const fs = require('fs/promises');
const path = require('path');
const { chromium } = require('playwright');
const pptxgen = require('pptxgenjs');

const inputUrl = process.argv[2];
const imageDir = process.argv[3];
const outputPptx = process.argv[4];

async function extractNotes(url) {
  const launchOptions = { headless: true };
  if (process.env.BROWSER_EXE) {
    launchOptions.executablePath = process.env.BROWSER_EXE;
  }

  const browser = await chromium.launch(launchOptions);
  const page = await browser.newPage({ viewport: { width: 1920, height: 1080 } });
  const baseUrl = url.includes('#') ? url.slice(0, url.indexOf('#')) : url;
  await page.goto(`${baseUrl}#1`, { waitUntil: 'load', timeout: 30000 });
  await page.waitForSelector('#speaker-notes', { state: 'attached', timeout: 10000 });
  const notes = await page.evaluate(() => JSON.parse(document.getElementById('speaker-notes').textContent));
  await browser.close();
  return notes;
}

(async () => {
  if (!inputUrl || !imageDir || !outputPptx) {
    throw new Error('Usage: node html_to_ppt_with_notes.js <file-url> <image-dir> <output-pptx>');
  }

  const notes = await extractNotes(inputUrl);
  const images = (await fs.readdir(imageDir))
    .filter((name) => /^slide_\d+\.png$/i.test(name))
    .sort()
    .map((name) => path.join(imageDir, name));

  if (notes.length !== images.length) {
    throw new Error(`Notes count (${notes.length}) does not match image count (${images.length})`);
  }

  await fs.mkdir(path.dirname(outputPptx), { recursive: true });
  await fs.writeFile(
    path.join(path.dirname(outputPptx), 'Generative_Image_Dynamics.notes.json'),
    JSON.stringify(notes.map((text, index) => ({ slide: index + 1, text })), null, 2),
    'utf8',
  );

  const pptx = new pptxgen();
  pptx.layout = 'LAYOUT_WIDE';
  pptx.author = 'Codex';
  pptx.subject = 'Generative Image Dynamics — CVPR 2024';
  pptx.title = 'Generative Image Dynamics';
  pptx.company = '';
  pptx.lang = 'en-US';
  pptx.theme = {
    headFontFace: 'Aptos',
    bodyFontFace: 'Aptos',
    lang: 'en-US',
  };

  for (let i = 0; i < images.length; i += 1) {
    const slide = pptx.addSlide();
    slide.background = { color: '000000' };
    slide.addImage({ path: images[i], x: 0, y: 0, w: 13.333333, h: 7.5 });
    slide.addNotes(notes[i]);
  }

  await pptx.writeFile({ fileName: outputPptx });
  console.log(`pptx=${outputPptx}`);
  console.log(`slides=${images.length}`);
  console.log(`notes=${notes.length}`);
})().catch((err) => {
  console.error(err);
  process.exit(1);
});