/////////////////////////// Table of Contents Script ///////////////////////////

/*
 * This script is used to generate a table of contents for the
 * release notes pages.
 */
export default function ReleaseToc({ component }) {
  // Use jQuery filter to get an array of all the *release* h2 elements
  const releases = $('h2').filter(
    (_i, el) => !el.id.match(/checkpoint-releases/)
  );

  // Extract data about each release from the array of releases
  const releaseData = releases.map((_i, el) => ({
    name: el.textContent,
    id: el.id,
    class: el.getAttribute('class'),
    date: el.getAttribute('date'),
  }));

  // Use release data to generate a list item for each release
  getReleaseItem = (releaseData) => {
    var li = document.createElement('li');
    if (releaseData.class !== null) {
      li.className = releaseData.class;
    }
    li.innerHTML = `<a href="#${releaseData.id}">${releaseData.name}</a>`;
    li.setAttribute('date', releaseData.date);
    return li;
  };

  // Use jQuery each to build the release table of contents
  releaseData.each((_i, release) => {
    $('#release-toc ul')[0].appendChild(getReleaseItem(release));
  });

  /*
   * This script is used to expand the release notes table of contents by the
   * number specified in the `show` attribute of `ul.release-list`.
   * Once all the release items are visible, the "Show More" button is hidden.
   */
  $('#release-toc .show-more').click(function () {
    const itemHeight = 1.885; // Item height in rem
    const releaseNum = releaseData.length;
    const maxHeight = releaseNum * itemHeight;
    const releaseIncrement = Number($('#release-list')[0].getAttribute('show'));
    const currentHeight = Number(
      $('#release-list')[0].style.height.match(/\d+\.?\d+/)[0]
    );
    const potentialHeight = currentHeight + releaseIncrement * itemHeight;
    const newHeight = potentialHeight > maxHeight ? maxHeight : potentialHeight;

    $('#release-list')[0].style.height = `${newHeight}rem`;

    if (newHeight >= maxHeight) {
      $('#release-toc .show-more').fadeOut(100);
    }
  });
}