AO3 author+tags quick-search 1.1

// ==UserScript==
// @name            AO3 author+tags quick-search
// @version     1.1
// @include     https://archiveofourown.org/works*
// ==/UserScript==

/* Adds extra links to the tags section at the top of an AO3 work page, redirecting user to any use of same tags by the same author.
* ie. a quick way to find out if the writer of the great fic you just read has written anything else for the same fandom/pairing/trope/etc.

* If printCounts is set to 'true', code will also calculate and display the number of uses of each tag in the fandom/relationship/character sections,
* though this will also make the links take longer to load, as code must pre-load each link individually. To limit load, I have not implemented this for freeform or other tags.

* Author-based search links are a bit of a hack, so the search tag WON'T be selected in the tags menu on the right.
* I've added a subheading to identify the tag instead.

*/

var quickSearchText = "*"; // text for new links - change this if you want something other than an * You can put <sup>TEXT</sup> to make it superscript
var printCounts = true;          // setting this to false will prevent script for printing tag counts, which may decrease loading times and server load

var loc = location.href;

var href="https://archiveofourown.org/works?utf8=%E2%9C%93&commit=Sort+and+Filter&work_search[relationship_names]=";
var workPage="https://archiveofourown.org/works/";
var scriptTag = "&greasemonkey"; //tag to flag that we've clicked an author quicktag link

if (loc.includes(workPage)) {
  // Story page, add extra links user-based search to each tag

  var h3=document.body.getElementsByClassName("byline heading");
  var authors=h3.item(0).getElementsByTagName('a');
  authors=parseAuthors(authors);

  var allTags=document.body.getElementsByClassName("work meta group").item(0);
  var dds = allTags.getElementsByTagName('dd');

  var links = dds.item(1).getElementsByTagName('a');

  for (var j=0; j<dds.length; j++) {
    var tags = dds.item(j);
    if (getTagType(tags) == "stats") break;

    links = tags.getElementsByTagName('a');
    for (var i=links.length-1; i>=0; i--) {

      for (var a=0; a<authors.length; a++) {

        var author=authors[a];
        var tag = getTag(links.item(i).href);
        var newHref = buildSearch(tag);

        var text = quickSearchText;
        var newlink=document.createElement('span');
        if (printCounts && printCountFor(tags)) {
          var count = getNumFics(newHref);
          if (count>1) {
            text = "<b><sup>(" + count.toString() + ")<sup></b>";
          }
          else {
            text = "<sup>(1)<sup></b>";
          }
        }
        newlink.innerHTML = " <a href=\"" + newHref + "\">" + text + "</a>";

        links.item(i).parentNode.appendChild(newlink);
      }
    }
  }
}


else if (loc.includes(scriptTag)) {
  // Quicktags search results page, add title to show which tag is in use

  var sTag = getBetween("work_search[relationship_names]=", loc, "&user_id=");
  var main = document.getElementById("main");
  var heading = main.getElementsByClassName("heading").item(0);

  sTag = unformatTag(sTag);
  sTag = " Author QuickSearch: " + sTag;
  var span=document.createElement('h3');
  span.innerHTML = sTag;

  heading.parentNode.insertBefore(span, heading.nextSibling);
}

function getTagType(element) {
  var name = element.className;
  name = name.replace(" tags", "");
  return name;
}

//Limit tag counts to fandom, relationship and character tags
function printCountFor(element) {
  var name = getTagType(element);
  var types = ["fandom","relationship","character"];
  for (var i=0; i<types.length; i++) {
    if (types[i] == name) return true;
  }
  return false;

}


//Retrieve page as javascript object
function getSourceAsDOM(url)
{
    var xmlhttp=new XMLHttpRequest();
    xmlhttp.open("GET",url,false);
    xmlhttp.send();
    var parser=new DOMParser();
    return parser.parseFromString(xmlhttp.responseText,"text/html");
}

//Counts results of author+tag search
function getNumFics(url) {
  var results = getSourceAsDOM(url);
  var works = results.getElementsByClassName("work index group")[0];

  if (works.children.length < 20) {
      return works.children.length;
  }

  var h=results.getElementsByTagName("h2");
  if (h.length>0) {
    h=h[0];
      var text = h.textContent;
    if (text.includes(" of ")) {
      text = getBetween(" of ", text, " Works");
      return text; //could convert this into an integer, but not much point
    }
  }
    return 20;
}

function parseAuthors(links) {
  var authors = [""];
  for (var i=0; i<links.length; i++) {
    var text = links.item(i).toString();
        authors[i] = getBetween("/users/", text, "/pseuds");
  }
  return authors;
}



function getBetween(tag1, str, tag2) {
    var ret = str.split(tag1);
  if (ret.length<2) return "";
  ret=ret[1];
    ret = ret.split(tag2);
  if (ret.length<1) return "";
  ret = ret[0];
  return ret;
}

//Format tag to pass to search
function getTag(href){
  var tag = getBetween("/tags/", href, "/works");
  tag = replaceAll(tag, "*s*","%2F");
  tag = replaceAll(tag, "*d*",".");
  tag = replaceAll(tag, "%20","+");
  return tag;
}

// Format tag from href for display in title
function unformatTag(tag) {
  tag = replaceAll(tag, "*s*","/");
  tag = replaceAll(tag, "*a*","&");
  tag = replaceAll(tag, "*d*",".");
  tag = replaceAll(tag, "%2F","/");
  tag = replaceAll(tag, "+", " ");
  tag = replaceAll(tag, "%7C", "|");
  tag = replaceAll(tag, "%22", "\"");
  return tag;
}

function replaceAll(str, search, replacement) {
    return str.split(search).join(replacement);
}

function buildSearch(tag){
    var href="https://archiveofourown.org/works?utf8=%E2%9C%93&commit=Sort+and+Filter&work_search[relationship_names]="
  href+=tag + "&user_id=" + author + scriptTag;
  return href;
}