node-helpers/dev-server-sse/index.ts

import path from 'node:path';
import fs from 'node:fs/promises';
import { setTimeout } from 'node:timers/promises';
import url from 'node:url';

import localIpUrl from 'local-ip-url';
import { parseGameStateFromAsyncIterator, InitOptions } from 'snakepipe';

import { makeServer } from './server.js'

/**
 * `__dirname` doesn't exist in esm, you need to create it.
 *
 * We could improve the code bellow with just `import.meta.dirname` - it needs at least node 20.11.
 * For the moment keeping retrocompatibility with all node 20 versions.
 *
 * Source: https://nodejs.org/docs/v20.11.0/api/esm.html#importmetadirname
 */
const __dirname = url.fileURLToPath(new URL('.', import.meta.url)); // __dirname for esm

const ExitCodeUsageError = 64; // The command was used incorrectly, e.g., with the wrong number of arguments, a bad flag, a bad syntax in a parameter, etc.

if (process.argv.length < 3) {
  console.log("You must pass the path of the file containing the recording of a game.");
  process.exit(ExitCodeUsageError);
}
if (process.argv.length > 3) {
  console.log("Too many arguments passed");
  process.exit(ExitCodeUsageError);
}

const [filePathOfGameRecording] = process.argv.slice(2, 3);

let resolvedFilePathOfGameRecording: string | null = null;

if (path.isAbsolute(filePathOfGameRecording)) {
  resolvedFilePathOfGameRecording = filePathOfGameRecording
} else {
  resolvedFilePathOfGameRecording = path.resolve(process.cwd(), filePathOfGameRecording);
}

main(resolvedFilePathOfGameRecording);

async function* infiniteAsyncGeneratorFromArrayString(input: Array<string>, delay = 120) {
  let currentIndex = 0;
  yield input[currentIndex];
  while (true) {
    currentIndex++;
    if (input[currentIndex]?.trim()) {
      await setTimeout(delay);
      yield input[currentIndex]
    }
    else {
      // loop back
      currentIndex = 1;
    }
  }
}

function makeInitOptionWithLocalIp(initOptions: InitOptions, port: number): InitOptions {
  const localIp = localIpUrl();
  return {
    ...initOptions,
    metadatas: {
      ...(initOptions.metadatas || {}),
      'render-browser-host': `https://${localIp}:${port}`
    }
  }
}

async function main(resolvedFilePathOfGameRecording: string, port = 8080) {
  const staticFolder = path.resolve(__dirname, '../..', 'static');
  const fileContent =
    (await fs.readFile(resolvedFilePathOfGameRecording))
      .toString()
      .split('\n')
      .filter(Boolean);
  const asyncGenerator = infiniteAsyncGeneratorFromArrayString(fileContent)
  const { options, lines } = await parseGameStateFromAsyncIterator(asyncGenerator);
  const initOptionsWithLocalIp = makeInitOptionWithLocalIp(options, port);
  makeServer({ options: initOptionsWithLocalIp, lines }, staticFolder).listen({ port, host: "0.0.0.0" }).then(() => {
    console.log(`Listening on ${initOptionsWithLocalIp.metadatas?.['render-browser-host']}`);
  });
}