TimeCache.ts

import dayjs from "dayjs";

const PREFIX = "Tcache-";

export class TimeCache<T> {
  private name: string;

  /** Unix timestamp of when the cache should expire */
  private expiry: number;

  /**
   * @param name The name of the cache. Must be unique
   * @param lifetime The number of seconds the cache should live for before being invalidated
   */
  constructor(
    name: string,
    lifetime: number,
    options?: { includeSearch?: boolean },
  ) {
    if (options?.includeSearch || options?.includeSearch === undefined) {
      const url = new URL(name);
      this.name = url.protocol + url.host + url.pathname;
    } else {
      this.name = name;
    }
    this.expiry = dayjs().add(lifetime, "seconds").unix();
  }

  /** Will return the cached value, or null if expired, or undefined if the cache item doesn't exist. */
  get(): T | null | undefined {
    const cache = localStorage.getItem(PREFIX + this.name);

    if (cache === null) {
      return undefined;
    }

    const parsed = JSON.parse(cache);

    // If expired, return null
    if (dayjs().unix() > parsed.expiry) {
      return null;
    }

    return parsed.data;
  }

  delete(): void {
    return localStorage.removeItem(PREFIX + this.name);
  }

  store(value: any) {
    localStorage.setItem(
      PREFIX + this.name,
      JSON.stringify({ data: value, expiry: this.expiry }),
    );
  }
}