package com.learn.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import jakarta.persistence.*;
import jakarta.validation.constraints.*;
import java.time.LocalDateTime;

/**
 * 学生实体 —— 同时兼容 JPA 和 MyBatis-Plus
 *
 * 对比观察：
 *   @Entity           (JPA)   ↔  @TableName        (MP)   —— 声明这是一个表映射类
 *   @Table            (JPA)   ↔  @TableName        (MP)   —— 指定对应的表名
 *   @Id               (JPA)   ↔  @TableId          (MP)   —— 主键
 *   @GeneratedValue    (JPA)   ↔  @TableId(type=...) (MP)   —— 主键生成策略
 *   @Column            (JPA)   ↔  @TableField       (MP)   —— 字段映射
 *
 * 注意：JPA 和 MP 的注解可以共存于同一个实体类上，互不冲突。
 *       因为它们分属不同的框架，各自读取各自的注解。
 */
@Entity
@Table(name = "student")
@TableName("student")            // MP 注解：指定表名
public class Student {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)  // JPA：数据库自增
    @TableId(type = IdType.AUTO)                         // MP：数据库自增
    private Long id;

    @NotBlank(message = "姓名不能为空")
    @Size(min = 1, max = 20, message = "姓名长度 1-20")
    @Column(name = "name", length = 20, nullable = false)
    @TableField("name")          // MP 注解（当字段名=列名时可省略，此处显式写出便于学习）
    private String name;

    @Min(value = 1, message = "年龄必须大于 0")
    @Max(value = 150, message = "年龄必须小于 150")
    @Column(name = "age", nullable = false)
    @TableField("age")
    private int age;

    @NotBlank(message = "邮箱不能为空")
    @Email(message = "邮箱格式不正确")
    @Column(name = "email", length = 50, nullable = false)
    @TableField("email")
    private String email;

    @Min(value = 0, message = "成绩不能为负数")
    @Max(value = 100, message = "成绩不能超过 100")
    @Column(name = "score", nullable = false)
    @TableField("score")
    private int score;

    // ---- 审计字段（由数据库自动管理）----
    @Column(name = "create_time", insertable = false, updatable = false)
    @TableField("create_time")
    private LocalDateTime createTime;

    @Column(name = "update_time", insertable = false, updatable = false)
    @TableField("update_time")
    private LocalDateTime updateTime;

    // ==================== 构造方法 ====================

    public Student() {}

    public Student(Long id, String name, int age, String email, int score) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.email = email;
        this.score = score;
    }

    // ==================== Getter / Setter ====================

    public Long getId() { return id; }
    public void setId(Long id) { this.id = id; }

    public String getName() { return name; }
    public void setName(String name) { this.name = name; }

    public int getAge() { return age; }
    public void setAge(int age) { this.age = age; }

    public String getEmail() { return email; }
    public void setEmail(String email) { this.email = email; }

    public int getScore() { return score; }
    public void setScore(int score) { this.score = score; }

    public LocalDateTime getCreateTime() { return createTime; }
    public void setCreateTime(LocalDateTime createTime) { this.createTime = createTime; }

    public LocalDateTime getUpdateTime() { return updateTime; }
    public void setUpdateTime(LocalDateTime updateTime) { this.updateTime = updateTime; }

    @Override
    public String toString() {
        return String.format("Student{id=%d, name='%s', age=%d, email='%s', score=%d}",
                id, name, age, email, score);
    }
}