import * as vscode from 'vscode';
import { ItemModel } from './items/item_model';

export class DataProvider implements vscode.TreeDataProvider<ItemModel | vscode.TreeItem> {
  private eventEmitter = new vscode.EventEmitter<void>();

  private children: ItemModel[] = [];

  onDidChangeTreeData = this.eventEmitter.event;

  // constructor() {
  //   extensionState.onDidChangeValid(this.refresh, this);
  // }

  async getChildren(el: ItemModel | undefined): Promise<ItemModel[] | vscode.TreeItem[]> {
    if (el) return el.getChildren();

    this.children.forEach(ch => ch.dispose());
    this.children = [];
    return this.children;
  }

  // eslint-disable-next-line class-methods-use-this
  getParent(): null {
    return null;
  }

  // eslint-disable-next-line class-methods-use-this
  getTreeItem(item: vscode.TreeItem | ItemModel) {
    if (item instanceof ItemModel) return item.getTreeItem();
    return item;
  }

  refresh(): void {
    this.eventEmitter.fire();
  }
}