lbry-desktop/build/downloadDaemon.js

const path = require('path');
const fs = require('fs');
const packageJSON = require('../package.json');
const fetch = require('node-fetch');
const decompress = require('decompress');
const os = require('os');
const del = require('del');

const downloadDaemon = targetPlatform =>
  new Promise((resolve, reject) => {
    const daemonURLTemplate = packageJSON.lbrySettings.lbrynetDaemonUrlTemplate;
    const daemonVersion = packageJSON.lbrySettings.lbrynetDaemonVersion;
    const daemonDir = path.join(__dirname, '..', packageJSON.lbrySettings.lbrynetDaemonDir);
    let daemonFileName = packageJSON.lbrySettings.lbrynetDaemonFileName;

    const currentPlatform = os.platform();

    let daemonPlatform = process.env.TARGET || targetPlatform || currentPlatform;
    if (daemonPlatform === 'mac' || daemonPlatform === 'darwin') daemonPlatform = 'mac';
    if (daemonPlatform === 'win32' || daemonPlatform === 'windows') {
      daemonPlatform = 'windows';
      daemonFileName += '.exe';
    }
    const daemonFilePath = path.join(daemonDir, daemonFileName);
    const daemonVersionPath = path.join(__dirname, 'daemon.ver');
    const tmpZipPath = path.join(__dirname, '..', 'dist', 'daemon.zip');
    const daemonURL = daemonURLTemplate.replace(/DAEMONVER/g, daemonVersion).replace(/OSNAME/g, daemonPlatform);

    // If a daemon and daemon.ver exists, check to see if it matches the current daemon version
    const hasDaemonDownloaded = fs.existsSync(daemonFilePath);
    const hasDaemonVersion = fs.existsSync(daemonVersionPath);
    let downloadedDaemonVersion;

    if (hasDaemonVersion) {
      downloadedDaemonVersion = fs.readFileSync(daemonVersionPath, 'utf8');
    }

    if (hasDaemonDownloaded && hasDaemonVersion && downloadedDaemonVersion === daemonVersion) {
      console.log('\x1b[34minfo\x1b[0m Daemon already downloaded');
      resolve('Done');
    } else {
      console.log('\x1b[34minfo\x1b[0m Downloading daemon...');
      fetch(daemonURL, {
        method: 'GET',
        headers: {
          'Content-Type': 'application/zip',
        },
      })
        .then(response => response.buffer())
        .then(
          result =>
            new Promise((newResolve, newReject) => {
              const distPath = path.join(__dirname, '..', 'dist');
              const hasDistFolder = fs.existsSync(distPath);

              if (!hasDistFolder) {
                fs.mkdirSync(distPath);
              }

              fs.writeFile(tmpZipPath, result, error => {
                if (error) return newReject(error);
                return newResolve();
              });
            })
        )
        .then(() => del(`${daemonFilePath}*`))
        .then()
        .then(() =>
          decompress(tmpZipPath, daemonDir, {
            filter: file => path.basename(file.path) === daemonFileName,
          })
        )
        .then(() => {
          console.log(`\x1b[32msuccess\x1b[0m Daemon downloaded! - v${daemonVersion}`);
          if (hasDaemonVersion) {
            del(daemonVersionPath);
          }

          fs.writeFileSync(daemonVersionPath, daemonVersion, 'utf8');
          resolve('Done');
        })
        .catch(error => {
          console.error(`\x1b[31merror\x1b[0m Daemon download failed due to: \x1b[35m${error}\x1b[0m`);
          reject(error);
        });
    }
  });

downloadDaemon();