garf.js

const got = require('got');
const fs = require('fs');
const os = require('os');
const { exec } = require('child_process');

const api = `http://images.ucomics.com/comics/ga`;
const startDate = new Date('19 June 1978 00:00:00 GMT');

function generateComicURL(date) {
  // http://images.ucomics.com/comics/ga/2000/ga001231.gif

  let day = String(date.getDate()).padStart(2, '0');
  let month = String(date.getMonth() + 1).padStart(2, '0');
  let year = String(date.getFullYear());

  return `${api}/${year}/ga${year.slice(2, 4)}${month}${day}`;
}

function randomComic() {
  let ms = startDate.getTime() + Math.random() * (Date.now() - startDate.getTime());
  return generateComicURL(new Date(ms));
}

function renderComic(data, format) {
  let file = `${os.tmpdir}/garfield.${format}`;

  fs.writeFileSync(file, data);
  exec(`viu -s -t ${file}`, (stdout, stderr) => {
    console.log(stderr || stdout);
    fs.unlinkSync(file);
  });
}

async function fetchComic(url) {
  let data;
  let format;

  try {
    data = await got(`${url}.gif`);
    format = 'gif';
  } catch(_) {
    data = await got(`${url}.jpg`);
    format = 'jpg';
  }

  return [data.rawBody, format];
}

async function renderRandomComic() {
  let comic = randomComic();
  let res = await fetchComic(comic);
  renderComic(res[0], res[1]);
}

renderRandomComic();