/**
 * @author songxiwen
 * @date 2020/08/17 15:41
 */

import { ArgumentMetadata, Injectable, PipeTransform } from '@nestjs/common';
import { validate } from 'class-validator';
import { plainToClass } from 'class-transformer';
import { ServerError } from '../error/server.error';

@Injectable()
export class ValidationPipe<T> implements PipeTransform<T> {
  async transform(value: T, { metatype }: ArgumentMetadata) {
    if (!metatype || !ValidationPipe.toValidate(metatype)) {
      return value;
    }
    const object = plainToClass(metatype, value);
    const errors = await validate(object);
    if (errors.length) {
      throw ServerError.code.ValidationFailed;
    }
    return value;
  }

  private static toValidate(metatype: Function): boolean {
    const types: Function[] = [String, Boolean, Number, Array, Object];
    return !types.includes(metatype);
  }
}