Better Board Menu

// ==UserScript==
// @name             Better Board Menu
// @namespace        dollars-bbs.org
// @author           Degritone
// @description      Makes the board menu stick to the screen and have drop-down arrows to expand sub-buards
// @match            *://*.dollars-bbs.org/*
// @grant            none
// ==/UserScript==

function work(loaded){
  if(!document.getElementById("boardmenu")){
    setTimeout(work,100,false);
    return;
  }
  if(!loaded){
    setTimeout(work,1000,true);
    return;
  }
  window.onscroll = ()=>document.getElementById("boardmenu").style.top=""+Math.max(189-window.scrollY,0)+"px";
  let boardmenu = document.getElementById("boardmenu");
  boardmenu.style.position = "fixed";
  boardmenu.style.top = ""+Math.max(189-window.scrollY,0)+"px";
  if(document.getElementById("posts"))
    document.getElementById("posts").style.marginLeft = "180px";
  if(document.getElementById("threadbox"))
    document.getElementById("threadbox").style.marginLeft = "180px";
  if(document.getElementById("contentarea"))
    document.getElementById("contentarea").style.marginLeft = "180px";
  if(document.getElementById("threads"))
    document.getElementById("threads").style.marginLeft = "180px";

  removeAllSubBoards(boardmenu);
  if(document.getElementById("testbutton"))
    removeAllSubBoards(boardmenu);

  let brs = boardmenu.getElementsByTagName("br");
  for(let i=brs.length-1;i>=0;i--){
    if(brs[i].previousElementSibling){
      if(brs[i].nextElementSibling){
        if(brs[i].previousElementSibling.outerHTML == brs[i].nextElementSibling.outerHTML)
          boardmenu.removeChild(brs[i]);
      }
    }
  }

  let styleBase = 'style="border-radius:7px; border:solid 2px #EEEEEE; background-color:#151515; padding:5px; text-decoration:none; font-size:13px; ';
  let mainsubs = '<br><a href="https://dollars-bbs.org/intro/" id="introbutton" name="inbu" '+styleBase+'padding-left:16px; padding-right:16px;">Introductions</a><br><br>'+
                 '<a href="https://dollars-bbs.org/countries/" id="countriesbutton" name="cobu" '+styleBase+'padding-left:26px; padding-right:26px;">Countries</a><br><br>'+
                 '<a href="https://dollars-bbs.org/missions/" id="missionsbutton" name="mibu" '+styleBase+'padding-left:29px; padding-right:29px;">Missions</a><br><br>'+
                 '<a href="https://dollars-bbs.org/suggestions/" id="suggestionsbutton" name="subu" '+styleBase+'padding-left:19px; padding-right:18px;">Suggestions</a>';
  let gamessubs = '<br><a href="https://dollars-bbs.org/vn/" id="vnbutton" name="vnbu" '+styleBase+'padding-left:15px; padding-right:15px;">Visual Novels</a>';
  let randomsubs = '<br><a href="https://dollars-bbs.org/test/" id="testbutton" name="tebu" '+styleBase+'padding-left:39px; padding-right:39px;">Test</a>';

  let ms = document.createElement("div");
  let gs = document.createElement("div");
  let rs = document.createElement("div");

  initializeDiv(ms,mainsubs,"main");
  initializeDiv(gs,gamessubs,"games");
  initializeDiv(rs,randomsubs,"random");

  let md = document.createElement("button");
  let gd = document.createElement("button");
  let rd = document.createElement("button");

  initializeButton(md,20,"main",boardmenu);
  initializeButton(gd,200,"games",boardmenu);
  initializeButton(rd,400,"random",boardmenu);
}

function removeAllSubBoards(boardmenu){
  remove("introbutton",boardmenu);
  remove("countriesbutton",boardmenu);
  remove("missionsbutton",boardmenu);
  remove("suggestionsbutton",boardmenu);
  remove("vnbutton",boardmenu);
  remove("testbutton",boardmenu);
}

function remove(name,boardmenu){
  let child = document.getElementById(name);
  if(!child)
    return;
  if(child.name)
    return;
  boardmenu.removeChild(child);
}

function isolateBoard(){
  return window.location.href.replace(/https:\/\/dollars-bbs\.org\//,"").replace("/","").replace("index.html","").replace(/res[0-9]+.html/,"");
}

function initializeDiv(d,s,b){
  d.innerHTML = s;
  d.style.display = "none";
  document.getElementById(b+"button").after(d);
  d.id = b+"dropdown";
  d.style.marginBottom = "-21px";
}

function showBoards(div,b){
  let thisLink = document.getElementById(b+"link");
  if(div.style.display == "none"){
    div.style.display = "";
    thisLink.innerHTML = "▲";
    thisLink.style.paddingBottom = "5px";
    thisLink.style.paddingTop = "3px";
    if(div.innerHTML.includes(isolateBoard())){
      document.getElementById(isolateBoard()+"button").style.backgroundColor = "#4D4D4D";
    }
  } else {
    div.style.display = "none";
    thisLink.innerHTML = "▼";
    thisLink.style.paddingBottom = "3px";
    thisLink.style.paddingTop = "5px";
  }
  if(document.getElementById("mainlink") && document.getElementById("gameslink") && document.getElementById("randomlink")){
    document.getElementById("mainlink").style.top = document.getElementById("mainbutton").offsetTop+4+"px";
    document.getElementById("gameslink").style.top = document.getElementById("gamesbutton").offsetTop+4+"px";
    document.getElementById("randomlink").style.top = document.getElementById("randombutton").offsetTop+4+"px";
  }
}

function initializeButton(d,t,b,boardmenu){
  boardmenu.appendChild(d);
  d.innerHTML = "▼";
  d.onclick = ()=>showBoards(document.getElementById(b+"dropdown"),b);
  d.style = "position:absolute; right:25px; border-radius:7px; border:solid 2px #EEEEEE; background-color:#151515; padding:5px; padding-bottom:3px; text-decoration:none; font-size:10px; cursor:pointer; color:#EEEEEE;";
  d.style.top = document.getElementById(b+"button").offsetTop+4+"px";
  d.id = b+"link";
  if(document.getElementById(b+"dropdown").innerHTML.includes(isolateBoard()) || b == isolateBoard()){
    showBoards(document.getElementById(b+"dropdown"),b);
  }
  removeAllSubBoards(boardmenu);
}

work(false);