roadmap/layouts/partials/search.html

<div id="search-container">
    <div>
        <input autocomplete="off" id="search-bar" name="search" type="text" aria-label="Search" placeholder="Search for something...">
        <div id="results-container">
        </div>
    </div>
</div>
<script src="https://cdn.jsdelivr.net/gh/nextapps-de/flexsearch@0.7.2/dist/flexsearch.bundle.js"></script>
<script>
  // code from https://github.com/danestves/markdown-to-text
  const removeMarkdown = (
    markdown,
    options = {
      listUnicodeChar: false,
      stripListLeaders: true,
      gfm: true,
      useImgAltText: false,
      preserveLinks: false,
    }
  ) => {
    let output = markdown || "";
    output = output.replace(/^(-\s*?|\*\s*?|_\s*?){3,}\s*$/gm, "");

    try {
      if (options.stripListLeaders) {
        if (options.listUnicodeChar)
          output = output.replace(
            /^([\s\t]*)([\*\-\+]|\d+\.)\s+/gm,
            options.listUnicodeChar + " $1"
          );
        else output = output.replace(/^([\s\t]*)([\*\-\+]|\d+\.)\s+/gm, "$1");
      }
      if (options.gfm) {
        output = output
          .replace(/\n={2,}/g, "\n")
          .replace(/~{3}.*\n/g, "")
          .replace(/~~/g, "")
          .replace(/`{3}.*\n/g, "");
      }
      if(options.preserveLinks) {
        output = output.replace(/\[(.*?)\][\[\(](.*?)[\]\)]/g, "$1 ($2)")
      }
      output = output
        .replace(/<[^>]*>/g, "")
        .replace(/^[=\-]{2,}\s*$/g, "")
        .replace(/\[\^.+?\](\: .*?$)?/g, "")
        .replace(/\s{0,2}\[.*?\]: .*?$/g, "")
        .replace(/\!\[(.*?)\][\[\(].*?[\]\)]/g, options.useImgAltText ? "$1" : "")
        .replace(/\[(.*?)\][\[\(].*?[\]\)]/g, "$1")
        .replace(/^\s{0,3}>\s?/g, "")
        .replace(/(^|\n)\s{0,3}>\s?/g, "\n\n")
        .replace(/^\s{1,2}\[(.*?)\]: (\S+)( ".*?")?\s*$/g, "")
        .replace(
          /^(\n)?\s{0,}#{1,6}\s+| {0,}(\n)?\s{0,}#{0,} {0,}(\n)?\s{0,}$/gm,
          "$1$2$3"
        )
        .replace(/([\*_]{1,3})(\S.*?\S{0,1})\1/g, "$2")
        .replace(/([\*_]{1,3})(\S.*?\S{0,1})\1/g, "$2")
        .replace(/(`{3,})(.*?)\1/gm, "$2")
        .replace(/`(.+?)`/g, "$1")
        .replace(/\n{2,}/g, "\n\n");
    } catch (e) {
      console.error(e);
      return markdown;
    }
    return output;
  };
</script>
<script>
  const contentIndex = new FlexSearch.Worker({
    tokenize: "strict",
    charset: "latin:advanced",
    context: true,
    depth: 3,
    cache: 10,
    suggest: true,
  })

  const scrapedContent = {{$.Site.Data.contentIndex}}
  for (const [key, value] of Object.entries(scrapedContent)) {
    contentIndex.add(key, value.content)
  }

