package binding

import (
	"git.sxidc.com/go-framework/baize/infrastructure/logger"
	"git.sxidc.com/service-supports/fserr"
	"reflect"
)

type DTO interface{}

func Field[T any](dto DTO, fieldName string) T {
	var zero T

	fieldValue, err := getDTOFieldValue(dto, fieldName)
	if err != nil {
		logger.GetInstance().Error(err)
		return zero
	}

	if !fieldValue.IsValid() {
		err := fserr.New("dto字段" + fieldName + "无法赋值")
		logger.GetInstance().Error(err)
		return zero
	}

	retValue, ok := fieldValue.Interface().(T)
	if !ok {
		err := fserr.New("dto字段" + fieldName + "无法转换类型")
		logger.GetInstance().Error(err)
		return zero
	}

	return retValue
}

func ToConcreteDTO[T DTO](object DTO) (T, error) {
	concrete, ok := object.(T)
	if !ok {
		var zero T
		return zero, fserr.New("DTO转化失败")
	}

	return concrete, nil
}

func getDTOFieldValue(dto DTO, fieldName string) (*reflect.Value, error) {
	dtoType := reflect.TypeOf(dto)

	if dtoType.Kind() != reflect.Ptr {
		return nil, fserr.New("dto必须是结构指针类型")
	}

	if dtoType.Kind() == reflect.Ptr && dtoType.Elem().Kind() != reflect.Struct {
		return nil, fserr.New("dto必须是结构指针类型")
	}

	dtoValue := reflect.ValueOf(dto)
	if !dtoValue.IsValid() {
		return nil, fserr.New("dto为nil")
	}

	fieldValue := dtoValue.Elem().FieldByName(fieldName)

	return &fieldValue, nil
}