///
/// Copyright 2015-2026 Micro Focus or one of its affiliates.
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
///      http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///

import { ElementRef, Renderer2 } from '@angular/core';
import { FocusIndicatorOriginService } from './focus-indicator-origin.service';

/**
 * When working with component host elements
 * we cannot apply directives, eg. FocusIndicatorOriginDirective
 * however we may still want the functionality to be applied to
 * the host element. This class allows the host element to become
 * a focus indicator origin
 */
export class FocusIndicatorOrigin {
  /** Store all event handlers */
  private readonly _handlers: (() => void)[] = [];

  /** Click events can be trigged by both mouse and keyboard so we want to ensure we emit the correct origin */
  private _isMouseEvent: boolean;

  constructor(
    private readonly _focusIndicatorOrigin: FocusIndicatorOriginService,
    elementRef: ElementRef,
    renderer: Renderer2
  ) {
    // add event handlers
    this._handlers = [
      renderer.listen(elementRef.nativeElement, 'click', () => this.onClick()),
      renderer.listen(elementRef.nativeElement, 'mousedown', () => this.onMouseDown()),
      renderer.listen(elementRef.nativeElement, 'keydown', () => this.onKeydown()),
    ];
  }

  /** Remove all event handlers */
  destroy(): void {
    this._handlers.forEach(handler => handler());
  }

  onMouseDown(): void {
    this._isMouseEvent = true;
  }

  onClick(): void {
    // if the click was triggered after a mousedown event then it is a keyboard event
    this._focusIndicatorOrigin.setOrigin(this._isMouseEvent ? 'mouse' : 'keyboard');

    // reset the mouse event flag
    this._isMouseEvent = false;
  }

  onKeydown(): void {
    this._isMouseEvent = false;
    this._focusIndicatorOrigin.setOrigin('keyboard');
  }
}