index.js

import MediaWikiBot from "mwbot";
import got from "got";
import sizeOf from "image-size";
import { stripIndent } from "common-tags";

function getFirstItem(object) {
	return object[Object.keys(object)[0]];
}

const [, , username, password] = process.argv;
const API_URL = "https://explainxkcd.com/wiki/api.php";
const USER_AGENT =
	"Netscape Navigator/4.0 (Apple IIGS; 1024x1; x64) Pentium 4 (JavaScript, with Ad Blockers) Boat mode, HIGH-HEAT DRYING DISABLED, explainxkcdBot";
const CURRENT_COMIC_PAGE_ID = "1923";
const REVISIONS_PAGE_ID = "27987";
const CHECK_INTERVAL = 120e3;
const NOT_EXPECTED_CHECK_INTERVAL = 9e5; // 15 minute intervals on days which are not Monday, Wednesday, Friday
const MAX_LOGIN_TIME = 6048e5; // 1 week, to be safe
const MONTHS = [
	"January",
	"February",
	"March",
	"April",
	"May",
	"June",
	"July",
	"August",
	"September",
	"October",
	"November",
	"December",
];
const REQUEST_OPTION = {
	headers: {
		"User-Agent": USER_AGENT,
	},
};
const EDIT_SUMMARY = "Created by theusafBOT: ";
const CHANGE_SUMMARY = "Changed by theusafBOT: ";
const LOGIN_DATA = {
	apiUrl: API_URL,
	username,
	password,
};

let expectedComicNumber = null;
let loginTimestamp = 0;
let dateChecked = new Date(0);
let bot = new MediaWikiBot();

function log(message) {
	console.log(`[${new Date().toISOString()}] - ${message}`);
}

function getInterval() {
	const d = new Date();
	const day = d.getDay();
	if (
		(day === 1 || day === 3 || day === 5) &&
		d.getDate() !== dateChecked.getDate()
	) {
		return CHECK_INTERVAL;
	}
	return NOT_EXPECTED_CHECK_INTERVAL;
}

/**
 * login - logs in and starts the updateWiki loop
 */
function login() {
	if (!username || !password) {
		console.log("[ERR] - Usage: node index.js <username> <password>");
		process.exit(0);
	} else {
		bot
			.loginGetEditToken(LOGIN_DATA)
			.then(() => {
				loginTimestamp = Date.now();
				updateWiki();
			})
			.catch((err) => {
				console.error("[ERR] - Failed to log in");
				console.error(err);
				process.exit(0);
			});
	}
}

/**
 * updateWiki
 * - Fetches information from xkcd and if there is a new comic, create a new page
 * - Runs at an interval of 2 minutes
 */
async function updateWiki() {
	// log in again after a certain amount of time
	if (Date.now() - loginTimestamp > MAX_LOGIN_TIME) {
		log("[INFO] - Logging in again");
		bot = new MediaWikiBot();
		login();
		return;
	}
	try {
		// Fetch latest xkcd information
		log("[INFO] - Fetching information from xkcd");
		const { body } = await got("https://xkcd.com/info.0.json", REQUEST_OPTION);
		const comicData = JSON.parse(body);
		const { num, img, day, month, year } = comicData;
		const date = `${MONTHS[+month - 1]} ${day}, ${year}`;

		// if expected number is already set, but current number is lower, no need to re-poll explainxkcd, ignore.
		if (expectedComicNumber !== null && expectedComicNumber > num) {
			log("[INFO] - No new comic found.");
			setTimeout(updateWiki, getInterval());
			return;
		}

		// Fetching expected xkcd number from explain xkcd.
		log("[INFO] - Fetching latest comic on explainxkcd");
		const currentWikiTemplate = await bot.read("Template:LATESTCOMIC");
		const currentRevision = (
			currentWikiTemplate.query.pages[CURRENT_COMIC_PAGE_ID] ??
			getFirstItem(currentWikiTemplate.query.pages)
		).revisions[0]["*"];
		const expectedNumber = +currentRevision.match(/\d+$/)[0] + 1;

		expectedComicNumber = expectedNumber;

