// From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys
if (!Object.keys) {
  Object.keys = (function () {
    var hasOwnProperty = Object.prototype.hasOwnProperty,
        hasDontEnumBug = !({toString: null}).propertyIsEnumerable('toString'),
        dontEnums = [
          'toString',
          'toLocaleString',
          'valueOf',
          'hasOwnProperty',
          'isPrototypeOf',
          'propertyIsEnumerable',
          'constructor'
        ],
        dontEnumsLength = dontEnums.length;

    return function (obj) {
      if (typeof obj !== 'object' && typeof obj !== 'function' || obj === null) throw new TypeError('Object.keys called on non-object');

      var result = [];

      for (var prop in obj) {
        if (hasOwnProperty.call(obj, prop)) result.push(prop);
      }

      if (hasDontEnumBug) {
        for (var i=0; i < dontEnumsLength; i++) {
          if (hasOwnProperty.call(obj, dontEnums[i])) result.push(dontEnums[i]);
        }
      }
      return result;
    };
  })();
}

// From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter
if (!Array.prototype.filter)
{
  Array.prototype.filter = function(fun /*, thisp */)
  {
    "use strict";

    if (this == null)
      throw new TypeError();

    var t = Object(this);
    var len = t.length >>> 0;
    if (typeof fun != "function")
      throw new TypeError();

    var res = [];
    var thisp = arguments[1];
    for (var i = 0; i < len; i++)
    {
      if (i in t)
      {
        var val = t[i]; // in case fun mutates this
        if (fun.call(thisp, val, i, t))
          res.push(val);
      }
    }

    return res;
  };
}

// From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/Trim
if (!String.prototype.trim) {
  String.prototype.trim = function () {
    return this.replace(/^\s+|\s+$/g, '');
  };
}

// From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach
if (!Array.prototype.forEach)
{
  Array.prototype.forEach = function(fun /*, thisArg */)
  {
    "use strict";

    if (this === void 0 || this === null)
      throw new TypeError();

    var t = Object(this);
    var len = t.length >>> 0;
    if (typeof fun !== "function")
      throw new TypeError();

    var thisArg = arguments.length >= 2 ? arguments[1] : void 0;
    for (var i = 0; i < len; i++)
    {
      if (i in t)
        fun.call(thisArg, t[i], i, t);
    }
  };
}

// Production steps of ECMA-262, Edition 5, 15.4.4.19
// Reference: http://es5.github.com/#x15.4.4.19
if (!Array.prototype.map) {
  Array.prototype.map = function(callback, thisArg) {

    var T, A, k;

    if (this == null) {
      throw new TypeError(" this is null or not defined");
    }

    // 1. Let O be the result of calling ToObject passing the |this| value as the argument.
    var O = Object(this);

    // 2. Let lenValue be the result of calling the Get internal method of O with the argument "length".
    // 3. Let len be ToUint32(lenValue).
    var len = O.length >>> 0;

    // 4. If IsCallable(callback) is false, throw a TypeError exception.
    // See: http://es5.github.com/#x9.11
    if (typeof callback !== "function") {
      throw new TypeError(callback + " is not a function");
    }

    // 5. If thisArg was supplied, let T be thisArg; else let T be undefined.
    if (thisArg) {
      T = thisArg;
    }

    // 6. Let A be a new array created as if by the expression new Array(len) where Array is
    // the standard built-in constructor with that name and len is the value of len.
    A = new Array(len);

    // 7. Let k be 0
    k = 0;

    // 8. Repeat, while k < len
    while(k < len) {

      var kValue, mappedValue;

      // a. Let Pk be ToString(k).
      //   This is implicit for LHS operands of the in operator
      // b. Let kPresent be the result of calling the HasProperty internal method of O with argument Pk.
      //   This step can be combined with c
      // c. If kPresent is true, then
      if (k in O) {

        // i. Let kValue be the result of calling the Get internal method of O with argument Pk.
        kValue = O[ k ];

        // ii. Let mappedValue be the result of calling the Call internal method of callback
        // with T as the this value and argument list containing kValue, k, and O.
        mappedValue = callback.call(T, kValue, k, O);

        // iii. Call the DefineOwnProperty internal method of A with arguments
        // Pk, Property Descriptor {Value: mappedValue, : true, Enumerable: true, Configurable: true},
        // and false.

        // In browsers that support Object.defineProperty, use the following:
        // Object.defineProperty(A, Pk, { value: mappedValue, writable: true, enumerable: true, configurable: true });

        // For best browser support, use the following:
        A[ k ] = mappedValue;
      }
      // d. Increase k by 1.
      k++;
    }

    // 9. return A
    return A;
  };
}

// From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf
if (!Array.prototype.indexOf) {
  Array.prototype.indexOf = function (searchElement, fromIndex) {
    if ( this === undefined || this === null ) {
      throw new TypeError( '"this" is null or not defined' );
    }

    var length = this.length >>> 0; // Hack to convert object.length to a UInt32

    fromIndex = +fromIndex || 0;

    if (Math.abs(fromIndex) === Infinity) {
      fromIndex = 0;
    }

    if (fromIndex < 0) {
      fromIndex += length;
      if (fromIndex < 0) {
        fromIndex = 0;
      }
    }

    for (;fromIndex < length; fromIndex++) {
      if (this[fromIndex] === searchElement) {
        return fromIndex;
      }
    }

    return -1;
  };
}
// Based on https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/isArray

if (! Array.isArray) {
    Array.isArray = function(obj) {
        return Object.prototype.toString.call(obj) === "[object Array]";
    };
}

// https://github.com/ttaubert/node-arraybuffer-slice
// (c) 2013 Tim Taubert <tim@timtaubert.de>
// arraybuffer-slice may be freely distributed under the MIT license.

"use strict";

if (typeof ArrayBuffer !== 'undefined' && !ArrayBuffer.prototype.slice) {
  ArrayBuffer.prototype.slice = function (begin, end) {
    begin = (begin|0) || 0;
    var num = this.byteLength;
    end = end === (void 0) ? num : (end|0);

    // Handle negative values.
    if (begin < 0) begin += num;
    if (end < 0) end += num;

    if (num === 0 || begin >= num || begin >= end) {
      return new ArrayBuffer(0);
    }

    var length = Math.min(num - begin, end - begin);
    var target = new ArrayBuffer(length);
    var targetArray = new Uint8Array(target);
    targetArray.set(new Uint8Array(this, begin, length));
    return target;
  };
}
