import { Directive, ElementRef, HostListener, Injector, Input } from '@angular/core';
import { Format } from './classes';
import { noCallbackProvidedError, isNotFunctionError } from './exceptions';


@Directive({
  selector: '[ang-format]',
})

export class FormatDirective extends Format {


  @Input('ang-format') formatFn: Function;
  isFunction: boolean;
  notProvided: boolean;

  constructor(ref: ElementRef, injector: Injector){
    super(ref,injector);
  }

  @HostListener('blur')
  onblur(){
    if(this.notProvided)noCallbackProvidedError();
    if(!this.isFunction)isNotFunctionError(this.formatFn);

    super.blurHandler(this.formatFn);
  }

  ngOnInit(){
    this.isFunction = typeof this.formatFn === 'function';
    this.notProvided = typeof this.formatFn === 'undefined';
  }


}