package com.kobe.schoolmanagement.dto.response;

import com.kobe.schoolmanagement.domain.entity.Major;
import lombok.Builder;
import lombok.Getter;

@Getter
@Builder
public class MajorInfoDto {

    private Long id;
    private String majorNumber;
    private String name;

    /**
     * Major 엔티티를 MajorInfoDto로 변환
     * 
     * @param major 변환할 Major 엔티티
     * @return MajorInfoDto 객체
     */
    public static MajorInfoDto fromEntity(Major major) {
        return MajorInfoDto.builder()
                .id(major.getId())
                .majorNumber(major.getMajorNumber())
                .name(major.getName())
                .build();
    }
}

@Getter
@Builder
public class StudentResponseDto {
    private Long id;
    private String studentId;
    private String name;
    private String major;  // ❌ 단순 문자열
    
    // ...
}

package com.kobe.schoolmanagement.dto.response;

import com.fasterxml.jackson.annotation.JsonProperty;
import com.kobe.schoolmanagement.domain.entity.Student;
import lombok.Builder;
import lombok.Getter;

@Getter
@Builder
public class StudentResponseDto {

    private String name;
    private int admissionYear;

    @JsonProperty("major_info")  // ✅ JSON 키를 스네이크 케이스로 변환
    private MajorInfoDto majorInfo;

    /**
     * Student 엔티티를 StudentResponseDto로 변환
     * 
     * @param student 변환할 Student 엔티티
     * @return StudentResponseDto 객체
     */
    public static StudentResponseDto fromEntity(Student student) {
        return StudentResponseDto.builder()
                .name(student.getName())
                .admissionYear(student.getAdmissionYear())
                .majorInfo(MajorInfoDto.fromEntity(student.getMajor()))  // ✅ 중첩 변환
                .build();
    }
}

// 향후 추가 정보가 필요할 때
@JsonProperty("major_info")
private MajorInfoDto majorInfo;

@JsonProperty("course_info")  // ✅ 동일한 패턴으로 확장
private CourseInfoDto courseInfo;

@PostMapping
public ResponseEntity<StudentResponseDto> createStudent(
    @RequestBody StudentRequestDto request
) {
    Student student = studentService.createStudent(request);
    
    // fromEntity 메서드로 간단히 변환
    return ResponseEntity.ok(
        StudentResponseDto.fromEntity(student)
    );
}