/**
 * @license
 * FOURBURNER CONFIDENTIAL
 * Unpublished Copyright (C) 2021 FourBurner Technologies, Inc. All Rights Reserved.
 *
 * NOTICE: All information contained herein is, and remains the property of FOURBURNER TECHNOLOGIES,
 * INC. The intellectual and technical concepts contained herein are proprietary to FOURBURNER
 * TECHNOLOGIES, INC. and may be covered by U.S. and Foreign Patents, patents in process, and are
 * protected by trade secret or copyright law. Dissemination of this information or reproduction of
 * this material is strictly forbidden unless prior written permission is obtained from FOURBURNER
 * TECHNOLOGIES, INC. Access to the source code contained herein is hereby forbidden to anyone
 * except current FOURBURNER TECHNOLOGIES, INC. employees, managers or contractors who have executed
 * Confidentiality and Non-disclosure agreements explicitly covering such access.
 *
 * The copyright notice above does not evidence any actual or intended publication or disclosure of
 * this source code, which includes information that is confidential and/or proprietary, and is a
 * trade secret, of FOURBURNER TECHNOLOGIES, INC. ANY REPRODUCTION, MODIFICATION, DISTRIBUTION,
 * PUBLIC PERFORMANCE, OR PUBLIC DISPLAY OF OR THROUGH USE OF THIS SOURCE CODE WITHOUT THE EXPRESS
 * WRITTEN CONSENT OF FOURBURNER TECHNOLOGIES, INC. IS STRICTLY PROHIBITED, AND IN VIOLATION OF
 * APPLICABLE LAWS AND INTERNATIONAL TREATIES. THE RECEIPT OR POSSESSION OF THIS SOURCE CODE AND/OR
 * RELATED INFORMATION DOES NOT CONVEY OR IMPLY ANY RIGHTS TO REPRODUCE, DISCLOSE OR DISTRIBUTE ITS
 * CONTENTS, OR TO MANUFACTURE, USE, OR SELL ANYTHING THAT IT MAY DESCRIBE, IN WHOLE OR IN PART.
 */

import {Attribute, Directive, ElementRef, InjectionToken, Input} from '@angular/core';

let nextUniqueId = 0;

/**
 * Injection token that can be used to reference instances of `TWNDError`. It serves as
 * alternative token to the actual `TWNDError` class which could cause unnecessary
 * retention of the class and its directive metadata.
 */
export const TWND_ERROR = new InjectionToken<TWNDError>('TWNDError');

/**
 * Single error message to be shown underneath the form field.
 */
@Directive({
  selector : 'twnd-error',
  host : {
          'class' : 'twnd-error',
          '[attr.id]' : 'id',
          'aria-atomic' : 'true',
          },
  providers : [ {provide : TWND_ERROR,                      useExisting : TWNDError                            }
    ],
})
export class TWNDError
{
  @Input() id: string = `twnd-error-${nextUniqueId++}`;

  constructor(@Attribute('aria-live') ariaLive: string, elementRef: ElementRef)
  {
    // If no aria-live value is set add 'polite' as a default. This is preferred over setting
    // role='alert' so that screen readers do not interrupt the current task to read this aloud.
    if (!ariaLive) {
      elementRef.nativeElement.setAttribute('aria-live', 'polite');
    }
  }
}