import Operator from "../Operator";
import TabPresenter from "../../presenters/TabPresenter";

export default class SelectTabPrevOperator implements Operator {
  constructor(
    private readonly tabPresenter: TabPresenter,
    private readonly count: number
  ) {}

  async run(): Promise<void> {
    const tabs = await this.tabPresenter.getAll();
    if (tabs.length < 2) {
      return;
    }
    const tab = tabs.find((t) => t.active);
    if (!tab) {
      return;
    }
    const select = (tab.index - this.count + tabs.length) % tabs.length;
    return this.tabPresenter.select(tabs[select].id as number);
  }
}