comment backend events and utils

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/event/AdoptionConfirmedEvent.java

@@ -1,3 +1,10 @@
+/*
+ * Event fired when an adoption is confirmed.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.event;
 
 public record AdoptionConfirmedEvent(Long adoptionId) {}

backend/src/main/java/com/petshop/backend/event/AdoptionReminderEvent.java

@@ -1,3 +1,10 @@
+/*
+ * Event fired to send an adoption reminder email.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.event;
 
 public record AdoptionReminderEvent(Long adoptionId) {}

backend/src/main/java/com/petshop/backend/event/AppointmentConfirmedEvent.java

@@ -1,3 +1,10 @@
+/*
+ * Event fired when an appointment is confirmed.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.event;
 
 public record AppointmentConfirmedEvent(Long appointmentId) {}

backend/src/main/java/com/petshop/backend/event/AppointmentReminderEvent.java

@@ -1,3 +1,10 @@
+/*
+ * Event fired to send an appointment reminder email.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.event;
 
 public record AppointmentReminderEvent(Long appointmentId) {}

backend/src/main/java/com/petshop/backend/event/EmailEventListener.java

@@ -1,3 +1,10 @@
+/*
+ * Listens for events and sends the matching emails.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.event;
 
 import com.petshop.backend.repository.AdoptionRepository;

backend/src/main/java/com/petshop/backend/event/SaleReceiptEvent.java

@@ -1,3 +1,10 @@
+/*
+ * Event fired to send a sale receipt email.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.event;
 
 public record SaleReceiptEvent(Long saleId) {}

backend/src/main/java/com/petshop/backend/exception/ApiErrorResponder.java

@@ -1,3 +1,10 @@
+/*
+ * Writes error responses to the client in a consistent format.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.exception;
 
 import com.fasterxml.jackson.databind.ObjectMapper;

backend/src/main/java/com/petshop/backend/exception/ApiErrorResponse.java

@@ -1,3 +1,10 @@
+/*
+ * Holds the structure of an error response sent to the client.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.exception;
 
 import java.time.LocalDateTime;

backend/src/main/java/com/petshop/backend/exception/BusinessException.java

@@ -1,3 +1,10 @@
+/*
+ * Thrown when a business rule is violated.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.exception;
 
 public class BusinessException extends RuntimeException {

backend/src/main/java/com/petshop/backend/exception/ConflictException.java

@@ -1,3 +1,10 @@
+/*
+ * Thrown when a request conflicts with existing data.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.exception;
 
 public class ConflictException extends RuntimeException {

backend/src/main/java/com/petshop/backend/exception/GlobalExceptionHandler.java

@@ -1,3 +1,10 @@
+/*
+ * Catches all exceptions and returns proper error responses.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.exception;
 
 import com.petshop.backend.service.PetService;

backend/src/main/java/com/petshop/backend/exception/ResourceNotFoundException.java

@@ -1,3 +1,10 @@
+/*
+ * Thrown when a requested resource does not exist.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.exception;
 
 public class ResourceNotFoundException extends RuntimeException {

backend/src/main/java/com/petshop/backend/util/AuthenticationHelper.java

@@ -1,3 +1,10 @@
+/*
+ * Retrieves the currently logged-in user from the security context.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.util;
 
 import com.petshop.backend.entity.User;

backend/src/main/java/com/petshop/backend/util/ContentFilter.java

@@ -1,3 +1,10 @@
+/*
+ * Checks user input for scripts and inappropriate language.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.util;
 
 import com.petshop.backend.exception.BusinessException;

backend/src/main/java/com/petshop/backend/util/ImageValidationUtil.java

@@ -1,3 +1,10 @@
+/*
+ * Validates uploaded image files for type and size.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.util;
 
 import com.petshop.backend.exception.BusinessException;

backend/src/main/java/com/petshop/backend/util/PhoneUtils.java

@@ -1,3 +1,10 @@
+/*
+ * Formats and normalizes phone numbers.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.util;
 
 public class PhoneUtils {

backend/src/main/java/com/petshop/backend/util/SafeContent.java

@@ -1,3 +1,10 @@
+/*
+ * Annotation that marks a field for content safety validation.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.util;
 
 import jakarta.validation.Constraint;

backend/src/main/java/com/petshop/backend/util/SafeContentValidator.java

@@ -1,3 +1,10 @@
+/*
+ * Validates fields annotated with SafeContent for dangerous input.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.util;
 
 import jakarta.validation.ConstraintValidator;

backend/src/main/java/com/petshop/backend/util/StringUtils.java

@@ -1,3 +1,10 @@
+/*
+ * Helper methods for trimming and formatting strings.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
+
 package com.petshop.backend.util;
 
 public final class StringUtils {