/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at <http://mozilla.org/MPL/2.0/>. */

// @flow

/**
 * When Flow 0.29 is released (very soon), we can use this Record type
 * instead of the builtin immutable.js Record type. This is better
 * because all the fields are actually typed, unlike the builtin one.
 * This depends on a performance fix that will go out in 0.29 though;
 * @module utils/makeRecord
 */

import * as I from "immutable";

/**
 * @memberof utils/makeRecord
 * @static
 */
export type Record<T: Object> = {
  equals<A>(other: A): boolean,
  get<A>(key: $Keys<T>, notSetValue?: any): A,
  getIn<A>(keyPath: Array<any>, notSetValue?: any): A,
  hasIn<A>(keyPath: Array<any>): boolean,
  set<A>(key: $Keys<T>, value: A): Record<T>,
  setIn(keyPath: Array<any>, ...iterables: Array<any>): Record<T>,
  merge(values: $Shape<T>): Record<T>,
  mergeIn(keyPath: Array<any>, ...iterables: Array<any>): Record<T>,
  delete<A>(key: $Keys<T>, value: A): Record<T>,
  deleteIn(keyPath: Array<any>, ...iterables: Array<any>): Record<T>,
  update<A>(key: $Keys<T>, value: A): Record<T>,
  updateIn(keyPath: Array<any>, ...iterables: Array<any>): Record<T>,
  remove<A>(key: $Keys<T>): Record<T>,
  toJS(): T
} & T;

/**
 * Make an immutable record type
 *
 * @param spec - the keys and their default values
 * @return a state record factory function
 * @memberof utils/makeRecord
 * @static
 */
function makeRecord<T>(spec: T & Object): (init: $Shape<T>) => Record<T> {
  return I.Record(spec);
}

export default makeRecord;