/**
 * Lo-Dash 2.4.1 (Custom Build) <http://lodash.com/>
 * Build: `lodash modularize modern exports="node" -o ./modern/`
 * Copyright 2012-2013 The Dojo Foundation <http://dojofoundation.org/>
 * Based on Underscore.js 1.5.2 <http://underscorejs.org/LICENSE>
 * Copyright 2009-2013 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 * Available under MIT license <http://lodash.com/license>
 */
var keys = require('./keys'),
    objectTypes = require('../internals/objectTypes');

/**
 * Assigns own enumerable properties of source object(s) to the destination
 * object for all destination properties that resolve to `undefined`. Once a
 * property is set, additional defaults of the same property will be ignored.
 *
 * @static
 * @memberOf _
 * @type Function
 * @category Objects
 * @param {Object} object The destination object.
 * @param {...Object} [source] The source objects.
 * @param- {Object} [guard] Allows working with `_.reduce` without using its
 *  `key` and `object` arguments as sources.
 * @returns {Object} Returns the destination object.
 * @example
 *
 * var object = { 'name': 'barney' };
 * _.defaults(object, { 'name': 'fred', 'employer': 'slate' });
 * // => { 'name': 'barney', 'employer': 'slate' }
 */
var defaults = function(object, source, guard) {
  var index, iterable = object, result = iterable;
  if (!iterable) return result;
  var args = arguments,
      argsIndex = 0,
      argsLength = typeof guard == 'number' ? 2 : args.length;
  while (++argsIndex < argsLength) {
    iterable = args[argsIndex];
    if (iterable && objectTypes[typeof iterable]) {
    var ownIndex = -1,
        ownProps = objectTypes[typeof iterable] && keys(iterable),
        length = ownProps ? ownProps.length : 0;

    while (++ownIndex < length) {
      index = ownProps[ownIndex];
      if (typeof result[index] == 'undefined') result[index] = iterable[index];
    }
    }
  }
  return result
};

module.exports = defaults;
