Youtube snippet utils to build timestamp lists

index.js

(function () {
  const ytPlayer  = document.getElementById("movie_player");
  const viewCount = document.querySelector(".ytd-video-view-count-renderer");

  const oldBtns = document.querySelectorAll("[data-timestamputils='true']");
  oldBtns.forEach(function (el) { el.remove(); });

  function buildButton(name, onClickFn) {
    const btn = document.createElement("button");
    btn.setAttribute("data-timestamputils", true);
    btn.innerText = name;
    btn.onclick = onClickFn;
    viewCount.insertAdjacentElement("afterend", btn);
  }

  // copy current timestamp to clipboard
  buildButton("copytime", function () {
    let sec = parseInt(ytPlayer.getCurrentTime());
    let min = (sec / 60);
    let hr  = (min / 60);
    sec = parseInt(sec % 60).toString().padStart(2, "0");
    min = parseInt(min % 60).toString().padStart(2, "0");
    hr  = parseInt(hr      ).toString().padStart(2, "0");
    // txt formatting: [hh:]mm:ss
    const txt = (hr == "00" ? "" : hr + ":") + min + ":" + sec;
    navigator.clipboard.writeText(txt);
  });

  // plays at 1x speed, goes back 3 secs
  buildButton("whoopskip", function () {
    // doesn't always work // ytPlayer.setPlaybackRate(1);
    document.querySelector("video").playbackRate = 1;
    const curr = ytPlayer.getCurrentTime();
    ytPlayer.seekTo(curr - 3);
    ytPlayer.playVideo();
  });
})();