conveyal/modeify

/**
 * dependencies.
 */

var unserialize = require('unserialize');
var each = require('each');
var storage;

/**
 * Safari throws when a user
 * blocks access to cookies / localstorage.
 */

try {
  storage = window.localStorage;
} catch (e) {
  storage = null;
}

/**
 * Expose `store`
 */

module.exports = store;

/**
 * Store the given `key`, `val`.
 *
 * @param {String|Object} key
 * @param {Mixed} value
 * @return {Mixed}
 * @api public
 */

function store(key, value){
  var length = arguments.length;
  if (0 == length) return all();
  if (2 <= length) return set(key, value);
  if (1 != length) return;
  if (null == key) return storage.clear();
  if ('string' == typeof key) return get(key);
  if ('object' == typeof key) return each(key, set);
}

/**
 * supported flag.
 */

store.supported = !! storage;

/**
 * Set `key` to `val`.
 *
 * @param {String} key
 * @param {Mixed} val
 */

function set(key, val){
  return null == val
    ? storage.removeItem(key)
    : storage.setItem(key, JSON.stringify(val));
}

/**
 * Get `key`.
 *
 * @param {String} key
 * @return {Mixed}
 */

function get(key){
  return unserialize(storage.getItem(key));
}

/**
 * Get all.
 *
 * @return {Object}
 */

function all(){
  var len = storage.length;
  var ret = {};
  var key;

  while (0 <= --len) {
    key = storage.key(len);
    ret[key] = get(key);
  }

  return ret;
}