function htmlToElement(html) {
  const template = document.createElement("template")
  html = html.trim()
  template.innerHTML = html
  return template.content.firstChild
}

function initPopover(baseURL, useContextualBacklinks) {
  const basePath = baseURL.replace(window.location.origin, "")
  fetchData.then(({ content }) => {
    const links = [...document.getElementsByClassName("internal-link")]
    links
      .filter(li => li.dataset.src || (li.dataset.idx && useContextualBacklinks))
      .forEach(li => {
        if (li.dataset.ctx) {
          const linkDest = content[li.dataset.src]
          const popoverElement = `<div class="popover">
    <h3>${linkDest.title}</h3>
    <p>${highlight(removeMarkdown(linkDest.content), li.dataset.ctx)}...</p>
    <p class="meta">${new Date(linkDest.lastmodified).toLocaleDateString()}</p>
</div>`
          const el = htmlToElement(popoverElement)
          li.appendChild(el)
          li.addEventListener("mouseover", () => {
            el.classList.add("visible")
          })
          li.addEventListener("mouseout", () => {
            el.classList.remove("visible")
          })
        } else {
          const linkDest = content[li.dataset.src.replace(/\/$/g, "").replace(basePath, "")]
          if (linkDest) {
            const popoverElement = `<div class="popover">
    <h3>${linkDest.title}</h3>
    <p>${removeMarkdown(linkDest.content).split(" ", 20).join(" ")}...</p>
    <p class="meta">${new Date(linkDest.lastmodified).toLocaleDateString()}</p>
</div>`
            const el = htmlToElement(popoverElement)
            li.appendChild(el)
            li.addEventListener("mouseover", () => {
              el.classList.add("visible")
            })
            li.addEventListener("mouseout", () => {
              el.classList.remove("visible")
            })
          }
        }
      })
  })
}