import { Injectable } from '@angular/core';
import { Subject, BehaviorSubject } from 'rxjs';

interface ViewItems {
  items: Array<string>;
}
interface viewContainer {
  [viewGroupIdId: string]: ViewItems;
}

@Injectable()
export class ViewChangeService {
  /**默认视图切换分组名称 */
  private readonly defaultId:string = 'default';
  //当前显示视图
  currentViewType:any = {};

  /**contents */
  viewContainers:viewContainer = {};

  changeCurrentViewId: BehaviorSubject<any> = new BehaviorSubject<any>(null);

  constructor() { }
  /**
   * 添加视图项目
   * @param itemId 
   * @param viewContainerId 
   */
  addViewItem(itemId:string, viewContainerId = this.defaultId){
    if(this.viewContainers[viewContainerId]){
      if (this.hasElement(itemId, viewContainerId)) {
        return;
      }
      else{
        this.viewContainers[viewContainerId].items.push(itemId);
      }
    }
    else{
      this.viewContainers[viewContainerId] = {
        items: []
      } as ViewItems;
      this.viewContainers[viewContainerId].items.push(itemId);
    }
  }

  removeViewItem(itemId, viewContainerId = this.defaultId){
    delete this.viewContainers[viewContainerId];
    if(this.viewContainers && this.viewContainers[viewContainerId]){
      const items = this.viewContainers[viewContainerId].items.filter(el=>{
        return el !== itemId;
      })
      if (!items.length) {
        delete this.viewContainers[viewContainerId];
        return;
      }
      this.viewContainers[viewContainerId].items = items;
    }
  }

  /**存储currentpageid */
  updateCurrentViewId(type:string, viewContainerId = this.defaultId){
    this.currentViewType[viewContainerId] = type ;
    let changeView={};
    changeView[viewContainerId]=type;
    this.changeCurrentViewId.next(changeView);
  }

  getChangeCurrentViewId(){
    return this.changeCurrentViewId;
  }

  private hasElement(itemId: string, groupId: string): boolean {
    return this.viewContainers[groupId].items.some((item): boolean => item === itemId);
  }
}