import {Directive, Input} from '@angular/core';
import {AbstractControl, NG_VALIDATORS} from '@angular/forms';
import {ValidationService} from './services/validation.service';

@Directive({
  selector: '[appValidate]',
  providers: [{provide: NG_VALIDATORS, useExisting: ValidateDirective, multi: true}]
})
export class ValidateDirective {
  @Input('appValidate') method: string;
  @Input('appValidateArgs') args: Array<any>;

  constructor(
    private validation: ValidationService
  ) { }

  validate(control: AbstractControl): {[key: string]: any} | null {
    let ok;
    let error;
    if (this.args) {
      ({ok, error} = this.validation[this.method](control.value, ...this.args));
    }
    else {
      ({ok, error} = this.validation[this.method](control.value));
    }
    return ok ? null : { failure: error };
  }
}