///
/// 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 {
  Component,
  EventEmitter,
  HostBinding,
  inject,
  Input,
  OnDestroy,
  OnInit,
  Output,
} from '@angular/core';
import { Subject } from 'rxjs';
import { takeUntil } from 'rxjs/operators';
import { FocusIndicatorDirective } from '../../../directives/accessibility/focus-indicator/focus-indicator.directive';
import { AccordionService } from '../accordion.service';

let uniqueId: number = 1;

@Component({
  selector: 'ux-accordion-panel',
  templateUrl: './accordion-panel.component.html',
  host: {
    class: 'panel panel-default',
  },
  imports: [FocusIndicatorDirective],
})
export class AccordionPanelComponent implements OnInit, OnDestroy {
  readonly accordion = inject(AccordionService);

  @Input() panelId: string = `ux-accordion-panel-${uniqueId++}`;
  @Input() headingId: string = `${this.panelId}-heading`;

  @Input() disabled: boolean = false;
  @Input() heading: string;
  @Input() @HostBinding('class.panel-open') expanded: boolean = false;

  @Output() expandedChange = new EventEmitter<boolean>();

  private readonly _onDestroy = new Subject<void>();

  ngOnInit(): void {
    this.accordion.collapse.pipe(takeUntil(this._onDestroy)).subscribe(() => this.collapse());
  }

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

  toggle(): void {
    if (this.expanded) {
      this.collapse();
      return;
    }

    // check if we should collapse others
    if (this.accordion.collapseOthers) {
      this.accordion.collapseAll();
    }

    // store the new expanded state
    this.expand();
  }

  expand(): void {
    if (this.disabled === false && this.expanded === false) {
      this.expanded = true;
      this.expandedChange.next(true);
    }
  }

  collapse(): void {
    if (this.disabled === false && this.expanded === true) {
      this.expanded = false;
      this.expandedChange.next(false);
    }
  }
}