const getTitle = () => {
  const title = document.title;
  const metaTitle = document.querySelector<HTMLMetaElement>(`meta[name="title"]`);
  const metaOgTitle = document.querySelector<HTMLMetaElement>(`meta[name="og:title"]`);

  if (metaOgTitle) {
    return metaOgTitle.getAttribute("content");;
  }

  if (metaTitle) {
    return metaTitle.getAttribute("content");;
  }

  if (title.includes(" - ")) {
    const end = title.lastIndexOf(" - ");

    return title.substring(0, end);
  }

  if (title.includes(" | ")) {
    const end = title.lastIndexOf(" | ");

    return title.substring(0, end);
  }

  return title;
}

const getDesc = () => {
  const articleFirstParagraph = document.querySelector<HTMLParagraphElement>("article p") || document.querySelector<HTMLParagraphElement>("p");
  const metaDescription = document.querySelector<HTMLMetaElement>(`meta[name="description"]`);
  const metaOgDescription = document.querySelector<HTMLMetaElement>(`meta[property="og:description"]`);

  if (metaOgDescription) {
    return metaOgDescription.getAttribute("content");
  }

  if (metaDescription) {
    return metaDescription.getAttribute("content");
  }

  if (articleFirstParagraph) {
    return articleFirstParagraph.innerText;
  }

  return "";
}

const getAuthor = () => {
  const metaAuthor = document.querySelector<HTMLMetaElement>(`meta[name="author"]`);
  const metaOgAuthor = document.querySelector<HTMLMetaElement>(`meta[property="og:article:author"]`);
  const itemPropAuthor = document.querySelector<HTMLMetaElement>(`[itemprop="author"] [itemprop="name"]`);

  if (metaAuthor) {
    return metaAuthor.getAttribute("content");
  }

  if (metaOgAuthor) {
    return metaOgAuthor.getAttribute("content");
  }

  if (itemPropAuthor) {
    return itemPropAuthor.getAttribute("content");
  }

  return "";
}

const getImage = () => {
  const metaOgImage = document.querySelector<HTMLMetaElement>(`meta[property="og:image"]`);

  if (metaOgImage) {
    return metaOgImage.getAttribute("content");
  }

  return "";
}

const getSiteName = () => {
  const title = document.title;
  const metaSiteName = document.querySelector<HTMLMetaElement>(`meta[property="og:site_name"]`);

  if (metaSiteName) {
    return metaSiteName.getAttribute("content");
  }

  if (title.includes(" - ")) {
    const start = title.lastIndexOf(" - ") + 3;

    return title.substring(start);
  }

  if (title.includes(" | ")) {
    const start = title.lastIndexOf(" | ") + 3;

    return title.substring(start);
  }

  return "";
}

const getTags = () => {
  const metaKeywords = document.querySelector<HTMLMetaElement>(`meta[name="keywords"]`);
  const itemPropKeywords = document.querySelector<HTMLMetaElement>(`meta[itemprop="keywords"]`);

  if (metaKeywords) {
    return metaKeywords.getAttribute("content");
  }

  if (itemPropKeywords) {
    return itemPropKeywords.getAttribute("content");
  }

  return "";
}

chrome.runtime.onMessage.addListener((req, sender, send) => {
  if (req.type === "toolbox:getInfo") {
    send({
      title: getTitle(),
      link: `${location.origin}${location.pathname}`,
      desc: getDesc(),
      author: getAuthor(),
      image: getImage(),
      sitename: getSiteName(),
      tags: getTags(),
    });
  }
});