		// if expected number is already set, but current number is lower, no need to create new posts.
		if (expectedComicNumber > num) {
			log("[INFO] - No new comic found.");
			setTimeout(updateWiki, getInterval());
			return;
		}

		// Fetch images
		log("[INFO] - Fetching images");
		const baseImage = await got(img, REQUEST_OPTION).buffer();
		const imageExtension = comicData.img.match(/(?<=\.)[a-z]+$/)[0];
		const largeImage = await got(
			`${img.match(/.*?(?=\.[a-z]+$)/)[0]}_2x.${imageExtension}`,
			REQUEST_OPTION,
		)
			.buffer()
			.catch(() => null);
		const baseImageSize = sizeOf(baseImage);
		const largeImageSize = largeImage ? sizeOf(largeImage) : null;
		const imageTitle =
			comicData.img.match(/(?<=\/comics\/).*?(?=\.[a-z]+$)/)[0] +
			(largeImage ? "_2x" : "");

		createNewExplanation({
			date,
			image: largeImage ?? baseImage,
			comicData,
			imageTitle,
			imageExtension,
			baseImageSize,
			largeImageSize,
			is2x: (largeImage ?? baseImage) === largeImage,
		});
	} catch (err) {
		console.error(
			"[ERR] - Failed to fetch xkcd information. See below for details:",
		);
		console.error(err);
		setTimeout(updateWiki, getInterval() * 2);
	}
}

async function isInteractiveComic(number) {
	try {
		const { body } = await got(`https://xkcd.com/${number}`, REQUEST_OPTION);
		return /<script src=".*?\/\d+\/[\/\w\d\s\-_]+?\.js/.test(body);
	} catch (err) {
		return false;
	}
}

/**
 * createNewExplanation - Creates and updates the various pages
 */
async function createNewExplanation(info) {
	try {
		const {
			imageTitle,
			comicData,
			imageExtension,
			image,
			date,
			baseImageSize,
			largeImageSize,
			is2x,
		} = info;
		const {
			safe_title: comicTitle,
			title: alternateTitle,
			alt,
			num: comicNum,
			transcript,
		} = comicData;
		const isInteractiveComicResult = await isInteractiveComic(comicNum);
		const title = alternateTitle.includes("&") ? alternateTitle : comicTitle;

		// Refresh the edit token to edit/create pages
		bot.editToken = null;
		await bot.getEditToken();

		// upload the image
		log("[INFO] - Uploading image to explainxkcd");
		await bot.upload(
			`${imageTitle}.${imageExtension}`,
			image,
			stripIndent`
      == Summary ==
      ${
				is2x
					? `Small size can be found at ${
							comicData.img.match(/.*?(?=\.[a-z]+$)/)[0]
						}.${imageExtension}`
					: ""
			}

      == Licensing ==
      {{XKCD file}}
      `,
		);

		// create/edit redirects
		log("[INFO] - Creating redirects");

		// If the comic title is a number underneath the current comic number, do not create this redirect
		if (!/^\d+$/.test(title) || +title > comicNum) {
			const comicTitleRedirect = `#REDIRECT [[${comicNum}: ${title}]]\n`;
			await bot.edit(
				title,
				comicTitleRedirect,
				`${EDIT_SUMMARY}${comicTitleRedirect}`,
			);
		} else {
			log(
				`[WARN] - Skipped creation of '${title}' due to lower numerical title`,
			);
		}
		const comicNumRedirect = `#REDIRECT [[${comicNum}: ${title}]]\n`;
		await bot.edit(
			`${comicNum}`,
			comicNumRedirect,
			`${EDIT_SUMMARY}${comicNumRedirect}`,
		);

