youtube-to-invidious/background.js

let urlFromStorage

// Storage init
browser.runtime.onInstalled.addListener(function() {
  browser.storage.sync.set({
    url: "https://invidious.snopyta.org"
  });
});

browser.storage.sync.onChanged.addListener(function(changes) {
  if (changes.url && changes.url.newValue) {
    urlFromStorage = changes.url.newValue
  }
})


// Url format
function getVideoToken(url) {
  // https://regexr.com/531i0
  var rx = /(?:\/|%3D|v=|vi=)([0-9A-z-_]{11})(?:[%#?&]|$)/g;
  var arr = rx.exec(url);
  return arr[1]; 
}

function cleanToken(token) {
  let t = token;
  // https://regexr.com/531i0
  t = t.replace(/^(vi=|v=)/,"");
  t = t.replace(/^(\/)/,"");
  t = t.replace(/^(%3D)/,"");
  t = t.replace(/(&|%)$/,"");
  return t;
}



function toInvidious(message) {
  let url = message.url;
  const name = message.targetName;
  const subst = urlFromStorage + `/watch?v=`;
  let token = getVideoToken(url)
  const cleanedToken = cleanToken(token)
  url = url.replace(/.*\/watch\?v=/gm, subst);

  if (name != "_self") {
    browser.tabs.create(
      {active: true, url: url}
    );
  } else {
    browser.tabs.update(
      {url: url, loadReplace: false}
    )
  }
  console.log('Youtube to invidious is redirecting you to invidious')
}


// Links click event handling
browser.runtime.onMessage.addListener(function(message) {
  toInvidious(message)
});


// Page action
browser.pageAction.onClicked.addListener(function(page) {
  toInvidious({url: page.url, targetName: "_self"});
});