import { useState } from 'react'

/**
 * This custom React hook is used to save information to local storage as a map of key-value pairs.
 * 
 * @category Custom Hooks
 * 
 * @param {string} key The key of the information to be saved.
 * @param {*} initialValue The value of the information to be saved.
 * @returns {*} Stored value for the given key.
 */
const useLocalStorage = (key, initialValue) => {
  // State to store our value
  // Pass initial state function to useState so logic is only executed once
  const [storedValue, setStoredValue] = useState(() => {
    try {
      // Get from local storage by key
      const item = window.localStorage.getItem(key)
      // Parse stored json or if none return initialValue
      return item ? JSON.parse(item) : initialValue
    } catch (error) {
      // If error also return initialValue
      console.log(error)
      return initialValue
    }
  })

  // Return a wrapped version of useState's setter function that ...
  // ... persists the new value to localStorage.
  const setValue = (value) => {
    try {
      // Allow value to be a function so we have same API as useState
      const valueToStore =
        value instanceof Function ? value(storedValue) : value
      // Save state
      setStoredValue(valueToStore)
      // Save to local storage
      window.localStorage.setItem(key, JSON.stringify(valueToStore))
    } catch (error) {
      // A more advanced implementation would handle the error case
      console.log(error)
    }
  }
  return [storedValue, setValue]
}

export default useLocalStorage;