import { Directive, Input } from '@angular/core';
import { Validator, AbstractControl, NG_VALIDATORS, ValidatorFn } from '@angular/forms';
import { emailValidator } from '../components/register/register.component';

@Directive({
  selector: '[appEmail]',
  /**
   * Angular recognizes the directive's role in the validation process because the directive
   * registers itself with the NG_VALIDATORS provider,
   */
  providers: [{provide: NG_VALIDATORS, useExisting: EmailDirective, multi: true}]
})
export class EmailDirective implements Validator{
  @Input('appEmail') appEmail: string;

  //Auto Generated to be Implemented
  validate(c: AbstractControl): { [key: string]: any; } {
    if(this.appEmail){
      return emailValidator(new RegExp(this.appEmail))(c)
    }
    else{
      return null;
    }
  }

  registerOnValidatorChange?(fn: () => void): void {
    return null;
  }
  constructor() { }
}
// validates the email as per the Regex and returns
// null --> Valid email format
// emailInvalid --> Invalid email format
export function emailValidator(nameRe: RegExp): ValidatorFn {
  return (control: AbstractControl): {[key: string]: any} => {
    let email=control.value
    const regResult = nameRe.test(email);
    return regResult ? null: {'emailInvalid': {value:email}};
  };
}