F95API/app/scripts/game-scraper.js

'use strict';

// Public modules from npm
const HTMLParser = require('node-html-parser');
const puppeteer = require('puppeteer');
const urlExist = require('url-exist');

// Modules from file
const shared = require('./shared.js');
const selectors = require('./costants/css-selectors.js');
const { preparePage } = require('./puppeteer-helper.js');
const GameDownload = require('./classes/game-download.js');
const GameInfo = require('./classes/game-info.js');
const { isStringAValidURL, isF95URL } = require('./urls-helper.js');

/**
 * @protected
 * Get information from the game's main page.
 * @param {puppeteer.Browser} browser Browser object used for navigation
 * @param {URL} url URL of the game/mod to extract data from
 * @return {Promise<GameInfo>} Complete information about the game you are looking for
 */
module.exports.getGameInfo = async function(browser, url) {
    if (shared.debug) console.log('Obtaining game info');

    // Verify the correctness of the URL
    if (!isF95URL(url)) throw url + ' is not a valid F95Zone URL';
    let exists = await urlExist(url.toString());
    if (!exists) return new GameInfo();

    let page = await preparePage(browser); // Set new isolated page
    await page.setCookie(...shared.cookies); // Set cookies to avoid login
    await page.goto(url.toString(), {
        waitUntil: shared.WAIT_STATEMENT
    }); // Go to the game page and wait until it loads

    // It asynchronously searches for the elements and 
    // then waits at the end to compile the object to be returned
    let info = new GameInfo();
    let title = getGameTitle(page);
    let author = getGameAuthor(page);
    let tags = getGameTags(page);
    let previewSource = getGamePreviewSource(page);
    let downloadData = getGameDownloadLink(page);
    info = await parsePrefixes(page, info); // Fill status/engines/isMod
    let structuredText = await getMainPostStructuredText(page);
    let overview = getOverview(structuredText, info.isMod);
    let parsedInfos = parseConversationPage(structuredText);

    // Fill in the GameInfo element with the information obtained
    info.name = await title;
    info.author = await author;
    info.overview = overview;
    info.tags = await tags;
    info.f95url = url;
    info.version = info.isMod ? parsedInfos['MOD VERSION'] : parsedInfos['VERSION'];
    info.lastUpdate = info.isMod ? parsedInfos['UPDATED'] : parsedInfos['THREAD UPDATED'];
    info.previewSource = await previewSource;
    info.downloadInfo = await downloadData;

    await page.close(); // Close the page
    if (shared.debug) console.log('Founded data for ' + info.name);
    return info;
}

//#region Private methods
/**
 * @private
 * Get the game description from its web page.
 * Different processing depending on whether the game is a mod or not.
 * @param {String} text Structured text extracted from the game's web page
 * @param {Boolean} isMod Specify if it is a game or a mod
 * @returns {Promise<String>} Game description
 */
function getOverview(text, isMod) {
    // Get overview (different parsing for game and mod)
    let overviewEndIndex;
    if (isMod) overviewEndIndex = text.indexOf('Updated');
    else overviewEndIndex = text.indexOf('Thread Updated');
    return text.substring(0, overviewEndIndex).replace('Overview:\n', '').trim();
}

/**
 * @private
 * Extrapolate the page structure by removing the element tags 
 * and leaving only the text and its spacing.
 * @param {puppeteer.Page} page Page containing the text
 * @returns {Promise<String>} Structured text
 */
async function getMainPostStructuredText(page) {
// Gets the first post, where are listed all the game's informations
let post = (await page.$$(selectors.THREAD_POSTS))[0];

// The info are plain text so we need to parse the HTML code
let bodyHTML = await page.evaluate( /* istanbul ignore next */ (mainPost) => mainPost.innerHTML, post);
return HTMLParser.parse(bodyHTML).structuredText;
}

/**
 * @private
 * Extrapolates and cleans the author from the page passed by parameter.
 * @param {puppeteer.Page} page Page containing the author to be extrapolated
 * @returns {Promise<String>} Game author
 */
async function getGameAuthor(page) {
    // Get the game/mod name (without square brackets)
    let titleHTML = await page.evaluate( /* istanbul ignore next */ (selector) =>
    document.querySelector(selector).innerHTML, 
    selectors.GAME_TITLE);
    let structuredTitle = HTMLParser.parse(titleHTML);