		// create main page
		log("[INFO] - Creating main page");
		let sizeString = `${baseImageSize.width}x${baseImageSize.height}px`;
		// Note 2022-02-03
		// If both the 'standard' and '2x' size seem to be the same size
		const isSameSize =
			largeImageSize &&
			baseImageSize.width === largeImageSize.width &&
			baseImageSize.height === largeImageSize.height;
		if (isSameSize) {
			sizeString = `${Math.floor(baseImageSize.width / 2)}x${Math.floor(
				baseImageSize.height / 2,
			)}px`;
		}
		// If the base image size is larger than the large image size, use the large image size / 2
		const isSmallImageLarger =
			largeImageSize &&
			baseImageSize.width > largeImageSize.width &&
			baseImageSize.height > largeImageSize.height;
		if (isSmallImageLarger) {
			sizeString = `${Math.floor(largeImageSize.width / 2)}x${Math.floor(
				largeImageSize.height / 2,
			)}px`;
		}
		await bot.edit(
			`${comicNum}: ${title}`,
			stripIndent`
      {{comic
      | number    = ${comicNum}
      | date      = ${date}
      | title     = ${title}
      ${
				sizeString === ""
					? `| image     = ${imageTitle}.${imageExtension}`
					: `| image     = ${imageTitle}.${imageExtension}
      | imagesize = ${sizeString}
      | noexpand  = true`
			}
      | titletext = ${alt.replace(/\n/g, "<br>")}
      }}${
				isInteractiveComicResult
					? stripIndent`
          * To experience the interactivity, visit the [https://xkcd.com/${comicNum}/ original comic].
          `
					: ""
			}

      ==Explanation==
      {{incomplete|Created by a BOT - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

      ==Transcript==
      {{incomplete transcript|Do NOT delete this tag too soon.}}
      ${transcript ? `${transcript}\n` : ""}
      {{comic discussion}}${
				isInteractiveComicResult
					? stripIndent`
          [[Category:Interactive comics]]
          `
					: ""
			}
      `,
			`${EDIT_SUMMARY}${comicNum}`,
		);

		// create talk page
		log("[INFO] - Creating talk page");
		await bot.edit(
			`Talk:${comicNum}: ${title}`,
			stripIndent`
      <!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.-->
      ${
				isSameSize || isSmallImageLarger
					? `The 'standard' and '2x' sized images had unexpected sizes, so an imagesize parameter has been added to render the image consistently with other comics on this website. See the web [https://web.archive.org/web/*/${imageTitle.replace(
							/_2x$/,
							"",
						)}.${imageExtension} archive] for more details. --~~~~`
					: ""
			}
      `,
			`${EDIT_SUMMARY} talk page for ${comicNum}`,
		);

		// update latest comic
		log("[INFO] - Updating latest comic");
		await bot.edit(
			"Template:LATESTCOMIC",
			`<noinclude>The latest [[xkcd]] comic is number: </noinclude>${comicNum}`,
			`${CHANGE_SUMMARY}${comicNum}`,
		);

		// update list of all comics
		log("[INFO] - Updating list of comics");
		const allComicsRead = await bot.read("List of all comics");
		const allComicsContent = (
			allComicsRead.query.pages[REVISIONS_PAGE_ID] ??
			getFirstItem(allComicsRead.query.pages)
		).revisions[0]["*"].split("\n"); // .slots.main["*"].split("\n");
		for (let i = 0; i < allComicsContent.length; i++) {
			if (allComicsContent[i] === "!Date<onlyinclude>") {
				const isoDate = new Date(date).toISOString().slice(0, 10);
				allComicsContent.splice(
					i + 1,
					0,
					`{{comicsrow|${comicNum}|${isoDate}|${title}|${imageTitle.replace(
						/_/g,
						" ",
					)}.${imageExtension}}}`,
				);
				break;
			}
		}
		await bot.edit(
			"List of all comics",
			allComicsContent.join("\n"),
			`${CHANGE_SUMMARY}${allComicsContent.length}`,
		);

		dateChecked = new Date();
		setTimeout(updateWiki, getInterval());

		// Archive it!
		try {
			const urls = [
				"https://xkcd.com",
				"https://explainxkcd.com",
				`https://xkcd.com/${comicNum}`,
				`https://explainxkcd.com/${comicNum - 1}`,
				`https://explainxkcd.com/${comicNum}`,
			];
			for (const url of urls) {
				await got(`https://web.archive.org/save/${url}`);
			}
		} catch (err) {
			/* Ignored */
		}
	} catch (err) {
		console.error(
			"[ERR] - Failed to create explanation. See below for details:",
		);
		console.error(err);
		setTimeout(updateWiki, getInterval() * 2);
	}
}

login();