const pdf = require("pdf-creator-node");
const QRCode = require("qrcode");
const fs = require("fs");
const path = require("path");
// Read HTML Template
const html = fs.readFileSync(path.join(__dirname, "./template.html"), "utf8");

// from https://stackoverflow.com/questions/58325771/how-to-generate-random-hex-string-in-javascript
const genRanHex = (size) =>
	[...Array(size)]
		.map(() => Math.floor(Math.random() * 16).toString(16))
		.join("");

const options = {
	format: "A4",
	orientation: "portrait",
	border: "0mm",
};

function generate_qrcodes(urldata) {
	return QRCode.toDataURL([{data: urldata, mode: 'Byte'}], { errorCorrectionLevel: 'L', margin: 0 });
}

const allPromises = [];
const promiseData = [];
for (let i = 0; i < 6 * 8; i++) {
	const randData = genRanHex(8);
	allPromises.push(generate_qrcodes("https://inventory.internal.thegreydiamond.de/" + randData));
	promiseData.push(randData);
}

Promise.all(allPromises).then((results) => {
	// console.log(results);

	const data = [];

	// Group qr codes into 8 per list element
	for (let i = 0; i < results.length; i += 6) {
		data.push({
			q0: {url: results[i], data: promiseData[i]},
			q1: {url: results[i + 1], data: promiseData[i + 1]},
			q2: {url: results[i + 2], data: promiseData[i + 2]},
			q3: {url: results[i + 3], data: promiseData[i + 3]},
			q4: {url: results[i + 4], data: promiseData[i + 4]},
			q5: {url: results[i + 5], data: promiseData[i + 5]},
		});
	}

	// console.log(users);

	const document = {
		html: html,
		data: { data: data },
		path: "./output.pdf",
		type: "",
	};
	// By default a file is created but you could switch between Buffer and Streams by using "buffer" or "stream" respectively.

	/* var document = {
	html: html,
	data: {
		users,
	},
	path: "./output.pdf",
	type: "", // "stream" || "buffer" || "" ("" defaults to)
}; */

	pdf.create(document, options)
		.then((res) => {
			console.log(res);
		})
		.catch((error) => {
			console.error(error);
		});
});