Merge pull request #336 from RecentRunner/commenting-backend-desktop

comment backend and desktop

backend/src/main/java/com/petshop/backend/BackendApplication.java

@@ -1,3 +1,10 @@
+/*
+ * Main entry point for the pet shop backend application.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend;
 
 import com.petshop.backend.config.BusinessProperties;

backend/src/main/java/com/petshop/backend/DevStackApplication.java

@@ -1,3 +1,10 @@
+/*
+ * Starts the backend with Docker and auto-reload for development.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend;
 
 import com.petshop.backend.config.FlywayContextInitializer;

backend/src/main/java/com/petshop/backend/DockerComposeSupport.java

@@ -1,3 +1,10 @@
+/*
+ * Manages Docker Compose for the development database.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend;
 
 import java.io.BufferedReader;

backend/src/main/java/com/petshop/backend/PortCleanupSupport.java

@@ -1,3 +1,10 @@
+/*
+ * Frees up a port by stopping whatever process is using it.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend;
 
 import java.io.BufferedReader;

backend/src/main/java/com/petshop/backend/ResetDatabaseApplication.java

@@ -1,3 +1,10 @@
+/*
+ * Resets the development database by recreating the Docker container.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend;
 
 public class ResetDatabaseApplication {

backend/src/main/java/com/petshop/backend/RuntimeClasspathValidator.java

@@ -1,3 +1,10 @@
+/*
+ * Checks that required resources are on the classpath at startup.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend;
 
 import java.net.URL;

backend/src/main/java/com/petshop/backend/config/ActivityLoggingFilter.java

@@ -1,3 +1,11 @@
+/*
+ * Logs write operations (POST, PUT, DELETE) to the activity log.
+ * Skips GET requests and internal endpoints like health checks.
+ * Builds a human-readable description for each action.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.config;
 
 import com.petshop.backend.entity.User;
@@ -77,11 +85,24 @@ public class ActivityLoggingFilter extends OncePerRequestFilter {
         activityLogService.record(userId, activity);
     }
 
+    /**
+     * Turns a request method + URL + status into a human-readable description
+     * like "Created a new product" or "Failed login attempt".
+     * Parses the URL as /api/v1/{resource}/{id?}/{sub?}/{subsub?} and matches
+     * against known patterns.
+     * @param method HTTP method (GET, POST, etc.)
+     * @param rawUri the request URI, possibly with query params
+     * @param status the HTTP response status code
+     * @return a readable description, or null if we don't recognize the pattern
+     */
     private String describe(String method, String rawUri, int status) {
+        // Strip query params so we only deal with the path
         String uri = rawUri.contains("?") ? rawUri.substring(0, rawUri.indexOf('?')) : rawUri;
+        // Split into segments: [api, v1, resource, id/action, sub, ...]
         String[] parts = uri.replaceFirst("^/+", "").split("/");
         if (parts.length < 3) return null;
 
+        // parts[2] is the resource name (e.g. "products", "auth", "cart")
         String r = parts[2];
         String seg3 = parts.length > 3 ? parts[3] : null;
         String seg4 = parts.length > 4 ? parts[4] : null;
@@ -89,6 +110,8 @@ public class ActivityLoggingFilter extends OncePerRequestFilter {
 
         boolean seg3IsId = seg3 != null && seg3.matches("\\d+");
         boolean seg4IsId = seg4 != null && seg4.matches("\\d+");
+        // Normalize: if seg3 is a numeric ID, treat seg4 as the sub-action
+        // otherwise seg3 itself is the sub-action (like "login", "add", etc.)
         String id = seg3IsId ? seg3 : null;
         String sub = seg3IsId ? seg4 : seg3;
         String subsub = seg3IsId ? seg5 : seg4;

backend/src/main/java/com/petshop/backend/config/ActivityLoggingFilterRegistrationConfig.java

