package service

import (
  zhongwen "github.com/go-playground/locales/zh"
  ut "github.com/go-playground/universal-translator"
  "github.com/go-playground/validator/v10"
  zh_translations "github.com/go-playground/validator/v10/translations/zh"
  "reflect"
  "strings"
)

var Validate *validator.Validate
var trans ut.Translator

func init() {
  zh := zhongwen.New()
  uni := ut.New(zh, zh)
  trans, _ = uni.GetTranslator("zh")

  Validate = validator.New()
  Validate.RegisterTagNameFunc(func(field reflect.StructField) string {
    label := field.Tag.Get("label")
    if label == "" {
      return field.Name
    }
    return label
  })
  zh_translations.RegisterDefaultTranslations(Validate, trans)
}
func Translate(errs validator.ValidationErrors) string {
  var errList []string
  for _, e := range errs {
    // can translate each error one at a time.
    errList = append(errList,e.Translate(trans))
  }
  return strings.Join(errList,"|")
}

type ArticlesPost struct {
  Title      string `json:"title" validate:"required,max=32,min=4" label:"標題"`
}
var ap ArticlePost
err = service.Validate.Struct(ap)
if err!=nil{
 errStr =Translate(errs)
 fmt.Sprintln(errStr)
}

// TagNameFunc allows for adding of a custom tag name parser
type TagNameFunc func(field reflect.StructField) string
// SetTagName allows for changing of the default tag name of 'validate'
func (v *Validate) SetTagName(name string) {
  v.tagName = name
}

// RegisterTagNameFunc registers a function to get alternate names for StructFields.
//
// eg. to use the names which have been specified for JSON representations of structs, rather than normal Go field names:
//
//  validate.RegisterTagNameFunc(func(fld reflect.StructField) string {
//    name := strings.SplitN(fld.Tag.Get("json"), ",", 2)[0]
//    if name == "-" {
//      return ""
//    }
//    return name
//  })
func (v *Validate) RegisterTagNameFunc(fn TagNameFunc) {
  v.tagNameFunc = fn
  v.hasTagNameFunc = true
}