Fragment {
                 if (sale.getItems() != null) {
                     binding.llSaleItems.removeAllViews();
                     for (SaleDTO.SaleItemDTO item : sale.getItems()) {
-                        addItemRow(item.getProductName(), Math.abs(item.getQuantity()), item.getUnitPrice());
+                        addItemRow(item.getProductName(), Math.abs(item.getQuantity()), item.getUnitPrice(), null);
                     }
                 }
             }
@@ -308,15 +308,16 @@ public class SaleDetailFragment extends Fragment {
                     break;
                 }
             }
-            addItemRow(name, item.getQuantity(), price);
+            addItemRow(name, item.getQuantity(), price, item.getProdId());
         }
     }
 
-    private void addItemRow(String name, int qty, BigDecimal price) {
+    private void addItemRow(String name, int qty, BigDecimal price, Long prodId) {
         if (getContext() == null) return;
         LinearLayout row = new LinearLayout(getContext());
         row.setOrientation(LinearLayout.HORIZONTAL);
         row.setPadding(0, 8, 0, 8);
+        row.setGravity(android.view.Gravity.CENTER_VERTICAL);
 
         TextView tvName = new TextView(getContext());
         tvName.setLayoutParams(new LinearLayout.LayoutParams(0, LinearLayout.LayoutParams.WRAP_CONTENT, 2f));
@@ -333,6 +334,20 @@ public class SaleDetailFragment extends Fragment {
         row.addView(tvName);
         row.addView(tvQty);
         row.addView(tvPrice);
+
+        if (prodId != null) {
+            Button btnRemove = new Button(getContext());
+            btnRemove.setLayoutParams(new LinearLayout.LayoutParams(
+                    LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT));
+            btnRemove.setText("✕");
+            btnRemove.setTextSize(12f);
+            btnRemove.setBackgroundTintList(android.content.res.ColorStateList.valueOf(0xFFE53935));
+            btnRemove.setTextColor(0xFFFFFFFF);
+            btnRemove.setPadding(16, 4, 16, 4);
+            btnRemove.setOnClickListener(v -> viewModel.removeFromCart(prodId));
+            row.addView(btnRemove);
+        }
+
         binding.llSaleItems.addView(row);
     }
 

android/app/src/main/java/com/example/petstoremobile/viewmodels/SaleDetailViewModel.java

@@ -95,6 +95,12 @@ public class SaleDetailViewModel extends ViewModel {
         cartItems.setValue(currentCart);
     }
 
+    public void removeFromCart(Long prodId) {
+        List<SaleDTO.SaleItemDTO> currentCart = new ArrayList<>(cartItems.getValue());
+        currentCart.removeIf(item -> item.getProdId().equals(prodId));
+        cartItems.setValue(currentCart);
+    }
+
     public LiveData<List<SaleDTO.SaleItemDTO>> getCartItems() { return cartItems; }
 
     public LiveData<Resource<CouponDTO>> lookupCoupon(String code) {

backend/src/main/java/com/petshop/backend/dto/sale/SaleResponse.java

@@ -12,6 +12,8 @@ public class SaleResponse {
     private String employeeName;
     private Long storeId;
     private String storeName;
+    private Long customerId;
+    private String customerName;
     private BigDecimal totalAmount;
     private BigDecimal subtotalAmount;
     private BigDecimal couponDiscountAmount;
@@ -77,6 +79,22 @@ public class SaleResponse {
         this.storeName = storeName;
     }
 
+    public Long getCustomerId() {
+        return customerId;
+    }
+
+    public void setCustomerId(Long customerId) {
+        this.customerId = customerId;
+    }
+
+    public String getCustomerName() {
+        return customerName;
+    }
+
+    public void setCustomerName(String customerName) {
+        this.customerName = customerName;
+    }
+
     public BigDecimal getTotalAmount() {
         return totalAmount;
     }

backend/src/main/java/com/petshop/backend/service/SaleService.java

@@ -13,6 +13,7 @@ import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
 import java.math.BigDecimal;
+import java.math.RoundingMode;
 import java.time.LocalDateTime;
 import java.util.ArrayList;
 import java.util.List;
@@ -20,6 +21,8 @@ import java.util.List;
 @Service
 public class SaleService {
 
+    private static final BigDecimal EMPLOYEE_DISCOUNT_PERCENT = new BigDecimal("0.10");
+
     private final SaleRepository saleRepository;
     private final ProductRepository productRepository;
     private final StoreRepository storeRepository;
@@ -76,6 +79,7 @@ public class SaleService {
         if (request.getCouponId() != null) {
             Coupon coupon = couponRepository.findById(request.getCouponId())
                     .orElseThrow(() -> new ResourceNotFoundException("Coupon not found with id: " + request.getCouponId()));
+            validateCoupon(coupon);
             sale.setCoupon(coupon);
         }
 
@@ -85,8 +89,9 @@ public class SaleService {
             sale.setCart(cart);
         }
 
+        User customer = null;
         if (request.getCustomerId() != null) {
-            User customer = userRepository.findById(request.getCustomerId())
+            customer = userRepository.findById(request.getCustomerId())
                     .orElseThrow(() -> new ResourceNotFoundException("Customer not found with id: " + request.getCustomerId()));
             sale.setCustomer(customer);
         }
@@ -97,7 +102,7 @@ public class SaleService {
             sale.setOriginalSale(originalSale);
         }
 