@@ -1,3 +1,9 @@
+/*
+ * Registers the activity logging filter with the servlet container.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.config;
 
 import org.springframework.boot.web.servlet.FilterRegistrationBean;

backend/src/main/java/com/petshop/backend/config/ApplicationStartupListener.java

@@ -1,3 +1,9 @@
+/*
+ * Runs once on startup to mark past appointments as completed.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.config;
 
 import com.petshop.backend.service.AppointmentService;

backend/src/main/java/com/petshop/backend/config/BusinessProperties.java

@@ -1,3 +1,10 @@
+/*
+ * Business settings loaded from application.yml (store hours,
+ * slot intervals, image size limits, discount/loyalty config).
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.config;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;

backend/src/main/java/com/petshop/backend/config/CacheConfig.java

@@ -1,3 +1,10 @@
+/*
+ * Sets up Caffeine caching for the app. Currently used to cache
+ * user auth lookups so the filter doesn't query the DB every time.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.config;
 
 import com.github.benmanes.caffeine.cache.Caffeine;

backend/src/main/java/com/petshop/backend/config/DataInitializer.java

@@ -1,3 +1,11 @@
+/*
+ * Creates default admin, staff, and customer accounts on startup
+ * if they don't already exist. Also fills in missing fields on
+ * existing accounts to keep them consistent.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.config;
 
 import com.petshop.backend.entity.User;

backend/src/main/java/com/petshop/backend/config/FlywayContextInitializer.java

@@ -1,3 +1,10 @@
+/*
+ * Runs Flyway migrations before the app starts. Retries up to
+ * 15 times so the app can wait for the database container to be ready.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.config;
 
 import org.flywaydb.core.Flyway;

backend/src/main/java/com/petshop/backend/config/LocalCatalogSeedInitializer.java

@@ -1,3 +1,10 @@
+/*
+ * Adds extra pet and product seed data in the local dev profile
+ * if the database only has the base seed rows.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.config;
 
 import com.petshop.backend.repository.PetRepository;

backend/src/main/java/com/petshop/backend/config/TomcatPathToleranceConfig.java

@@ -1,3 +1,10 @@
+/*
+ * Tells Tomcat to accept backslashes in URLs so the Android
+ * and desktop clients don't get rejected for path issues.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.config;
 
 import org.springframework.boot.tomcat.servlet.TomcatServletWebServerFactory;

backend/src/main/java/com/petshop/backend/config/TrailingSlashNormalizationFilter.java

@@ -1,3 +1,10 @@
+/*
+ * Strips trailing slashes and normalizes paths so /api/pets/
+ * and /api/pets both hit the same controller.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.config;
 
 import jakarta.servlet.FilterChain;
@@ -63,6 +70,12 @@ public class TrailingSlashNormalizationFilter extends OncePerRequestFilter {
         filterChain.doFilter(wrapper, response);
     }
 
+    /**
+     * Cleans up a URL path by fixing backslashes, collapsing double slashes,
+     * lowercasing API/WS paths, and stripping trailing slashes.
+     * @param value the raw path string
+     * @return the normalized path, or null if input was null
+     */
     private String normalizePath(String value) {
         if (value == null) {
             return null;
@@ -74,6 +87,7 @@ public class TrailingSlashNormalizationFilter extends OncePerRequestFilter {
         if (shouldLowercase(normalized)) {
             normalized = normalized.toLowerCase(java.util.Locale.ROOT);
         }
+        // Strip trailing slashes but keep the root "/" intact
         int end = normalized.length();
         while (end > 1 && normalized.charAt(end - 1) == '/') {
             end--;

backend/src/main/java/com/petshop/backend/config/WebSocketAuthChannelInterceptor.java

@@ -1,3 +1,11 @@
+/*
+ * Intercepts WebSocket messages to authenticate and authorize users.
+ * Validates the token on CONNECT, then checks permissions on
+ * SUBSCRIBE and SEND for chat topics.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.config;
 
 import com.petshop.backend.entity.User;
@@ -33,6 +41,14 @@ public class WebSocketAuthChannelInterceptor implements ChannelInterceptor {
         this.chatService = chatService;
     }
 
