const fs = require("fs");
const jsdom = require("jsdom");
const { JSDOM } = jsdom;
const { window } = new JSDOM("");
global.window = window;
var showdown = require("showdown");
const converterShowdown = new showdown.Converter();
const libxmljs = require("libxmljs");
const getTerm = require("./getTerm.js");

fs.readFile("../../events.xml", "utf8", (err, data) => {
  if (err) {
    console.error(err);
    return;
  }
  data = data.replace(/<!DOCTYPE.*>/, "");
  parseXML(data);
});

fs.mkdir("./markdown-events/", { recursive: true }, (err) => {
  if (err) throw err;
});

const parseTime = (dateStr, timeStr) => {
  // if timeStr is a range (ex. 7pm - 9pm) we take the first time (ex. 7pm)
  if (/-/.exec(timeStr)) {
    timeStr = timeStr.split("-")[0];
  }
  // converting cases like 7pm to 7PM
  timeStr = timeStr.toUpperCase();
  // converting cases like 7PM to 7 PM
  if (/[0-9](a|A|p|P)/g.exec(timeStr)) {
    timeStr = timeStr.replace(/[0-9](?=(a|A|p|P))/g, "$& ");
  }
  // converting cases like 7 PM to 7:00 PM
  if (/(?<!:[0-9])[0-9] (a|A|p|P)/g.exec(timeStr)) {
    timeStr = timeStr.replace(/[0-9](?= )/, "$&:00");
  }
  // convert from CST to EST
  const OFFSET_FROM_EST = +1;
  let date = new Date(`${dateStr} ${timeStr}`);
  date.setHours(date.getHours() + OFFSET_FROM_EST);
  return date;
};

const nodeChildrenToString = (nodeChildren) => {
  let string = "";
  for (let i = 0; i < nodeChildren.length; ++i) {
    if (nodeChildren[i].type() === "text") {
      string += nodeChildren[i];
    } else {
      string += nodeChildren[i].toString();
    }
  }
  return string;
};

const parseXML = (XML) => {
  const xmlDoc = libxmljs.parseHtml(XML);
  let eventdefsChildren = xmlDoc.get("//eventdefs").childNodes();
  eventdefsChildren.forEach((eventItem) => {
    if (eventItem.type() === "element") {
      const title = eventItem.attr("title").value();
      const shortNodes = eventItem.get(".//short").childNodes();
      let short = converterShowdown.makeMarkdown(
        nodeChildrenToString(shortNodes)
      );
      const dateStr = eventItem.attr("date").value();
      const timeStr = eventItem.attr("time").value();
      const date = parseTime(dateStr, timeStr);
      currentTerm = getTerm(date);
      const location = eventItem.attr("room").value();
      const online = location.toLowerCase() === "online" ? true : false;
      let abstract = short;
      if (eventItem.get(".//abstract") !== undefined) {
        const abstractNodes = eventItem.get(".//abstract").childNodes();
        abstract = converterShowdown.makeMarkdown(
          nodeChildrenToString(abstractNodes)
        );
      }
      const md = `---
name: '${title.replace(/'/g, "''")}'
short: '${short.replace(/\n/g, "").replace(/'/g, "''")}'
date: '${date.toString().replace(/'/g, "''")}'
online: ${online}
location: '${location.replace(/'/g, "''")}'
---

${abstract.replace(/<br>/g, "\n")}`;

      // remove invalid characters from filenames
      let mdTitle = title.replace(/[\\\\/:*?\"<>|]/g, "").replace(/(\s+)/g, "-");
      fs.mkdirSync(
        `./markdown-events/${currentTerm.year}/${currentTerm.term}`,
        { recursive: true },
        (err) => {
          if (err) throw err;
        }
      );
      fs.writeFileSync(
        `./markdown-events/${currentTerm.year}/${currentTerm.term}/${mdTitle}.md`,
        md,
        (err) => {
          if (err) {
            throw err;
          }
        }
      );
    }
  });
};