DeviceManager/src/lib/storage.ts

import type {Writable} from "svelte/store"
import {writable} from "svelte/store"
import {browser} from "$app/environment"

export function persistentWritable<T>(key: string, value: T, condition?: () => boolean): Writable<T> {
  if (browser) {
    const persistedValue = localStorage.getItem(key)
    const store = persistedValue !== null ? writable(JSON.parse(persistedValue)) : writable(value)
    store.subscribe(value => {
      if (!condition || condition()) localStorage.setItem(key, JSON.stringify(value))
    })

    return store
  } else {
    return writable(value)
  }
}