+    /**
+     * Intercepts every STOMP message before it's sent. On CONNECT it validates the
+     * JWT and stores the authenticated user. On SUBSCRIBE/SEND it checks that the
+     * user has access to the requested chat destination.
+     * @param message the STOMP message being sent
+     * @param channel the channel the message is going through
+     * @return the original message if everything checks out
+     */
     @Override
     public Message<?> preSend(Message<?> message, MessageChannel channel) {
         StompHeaderAccessor accessor = StompHeaderAccessor.wrap(message);
@@ -95,6 +111,14 @@ public class WebSocketAuthChannelInterceptor implements ChannelInterceptor {
         return message;
     }
 
+    /**
+     * Tries to figure out who the user is from multiple sources: the principal on the
+     * message, the session attributes (fallback for some STOMP clients), or by
+     * re-parsing the token from headers as a last resort.
+     * @param principal the principal attached to the message, may be null
+     * @param accessor the STOMP header accessor for fallback lookups
+     * @return the User entity, or null if unauthenticated
+     */
     private User resolveUser(Principal principal, StompHeaderAccessor accessor) {
         Principal currentPrincipal = principal;
         if (currentPrincipal == null && accessor.getSessionAttributes() != null) {
@@ -136,6 +160,13 @@ public class WebSocketAuthChannelInterceptor implements ChannelInterceptor {
         return user;
     }
 
+    /**
+     * Checks if the user is allowed to subscribe to this destination.
+     * Customers can only subscribe to their own conversations, not the
+     * staff-wide conversation feed.
+     * @param destination the STOMP destination being subscribed to
+     * @param user the user trying to subscribe
+     */
     private void authorizeSubscription(String destination, User user) {
         destination = normalizeDestination(destination);
         if (destination == null || destination.startsWith("/user/queue/")) {
@@ -157,6 +188,12 @@ public class WebSocketAuthChannelInterceptor implements ChannelInterceptor {
         throw new IllegalArgumentException("Not authorized to subscribe to destination");
     }
 
+    /**
+     * Checks if the user is allowed to send a message to this destination.
+     * Only allows sending to conversation message endpoints that the user has access to.
+     * @param destination the STOMP destination being sent to
+     * @param user the user trying to send
+     */
     private void authorizeSend(String destination, User user) {
         destination = normalizeDestination(destination);
         Long conversationId = extractConversationId(destination, "/app/chat/conversations/");

backend/src/main/java/com/petshop/backend/config/WebSocketConfig.java

@@ -1,3 +1,10 @@
+/*
+ * WebSocket configuration for the live chat feature.
+ * Registers STOMP endpoints and the auth interceptor.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.config;
 
 import org.springframework.context.annotation.Configuration;

backend/src/main/java/com/petshop/backend/controller/ActivityLogController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles requests for viewing user activity logs.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.activity.ActivityLogResponse;

backend/src/main/java/com/petshop/backend/controller/AdoptionController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles pet adoption requests and approvals.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.adoption.AdoptionRequest;

backend/src/main/java/com/petshop/backend/controller/AiChatController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles AI-powered chat for getting pet care advice.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.ai.AiChatRequest;

backend/src/main/java/com/petshop/backend/controller/AnalyticsController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles dashboard analytics and sales reporting for staff and admins.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.analytics.DashboardResponse;

backend/src/main/java/com/petshop/backend/controller/AppointmentController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles booking and managing pet service appointments.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.appointment.AppointmentRequest;

backend/src/main/java/com/petshop/backend/controller/AuthController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles user login, registration, password reset, and profile updates.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.auth.AvatarUploadResponse;

backend/src/main/java/com/petshop/backend/controller/CartController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles shopping cart operations like adding and removing items.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.cart.*;

backend/src/main/java/com/petshop/backend/controller/CategoryController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles managing product and pet categories.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.category.CategoryRequest;

backend/src/main/java/com/petshop/backend/controller/ChatController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles chat conversations and messages between users.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.chat.ConversationRequest;

backend/src/main/java/com/petshop/backend/controller/ChatWebSocketController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles real-time chat messaging over WebSocket connections.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.config.WebSocketAuthChannelInterceptor;

