///
/// 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 { Injectable } from '@angular/core';
import { BehaviorSubject } from 'rxjs';
import { TabComponent } from './tab/tab.component';

@Injectable()
export class TabsetService {
  /** Store the list of tabs */
  tabs: ReadonlyArray<TabComponent> = [];

  activeTab$ = new BehaviorSubject<TabComponent>(null);

  /** Store the manual state */
  manual: boolean = false;

  /** Update the array of tabs - required to preserve order */
  update(tabs: TabComponent[]): void {
    this.tabs = [...tabs];
  }

  /** Select a tab (from user input) */
  select(tab: TabComponent): void {
    if (tab.disabled) {
      return;
    }

    if (this.manual) {
      // In manual mode, emit the activated/deactivated events.
      // The application is responsible for updating the active state on each tab, which will then update the UI.
      this.tabs.forEach(_tab => (_tab === tab ? _tab.activate() : _tab.deactivate()));
    } else {
      this.activeTab$.next(tab);
    }
  }

  /** Set tab active state */
  setTabActive(tab: TabComponent): void {
    if (!tab.disabled) {
      this.activeTab$.next(tab);
    }
  }

  /** Determine if there is a selected tab */
  isTabActive(): boolean {
    return this.activeTab$.getValue() !== null;
  }

  /** Select the first non-disabled tab */
  selectFirstTab(): void {
    // find the index of the first non-disabled tab
    const tab = this.tabs.find(_tab => !_tab.disabled);

    if (tab) {
      this.select(tab);
    }
  }
}