General URL Cleaner

// ==UserScript==
// @run-at document-start
// @name           General URL Cleaner
// @namespace
// @description    Cleans URL's from various popular sites. Also, makes sure the sites are using HTTPS.
// @include        *
// @grant   unsafeWindow
// @version        1.3.0
// ==/UserScript==

var bing = new RegExp(/^https?:\/\/www\.bing\.(.+?)\/search\?/);
var google = new RegExp(/^https?:\/\/(www|maps)\.google\.(.+?)\/(search|maps)\?/);
var googleInstant = new RegExp(/^https?:\/\/(www|maps)\.google\.(.+?)\/(search|maps)\?.*\#q\=/);
var youtube = new RegExp(/^https?:\/\/www\.youtube\.com\/watch/);
var ebay = new RegExp(/^https?:\/\/www\.ebay\.(.+?)\/itm/);
var amazon = new RegExp(/^https?:\/\/www\.amazon\.*\/gp\/product\//);
var newegg = new RegExp(/^http:\/\/www\.newegg\.(com|ca)\/Product\/Product\.aspx/);
var dealtime = new RegExp(/http:\/\/stat\.dealtime\.com\/DealFrame\/DealFrame\.cmp\?/);


// Clean the current page URL if it needs cleaning
var newPageUrl = cleanUrl(document.URL);
if (newPageUrl != document.URL) location.replace(newPageUrl);

// If the current page is a google search results page, removes redirection of the search results
// Code taken from https://greasyfork.org/en/scripts/5357-remove-google-results-redirect
if (google.test(newPageUrl)) {
    if(unsafeWindow.top == unsafeWindow.self){
        document.addEventListener('DOMNodeInserted',function(e){
            window.setTimeout(function(){
            var rl = document.querySelectorAll('a[onmousedown*="return rwt"]');
            for (var l=0;l<rl.length;l++)
                rl[l].removeAttribute('onmousedown');
            }, 250);}
        , false);
    }

    // Google Instant: if the search terms change, remove the extra stuff. Eg: "google.com/search?q=example1#q=example2" -> "google.com/search?q=example2"
    window.addEventListener('hashchange', function() {
        var newSearchString = String(document.URL.match(/\#.*/)).replace(/^\#/,"");
        var newSearchUrl = String(document.URL.replace(/search\?.*/,"search?" + newSearchString));
        location.replace(newSearchUrl);
    }, false);
}

// Waits until page has finished loading, then cleans links on the page
window.addEventListener('load', function() {
    console.time('Cleaning links took');
    var elems = document.getElementsByTagName('a');
    for (var i = 0; i < elems.length; i++) {
        var newurl = cleanUrl(elems[i]['href'])
        if (newurl != elems[i]['href']) {
            // console.log("Cleaned link: " + elems[i]['href'] + " -> " + newurl);
            elems[i]['href'] = newurl;
        }
    }
    console.timeEnd('Cleaning links took');
}, false);

// Main function for cleaning the url's
function cleanUrl(oldurl) {
    var parser = document.createElement('a');
    parser.href = oldurl;
    var newurl = oldurl;
    switch(true) {
        case google.test(oldurl):
            newurl = oldurl.replace("search?","search?&")
                           .replace(/\&(num|hl|safe|tbo|sclient|sourceid|spell|client|complete|as_qdr|um|sa|tab|authuser|rlz|cad|rct|ved|usg|site|source|oe|oq|sa|ei|ie|dpr|gs\_l|ved|tbas|sei|biw|bih)\=[^&]*/g,"")
                           .replace("search?&","search?");
            break;
        case bing.test(oldurl):
            newurl = oldurl.replace("search?","search?&")
                           .replace(/\&(go|qs|form|FORM|filt|pq|sc|sp|sk|qpvt)\=[^&]*/g,"")
                           .replace("search?&","search?");
            break;
        case youtube.test(oldurl):
            newurl = "https://www.youtube.com/watch?" + oldurl.match(/v\=[^&]*/);
            break;
        case ebay.test(oldurl):
            newurl = "https://" + parser.hostname + "/itm" + oldurl.match(/\/[0-9]{11,13}[^#?&\/]/);
            break;
        case amazon.test(oldurl):
            newurl = "https://" + parser.hostname + oldurl.match(/\/gp\/product\/[A-Z0-9]{10}/);
            break;
        case newegg.test(oldurl):
            newurl = "http://" + parser.hostname + oldurl.match(/\/Product\/Product\.aspx\?Item\=[^&]*/);
            break;
        case dealtime.test(oldurl):
            newurl = decodeURIComponent(oldurl.replace(/.*\&url\=/,"").replace(/(\%26|)\&linkin_id\=.*$/,"")).replace(/\&(url|partner)\=[^&]*/g,"");
            break;
        default:
            break;
    }
    if (/((\?|\&|)utm_(source|medium|campaign)\=[^&\/]*|\&amp\;)/g.test(newurl))
        newurl = newurl.replace(/((\?|\&|)utm_(source|medium|campaign)\=[^&]*|\&amp\;)/g,"");
    return newurl;
}