package validate

import (
	"fmt"
	"reflect"

	"github.com/go-playground/validator/v10"
	"pkg.local/utils"
)

// ValidatorMessages 自定义错误消息
type ValidatorMessages map[string]string

// IValidator 业务结构体实现该接口
type IValidator interface {
	GetMessage() ValidatorMessages
}

var v *validator.Validate

func init() {
	v = validator.New()
}

// CopySameField 反射自动拷贝同名字段：src(proto入参) → dst(校验model结构体指针)
// src: proto message对象，传值in
// dst: model校验结构体指针 &model.AdminGroupValidator{}
func CopySameField(src interface{}, dst interface{}) {
	srcVal := reflect.ValueOf(src)
	dstVal := reflect.ValueOf(dst).Elem()

	// 如果src是指针，取element
	if srcVal.Kind() == reflect.Ptr {
		srcVal = srcVal.Elem()
	}

	for i := 0; i < srcVal.NumField(); i++ {
		srcField := srcVal.Field(i)
		fieldName := srcVal.Type().Field(i).Name

		// 查找dst中同名的字段
		dstField := dstVal.FieldByName(fieldName)
		if !dstField.IsValid() || !dstField.CanSet() {
			continue
		}
		// 类型相同才赋值
		if srcField.Type() == dstField.Type() {
			dstField.Set(srcField)
		}
	}
}

// ValidateStruct 校验，返回 *admin.Response
func ValidateStruct(obj IValidator) string {
	err := v.Struct(obj)
	if err == nil {
		return utils.StringEmpty
	}

	customMsg := obj.GetMessage()
	var errMsg string
	if ves, ok := err.(validator.ValidationErrors); ok {
		ve := ves[0]
		key := fmt.Sprintf("%s.%s", ve.Field(), ve.Tag())
		if msg, exist := customMsg[key]; exist {
			errMsg = msg
		} else {
			errMsg = fmt.Sprintf("%s校验失败:%s", ve.Field(), ve.Tag())
		}
	} else {
		errMsg = err.Error()
	}
	return errMsg
}

// ValidateFromProto 一步到位：自动拷贝proto同名字段 + 校验
// src: proto请求 in (*admin.XXXRequest)
// dst: model校验结构体实例指针 &model.AdminGroupValidator{}
func ValidateFromProto(src interface{}, dst IValidator) string {
	CopySameField(src, dst)
	return ValidateStruct(dst)
}