backend/src/main/java/com/petshop/backend/controller/ContactController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles sending contact form messages from customers.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.entity.User;

backend/src/main/java/com/petshop/backend/controller/CouponController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles creating and managing discount coupons.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.common.BulkDeleteRequest;

backend/src/main/java/com/petshop/backend/controller/CustomerController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles staff and admin operations for managing customer accounts.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.common.BulkDeleteRequest;

backend/src/main/java/com/petshop/backend/controller/DropdownController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles providing dropdown menu options for forms across the app.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.common.DropdownOption;

backend/src/main/java/com/petshop/backend/controller/EmployeeController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles admin operations for managing employee accounts.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.user.UserRequest;

backend/src/main/java/com/petshop/backend/controller/HealthController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles health check requests to verify the server is running.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import org.springframework.http.ResponseEntity;

backend/src/main/java/com/petshop/backend/controller/InventoryController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles tracking product stock levels across store locations.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.common.BulkDeleteRequest;

backend/src/main/java/com/petshop/backend/controller/MyPetController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles customers viewing and managing their own pets.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.pet.MyPetRequest;

backend/src/main/java/com/petshop/backend/controller/PetController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles managing pets available in the shop.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.common.BulkDeleteRequest;

backend/src/main/java/com/petshop/backend/controller/PetImageController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles uploading, retrieving, and deleting pet images.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.pet.PetResponse;

backend/src/main/java/com/petshop/backend/controller/ProductController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles creating, updating, and browsing products in the shop.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.common.BulkDeleteRequest;

backend/src/main/java/com/petshop/backend/controller/ProductImageController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles uploading, retrieving, and deleting product images.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.product.ProductResponse;

backend/src/main/java/com/petshop/backend/controller/ProductSupplierController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles linking products to their suppliers.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.productsupplier.BulkDeleteProductSupplierRequest;

backend/src/main/java/com/petshop/backend/controller/PurchaseOrderController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles purchase orders for restocking products from suppliers.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.purchaseorder.PurchaseOrderResponse;

backend/src/main/java/com/petshop/backend/controller/RefundController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles requesting and processing refunds for orders.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.refund.RefundRequest;

backend/src/main/java/com/petshop/backend/controller/SaleController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles creating and viewing sales and customer orders.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.sale.SaleRequest;

backend/src/main/java/com/petshop/backend/controller/ServiceController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles managing pet services like grooming and veterinary care.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.common.BulkDeleteRequest;

backend/src/main/java/com/petshop/backend/controller/StoreController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles managing store locations for the pet shop.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.common.BulkDeleteRequest;

backend/src/main/java/com/petshop/backend/controller/SupplierController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles managing suppliers who provide products to the shop.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.common.BulkDeleteRequest;

backend/src/main/java/com/petshop/backend/controller/UserAvatarController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles uploading, retrieving, and deleting user profile pictures.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.entity.User;

backend/src/main/java/com/petshop/backend/controller/UserController.java

@@ -1,3 +1,9 @@
+/*
+ * Handles admin operations for managing all user accounts.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.controller;
 
 import com.petshop.backend.dto.common.BulkDeleteRequest;

backend/src/main/java/com/petshop/backend/dto/activity/ActivityLogResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Activity log entry returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.activity;
 
 import java.time.LocalDateTime;

backend/src/main/java/com/petshop/backend/dto/adoption/AdoptionRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when creating or updating an adoption.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.adoption;
 
 import jakarta.validation.constraints.NotBlank;

backend/src/main/java/com/petshop/backend/dto/adoption/AdoptionResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Adoption record returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.adoption;
 
 import java.math.BigDecimal;

backend/src/main/java/com/petshop/backend/dto/adoption/CustomerAdoptionRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when a customer requests to adopt a pet.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.adoption;
 
 import jakarta.validation.constraints.NotNull;

backend/src/main/java/com/petshop/backend/dto/ai/AiChatRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when asking the AI chatbot a question.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.ai;
 
 import java.util.List;

