import ext from "./utils/ext";

let extractDOM = () => {
  let indexInParent = node => {
    let children = node.parentNode.childNodes;
    let num = 0;
    for (let i = 0; i < children.length; i++) {
      if (children[i] === node) return num;
      if (children[i].nodeType === 1) num++;
    }
    return -1;
  };

  let gx = el => {
    let xp = "";
    for (; el && el.nodeType === 1; el = el.parentNode) {
      let id = indexInParent(el) + 1; // jQuery(el.parentNode).children(el.tagName).index(el)+1;
      id = id > 1 ? "[" + id + "]" : "";
      xp = "/" + el.tagName.toLowerCase() + id + xp;
    }

    return xp;
  };

  document.addEventListener("click", function(evt) {
    let tar = evt.target;
    while (tar && tar !== this) {
      if (tar.matches(".shikihover")) {
        let data = extractTags();
        data.xpath = gx(tar);
      }
    }
  });
};

let extractTags = () => {
  let url = document.location.href;
  if (!url || !url.match(/^http/)) {
    console.error("Invalid URL : " + url);
    return;
  }

  let data = {
    title: "",
    description: "",
    image: "",
    url: url
  };

  let ogTitle = document.querySelector("meta[property='og:title']");
  if (ogTitle) {
    data.title = ogTitle.getAttribute("content");
  } else {
    data.title = document.title;
  }

  let descriptionTag =
    document.querySelector("meta[property='og:description']") ||
    document.querySelector("meta[name='description']");
  if (descriptionTag) {
    data.description = descriptionTag.getAttribute("content");
  }

  let imgTag =
    document.querySelector("meta[property='og:image']") ||
    document.querySelector("meta[property='twitter-image']");
  if (imgTag) {
    data.image = imgTag.getAttribute("content");
  } else {
    imgTag =
      document.querySelector("link[rel=icon]") ||
      document.querySelector("link[rel=apple-touch-icon]");
    if (imgTag) {
      data.image = imgTag.getAttribute("href");
    }
  }

  return data;
};

function onRequest(request, sender, sendResponse) {
  if (request.action === "process-page") {
    sendResponse(extractTags());
  }
  if (request.action === "DOM") {
    console.log("DOM");
    sendResponse(extractDOM());
  }
}

ext.runtime.onMessage.addListener(onRequest);