import browser from 'webextension-polyfill';

export class History {
  public static async clear(): Promise<void> {
    await browser.storage.local.remove('history');
  }

  public static async fromLocalStorage(): Promise<History> {
    const history = new History();

    const stored = await browser.storage.local.get({history: []});
    history.queue = stored.history as Queue.Item[];

    // Initialize all the non-JSON values since they are stringified when saved.
    for (const item of history.queue) {
      item.added = new Date(item.added);
    }

    return history;
  }

  public queue: Queue.Item[];

  private constructor() {
    this.queue = [];
  }

  public async clear(): Promise<void> {
    await History.clear();
  }

  public async insertItems(items: Queue.Item[]): Promise<void> {
    this.queue = this.queue.concat(items);

    for (const [index, item] of this.queue.entries()) {
      item.id = index;
    }

    await this.save();
  }

  public async save(): Promise<void> {
    await browser.storage.local.set({history: this.queue});
  }
}