// Crawls the website to discover pages using PROPFIND

import { url as root_url } from "./editor.js";

export const __files__ = Symbol("crawlerFiles");

function nodeTextToHrefs(nodes, exclude) {
  const result = [];
  for (const node of nodes) {
    const href = new URL(node.textContent, root_url).href;
    if (href != exclude) {
      result.push(href);
    }
  }
  return result;
}

async function crawl(url) {
  const response = await fetch(url, {
    method: "PROPFIND",
    headers: { Depth: "1" },
  });
  const text = await response.text();
  const parser = new DOMParser();
  const doc = parser.parseFromString(text, "text/xml");
  const collections = nodeTextToHrefs(
    doc.querySelectorAll("response:has(resourcetype collection) href"),
    url,
  );
  const files = nodeTextToHrefs(
    doc.querySelectorAll("response:not(:has(resourcetype collection)) href"),
    url,
  );
  return [collections, files];
}

async function crawlCollection(url) {
  const result = {};
  const [subcollections, subfiles] = await crawl(url);
  for (const subcollection of subcollections) {
    result[subcollection] = await crawlCollection(subcollection);
  }
  result[__files__] = subfiles;
  return result;
}

async function recursiveCrawl(url) {
  return {
    [url]: await crawlCollection(url),
  };
}

function formattedIndexDirectory(url, recursiveCrawlResult) {
  const subcollections = Object.getOwnPropertyNames(recursiveCrawlResult);
  const ul = document.createElement("ul");
  const a = document.createElement("a");
  a.href = url;
  a.innerText = "/" + url.replace(root_url, "");
  ul.appendChild(a);
  for (const subcollection of subcollections) {
    const li = document.createElement("li");
    li.appendChild(
      formattedIndexDirectory(
        subcollection,
        recursiveCrawlResult[subcollection],
      ),
    );
    ul.appendChild(li);
  }
  for (const file of recursiveCrawlResult[__files__]) {
    const li = document.createElement("li");
    const a = document.createElement("a");
    li.appendChild(a);
    ul.appendChild(li);
    a.href = file;
    a.innerText = "/" + file.replace(root_url, "");
  }
  return ul;
}

const rcr = await recursiveCrawl(root_url);
const root = Object.getOwnPropertyNames(rcr)[0];
const formatted = formattedIndexDirectory(root, rcr[root]);
document.body.appendChild(formatted);