createStorage.ts

import { createObserver } from "./createObserver.ts";

const createMemoryStorage = (): Storage => {
  const store = new Map<string, string>();
  return {
    get length() {
      return store.size;
    },
    clear() {
      store.clear();
    },
    getItem(key: string) {
      return store.has(key) ? store.get(key)! : null;
    },
    key(index: number) {
      return Array.from(store.keys())[index] ?? null;
    },
    removeItem(key: string) {
      store.delete(key);
    },
    setItem(key: string, value: string) {
      store.set(key, value);
    },
  } as Storage;
};

export const createStorage = <T>(
  key: string,
  storage: Storage = typeof window !== "undefined" ? window.localStorage : createMemoryStorage(),
) => {
  let data: T | null = JSON.parse(storage.getItem(key) ?? "null");
  const { subscribe, notify } = createObserver();

  const get = () => data;

  const set = (value: T) => {
    try {
      data = value;
      storage.setItem(key, JSON.stringify(data));
      notify();
    } catch (error) {
      console.error(`Error setting storage item for key "${key}":`, error);
    }
  };

  const reset = () => {
    try {
      data = null;
      storage.removeItem(key);
      notify();
    } catch (error) {
      console.error(`Error removing storage item for key "${key}":`, error);
    }
  };

  return { get, set, reset, subscribe };
};