///
/// 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 { FocusOrigin } from '@angular/cdk/a11y';
import { DOWN_ARROW, ENTER, LEFT_ARROW, RIGHT_ARROW, SPACE, UP_ARROW } from '@angular/cdk/keycodes';
import {
  Directive,
  ElementRef,
  EventEmitter,
  HostListener,
  inject,
  Input,
  OnDestroy,
  Output,
} from '@angular/core';
import { FocusIndicator, FocusIndicatorService } from '../accessibility/index';

@Directive({
  selector: '[uxMenuNavigationToggle]',
  exportAs: 'uxMenuNavigationToggle',
})
export class MenuNavigationToggleDirective implements OnDestroy {
  readonly elementRef = inject(ElementRef);

  readonly focusIndicatorService = inject(FocusIndicatorService);

  /** Define if the menu is open */
  @Input()
  get menuOpen(): boolean {
    return this._menuOpen;
  }

  set menuOpen(value: boolean) {
    this._menuOpen = value;
    this.menuOpenChange.emit(value);
  }

  /** Define the position the menu appears relative to the button */
  @Input() menuPosition: 'top' | 'right' | 'bottom' | 'left' = 'bottom';

  /** Emit when the menu open state changes */
  @Output() menuOpenChange = new EventEmitter<boolean>();

  /** Emits whenever a key that opens the menu is pressed */
  @Output() keyEnter = new EventEmitter<void>();

  /** Store the current menu open state */
  private _menuOpen: boolean;

  /** Store a reference to the focus indicator */
  private readonly _focusIndicator: FocusIndicator;

  constructor() {
    this._focusIndicator = this.focusIndicatorService.monitor(this.elementRef.nativeElement);
  }

  ngOnDestroy(): void {
    this._focusIndicator.destroy();
  }

  focus(origin?: FocusOrigin): void {
    this._focusIndicator.focus(origin);
  }

  @HostListener('keydown', ['$event'])
  keydownHandler(event: KeyboardEvent): void {
    if (this.isKeyMatch(event.which)) {
      // Open the menu
      this.menuOpen = true;

      // Allow the menu to init, then send the event to give it focus
      setTimeout(() => this.keyEnter.emit());

      event.preventDefault();
      event.stopPropagation();
    }
  }

  private isKeyMatch(key: number): boolean {
    switch (key) {
      case ENTER:
      case SPACE:
        return true;

      case UP_ARROW:
        return this.menuPosition === 'top';

      case DOWN_ARROW:
        return this.menuPosition === 'bottom';

      case LEFT_ARROW:
        return this.menuPosition === 'left';

      case RIGHT_ARROW:
        return this.menuPosition === 'right';
    }

    return false;
  }
}