// ==UserScript==
// @name         Twitter direct link to original size
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  Automatically changes twitter images from direct links to maximum quality PNG
// @author       VoltSwitch
// @match        https://pbs.twimg.com/media/*
// @require      https://code.jquery.com/jquery-2.1.4.min.js
// ==/UserScript==
var lastPost;
var regEx = /name=.*/;
var regEx2 = /4096x4096$/;
var regEx3 = /format=jpg/;
var strPng = '=png'
var strOrig = '=4096x4096'
var updateInterval = 250;
var wrapImages = true;

function UrlExists(url, cb){
    jQuery.ajax({
        url:      url,
        dataType: 'text',
        type:     'GET',
        complete:  function(xhr){
            if(typeof cb === 'function')
            {
                cb.apply(this, [xhr.status])
            };
        }
    });
}

function replaceImageSrc() {
    var src1 = window.location.href;
    var src2 = src1;
    // If the src string matches our regex replace it to be a raw image
    if((src1.search(regEx) >= 0|| (src1.search(regEx3) >= 0))&& src1.search(regEx2) <= 0)
    {
        src2 = src1.replace(/=jpg/g, strPng);
        console.log(src2);
        src2 = src2.replace(/name.*/, "name"+strOrig);
        // If the new URL doesn't exist revert it
        console.log(src2);
        UrlExists(src2, function(status){
            if(status != 404){
                window.location.href = src2;
            }
            else {
                console.log("URL " + src2 + " does not exist, reverting...");
            }
        });
    }
}

(function() {
    'use strict';
    replaceImageSrc();
})();