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

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

export class ForbiddenDirective {

  @Input('ang-forbidden') forbiddenKeys: KeySet;
  
  @HostListener('keydown', ['$event'])
  whileTyping(e: KeyboardEvent){
    
    if(!(this.forbiddenKeys instanceof KeySet)){
      invalidInputError();
    }

    const forbidden = this.forbiddenKeys.has(e.key);

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

}