///
/// 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 { FocusableOption, FocusOrigin } from '@angular/cdk/a11y';
import {
  Directive,
  ElementRef,
  HostListener,
  inject,
  Input,
  OnDestroy,
  OnInit,
  Renderer2,
} from '@angular/core';
import { Subject } from 'rxjs';
import { takeUntil } from 'rxjs/operators';
import { FocusIndicator, FocusIndicatorService } from '../../../directives/accessibility/index';
import { MenuItemType } from '../menu-item/menu-item-type.enum';
import { MenuComponent } from '../menu/menu.component';

@Directive({ selector: '[uxMenuTabbableItem]' })
export class MenuTabbableItemDirective implements OnInit, OnDestroy, FocusableOption {
  protected readonly _menu = inject(MenuComponent);

  protected readonly _elementRef = inject<ElementRef<HTMLElement>>(ElementRef);

  protected readonly _focusIndicatorService = inject(FocusIndicatorService);

  protected readonly _renderer = inject(Renderer2);

  /** Define if this item is disabled or not */
  @Input() disabled: boolean = false;

  /** Indicate the type of the menu item */
  readonly type: MenuItemType = MenuItemType.Default;

  /** Store the focus indicator instance */
  protected focusIndicator: FocusIndicator;

  /** Automatically unsubscribe when directive is destroyed */
  protected _onDestroy$ = new Subject<void>();

  ngOnInit(): void {
    // register this item in the MenuComponent
    this._menu._addItem(this);

    // we only want to show the focus indicator whenever the keyboard is used
    this.focusIndicator = this._focusIndicatorService.monitor(this._elementRef.nativeElement);

    // subscribe to active item changes
    this._menu._activeItem$
      .pipe(takeUntil(this._onDestroy$))
      .subscribe(item => this.setTabIndex(item === this));
  }

  ngOnDestroy(): void {
    this._onDestroy$.next();
    this._onDestroy$.complete();
    this.focusIndicator.destroy();
  }

  /** Focus this item with a given origin */
  focus(origin: FocusOrigin): void {
    this.focusIndicator.focus(origin);
  }

  /** This function is built into the CDK manager to allow jumping to items based on text content */
  getLabel(): string {
    return this._elementRef.nativeElement.textContent.trim();
  }

  /** Forward any keyboard events to the MenuComponent for accessibility */
  @HostListener('keydown', ['$event'])
  _onKeydown(event: KeyboardEvent): void {
    this._menu._onKeydown(event);
  }

  /** Update the tab index on this item */
  protected setTabIndex(isTabbable: boolean): void {
    this._renderer.setAttribute(
      this._elementRef.nativeElement,
      'tabindex',
      isTabbable ? '0' : '-1'
    );
  }
}