// ==UserScript==
// @name        YouTube to Invidious
// @author      OdinBrood, Jesús E.
// @namespace   InvidiousRedirect
// @description Scan page for Youtube urls and replace with Invidious.
// @homepageURL https://git.sr.ht/~heckyel/book/blob/master/scripts-greasemonkey
// @include     *
// @exclude     /^http(s|)://(www[.]|)invidio[.]us/.*$/
// @exclude     /^http(s|)://(www[.]|proxy[.]|)invidious[.]snopyta[.]org/.*$/
// @exclude     /^http(s|)://(www[.]|)vid[.]wxzm[.]sx/.*$/
// @exclude     /^http(s|)://(www[.]|)invidious[.]kabi[.]tk/.*$/
// @exclude     /^http(s|)://(www[.]|)invidiou[.]sh/.*$/
// @exclude     /^http(s|)://(www[.]|)yewtu[.]be/.*$/
// @exclude     /^http(s|)://(www[.]|)invidious[.]ggc-project[.]de/.*$/
// @exclude     /^http(s|)://(www[.]|)invidious[.]enkirton[.]net/.*$/
// @exclude     /^http(s|)://(www[.]|)tube[.]poal[.]co/.*$/
// @exclude     /^http(s|)://(www[.]|)invidious[.]13ad[.]de/.*$/
// @grant       none
// @version     8.4.9
// @license     GPL version 3 or any later version::: https://www.gnu.org/licenses/gpl-3.0.html
// ==/UserScript==
/* jshint esversion: 6 */

// set you favorite Invidious instance! (https://github.com/omarroth/invidious/wiki/Invidious-Instances)
let instance = 'invidious.13ad.de';

// Console Style - Debug
const consoleCSS = 'background: #000; color: #00FF00; padding: 0px 7px; border: 1px solid #00FF00; line-height: 16px;';
const name = GM_info.script.name;
const version = GM_info.script.version;
const log = (...args) => console.log('%cUSERSCRIPT | %s %s | %s', consoleCSS, name, version, ...args);

// change script options, default values recommended
let a=1; //set to 0 to force autoplay off, set to 1 to keep embed's value [default 1]
let b=1; //set to 0 to not replace all youtube links to Invidious [default 1]

let ytdomains=new RegExp(/http(s|):\/\/(m[.]|i[.]|www[.]|img[.]|)(youtu(|be|be-nocookie)|.*ytimg)[.](com|be)\/.*/);
let params=new RegExp(/^(autoplay|channel|v|playlist|list)$/);
let current=window.location.href.match(ytdomains)===null;
let thumbs,links,skip;

function link(){
  for(let i=0;i<links.length;i++){
    let url=new URL(links[i].href.match(ytdomains)[0]);
    url.hostname=instance;
    links[i].href=url;
  }
}

function ytel(el){
  for(let i=0;i<el.attributes.length;i++){
    let val=el.attributes[i].value;
    if(val.substring(0,2)=='//')val='https:'+val;
    try{val=decodeURIComponent(val);}catch(e){}
    if(val.match(ytdomains)){
      el.attributes[i].value=val;
      return true;
    }
  }
}

function ythref(el){
  return(decodeURIComponent(el.href).match(ytdomains));
}

function thumb(){
  for(let i=0;i<thumbs.length;i++){
    let url=new URL(thumbs[i].src.match(ytdomains)[0]);
    url.hostname=instance;
    thumbs[i].src=url;
  }
}

function redir(){
  let url=new URL(window.location.href);
  url.hostname=instance;
  location.href=url;
}

function addbtn(){
  for(let i=0;i<title.length;i++){
    let btn=document.createElement('a');
    btn.innerHTML='<h2>Watch on '+instance+'</h2>';
    btn.href='javascript:void(0)';
    btn.onclick=function(){
      redir();
    }
    btn.className='skipinv';
    title[i].parentNode.appendChild(btn);
  }
}

if(current){
  thumbs=Array.prototype.slice.call(document.getElementsByTagName('img')).filter(ytel);
  if(b==1)links=Array.prototype.slice.call(document.getElementsByTagName('a')).filter(ythref);
  if(thumbs.length>0){
    thumb();
  }
  if(links.length>0){
    link();
  }
  log('successfully initialized');
}else{
  let title=Array.prototype.slice.call(document.getElementsByTagName('h1'));
  addbtn();
}

let observer=new MutationObserver(function(mutations){
  mutations.forEach(function(mutation){
    if(current){
      thumbs=Array.prototype.slice.call(mutation.target.getElementsByTagName('img')).filter(ytel);
      if(thumbs.length>0){
        thumb();
      }
      if(b==1){
        links=Array.prototype.slice.call(mutation.target.getElementsByTagName('a')).filter(ythref);
        if(links.length>0){
          link();
        }
      }
    }else{
      skip=Array.prototype.slice.call(mutation.target.getElementsByClassName('skipinv'));
      if(skip<1){
        title=Array.prototype.slice.call(mutation.target.getElementsByTagName('h1'));
        addbtn();
      }
    }
  });
});

observer.observe(document.body,{childList:true,subtree:true});