import { Directive, Input, HostListener } from '@angular/core';
import { KeySet, ForbiddenInput } from './classes';
import { invalidInputError } from './exceptions';

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

export class AllowedDirective {

  @Input('ang-allowed') allowedKeys: KeySet;

  @HostListener('keydown', ['$event'])
  whileTyping(e: KeyboardEvent){

    if(!(this.allowedKeys instanceof KeySet)){
      invalidInputError();
    }

    const forbidden = !this.allowedKeys.has(e.key)

    if(forbidden){
      !e.repeat && this.allowedKeys.forbiddenInput.next(new ForbiddenInput(e));
      return false;
    }
    
  }

}