Compass/web/hooks/use-persistent-local-state.ts

import {safeJsonParse} from 'common/util/json'
import {useEffect} from 'react'
import {safeLocalStorage} from 'web/lib/util/local'
import {isFunction} from 'web/hooks/use-persistent-in-memory-state'
import {useStateCheckEquality} from 'web/hooks/use-state-check-equality'
import {useEvent} from 'web/hooks/use-event'
import {useIsClient} from 'web/hooks/use-is-client'

export const usePersistentLocalState = <T>(initialValue: T, key: string) => {
  // Note: use a version (like "-v1") in the key to increment after backwards-incompatible changes
  const isClient = useIsClient()
  const [state, setState] = useStateCheckEquality<T>(
    (isClient && safeJsonParse(safeLocalStorage?.getItem(key))) || initialValue,
  )
  const saveState = useEvent((newState: T | ((prevState: T) => T)) => {
    setState((prevState: T) => {
      const updatedState = isFunction(newState) ? newState(prevState) : newState
      safeLocalStorage?.setItem(key, JSON.stringify(updatedState))
      return updatedState
    })
  })

  useEffect(() => {
    if (safeLocalStorage) {
      const storedJson = safeJsonParse(safeLocalStorage.getItem(key))
      const storedValue = storedJson ?? initialValue
      if (storedJson === null && initialValue === undefined) return
      saveState(storedValue as T)
    }
  }, [key])

  return [state, saveState] as const
}