  const stopwords = ['i','me','my','myself','we','our','ours','ourselves','you','your','yours','yourself','yourselves','he','him','his','himself','she','her','hers','herself','it','its','itself','they','them','their','theirs','themselves','what','which','who','whom','this','that','these','those','am','is','are','was','were','be','been','being','have','has','had','having','do','does','did','doing','a','an','the','and','but','if','or','because','as','until','while','of','at','by','for','with','about','against','between','into','through','during','before','after','above','below','to','from','up','down','in','out','on','off','over','under','again','further','then','once','here','there','when','where','why','how','all','any','both','each','few','more','most','other','some','such','no','nor','not','only','own','same','so','than','too','very','s','t','can','will','just','don','should','now']
  const highlight = (content, term) => {
    const highlightWindow = 15
    const tokenizedTerm = term.split(/\s+/).filter(t => t !== "")
    const splitText = content.split(/\s+/).filter(t => t !== "")
    const includesCheck = (token) => tokenizedTerm.some(term => token.toLowerCase().includes(term.toLowerCase()))

    const occurrencesIndices = splitText
      .map(includesCheck)

    // calculate best index
    let bestSum = 0
    let bestIndex = 0
    for (let i = 0; i < Math.max(occurrencesIndices.length - highlightWindow, 0); i++) {
      const window = occurrencesIndices.slice(i, i + highlightWindow)
      const windowSum = window.reduce((total, cur) => total + cur, 0)
      if (windowSum > bestSum) {
        bestSum = windowSum
        bestIndex = i
      }
    }

    const startIndex = Math.max(bestIndex - highlightWindow, 0)
    const endIndex = Math.min(startIndex + 2 * highlightWindow, splitText.length)
    const mappedText = splitText
      .slice(startIndex, endIndex)
      .map(token => {
        if (includesCheck(token)) {
          return `<span class="search-highlight">${token}</span>`
        }
        return token
      })
      .join(" ")
      .replaceAll('</span> <span class="search-highlight">', " ")
    return `${startIndex === 0 ? "" : "..."}${mappedText}${endIndex === splitText.length ? "" : "..."}`
  }

  const resultToHTML = ({url, title, content, term}) => {
    const md = content.split("---")[2]
    const text = removeMarkdown(md)
    const resultTitle = highlight(title, term)
    const resultText = highlight(text, term)
    return `<div class="result-card" id="${url}">
        <h3>${resultTitle}</h3>
        <p>${resultText}</p>
    </div>`
  }

  const source = document.getElementById('search-bar')
  const results = document.getElementById("results-container")
  source.addEventListener('input', (e) => {
    const term = e.target.value
    contentIndex.search(term, {
      limit: 5,
      depth: 3,
      suggest: true,
    }).then(searchResults => {
      const resultIds = [...new Set(searchResults)]
      const finalResults = resultIds.map(id => ({
        url: id,
        title: scrapedContent[id].title,
        content: scrapedContent[id].content
      }))

      // display
      if (finalResults.length === 0) {
        results.innerHTML = `<div class="result-card">
            <p>No results.</p>
        </div>`
      } else {
        results.innerHTML = finalResults
          .map(result => resultToHTML({
            ...result,
            term,
          }))
          .join("\n")
        const anchors = document.getElementsByClassName("result-card");
        [...anchors].forEach(anchor => {
          anchor.onclick = () => {
            window.location.href = `${anchor.id}#:~:text=${encodeURIComponent(term)}`
          }
        })
      }
    })
  })


  const searchContainer = document.getElementById("search-container")
  function openSearch() {
    if (searchContainer.style.display === "none" || searchContainer.style.display === "") {
      source.value = ""
      results.innerHTML = ""
      searchContainer.style.display = "block"
      source.focus()
    } else {
      searchContainer.style.display = "none"
    }
  }

  function closeSearch() {
    searchContainer.style.display = "none"
  }

  document.addEventListener('keydown', (event) => {
    if (event.key === "/") {
      event.preventDefault()
      openSearch()
    }
    if (event.key === "Escape") {
      event.preventDefault()
      closeSearch()
    }
  })

  window.addEventListener('DOMContentLoaded', () => {
    const searchButton = document.getElementById("search-icon")
    searchButton.addEventListener('click', (evt) => {
      openSearch()
    })
    searchButton.addEventListener('keydown', (evt) => {
      openSearch()
    })
  })

</script>