import { BadRequestException, PipeTransform } from '@nestjs/common';
import { isDefined, isEnum } from 'class-validator';

export class ValidateEnumPipe
  implements PipeTransform<string, Promise<any> | string | string[]>
{
  constructor(private enumEntity: any) {}

  transform(value: string): Promise<any> | string | string[] {
    const validateEnum = (enumValue) => {
      if (isDefined(enumValue)) {
        if (isEnum(enumValue, this.enumEntity)) {
          return this.enumEntity[enumValue];
        } else {
          const errorMessage = `the value ${enumValue} is not valid. See the acceptable values: ${Object.keys(
            this.enumEntity,
          ).map((key) => this.enumEntity[key])}`;
          throw new BadRequestException(errorMessage);
        }
      } else {
        return value;
      }
    };

    if (Array.isArray(value)) {
      return value.map((item) => validateEnum(item));
    } else {
      return validateEnum(value);
    }
  }
}