    // The last element **shoud be** the title without prefixes (engines, status, other...)
    let gameTitle = structuredTitle.childNodes.pop().rawText;

    // The last square brackets contain the author
    let startTitleIndex = gameTitle.lastIndexOf('[') + 1;
    return gameTitle.substring(startTitleIndex, gameTitle.length - 1).trim();
}

/**
 * @private
 * Process the post text to get all the useful 
 * information in the format *DESCRIPTOR : VALUE*.
 * @param {String} text Structured text of the post
 * @returns {Object} Dictionary of information
 */
function parseConversationPage(text) {
    let dataPairs = {};

    // The information searched in the game post are one per line
    let splittedText = text.split('\n');
    for (let line of splittedText) {

        if (!line.includes(':')) continue;

        // Create pair key/value
        let splitted = line.split(':');
        let key = splitted[0].trim().toUpperCase(); // Uppercase to avoid mismatch
        let value = splitted[1].trim();

        // Add pair to the dict if valid
        if (value != '') dataPairs[key] = value;
    }

    return dataPairs;
}

/**
 * @private
 * Gets the URL of the image used as a preview for the game in the conversation.
 * @param {puppeteer.Page} page Page containing the URL to be extrapolated
 * @returns {Promise<URL>} URL of the image or null if failed to get it
 */
async function getGamePreviewSource(page) {
    let src = await page.evaluate( /* istanbul ignore next */ (selector) => {
        // Get the firs image available
        let img = document.querySelector(selector);

        if (img) return img.getAttribute('src');
        else return null;
    }, selectors.GAME_IMAGES);

    // Check if the URL is valid
    return isStringAValidURL(src) ? new URL(src) : null;
}

/**
 * @private
 * Extrapolates and cleans the title from the page passed by parameter.
 * @param {puppeteer.Page} page Page containing the title to be extrapolated
 * @returns {Promise<String>} Game title
 */
async function getGameTitle(page) {
    // Get the game/mod name (without square brackets)
    let titleHTML = await page.evaluate( /* istanbul ignore next */ (selector) =>
    document.querySelector(selector).innerHTML, 
    selectors.GAME_TITLE);
    let structuredTitle = HTMLParser.parse(titleHTML);

    // The last element **shoud be** the title without prefixes (engines, status, other...)
    let gameTitle = structuredTitle.childNodes.pop().rawText;
    let endTitleIndex = gameTitle.indexOf('[');
    return gameTitle.substring(0, endTitleIndex).trim();
}

/**
 * @private
 * Get the alphabetically sorted list of tags associated with the game.
 * @param {puppeteer.Page} page Page containing the tags to be extrapolated
 * @returns {Promise<String[]>} List of uppercase tags
 */
async function getGameTags(page) {
    let tags = [];

    // Get the game tags
    for (let handle of await page.$$(selectors.GAME_TAGS)) {
        let tag = await page.evaluate( /* istanbul ignore next */ (element) => element.innerText, handle);
        tags.push(tag.toUpperCase());
    }
    return tags.sort();
}

/**
 * @private
 * Process the game title prefixes to extract information such as game status, 
 * graphics engine used, and whether it is a mod or original game.
 * @param {puppeteer.Page} page Page containing the prefixes to be extrapolated
 * @param {GameInfo} info Object to assign the identified information to
 * @returns {Promise<GameInfo>} GameInfo object passed in to which the identified information has been added
 */
async function parsePrefixes(page, info) {
    const MOD_PREFIX = 'MOD';
    
    // The 'Ongoing' status is not specified, only 'Abandoned'/'OnHold'/'Complete'
    info.status = 'Ongoing';
    for (let handle of await page.$$(selectors.GAME_TITLE_PREFIXES)) {
        let value = await page.evaluate( /* istanbul ignore next */ (element) => element.innerText, handle);

        // Clean the prefix
        let prefix = value.toUpperCase().replace('[', '').replace(']', '').trim();

