import { Directive } from '@angular/core';
import {
  AbstractControl,
  NG_VALIDATORS,
  Validators,
  ValidatorFn
} from '@angular/forms';

export function multiEmailValidator(regexPattern: RegExp): ValidatorFn {
  return (control: AbstractControl): { [key: string]: any } => {
    const emails = control.value.split(',');
    const valid = emails.find((email: string) => {
      email = email.trim();
      const test = regexPattern.test(email);
      return test === false;
    });
    return valid ? { multiEmail: { emails } } : null;
  };
}

@Directive({
  selector: '[bomMultiEmail]',
  providers: [
    {
      provide: NG_VALIDATORS,
      useExisting: MultiEmailValidatorDirective,
      multi: true
    }
  ]
})
export class MultiEmailValidatorDirective {
  private valFn = Validators.nullValidator;

  validate(control: AbstractControl): { [key: string]: any } {
    return this.valFn(control);
  }
}