package model

import (
	"database/sql/driver"
	"errors"
	"fmt"
	"gorm.io/gorm"
	"strings"
	"time"
)

type Model struct {
	CreatedAt LocalTime `gorm:"column:created_at;type:datetime;comment:创建时间" json:"created_at"`
	UpdatedAt LocalTime `gorm:"column:updated_at;type:datetime;comment:修改时间" json:"updated_at"`
}

// LocalTime 自定义数据类型
type LocalTime time.Time

func (t *LocalTime) UnmarshalJSON(data []byte) error {
	if string(data) == "null" {
		return nil
	}
	var err error
	// 前端接收的时间字符串
	str := string(data)
	// 去除接收的str收尾多余的"
	timeStr := strings.Trim(str, "\"")
	t1, err := time.Parse("2006-01-02 15:04:05", timeStr)
	*t = LocalTime(t1)
	return err
}

func (t LocalTime) MarshalJSON() ([]byte, error) {
	formatted := fmt.Sprintf("\"%v\"", time.Time(t).Format("2006-01-02 15:04:05"))
	return []byte(formatted), nil
}

func (t LocalTime) Value() (driver.Value, error) {
	// MyTime 转换成 time.Time 类型
	tTime := time.Time(t)
	return tTime.Format("2006-01-02 15:04:05"), nil
}

func (t *LocalTime) Scan(v interface{}) error {
	switch vt := v.(type) {
	case time.Time:
		// 字符串转成 time.Time 类型
		*t = LocalTime(vt)
	default:
		return errors.New("类型处理错误")
	}
	return nil
}

func (t *LocalTime) String() string {
	return fmt.Sprintf("hhh:%s", time.Time(*t).String())
}

func (t *LocalTime) IsEmpty() bool {
	return time.Time(*t).IsZero()
}

func (m *Model) BeforeUpdate(tx *gorm.DB) (err error) {
	m.UpdatedAt = LocalTime(time.Now())
	tx.Statement.SetColumn("UpdatedAt", m.UpdatedAt)

	return nil
}

func Paginate(page, pageSize int) func(db *gorm.DB) *gorm.DB {
	return func(db *gorm.DB) *gorm.DB {
		if page <= 0 {
			page = 1
		}

		switch {
		case pageSize > 100:
			pageSize = 100
		case pageSize <= 0:
			pageSize = 10
		}

		offset := (page - 1) * pageSize
		return db.Offset(offset).Limit(pageSize)
	}
}