fix filter

lib/features/products/data/datasources/products_remote_datasource.dart

@@ -200,4 +200,165 @@ class ProductsRemoteDataSource {
         .where((product) => product.category == categoryId)
         .toList();
   }
+
+  /// Get product groups (Item Groups)
+  ///
+  /// Fetches product groups from Frappe ERPNext.
+  /// Returns a list of group objects with name and item_group_name.
+  ///
+  /// API endpoint: POST https://land.dbiz.com/api/method/frappe.client.get_list
+  /// Request body:
+  /// ```json
+  /// {
+  ///   "doctype": "Item Group",
+  ///   "fields": ["item_group_name", "name"],
+  ///   "filters": {"is_group": 0},
+  ///   "limit_page_length": 0
+  /// }
+  /// ```
+  Future<List<Map<String, dynamic>>> getProductGroups() async {
+    try {
+      final headers = await _frappeAuthService.getHeaders();
+      final url =
+          '${ApiConstants.baseUrl}${ApiConstants.frappeApiMethod}${ApiConstants.frappeGetList}';
+
+      final response = await _dioClient.post<Map<String, dynamic>>(
+        url,
+        data: {
+          'doctype': 'Item Group',
+          'fields': ['item_group_name', 'name'],
+          'filters': {'is_group': 0},
+          'limit_page_length': 0,
+        },
+        options: Options(headers: headers),
+      );
+
+      if (response.data == null) {
+        throw Exception('Empty response from server');
+      }
+
+      final message = response.data!['message'];
+      if (message == null) {
+        throw Exception('No message field in response');
+      }
+
+      return (message as List).cast<Map<String, dynamic>>();
+    } on DioException catch (e) {
+      if (e.response?.statusCode == 404) {
+        throw Exception('Product groups endpoint not found');
+      } else if (e.response?.statusCode == 500) {
+        throw Exception('Server error while fetching product groups');
+      } else {
+        throw Exception('Failed to fetch product groups: ${e.message}');
+      }
+    } catch (e) {
+      throw Exception('Unexpected error fetching product groups: $e');
+    }
+  }
+
+  /// Get product brands
+  ///
+  /// Fetches brands from Frappe ERPNext.
+  /// Returns a list of brand names.
+  ///
+  /// API endpoint: POST https://land.dbiz.com/api/method/frappe.client.get_list
+  /// Request body:
+  /// ```json
+  /// {
+  ///   "doctype": "Brand",
+  ///   "fields": ["name"],
+  ///   "limit_page_length": 0
+  /// }
+  /// ```
+  Future<List<String>> getProductBrands() async {
+    try {
+      final headers = await _frappeAuthService.getHeaders();
+      final url =
+          '${ApiConstants.baseUrl}${ApiConstants.frappeApiMethod}${ApiConstants.frappeGetList}';
+
+      final response = await _dioClient.post<Map<String, dynamic>>(
+        url,
+        data: {
+          'doctype': 'Brand',
+          'fields': ['name'],
+          'limit_page_length': 0,
+        },
+        options: Options(headers: headers),
+      );
+
+      if (response.data == null) {
+        throw Exception('Empty response from server');
+      }
+
+      final message = response.data!['message'];
+      if (message == null) {
+        throw Exception('No message field in response');
+      }
+
+      return (message as List)
+          .map((item) => item['name'] as String)
+          .toList();
+    } on DioException catch (e) {
+      if (e.response?.statusCode == 404) {
+        throw Exception('Product brands endpoint not found');
+      } else if (e.response?.statusCode == 500) {
+        throw Exception('Server error while fetching product brands');
+      } else {
+        throw Exception('Failed to fetch product brands: ${e.message}');
+      }
+    } catch (e) {
+      throw Exception('Unexpected error fetching product brands: $e');
+    }
+  }
+
+  /// Get product attributes
+  ///
+  /// Fetches product attributes from Frappe ERPNext.
+  /// Returns a list of attribute objects.
+  ///
+  /// API endpoint: POST https://land.dbiz.com/api/method/building_material.building_material.api.item_attribute.get_list
+  /// Request body:
+  /// ```json
+  /// {
+  ///   "filters": {"is_group": 0},
+  ///   "limit_page_length": 0
+  /// }
+  /// ```
+  Future<List<Map<String, dynamic>>> getProductAttributes() async {
+    try {
+      final headers = await _frappeAuthService.getHeaders();
+      final url =
+          '${ApiConstants.baseUrl}${ApiConstants.frappeApiMethod}${ApiConstants.frappeGetItemAttributes}';
+
+      final response = await _dioClient.post<Map<String, dynamic>>(
+        url,
+        data: {
+          'filters': {'is_group': 0},
+          'limit_page_length': 0,
+        },
+        options: Options(headers: headers),
+      );
+
+      if (response.data == null) {
+        throw Exception('Empty response from server');
+      }
+
+      final message = response.data!['message'];
+      if (message == null) {
+        throw Exception('No message field in response');
+      }
+
+      return (message as List).cast<Map<String, dynamic>>();
+    } on DioException catch (e) {
+      if (e.response?.statusCode == 404) {
+        throw Exception('Product attributes endpoint not found');
+      } else if (e.response?.statusCode == 500) {
+        throw Exception('Server error while fetching product attributes');
+      } else {
+        throw Exception('Failed to fetch product attributes: ${e.message}');
+      }
+    } catch (e) {
+      throw Exception('Unexpected error fetching product attributes: $e');
+    }
+  }
 }