/**
 * Lo-Dash 2.4.1 (Custom Build) <http://lodash.com/>
 * Build: `lodash modularize underscore exports="node" -o ./underscore/`
 * 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 createCallback = require('../functions/createCallback'),
    forEach = require('./forEach'),
    forOwn = require('../objects/forOwn');

/**
 * Retrieves the maximum value of a collection. If the collection is empty or
 * falsey `-Infinity` is returned. If a callback is provided it will be executed
 * for each value in the collection to generate the criterion by which the value
 * is ranked. The callback is bound to `thisArg` and invoked with three
 * arguments; (value, index, collection).
 *
 * If a property name is provided for `callback` the created "_.pluck" style
 * callback will return the property value of the given element.
 *
 * If an object is provided for `callback` the created "_.where" style callback
 * will return `true` for elements that have the properties of the given object,
 * else `false`.
 *
 * @static
 * @memberOf _
 * @category Collections
 * @param {Array|Object|string} collection The collection to iterate over.
 * @param {Function|Object|string} [callback=identity] The function called
 *  per iteration. If a property name or object is provided it will be used
 *  to create a "_.pluck" or "_.where" style callback, respectively.
 * @param {*} [thisArg] The `this` binding of `callback`.
 * @returns {*} Returns the maximum value.
 * @example
 *
 * _.max([4, 2, 8, 6]);
 * // => 8
 *
 * var characters = [
 *   { 'name': 'barney', 'age': 36 },
 *   { 'name': 'fred',   'age': 40 }
 * ];
 *
 * _.max(characters, function(chr) { return chr.age; });
 * // => { 'name': 'fred', 'age': 40 };
 *
 * // using "_.pluck" callback shorthand
 * _.max(characters, 'age');
 * // => { 'name': 'fred', 'age': 40 };
 */
function max(collection, callback, thisArg) {
  var computed = -Infinity,
      result = computed;

  // allows working with functions like `_.map` without using
  // their `index` argument as a callback
  if (typeof callback != 'function' && thisArg && thisArg[callback] === collection) {
    callback = null;
  }
  var index = -1,
      length = collection ? collection.length : 0;

  if (callback == null && typeof length == 'number') {
    while (++index < length) {
      var value = collection[index];
      if (value > result) {
        result = value;
      }
    }
  } else {
    callback = createCallback(callback, thisArg, 3);

    forEach(collection, function(value, index, collection) {
      var current = callback(value, index, collection);
      if (current > computed) {
        computed = current;
        result = value;
      }
    });
  }
  return result;
}

module.exports = max;