-        BigDecimal totalAmount = BigDecimal.ZERO;
+        BigDecimal subtotalAmount = BigDecimal.ZERO;
         List<SaleItem> saleItems = new ArrayList<>();
 
         if (sale.getIsRefund() && sale.getOriginalSale() != null) {
@@ -145,9 +150,11 @@ public class SaleService {
                 saleItem.setUnitPrice(unitPrice);
 
                 saleItems.add(saleItem);
-                totalAmount = totalAmount.add(itemTotal);
+                subtotalAmount = subtotalAmount.add(itemTotal);
             }
-            totalAmount = totalAmount.negate();
+            subtotalAmount = subtotalAmount.negate();
+            sale.setSubtotalAmount(subtotalAmount);
+            sale.setTotalAmount(subtotalAmount);
         } else {
             for (var itemRequest : request.getItems()) {
                 Product product = productRepository.findById(itemRequest.getProdId())
@@ -174,17 +181,77 @@ public class SaleService {
                 saleItem.setUnitPrice(unitPrice);
 
                 saleItems.add(saleItem);
-                totalAmount = totalAmount.add(itemTotal);
+                subtotalAmount = subtotalAmount.add(itemTotal);
+            }
+            sale.setSubtotalAmount(subtotalAmount);
+
+            BigDecimal couponDiscount = calculateCouponDiscount(sale.getCoupon(), subtotalAmount);
+            sale.setCouponDiscountAmount(couponDiscount);
+
+            BigDecimal employeeDiscount = calculateEmployeeDiscount(customer, subtotalAmount.subtract(couponDiscount));
+            sale.setEmployeeDiscountAmount(employeeDiscount);
+
+            BigDecimal finalTotal = subtotalAmount.subtract(couponDiscount).subtract(employeeDiscount);
+            sale.setTotalAmount(finalTotal.max(BigDecimal.ZERO));
+
+            sale.setPointsEarned(sale.getTotalAmount().setScale(0, RoundingMode.FLOOR).intValue());
+            if (customer != null) {
+                customer.setLoyaltyPoints(customer.getLoyaltyPoints() + sale.getPointsEarned());
+                userRepository.save(customer);
             }
         }
 
-        sale.setTotalAmount(totalAmount);
         sale.setItems(saleItems);
 
         Sale savedSale = saleRepository.save(sale);
         return mapToResponse(savedSale);
     }
 
+    private void validateCoupon(Coupon coupon) {
+        if (!Boolean.TRUE.equals(coupon.getActive())) {
+            throw new BusinessException("Coupon is not active");
+        }
+        LocalDateTime now = LocalDateTime.now();
+        if (coupon.getStartsAt() != null && now.isBefore(coupon.getStartsAt())) {
+            throw new BusinessException("Coupon has not started yet");
+        }
+        if (coupon.getEndsAt() != null && now.isAfter(coupon.getEndsAt())) {
+            throw new BusinessException("Coupon has expired");
+        }
+    }
+
+    private BigDecimal calculateCouponDiscount(Coupon coupon, BigDecimal subtotal) {
+        if (coupon == null || subtotal.compareTo(BigDecimal.ZERO) <= 0) {
+            return BigDecimal.ZERO;
+        }
+
+        if (coupon.getMinOrderAmount() != null && subtotal.compareTo(coupon.getMinOrderAmount()) < 0) {
+            return BigDecimal.ZERO;
+        }
+
+        BigDecimal discount = BigDecimal.ZERO;
+        String type = coupon.getDiscountType().trim().toUpperCase();
+        if ("PERCENTAGE".equals(type) || "PERCENT".equals(type)) {
+            discount = subtotal.multiply(coupon.getDiscountValue().divide(new BigDecimal("100"), 4, RoundingMode.HALF_UP));
+        } else if ("FIXED".equals(type)) {
+            discount = coupon.getDiscountValue();
+        }
+
+        return discount.min(subtotal).setScale(2, RoundingMode.HALF_UP);
+    }
+
+    private BigDecimal calculateEmployeeDiscount(User customer, BigDecimal remainingAmount) {
+        if (customer == null || remainingAmount.compareTo(BigDecimal.ZERO) <= 0) {
+            return BigDecimal.ZERO;
+        }
+
+        if (customer.getRole() == User.Role.STAFF || customer.getRole() == User.Role.ADMIN) {
+            return remainingAmount.multiply(EMPLOYEE_DISCOUNT_PERCENT).setScale(2, RoundingMode.HALF_UP);
+        }
+
+        return BigDecimal.ZERO;
+    }
+
     private SaleResponse mapToResponse(Sale sale) {
         SaleResponse response = new SaleResponse();
         response.setSaleId(sale.getSaleId());
@@ -197,6 +264,11 @@ public class SaleService {
             response.setStoreName(sale.getStore().getStoreName());
         }
 
+        if (sale.getCustomer() != null) {
+            response.setCustomerId(sale.getCustomer().getId());
+            response.setCustomerName(sale.getCustomer().getFirstName() + " " + sale.getCustomer().getLastName());
+        }
+
         response.setTotalAmount(sale.getTotalAmount());
         response.setSubtotalAmount(sale.getSubtotalAmount());
         response.setCouponDiscountAmount(sale.getCouponDiscountAmount());