ngenv/ngenv

#!/usr/bin/env node
const fs = require("fs");
const os = require("os");
const path = require("path");
const { spawn, exec } = require("child_process");
const commandLineArgs = require("command-line-args");
const ngrok = require("ngrok");

const projectFolder = findProjectFolder();
if (!projectFolder) {
  console.error("No project folder found");
  process.exit(1);
}
if (!fs.existsSync(`${projectFolder}/.ngenv`)) {
  fs.mkdirSync(`${projectFolder}/.ngenv`);
}
const lockFile = `${projectFolder}/.ngenv/running.lock`;
const outLogFile = `${projectFolder}/.ngenv/out.log`;
const errLogFile = `${projectFolder}/.ngenv/err.log`;

let authToken = null; // string || null

function isAlreadyRunning() {
  return fs.existsSync(lockFile);
}

function createLockFile(pid) {
  fs.writeFileSync(lockFile, pid.toString());
}

function removeLockFile() {
  if (isAlreadyRunning()) {
    fs.unlinkSync(lockFile);
  }
}

function removeLogFiles() {
  if (fs.existsSync(outLogFile)) {
    fs.unlinkSync(outLogFile);
  }
  if (fs.existsSync(errLogFile)) {
    fs.unlinkSync(errLogFile);
  }
}

function startBackgroundProcess() {
  if (isAlreadyRunning()) {
    console.log("An instance is already running.");
    process.exit(1);
  }

  // Remove old log files
  removeLogFiles();

  const out = fs.openSync(outLogFile, "a");
  const err = fs.openSync(errLogFile, "a");

  const subprocess = spawn(
    process.argv[0],
    [process.argv[1], "background", ...process.argv.slice(3)],
    {
      detached: true,
      stdio: ["ignore", out, err],
    }
  );

  createLockFile(subprocess.pid);
  console.log(`Started background process with PID: ${subprocess.pid}`);

  subprocess.unref();
}

function stopBackgroundProcess() {
  if (!isAlreadyRunning()) {
    console.log("No running instance found.");
    return;
  }

  const pid = fs.readFileSync(lockFile, "utf-8");

  exec(`ps -p ${pid}`, (error, stdout, stderr) => {
    if (error || stderr) {
      console.log(`No process with PID ${pid} is running.`);
      removeLockFile();
      return;
    }

    // If the process exists, attempt to kill it
    try {
      process.kill(pid, "SIGTERM");
      removeLockFile();
      console.log(`Stopped process with PID: ${pid}`);
    } catch (err) {
      console.error(
        `Failed to stop process with PID: ${pid}. Error: ${err.message}`
      );
    }
  });
}

function readLog(path) {
  try {
    return fs.readFileSync(path, "utf-8");
  } catch (err) {
    return "";
  }
}

function displayLogs() {
  const outLog = readLog(outLogFile);
  const errLog = readLog(errLogFile);

  console.log("STDOUT:\n", outLog.trimStart());
  console.log("STDERR:\n", errLog.trimStart());
}

function clearLogs() {
  fs.rmSync(outLogFile, { force: true });
  fs.rmSync(errLogFile, { force: true });

  console.log("Log files cleared.");
}

function getOptions() {
  const optionDefinitions = [
    { name: "proto", alias: "P", type: String },
    { name: "port", alias: "p", type: Number },
    { name: "env", alias: "e", type: String },
  ];

  // Parse options, skipping the first three arguments ('node', script name and verb)
  const options = commandLineArgs(optionDefinitions, {
    argv: process.argv.slice(3),
  });

  return options;
}

// Process command line arguments
if (process.argv[2] === "start") {
  // The result is only used in the background process, but the check is also done here, before the
  // background process is started to prevent bad arguments from being passed to the background process.
  getOptions();
  // Spawn the background process
  startBackgroundProcess();
} else if (process.argv[2] === "stop") {
  // Stop the background process
  stopBackgroundProcess();
} else if (process.argv[2] === "clear") {
  // Clear the log files
  clearLogs();
} else if (process.argv[2] === "logs") {
  // Display the log files
  displayLogs();
  // tailLogs();
} else if (process.argv[2] === "run" || process.argv[2] === "background") {
  if (process.argv[2] === "background") {
    // Start-up for the background process
    process.on("SIGTERM", () => {
      console.log("Stopping background process...");
      removeLockFile();
      process.exit(0);
    });
    process.on("exit", (code) => {
      console.log(`About to exit with code: ${code}`);
      // Perform cleanup or final operations here
      removeLockFile();
    });
  }

  const options = getOptions();
  backgroundMain(options);
} else {
  const scriptName = path.basename(process.argv[1]);
  console.log(`Usage: node ${scriptName} [run|start|stop|logs|clear]`);
  console.log(`\nCommands:`);
  console.log(
    `  start\t\tStart the background process if it's not already running.`
  );
  console.log(`  stop\t\tStop the background process if it's running.`);
  console.log(`  logs\t\tDisplay the output and error logs.`);
  console.log(`  clear\t\tClear the content of the output and error logs.`);
  console.log(`\nExample:`);
  console.log(`  node ${scriptName} start\t\t# Starts the background process`);
}

async function backgroundMain(options) {
  // Get the ngrok config file path
  let ngrokConfig = getNgrokConfig();