backend/src/main/java/com/petshop/backend/dto/ai/AiChatResponse.java

@@ -1,3 +1,9 @@
+/*
+ * AI chatbot reply returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.ai;
 
 public class AiChatResponse {

backend/src/main/java/com/petshop/backend/dto/analytics/DashboardResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Dashboard analytics data returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.analytics;
 
 import java.math.BigDecimal;

backend/src/main/java/com/petshop/backend/dto/appointment/AppointmentRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when booking or updating an appointment.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.appointment;
 
 import jakarta.validation.constraints.NotBlank;

backend/src/main/java/com/petshop/backend/dto/appointment/AppointmentResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Appointment details returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.appointment;
 
 import java.time.LocalDate;

backend/src/main/java/com/petshop/backend/dto/auth/AvatarUploadResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Avatar upload result returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.auth;
 
 import java.util.Objects;

backend/src/main/java/com/petshop/backend/dto/auth/ForgotPasswordRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when a user requests a password reset.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.auth;
 
 import jakarta.validation.constraints.NotBlank;

backend/src/main/java/com/petshop/backend/dto/auth/ForgotPasswordResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Forgot password result returned with a reset token.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.auth;
 
 public class ForgotPasswordResponse {

backend/src/main/java/com/petshop/backend/dto/auth/LoginRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when a user logs in.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.auth;
 
 import jakarta.validation.constraints.NotBlank;

backend/src/main/java/com/petshop/backend/dto/auth/LoginResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Login result returned to the client with a token.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.auth;
 
 import java.util.Objects;

backend/src/main/java/com/petshop/backend/dto/auth/ProfileUpdateRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when a user updates their profile.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.auth;
 
 import jakarta.validation.constraints.Email;

backend/src/main/java/com/petshop/backend/dto/auth/RegisterRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when a new user registers an account.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.auth;
 
 import jakarta.validation.constraints.Email;

backend/src/main/java/com/petshop/backend/dto/auth/RegisterResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Registration result returned to the client after signing up.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.auth;
 
 import java.util.Objects;

backend/src/main/java/com/petshop/backend/dto/auth/ResetPasswordRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when a user sets a new password using a reset token.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.auth;
 
 import jakarta.validation.constraints.NotBlank;

backend/src/main/java/com/petshop/backend/dto/auth/ResetPasswordResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Password reset confirmation returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.auth;
 
 public class ResetPasswordResponse {

backend/src/main/java/com/petshop/backend/dto/auth/UserInfoResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Logged-in user profile data returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.auth;
 
 import java.util.Objects;

backend/src/main/java/com/petshop/backend/dto/cart/AddToCartRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when adding a product to the shopping cart.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.cart;
 
 import jakarta.validation.constraints.Min;

backend/src/main/java/com/petshop/backend/dto/cart/ApplyCouponRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when applying a coupon code to the cart.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.cart;
 
 import jakarta.validation.constraints.NotBlank;

backend/src/main/java/com/petshop/backend/dto/cart/CartItemResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Single cart item returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.cart;
 
 import java.math.BigDecimal;

backend/src/main/java/com/petshop/backend/dto/cart/CartResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Full shopping cart data returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.cart;
 
 import java.math.BigDecimal;

backend/src/main/java/com/petshop/backend/dto/cart/CheckoutRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when a customer checks out their cart.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.cart;
 
 import jakarta.validation.constraints.NotNull;

backend/src/main/java/com/petshop/backend/dto/cart/CheckoutResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Checkout result returned to the client after placing an order.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.cart;
 
 import java.math.BigDecimal;

backend/src/main/java/com/petshop/backend/dto/cart/UpdateCartItemRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when updating the quantity of a cart item.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.cart;
 
 import jakarta.validation.constraints.Min;

backend/src/main/java/com/petshop/backend/dto/category/CategoryRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when creating or updating a category.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.category;
 
 import com.petshop.backend.util.SafeContent;

backend/src/main/java/com/petshop/backend/dto/category/CategoryResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Category data returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.category;
 
