Feature/comment logic

src/main/java/org/example/visacasemanagementsystem/comment/controller/CommentController.java

@@ -0,0 +1,37 @@
+package org.example.visacasemanagementsystem.comment.controller;
+
+import jakarta.validation.Valid;
+import org.example.visacasemanagementsystem.comment.dto.CommentDTO;
+import org.example.visacasemanagementsystem.comment.dto.CreateCommentDTO;
+import org.example.visacasemanagementsystem.comment.service.CommentService;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/api/comments")
+public class CommentController {
+
+    private final CommentService commentService;
+
+    public CommentController(CommentService commentService) {
+        this.commentService = commentService;
+    }
+
+    // Create new comment
+    @PostMapping
+    public ResponseEntity<CommentDTO> createComment(@Valid @RequestBody CreateCommentDTO dto){
+        CommentDTO createComment =  commentService.createComment(dto);
+        return new ResponseEntity<>(createComment, HttpStatus.CREATED);
+    }
+
+    // Get all comments for a selected visa case
+    @GetMapping("/visa/{visaId}")
+    public ResponseEntity<List<CommentDTO>> getCommentsByVisa(@PathVariable Long visaId){
+        List<CommentDTO> comments = commentService.getCommentsByVisaId(visaId);
+        return new ResponseEntity<>(comments, HttpStatus.OK);
+
+    }
+}

src/main/java/org/example/visacasemanagementsystem/comment/dto/CreateCommentDTO.java

@@ -5,7 +5,7 @@
 
 public record CreateCommentDTO(
         @NotNull(message = "Visa ID is required") Long visaId,
-        @NotNull(message = "Author ID is required") Long authorId,
+        @NotNull(message = "Author ID is required") Long authorId, // Todo: Remove this and let Spring Security handle it
         @NotBlank(message = "Comment text cannot be empty") String  text
         ) {
 }

src/main/java/org/example/visacasemanagementsystem/comment/repository/CommentRepository.java

@@ -0,0 +1,11 @@
+package org.example.visacasemanagementsystem.comment.repository;
+
+import org.example.visacasemanagementsystem.comment.entity.Comment;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.List;
+
+public interface CommentRepository extends JpaRepository<Comment, Long> {
+
+    List<Comment> findByVisaIdOrderByCreatedAtDesc(Long visaId);
+}

src/main/java/org/example/visacasemanagementsystem/comment/service/CommentService.java

@@ -0,0 +1,82 @@
+package org.example.visacasemanagementsystem.comment.service;
+
+import org.example.visacasemanagementsystem.comment.dto.CommentDTO;
+import org.example.visacasemanagementsystem.comment.dto.CreateCommentDTO;
+import org.example.visacasemanagementsystem.comment.entity.Comment;
+import org.example.visacasemanagementsystem.comment.mapper.CommentMapper;
+import org.example.visacasemanagementsystem.comment.repository.CommentRepository;
+import org.example.visacasemanagementsystem.exception.ResourceNotFoundException;
+import org.example.visacasemanagementsystem.user.entity.User;
+import org.example.visacasemanagementsystem.user.repository.UserRepository;
+import org.example.visacasemanagementsystem.visa.entity.Visa;
+import org.example.visacasemanagementsystem.visa.repository.VisaRepository;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+
+@Service
+public class CommentService {
+
+    private final CommentRepository commentRepository;
+    private final CommentMapper commentMapper;
+    private final UserRepository userRepository;
+    private final VisaRepository visaRepository;
+
+    public CommentService(CommentRepository commentRepository, CommentMapper commentMapper , UserRepository userRepository, VisaRepository visaRepository) {
+        this.commentRepository = commentRepository;
+        this.commentMapper = commentMapper;
+        this.userRepository = userRepository;
+        this.visaRepository = visaRepository;
+    }
+
+
+     // Create Comment
+     // TODO: Security Risk - Replace authorId from DTO with authenticated user from
+     // SecurityContext once Spring Security is integrated to prevent IDOR vulnerabilities.
+    @Transactional
+    public CommentDTO createComment(CreateCommentDTO dto) {
+        if (dto == null) {
+            throw new IllegalArgumentException("Comment payload cannot be null");
+        }
+
+        if (dto.text() == null || dto.text().isBlank()) {
+            throw new IllegalArgumentException("Comment text cannot be empty");
+        }
+
+        // Get User and Visa from database
+        User author = userRepository.findById(dto.authorId())
+                .orElseThrow(() -> new ResourceNotFoundException("User not found with id: " + dto.authorId()));
+
+        Visa visa = visaRepository.findById(dto.visaId())
+                .orElseThrow(() -> new ResourceNotFoundException("Visa case not found with id: " + dto.visaId()));
+
+        // Map DTO to Entity
+        Comment comment = commentMapper.toEntity(dto);
+
+        // Set author and visaCase
+        comment.setAuthor(author);
+        comment.setVisa(visa);
+
+        // Save and return
+        Comment savedComment = commentRepository.save(comment);
+        return commentMapper.toDTO(savedComment);
+    }
+
+    // Get all comments for a selected visa case
+    @Transactional (readOnly = true)
+    public List<CommentDTO> getCommentsByVisaId(Long visaId) {
+        if (visaId == null || visaId <= 0) {
+            throw new IllegalArgumentException("Visa ID must be a positive number");
+        }
+
+       List<Comment> comments = commentRepository.findByVisaIdOrderByCreatedAtDesc(visaId);
+       if(comments.isEmpty() && !visaRepository.existsById(visaId)) {
+           throw new ResourceNotFoundException("Visa case not found with id: " + visaId);
+       }
+
+       return comments.stream()
+               .map(commentMapper::toDTO)
+               .toList();
+    }
+}

src/main/java/org/example/visacasemanagementsystem/exception/GlobalExceptionHandler.java

@@ -18,9 +18,16 @@ public String handleUnauthorizedException(UnauthorizedException exception) {
     }
 
     @ResponseStatus(value = HttpStatus.NOT_FOUND)
-    @ExceptionHandler(EntityNotFoundException.class)
+    @ExceptionHandler({EntityNotFoundException.class, ResourceNotFoundException.class})
     @ResponseBody
-    public String handleNotFoundException(EntityNotFoundException exception) {
+    public String handleNotFoundException(RuntimeException exception) {
         return exception.getMessage();
     }
+
+    @ResponseStatus(value = HttpStatus.BAD_REQUEST)
+    @ExceptionHandler(IllegalArgumentException.class)
+    @ResponseBody
+    public String handleIllegalArgumentException(IllegalArgumentException exception) {
+        return "Invalid Request: " + exception.getMessage();
+    }
 }

src/main/java/org/example/visacasemanagementsystem/exception/ResourceNotFoundException.java

@@ -0,0 +1,7 @@
+package org.example.visacasemanagementsystem.exception;
+
+public class ResourceNotFoundException extends RuntimeException {
+    public ResourceNotFoundException(String message) {
+        super(message);
+    }
+}