const fs = require("node:fs");
const https = require("node:https");
const path = require("node:path");
const child_process = require("node:child_process");
const crypto = require("node:crypto");

const manifestURL = "https://cdn.plutonium.pw/updater/prod/info.json";

var basePath = path.join(process.env["LOCALAPPDATA"], "Plutonium");

function httpsGet(url) {
	return new Promise(function (resolve, reject) {
		var request = https.request(url, function (response) {
			var body = "";

			response.setEncoding("utf-8");
			response.on("data", function (chunk) {
				body += chunk;
			});

			response.on("end", function () {
				resolve({
					"status": response.statusCode,
					"headers": response.headers,
					"body": body
				});
			});
		});

		request.on("error", function (error) {
			reject(error.message);
		});

		request.end();
	});
}

function httpsDownload(url, filePath) {
	return new Promise(function (resolve, reject) {
		var fileDirectory = path.dirname(filePath);

		if (!fs.existsSync(fileDirectory)) {
			fs.mkdirSync(fileDirectory, {
				"recursive": true
			});
		}

		var fileWriter = fs.createWriteStream(filePath);

		var request = https.request(url, function (response) {
			var body = "";

			response.pipe(fileWriter);

			response.on("end", function () {
				resolve();
			});
		});

		request.on("error", function (error) {
			reject(error.message);
			fileWriter.close();
		});

		request.end();
	});
}

function getFileSHA1(filePath) {
	return new Promise(function (resolve, reject) {
		var fileStream = fs.createReadStream(filePath);

		var hash = crypto.createHash("sha1");
		hash.setEncoding("hex");

		fileStream.on("end", function () {
			hash.end();

			resolve(hash.read());
		});

		fileStream.pipe(hash);
	});
}

async function checkFiles(manifest) {
	var filesToDownload = [];

	for (var f = 0; f < manifest.files.length; f++) {
		var file = manifest.files[f];
		var filePath = path.join(basePath, ...(file.name.split("/")));

		if (!fs.existsSync(filePath)) {
			console.log("File " + file.name + " needs to be downloaded. ");
			filesToDownload.push(file);
			continue;
		}

		var sum = await getFileSHA1(filePath);

		if (sum !== file.hash) {
			console.log("File " + file.name + " needs to be downloaded again. ");
			filesToDownload.push(file);
		} else {
			console.log("File " + file.name + " doesn't need to be downloaded again. ");
		}
	}

	return filesToDownload;
}

async function downloadFiles(baseURL, files) {
	for (var f = 0; f < files.length; f++) {
		var file = files[f];
		var filePath = path.join(basePath, ...(file.name.split("/")));

		console.log("Downloading file " + file.name + "... ");

		await httpsDownload(baseURL + file.hash, filePath);
	}
}

function launchLauncher() {
	console.log("Launching the launcher ! ");

	var launcherPath = path.join(basePath, "bin", "plutonium-launcher-win32.exe");

	var subprocess = child_process.spawn(launcherPath, [], {
		"detached": true,
		"stdio": "ignore"
	});

	subprocess.on("spawn", function () {
		subprocess.unref();
	});
}

console.log("Getting manifest...");
httpsGet(manifestURL).then(async function (response) {
	try {
		var data = JSON.parse(response.body);

		checkFiles(data).then(function (wrongFiles) {
			if (wrongFiles.length > 0) {
				console.log("We have " + wrongFiles.length + " files to download. ");
				downloadFiles(data.baseUrl, wrongFiles).then(function () {
					launchLauncher().then(function () {

					}).catch(function (error) {
						console.error("An error has occurred while opening the launcher. \n" + error.stack);
					});

				}).catch(function (error) {
					console.error("An error has occurred while downloading a file. \n" + error.stack);
				});
			} else {
				console.log("All files seem good ! ");
			}
		}).catch(function (error) {
			console.error("An error has occurred while checking the files. \n" + error.stack);
		});
	} catch (error) {
		console.error("An error has occurred while decoding the main manifest. \n" + error.stack);
	}
}).catch(function (error) {
	console.error("An error has occurred while getting the main manifest. \n" + error.stack);
});