diff --git a/backend/src/main/java/com/petshop/backend/controller/AnalyticsController.java b/backend/src/main/java/com/petshop/backend/controller/AnalyticsController.java
index 9d44f2d4..fedf5a16 100644
--- a/backend/src/main/java/com/petshop/backend/controller/AnalyticsController.java
+++ b/backend/src/main/java/com/petshop/backend/controller/AnalyticsController.java
@@ -5,12 +5,15 @@ import com.petshop.backend.entity.User;
 import com.petshop.backend.repository.UserRepository;
 import com.petshop.backend.service.AnalyticsService;
 import com.petshop.backend.util.AuthenticationHelper;
+import org.springframework.format.annotation.DateTimeFormat;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.web.bind.annotation.*;
 import org.springframework.web.server.ResponseStatusException;
 
+import java.time.LocalDate;
+
 @RestController
 @RequestMapping("/api/v1/analytics")
 @PreAuthorize("hasAnyRole('ADMIN', 'STAFF')")
@@ -27,7 +30,11 @@ public class AnalyticsController {
     @GetMapping("/dashboard")
     public ResponseEntity<DashboardResponse> getDashboard(
             @RequestParam(defaultValue = "30") int days,
-            @RequestParam(defaultValue = "10") int top) {
+            @RequestParam(defaultValue = "10") int top,
+            @RequestParam(required = false) String paymentMethod,
+            @RequestParam(required = false) Long storeId,
+            @RequestParam(required = false) String channel,
+            @RequestParam(required = false) @DateTimeFormat(iso = DateTimeFormat.ISO.DATE) LocalDate endDate) {
         if (days < 1 || days > 365) {
             throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "days must be between 1 and 365");
         }
@@ -35,6 +42,7 @@ public class AnalyticsController {
             throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "top must be between 1 and 50");
         }
         User user = AuthenticationHelper.getAuthenticatedUser(userRepository);
-        return ResponseEntity.ok(analyticsService.getDashboardData(days, top, user));
+        java.time.LocalDateTime endDateTime = endDate != null ? endDate.plusDays(1).atStartOfDay() : null;
+        return ResponseEntity.ok(analyticsService.getDashboardData(days, top, user, paymentMethod, storeId, channel, endDateTime));
     }
 }
diff --git a/backend/src/main/java/com/petshop/backend/repository/SaleRepository.java b/backend/src/main/java/com/petshop/backend/repository/SaleRepository.java
index bf8c050e..4313ba51 100644
--- a/backend/src/main/java/com/petshop/backend/repository/SaleRepository.java
+++ b/backend/src/main/java/com/petshop/backend/repository/SaleRepository.java
@@ -3,6 +3,7 @@ package com.petshop.backend.repository;
 import com.petshop.backend.entity.Sale;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
+import java.time.LocalDateTime;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
@@ -26,6 +27,19 @@ public interface SaleRepository extends JpaRepository<Sale, Long> {
            "(:customerId IS NULL OR s.customer.id = :customerId)")
     Page<Sale> searchSales(@Param("q") String query, @Param("paymentMethod") String paymentMethod, @Param("storeId") Long storeId, @Param("isRefund") Boolean isRefund, @Param("customerId") Long customerId, Pageable pageable);
 
+    long countByCoupon_CouponId(Long couponId);
+
+    @Query("SELECT s FROM Sale s WHERE s.saleDate > :startDate " +
+           "AND (:endDate IS NULL OR s.saleDate <= :endDate) " +
+           "AND (:paymentMethod IS NULL OR LOWER(s.paymentMethod) = LOWER(:paymentMethod)) " +
+           "AND (:storeId IS NULL OR s.store.storeId = :storeId) " +
+           "AND (:channel IS NULL OR s.channel = :channel)")
+    List<Sale> findForAnalytics(@Param("startDate") LocalDateTime startDate,
+                                @Param("endDate") LocalDateTime endDate,
+                                @Param("paymentMethod") String paymentMethod,
+                                @Param("storeId") Long storeId,
+                                @Param("channel") String channel);
+
     List<Sale> findByOriginalSaleSaleId(Long originalSaleId);
 
     Optional<Sale> findByCartCartId(Long cartId);
diff --git a/backend/src/main/java/com/petshop/backend/service/AnalyticsService.java b/backend/src/main/java/com/petshop/backend/service/AnalyticsService.java
index f4841228..7a69357b 100644
--- a/backend/src/main/java/com/petshop/backend/service/AnalyticsService.java
+++ b/backend/src/main/java/com/petshop/backend/service/AnalyticsService.java
@@ -34,10 +34,17 @@ public class AnalyticsService {
 
     @Transactional(readOnly = true)
     public DashboardResponse getDashboardData(int days, int top, User user) {
+        return getDashboardData(days, top, user, null, null, null, null);
+    }
+
+    @Transactional(readOnly = true)
+    public DashboardResponse getDashboardData(int days, int top, User user,
+                                               String paymentMethod, Long storeId,
+                                               String channel, LocalDateTime endDate) {
         LocalDateTime startDate = LocalDateTime.now().minusDays(days);
 
-        List<Sale> sales = saleRepository.findAll().stream()
-                .filter(sale -> sale.getSaleDate().isAfter(startDate))
+        List<Sale> sales = saleRepository.findForAnalytics(startDate, endDate, paymentMethod, storeId, channel)
+                .stream()
                 .filter(sale -> includeSaleForUser(sale, user))
                 .collect(Collectors.toList());
 
diff --git a/backend/src/main/java/com/petshop/backend/service/CartService.java b/backend/src/main/java/com/petshop/backend/service/CartService.java
index 8fd8c053..f2e304d2 100644
--- a/backend/src/main/java/com/petshop/backend/service/CartService.java
+++ b/backend/src/main/java/com/petshop/backend/service/CartService.java
@@ -206,6 +206,13 @@ public class CartService {
             throw new BusinessException("Minimum order amount of $" + coupon.getMinOrderAmount() + " required");
         }
 
+        if (coupon.getUsageLimit() != null) {
+            long used = saleRepository.countByCoupon_CouponId(coupon.getCouponId());
+            if (used >= coupon.getUsageLimit()) {
+                throw new BusinessException("Coupon usage limit has been reached");
+            }
+        }
+
         cart.setCoupon(coupon);
         recalculate(cart);