import { emitter } from '../util/emitter';
import { VscodeListener } from '../listeners/vscode';
import { VSCodeInterface, EditorType } from '../models/ext_models';

export class EditorFlow {

  private static instance: EditorFlow;

  public static selectedType: EditorType = EditorType.VSCODE;
  private vscodeListener: VscodeListener | undefined;

  static getInstance(type: EditorType, iface: VSCodeInterface): EditorFlow {
    if (!EditorFlow.instance) {
      EditorFlow.instance = new EditorFlow(type, iface);
    }

    return EditorFlow.instance;
  }

  private constructor(type: EditorType, iface: VSCodeInterface) {
    EditorFlow.selectedType = type;
    if (EditorFlow.selectedType === EditorType.VSCODE) {
      this.vscodeListener = new VscodeListener(iface);
    } else {
      throw new Error(`${EditorFlow.selectedType} is currently not supported`);
    }
  }

  public getEmitter() {
    return emitter;
  }

  public getSubscriptions() {
    if (EditorFlow.selectedType === EditorType.VSCODE && this.vscodeListener) {
      return this.vscodeListener.getSubscriptions();
    }
    return [];
  }

  public dispose() {
    if (EditorFlow.selectedType === EditorType.VSCODE && this.vscodeListener) {
      this.vscodeListener.dispose();
    }
  }
}