/**
 * lodash 4.0.4 (Custom Build) <https://lodash.com/>
 * Build: `lodash modularize exports="npm" -o ./`
 * Copyright jQuery Foundation and other contributors <https://jquery.org/>
 * Released under MIT license <https://lodash.com/license>
 * Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
 * Copyright Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 */
var keysIn = require('lodash.keysin');

/** Used for built-in method references. */
var objectProto = Object.prototype;

/** Used to check objects for own properties. */
var hasOwnProperty = objectProto.hasOwnProperty;

/**
 * Assigns `value` to `key` of `object` if the existing value is not equivalent
 * using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
 * for equality comparisons.
 *
 * @private
 * @param {Object} object The object to modify.
 * @param {string} key The key of the property to assign.
 * @param {*} value The value to assign.
 */
function assignValue(object, key, value) {
  var objValue = object[key];
  if (!(hasOwnProperty.call(object, key) && eq(objValue, value)) ||
      (value === undefined && !(key in object))) {
    object[key] = value;
  }
}

/**
 * Copies properties of `source` to `object`.
 *
 * @private
 * @param {Object} source The object to copy properties from.
 * @param {Array} props The property identifiers to copy.
 * @param {Object} [object={}] The object to copy properties to.
 * @param {Function} [customizer] The function to customize copied values.
 * @returns {Object} Returns `object`.
 */
function copyObject(source, props, object, customizer) {
  object || (object = {});

  var index = -1,
      length = props.length;

  while (++index < length) {
    var key = props[index];

    var newValue = customizer
      ? customizer(object[key], source[key], key, object, source)
      : source[key];

    assignValue(object, key, newValue);
  }
  return object;
}

/**
 * Performs a
 * [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
 * comparison between two values to determine if they are equivalent.
 *
 * @static
 * @memberOf _
 * @since 4.0.0
 * @category Lang
 * @param {*} value The value to compare.
 * @param {*} other The other value to compare.
 * @returns {boolean} Returns `true` if the values are equivalent, else `false`.
 * @example
 *
 * var object = { 'user': 'fred' };
 * var other = { 'user': 'fred' };
 *
 * _.eq(object, object);
 * // => true
 *
 * _.eq(object, other);
 * // => false
 *
 * _.eq('a', 'a');
 * // => true
 *
 * _.eq('a', Object('a'));
 * // => false
 *
 * _.eq(NaN, NaN);
 * // => true
 */
function eq(value, other) {
  return value === other || (value !== value && other !== other);
}

/**
 * Converts `value` to a plain object flattening inherited enumerable string
 * keyed properties of `value` to own properties of the plain object.
 *
 * @static
 * @memberOf _
 * @since 3.0.0
 * @category Lang
 * @param {*} value The value to convert.
 * @returns {Object} Returns the converted plain object.
 * @example
 *
 * function Foo() {
 *   this.b = 2;
 * }
 *
 * Foo.prototype.c = 3;
 *
 * _.assign({ 'a': 1 }, new Foo);
 * // => { 'a': 1, 'b': 2 }
 *
 * _.assign({ 'a': 1 }, _.toPlainObject(new Foo));
 * // => { 'a': 1, 'b': 2, 'c': 3 }
 */
function toPlainObject(value) {
  return copyObject(value, keysIn(value));
}

module.exports = toPlainObject;
