import puppeteer from 'puppeteer';
import fs from 'fs';
import moment from 'moment';
import PDFMerger from 'pdf-merger-js';

// get params from console
let [
  url,
  title = '',
  subtitle = '',
  date = moment().format('YYYY-MM-DD')
] = process.argv.slice(2);

const path = './pdf';

if (!fs.existsSync(path)) fs.mkdirSync(path);


let browser;
try{
  // start puppeteer
  browser = await puppeteer.launch({
    headless: true,
    args: [
      "--disable-gpu",
      "--disable-dev-shm-usage",
      "--disable-setuid-sandbox",
      "--no-sandbox",
    ]
  });

  // open page
  const page = await browser.newPage();
  page.setDefaultNavigationTimeout(0);
  await page.goto(url);
  await Promise.any([
    page.mainFrame().waitForNavigation({waitUntil: 'networkidle0'}),
    new Promise(resolve => setTimeout(resolve,2000))
  ]);

  // search for header and subheader in document
  if (!title) title = await (await page.waitForSelector('h1')).evaluate(el => el.textContent);
  if (!subtitle) subtitle = await (await page.waitForSelector('h2')).evaluate(el => el.textContent);
  console.log(title,subtitle);

  const filename = `${date}_${title.trim().replaceAll(' ', '_')}`;

  // deactivate @print css and add custom css (for pretty code)
  await page.emulateMediaType('screen');
  await page.addStyleTag({content: `
    .hidden-print {
      display: none !important;
    }
    *:not(code, .code > *){
      color: #000 !important;
    }
  `});

  // create pdf for pages
  const pages = await page.pdf({
    //path: `${path}/${filename}_pages.pdf`,
    format: 'A4',
    margin: {
      top: '20mm',
      bottom: '20mm',
      left: '12mm',
      right: '12mm'
    },
    displayHeaderFooter: true,
    headerTemplate: `
      <div style="
        text-align: center;
        color: #000;
        font-family: sans-serif;
        font-size: 10px;
        width: 100%;
        padding: 2mm;
        border-bottom: 1px #222 solid;
      ">${[title, subtitle].map(el=>el.trim()).filter(el=>!!el).join(' - ')}</div>
    `,
    footerTemplate: `
      <div style="
        text-align: center;
        color: #000;
        font-family: sans-serif;
        font-size: 10px;
        width: 100%;
        padding: 2mm;
      ">Page <span class="pageNumber"></span></div>
    `,
    printBackground: true
  });

  // load cover template and replace values
  let coverHTML = fs.readFileSync('./cover.html', {encoding: 'utf-8', flag: 'r'});

  Object.entries({
    title, subtitle, date
  }).forEach(([key, value]) => {
    coverHTML = coverHTML.replaceAll(`{{${key}}}`, value);
  });

  // open new page and set template
  const page2 = await browser.newPage();
  await page2.setContent(coverHTML);

  // create pdf for cover
  const cover = await page2.pdf({
    //path: `${path}/${filename}_cover.pdf`,
    format: 'A4',
    margin: {
      top: '20mm',
      bottom: '20mm',
      left: '12mm',
      right: '12mm'
    }
  });

  // close puppeteer
  await browser.close();

  // merge both pdfs and save
  const merger = new PDFMerger();
  merger.add(cover);
  merger.add(pages);
  await merger.save(`${path}/${filename}.pdf`)

  console.log('finished');
  console.log(`saved at ${path}/${filename}.pdf`);

} catch (e) {
  // try to close browser on exception
  if (browser) await browser.close();
  console.error(e);
}