scheduler.js

const cron = require('node-cron');
const { spawn } = require('child_process');
const fs = require('fs');
const path = require('path');
const logToFile = require('./logger');
const config = JSON.parse(fs.readFileSync('config.json', 'utf8'));

async function verifyTodaysImages() {
  const todaysDate = new Date().toISOString().split('T')[0];
  const subfolder = 'memes-archive';
  const imagesFolderPath = path.join(__dirname, subfolder, todaysDate);

  // check for memes-archive subfolder, make if not present
  if (!fs.existsSync(path.join(__dirname, subfolder))) {
    logToFile('made memes-archive folder');
    fs.mkdirSync(path.join(__dirname, subfolder));
  }

  // check for today's dated images folder, make if not present
  if (!fs.existsSync(imagesFolderPath)) {
    logToFile('made todays memes images folder');
    fs.mkdirSync(imagesFolderPath);
    // since we just made the folder, we need to run the script to download the images for today (since it won't exist yet)
    logToFile('today\'s memes images folder didn\'t exist yet, running script to download images');
    await runScript();
  }
  // if it does exist, make sure it contains the number of images we want, otherwise run the update again to populate them
  else if (fs.readdirSync(imagesFolderPath).length < config.imageCount) {
    logToFile('today\'s memes images folder exists but is missing images, running script to download images');
    await runScript();
  }
}

logToFile('Job scheduler for updating images is activated!');

// Schedule the task to run every day at 8 AM
cron.schedule('0 8 * * *', () => {
  logToFile('Running cron job...');
  runScript();
});

function runScript() {
  return new Promise((resolve, reject) => {
    logToFile('Running download-todays-memes.js script...');

    // Execute the download-todays-memes.js script
    const script = spawn('node', ['./download-todays-memes.js']);

    // Log the script's output
    script.stdout.on('data', (data) => {
      // trim the newline character from the end
      data = data.toString().trim();
      logToFile(data);
    });

    // Log any errors
    script.stderr.on('data', (data) => {
      // trim the newline character from the end
      data = data.toString().trim();
      logToFile(`Error: ${data}`);
    });

    // Log when the script is done running
    script.on('close', (code) => {
      logToFile(`Memes download script exited with code ${code} (${(code) ? 'There were errors' : 'No errors'})`);
      if (code === 0) {
        resolve();
      } else {
        // Script failed. Retry in 5 minutes and keep this promise chain alive until a retry succeeds.
        setTimeout(() => {
          runScript()
            .then(resolve)
            .catch(reject);
        }, 300000); // 5 minutes
      }
    });
  });
}

module.exports = verifyTodaysImages;