HORIZON PROJECT

var arrayEach = require('./_arrayEach'),

    arrayPush = require('./_arrayPush'),

    baseFunctions = require('./_baseFunctions'),

    copyArray = require('./_copyArray'),

    isFunction = require('./isFunction'),

    isObject = require('./isObject'),

    keys = require('./keys');

/**

 * Adds all own enumerable string keyed function properties of a source

 * object to the destination object. If `object` is a function, then methods

 * are added to its prototype as well.

 *

 * **Note:** Use `_.runInContext` to create a pristine `lodash` function to

 * avoid conflicts caused by modifying the original.

 *

 * @static

 * @since 0.1.0

 * @memberOf _

 * @category Util

 * @param {Function|Object} [object=lodash] The destination object.

 * @param {Object} source The object of functions to add.

 * @param {Object} [options={}] The options object.

 * @param {boolean} [options.chain=true] Specify whether mixins are chainable.

 * @returns {Function|Object} Returns `object`.

 * @example

 *

 * function vowels(string) {

 *   return _.filter(string, function(v) {

 *     return /[aeiou]/i.test(v);

 *   });

 * }

 *

 * _.mixin({ 'vowels': vowels });

 * _.vowels('fred');

 * // => ['e']

 *

 * _('fred').vowels().value();

 * // => ['e']

 *

 * _.mixin({ 'vowels': vowels }, { 'chain': false });

 * _('fred').vowels();

 * // => ['e']

 */

function mixin(object, source, options) {

  var props = keys(source),

      methodNames = baseFunctions(source, props);

  var chain = !(isObject(options) && 'chain' in options) || !!options.chain,

      isFunc = isFunction(object);

  arrayEach(methodNames, function(methodName) {

    var func = source[methodName];

    object[methodName] = func;

    if (isFunc) {

      object.prototype[methodName] = function() {

        var chainAll = this.__chain__;

        if (chain || chainAll) {

          var result = object(this.__wrapped__),

              actions = result.__actions__ = copyArray(this.__actions__);

          actions.push({ 'func': func, 'args': arguments, 'thisArg': object });

          result.__chain__ = chainAll;

          return result;

        }

        return func.apply(object, arrayPush([this.value()], arguments));

      };

    }

  });

  return object;

}

module.exports = mixin;