package main

import (
	"encoding/json"
	"fmt"
	"time"
)

// CustomTime 自定义时间类型
type CustomTime time.Time

const timeLayout = "2006-01-02 15:04:05"

func (t CustomTime) MarshalJSON() ([]byte, error) {
	return json.Marshal(time.Time(t).Format(timeLayout))
}

func (t *CustomTime) UnmarshalJSON(data []byte) error {
	var timeStr string
	if err := json.Unmarshal(data, &timeStr); err != nil {
		return err
	}
	val, err := time.Parse(timeLayout, timeStr)
	if err != nil {
		return err
	}
	*t = CustomTime(val)
	return nil
}

// Mobile 手机号脱敏
type Mobile string

func (m Mobile) MarshalJSON() ([]byte, error) {
	num := string(m)
	if len(num) == 11 {
		return json.Marshal(num[:3] + "****" + num[7:])
	}
	return json.Marshal(num)
}

// UserDTO 数据传输对象
type UserDTO struct {
	Name     string     `json:"name"`
	Phone    Mobile     `json:"phone"`
	CreateAt CustomTime `json:"create_at"`
}

func main() {
	dto := UserDTO{
		Name:     "bulma",
		Phone:    Mobile("10012345678"),
		CreateAt: CustomTime(time.Now()),
	}
	data, _ := json.MarshalIndent(dto, "", "  ")
	fmt.Println("\n=== 自定义序列化结果 ===")
	fmt.Println(string(data))
}