lifeto-shop/src/state/storage.ts

import { AsyncStorage, AsyncStringStorage, SyncStorage, SyncStringStorage } from "jotai/vanilla/utils/atomWithStorage"
import superjson from 'superjson'

const isPromiseLike = (x: unknown): x is PromiseLike<unknown> =>
  typeof (x as any)?.then === 'function'

type Unsubscribe = () => void

type Subscribe<Value> = (
  key: string,
  callback: (value: Value) => void,
  initialValue: Value,
) => Unsubscribe | undefined

type StringSubscribe = (
  key: string,
  callback: (value: string | null) => void,
) => Unsubscribe | undefined

export function createSuperjsonStorage<Value>(): SyncStorage<Value>
export function createSuperjsonStorage<Value>(
  getStringStorage: () =>
    | AsyncStringStorage
    | SyncStringStorage
    | undefined = () => {
    try {
      return window.localStorage
    } catch (e) {
      if (import.meta.env?.MODE !== 'production') {
        if (typeof window !== 'undefined') {
          console.warn(e)
        }
      }
      return undefined
    }
  },
): AsyncStorage<Value> | SyncStorage<Value> {
  let lastStr: string | undefined
  let lastValue: Value

  const storage: AsyncStorage<Value> | SyncStorage<Value> = {
    getItem: (key, initialValue) => {
      const parse = (str: string | null) => {
        str = str || ''
        if (lastStr !== str) {
          try {
            lastValue = superjson.parse(str)
          } catch {
            return initialValue
          }
          lastStr = str
        }
        return lastValue
      }
      const str = getStringStorage()?.getItem(key) ?? null
      if (isPromiseLike(str)) {
        return str.then(parse) as never
      }
      return parse(str) as never
    },
    setItem: (key, newValue) =>
      getStringStorage()?.setItem(
        key,
        superjson.stringify(newValue),
      ),
    removeItem: (key) => getStringStorage()?.removeItem(key),
  }

  const createHandleSubscribe =
    (subscriber: StringSubscribe): Subscribe<Value> =>
    (key, callback, initialValue) =>
      subscriber(key, (v) => {
        let newValue: Value
        try {
          newValue = superjson.parse(v || '')
        } catch {
          newValue = initialValue
        }
        callback(newValue)
      })

  let subscriber: StringSubscribe | undefined
  try {
    subscriber = getStringStorage()?.subscribe
  } catch {
    // ignore
  }
  if (
    !subscriber &&
    typeof window !== 'undefined' &&
    typeof window.addEventListener === 'function' &&
    window.Storage
  ) {
    subscriber = (key, callback) => {
      if (!(getStringStorage() instanceof window.Storage)) {
        return () => {}
      }
      const storageEventCallback = (e: StorageEvent) => {
        if (e.storageArea === getStringStorage() && e.key === key) {
          callback(e.newValue)
        }
      }
      window.addEventListener('storage', storageEventCallback)
      return () => {
        window.removeEventListener('storage', storageEventCallback)
      }
    }
  }

  if (subscriber) {
    storage.subscribe = createHandleSubscribe(subscriber)
  }
  return storage
}

export const superJsonStorage = createSuperjsonStorage()