index.js

import sqlite3 from "sqlite3";
import AdmZip from "adm-zip";
import PDFMerger from "pdf-merger-js";
import fetch from "node-fetch";
import fsExtra from "fs-extra";
import fs from "fs/promises";
import yargs from "yargs";
import PromptSync from "prompt-sync";

const prompt = PromptSync({ sigint: true });

const argv = yargs(process.argv)
    .option("platform", {
        alias: "p",
        description:
            'Platform to download from, either "hubyoung" or "hubkids"',
        type: "string",
		choices: ["hubyoung", "hubkids"]
    })
    .option("volumeId", {
        alias: "v",
        description: "Volume ID of the book to download",
        type: "string",
    })
    .option("token", {
        alias: "t",
        description: "Token of the user",
        type: "string",
    })
    .option("file", {
        alias: "f",
        description: "The output file (defaults to book name)",
        type: "string",
    })
	.option("noCleanUp", {
		alias: "n",
		description: "Don't clean up the temp folder after merging",
		type: "boolean",
		default: false
	})
    .help()
    .alias("help", "h").argv;



(async () => {
	await fsExtra.ensureDir("temp");

	// make sure folder is empty
	await fs.readdir("temp").then(async files => {
		for (const file of files) {
			await fsExtra.remove(`temp/${file}`);
		}
	});

    let platform = argv.platform;

    while (!platform) {
        platform = prompt(
            "Input the platform (either 'hubyoung' or 'hubkids'): "
        );
        if (platform !== "hubyoung" && platform !== "hubkids") {
            console.log(
                "Invalid platform, please input either 'hubyoung' or 'hubkids'"
            );
            platform = null;
        }
    }
    platform = platform === "hubyoung" ? "young" : "kids";

    let volumeId = argv.volumeId;
    while (!volumeId) volumeId = prompt("Input the volume ID: ");

    let token = argv.token;
    while (!token) token = prompt("Input the token: ");

	console.log("Fetching book info...");

	let title;

    let response = await fetch("https://ms-api.hubscuola.it/me" + platform + "/publication/" + volumeId, { method: "GET", headers: { "Token-Session": token, "Content-Type": "application/json" } });
    const code = response.status;
    if (code === 500) {
        console.log("Volume ID not valid");
    } else if (code === 401) {
        console.log("Token Session not valid, you may have copied it wrong or you don't own this book.");
    } else {
        let result = await response.json();
        title = result.title;
        console.log(`Downloading "${title}"...`);
    }

	console.log("Downloading chapter...");

	var res = await fetch(
		`https://ms-mms.hubscuola.it/downloadPackage/${volumeId}/publication.zip?tokenId=${token}`,
		{ headers: { "Token-Session": token } }
	);
	if (res.status !== 200) {
		console.error("API error:", res.status);
		reject(res.status);
	}

	console.log("Extracting...");

    const zip = new AdmZip(Buffer.from(await res.arrayBuffer()));
    await zip.extractAllTo("temp/extracted-files");

	console.log("Reading chapter list...");

	let db = new sqlite3.Database(
		"./temp/extracted-files/publication/publication.db",
		(err) => {
			if (err) {
				console.error(err.message);
				process.exit(1);
			}
		}
	);
	let chapters = await new Promise((resolve) => {
		db.get("SELECT offline_value FROM offline_tbl WHERE offline_path=?",[`meyoung/publication/${volumeId}`], (err, row) => {
			resolve(JSON.parse(row.offline_value).indexContents.chapters);
		});
	});
	db.close();

	console.log("Downloading pages...")

	for (const chapter of chapters) {
        const url = `https://ms-mms.hubscuola.it/public/${volumeId}/${chapter.chapterId}.zip?tokenId=${token}&app=v2`;
        var res = await fetch(url, {
            headers: { "Token-Session": token },
        }).then((res) => res.arrayBuffer());
        const zip = new AdmZip(Buffer.from(res));
        await zip.extractAllTo(`temp/build`);
    }

	console.log("Merging pages...");

	const merger = new PDFMerger();
    for (const chapter of chapters) {
        let base = `./temp/build/${chapter.chapterId}`;
        const files = fsExtra.readdirSync(base);
        for (const file of files) {
            if (file.includes(".pdf")) {
                await merger.add(`${base}/${file}`);
            }
        }
    }
    merger.save(argv.file || `${title}.pdf`);

    if (!argv.noCleanUp) fsExtra.removeSync("temp");

    console.log("Book saved");

})();