1var arrayEach = require('./_arrayEach'),
2    arrayPush = require('./_arrayPush'),
3    baseFunctions = require('./_baseFunctions'),
4    copyArray = require('./_copyArray'),
5    isFunction = require('./isFunction'),
6    isObject = require('./isObject'),
7    keys = require('./keys');
8
9/**
10 * Adds all own enumerable string keyed function properties of a source
11 * object to the destination object. If `object` is a function, then methods
12 * are added to its prototype as well.
13 *
14 * **Note:** Use `_.runInContext` to create a pristine `lodash` function to
15 * avoid conflicts caused by modifying the original.
16 *
17 * @static
18 * @since 0.1.0
19 * @memberOf _
20 * @category Util
21 * @param {Function|Object} [object=lodash] The destination object.
22 * @param {Object} source The object of functions to add.
23 * @param {Object} [options={}] The options object.
24 * @param {boolean} [options.chain=true] Specify whether mixins are chainable.
25 * @returns {Function|Object} Returns `object`.
26 * @example
27 *
28 * function vowels(string) {
29 *   return _.filter(string, function(v) {
30 *     return /[aeiou]/i.test(v);
31 *   });
32 * }
33 *
34 * _.mixin({ 'vowels': vowels });
35 * _.vowels('fred');
36 * // => ['e']
37 *
38 * _('fred').vowels().value();
39 * // => ['e']
40 *
41 * _.mixin({ 'vowels': vowels }, { 'chain': false });
42 * _('fred').vowels();
43 * // => ['e']
44 */
45function mixin(object, source, options) {
46  var props = keys(source),
47      methodNames = baseFunctions(source, props);
48
49  var chain = !(isObject(options) && 'chain' in options) || !!options.chain,
50      isFunc = isFunction(object);
51
52  arrayEach(methodNames, function(methodName) {
53    var func = source[methodName];
54    object[methodName] = func;
55    if (isFunc) {
56      object.prototype[methodName] = function() {
57        var chainAll = this.__chain__;
58        if (chain || chainAll) {
59          var result = object(this.__wrapped__),
60              actions = result.__actions__ = copyArray(this.__actions__);
61
62          actions.push({ 'func': func, 'args': arguments, 'thisArg': object });
63          result.__chain__ = chainAll;
64          return result;
65        }
66        return func.apply(object, arrayPush([this.value()], arguments));
67      };
68    }
69  });
70
71  return object;
72}
73
74module.exports = mixin;
75