 import java.time.LocalDateTime;

backend/src/main/java/com/petshop/backend/dto/chat/ConversationRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when starting a new conversation.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.chat;
 
 public class ConversationRequest {

backend/src/main/java/com/petshop/backend/dto/chat/ConversationResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Conversation details returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.chat;
 
 import com.petshop.backend.entity.Conversation;

backend/src/main/java/com/petshop/backend/dto/chat/MessageRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when sending a chat message.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.chat;
 
 public class MessageRequest {

backend/src/main/java/com/petshop/backend/dto/chat/MessageResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Chat message returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.chat;
 
 import com.petshop.backend.entity.Message;

backend/src/main/java/com/petshop/backend/dto/chat/UpdateConversationRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when changing the status of a conversation.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.chat;
 
 import jakarta.validation.constraints.NotBlank;

backend/src/main/java/com/petshop/backend/dto/common/BulkDeleteRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when deleting multiple records at once.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.common;
 
 import jakarta.validation.constraints.NotEmpty;

backend/src/main/java/com/petshop/backend/dto/common/CouponRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when creating or updating a coupon.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.common;
 
 import jakarta.validation.constraints.NotBlank;

backend/src/main/java/com/petshop/backend/dto/common/CouponResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Coupon details returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.common;
 
 import java.math.BigDecimal;

backend/src/main/java/com/petshop/backend/dto/common/DropdownOption.java

@@ -1,3 +1,9 @@
+/*
+ * Simple id and label pair used for dropdown menus.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.common;
 
 import java.util.Objects;

backend/src/main/java/com/petshop/backend/dto/inventory/InventoryRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when updating inventory for a product.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.inventory;
 
 import jakarta.validation.constraints.NotNull;

backend/src/main/java/com/petshop/backend/dto/inventory/InventoryResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Inventory record returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.inventory;
 
 import java.time.LocalDateTime;

backend/src/main/java/com/petshop/backend/dto/pet/MyPetRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when a customer adds or updates their own pet.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.pet;
 
 import jakarta.validation.constraints.Max;

backend/src/main/java/com/petshop/backend/dto/pet/MyPetResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Customer's own pet data returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.pet;
 
 public class MyPetResponse {

backend/src/main/java/com/petshop/backend/dto/pet/PetRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when creating or updating a pet listing.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.pet;
 
 import com.petshop.backend.util.SafeContent;

backend/src/main/java/com/petshop/backend/dto/pet/PetResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Pet data returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.pet;
 
 import java.math.BigDecimal;

backend/src/main/java/com/petshop/backend/dto/product/ProductRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when creating or updating a product.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.product;
 
 import com.petshop.backend.util.SafeContent;

backend/src/main/java/com/petshop/backend/dto/product/ProductResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Product data returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.product;
 
 import java.math.BigDecimal;

backend/src/main/java/com/petshop/backend/dto/productsupplier/BulkDeleteProductSupplierRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when deleting multiple product-supplier links at once.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.productsupplier;
 
 import jakarta.validation.constraints.NotEmpty;

backend/src/main/java/com/petshop/backend/dto/productsupplier/ProductSupplierKey.java

@@ -1,3 +1,9 @@
+/*
+ * Composite key identifying a product-supplier relationship.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.productsupplier;
 
 import java.util.Objects;

backend/src/main/java/com/petshop/backend/dto/productsupplier/ProductSupplierRequest.java

@@ -1,3 +1,9 @@
+/*
+ * Data sent when linking a product to a supplier.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.productsupplier;
 
 import jakarta.validation.constraints.NotNull;

backend/src/main/java/com/petshop/backend/dto/productsupplier/ProductSupplierResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Product-supplier link data returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.productsupplier;
 
 import java.math.BigDecimal;

backend/src/main/java/com/petshop/backend/dto/purchaseorder/PurchaseOrderResponse.java

@@ -1,3 +1,9 @@
+/*
+ * Purchase order data returned to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package com.petshop.backend.dto.purchaseorder;
 
 import java.time.LocalDate;