예외 처리 핸들러

// 커스텀 예외
public class ResourceNotFoundException extends RuntimeException {
    public ResourceNotFoundException(String message) { super(message); }
}

// 에러 응답 형식
@Getter @AllArgsConstructor
public class ErrorResponse {
    private int status;
    private String error;
    private String message;
    private LocalDateTime timestamp = LocalDateTime.now();
}

// 전역 예외 핸들러
@RestControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(ResourceNotFoundException.class)
    public ResponseEntity<ErrorResponse> handleNotFound(ResourceNotFoundException e) {
        return ResponseEntity.status(404)
            .body(new ErrorResponse(404, "Not Found", e.getMessage(), LocalDateTime.now()));
    }

    @ExceptionHandler(IllegalArgumentException.class)
    public ResponseEntity<ErrorResponse> handleBadRequest(IllegalArgumentException e) {
        return ResponseEntity.status(400)
            .body(new ErrorResponse(400, "Bad Request", e.getMessage(), LocalDateTime.now()));
    }

    @ExceptionHandler(Exception.class)
    public ResponseEntity<ErrorResponse> handleGeneral(Exception e) {
        return ResponseEntity.status(500)
            .body(new ErrorResponse(500, "Internal Server Error", "서버 오류", LocalDateTime.now()));
    }
}