  // Check if the ngrok config file exists
  if (!fs.existsSync(ngrokConfig)) {
    throw new Error("No ngrok config file found");
  }

  // Read the ngrok config file
  try {
    const { authToken } = readNgrokConfig(ngrokConfig);
    global.authToken = authToken;
  } catch (err) {
    console.error(err);
    process.exit(1);
  }

  // Start ngrok
  const proto = options?.proto ?? "http";
  const addr = options?.port ? options.port : 3000;
  try {
    const url = await ngrok.connect({
      authtoken: authToken,
      proto,
      addr,
      onLogEvent: (data) => {
        // console.log(data);
      },
    });
    writeDotEnv(url); // Sync the .env file
    console.log(`Started ngrok: protocol '${proto}', addr '${addr}'`);
    console.log(`Your current ngrok url is ${url}.`);
    console.log(`Your .env file has been updated.`);
  } catch (err) {
    console.error(err.message);
    process.exit(1);
  }
}

function getNgrokConfig() {
  // Newer versions of ngrok
  let ngrokConfig = os.homedir() + "/.ngrok2/ngrok.yml";
  if (fs.existsSync(ngrokConfig)) {
    return ngrokConfig;
  }

  // Alternative location for linux
  ngrokConfig = os.homedir() + "/.config/ngrok/ngrok.yml";
  if (fs.existsSync(ngrokConfig)) {
    return ngrokConfig;
  }

  // MacOS
  ngrokConfig = os.homedir() + "/Library/Application Support/ngrok/ngrok.yml";
  if (fs.existsSync(ngrokConfig)) {
    return ngrokConfig;
  }

  // Windows
  ngrokConfig = os.homedir() + "/AppData/Local/ngrok/ngrok.yml";
  if (fs.existsSync(ngrokConfig)) {
    return ngrokConfig;
  }

  throw new Error("ngrok config file not found");
}

function readNgrokConfig(ngrokConfig) {
  const data = fs.readFileSync(ngrokConfig, "utf8");

  let authToken;

  // Convert string to string array, split at newlines
  let lines = data.split("\n"); // string[]

  // find the auth token (format: authtoken: token_goes_here)
  lines.forEach((element) => {
    const [name, value] = element.split(": ");
    if (name === "authtoken") authToken = value;
  });

  // No token found
  if (!authToken) {
    // https://dashboard.ngrok.com/get-started/your-authtoken
    throw new Error("Setup NGROK_AUTHTOKEN in your .env file");
  }

  return { authToken };
}

function findProjectFolder(filename = ".env") {
  // Walk the path to find .env file... options?.env
  let currentDir = __dirname;
  while (true) {
    const packageJsonPath = path.join(currentDir, "package.json");
    if (fs.existsSync(packageJsonPath)) {
      break;
    }
    const envPath = path.join(currentDir, filename);
    if (fs.existsSync(envPath)) {
      break;
    }
    const parentDir = path.resolve(currentDir, "..");
    if (parentDir === currentDir) {
      throw new Error("No project folder found");
    }
    currentDir = parentDir;
  }
  return currentDir;
}

// Walk the path to find .env file...
function findDotEnv(filename = ".env") {
  const currentDir = findProjectFolder(filename);
  return `${currentDir}/${filename}`;
}

function readDotEnv(path) {
  const data = fs.readFileSync(path, "utf8");

  // Convert string to string array, split at newlines
  let lines = data.split("\n"); // string[]

  return lines;
}

function writeDotEnv(url) {
  // Read the .env file
  let lines = readDotEnv(findDotEnv());

  // Rebuild lines with the new url
  let found = false;
  lines = lines.map((element) => {
    const [name] = element.split("=");
    if (name === "NGROK_SERVERHOST") {
      found = true;
      return `${name}=${url}`;
    }
    return element;
  });

  // Is this variable already in the .env, if not add it.
  if (!found) {
    lines.unshift(`NGROK_SERVERHOST=${url}`);
  }

  // convert back to string format
  let writeData = "";
  lines.forEach((element) => {
    writeData += element + "\n";
  });
  writeData = writeData.slice(0, writeData.length - 1);

  // Write the new .env file
  fs.writeFileSync(findDotEnv(), writeData);
}