        // Getting infos...
        if (shared.statuses.includes(prefix)) info.status = prefix;
        else if (shared.engines.includes(prefix)) info.engine = prefix;

        // This is not a game but a mod
        else if (prefix === MOD_PREFIX) info.isMod = true;
    }
    return info;
}

/**
 * @private
 * Get game download links for different platforms.
 * @param {puppeteer.Page} page Page containing the links to be extrapolated
 * @returns {Promise<GameDownload[]>} List of objects used for game download
 */
async function getGameDownloadLink(page) {
    // Most used hosting platforms
    let hostingPlatforms = ['MEGA', 'NOPY', 'FILESUPLOAD', 'MIXDROP', 'UPLOADHAVEN', 'PIXELDRAIN', 'FILESFM'];
    
    // Supported OS platforms
    let platformOS = ['WIN', 'LINUX', 'MAC', 'ALL']

    // Gets the <span> which contains the download links
    let temp = await page.$$(selectors.DOWNLOAD_LINKS_CONTAINER);
    if(temp.length === 0) return [];

    // Look for the container that contains the links
    // It is necessary because the same css selector 
    // also identifies other elements on the page
    let container = null;
    for(let candidate of temp) {
        if (container !== null) break;
        let upperText = (await page.evaluate( /* istanbul ignore next */ (e) => e.innerText, candidate)).toUpperCase();

        // Search if the container contains the name of a hosting platform
        for (let p of hostingPlatforms) {
            if(upperText.includes(p)) {
                container = candidate;
                break;
            }
        }
    }
    if(container === null) return [];

    // Extract the HTML text from the container
    let searchText = (await page.evaluate( /* istanbul ignore next */ (e) => e.innerHTML, container)).toLowerCase();

    // Parse the download links
    let downloadData = [];
    for(let platform of platformOS) {
        let data = extractGameHostingData(platform, searchText);
        downloadData.push(...data);
    }
    return downloadData;
}

/**
 * @private
 * From the HTML text it extracts the game download links for the specified operating system.
 * @param {String} platform Name of the operating system to look for a compatible link to.
 * It can only be *WIN/LINUX/MAC/ALL*
 * @param {String} text HTML string to extract links from
 * @returns {GameDownload[]} List of game download links for the selected platform
 */
function extractGameHostingData(platform, text) {
    const PLATFORM_BOLD_OPEN = '<b>';
    const CONTAINER_SPAN_CLOSE = '</span>';
    const LINK_OPEN = '<a';
    const LINK_CLOSE = '</a>';
    const HREF_START = 'href="';
    const HREF_END = '\"';
    const TAG_CLOSE = '>';

    // Identify the individual platforms
    let startIndex = text.indexOf(platform.toLowerCase());
    if(startIndex === -1) return [];
    else startIndex += platform.length

    // Find the <b>platform</b>
    let endIndex = text.indexOf(
        PLATFORM_BOLD_OPEN,
        startIndex) + PLATFORM_BOLD_OPEN.length;

    // Find the end of the container
    if (endIndex === -1) text.indexOf(
        CONTAINER_SPAN_CLOSE,
        startIndex) + CONTAINER_SPAN_CLOSE.length;

    text = text.substring(startIndex, endIndex);
    
    let downloadData = [];
    let linkTags = text.split(LINK_OPEN);
    for(let tag of linkTags) {
        // Ignore non-link string
        if (!tag.includes(HREF_START)) continue;

        // Find the hosting platform name
        startIndex = tag.indexOf(TAG_CLOSE) + TAG_CLOSE.length;
        endIndex = tag.indexOf(LINK_CLOSE, startIndex);
        let hosting = tag.substring(startIndex, endIndex);

        // Find the 'href' attribute
        startIndex = tag.indexOf(HREF_START) + HREF_START.length;
        endIndex = tag.indexOf(HREF_END, startIndex);
        let link = tag.substring(startIndex, endIndex);

        if (isStringAValidURL(link)) {
            let gd = new GameDownload();
            gd.hosting = hosting.toUpperCase();
            gd.link = new URL(link);
            gd.supportedOS = platform.toUpperCase();

            downloadData.push(gd);
        }
    }
    return downloadData;
}
//#endregion Private methods