Zumri-Backend/app/logic/documents/engine/pdf.engine.js

/**
 * Copyright (c) 2026 Niolla
 * All rights reserved.
 *
 * This source code is proprietary and confidential.
 * Unauthorized copying, modification, distribution, or use
 * of this file, via any medium, is strictly prohibited.
 */

// app/logic/documents/engine/pdf.engine.js

const puppeteer = require("puppeteer");

const generatePDF = async (html) => {
  const launchConfig = {
    args: ["--no-sandbox", "--disable-setuid-sandbox"],
  };

  if (process.env.PUPPETEER_EXECUTABLE_PATH) {
    launchConfig.executablePath = process.env.PUPPETEER_EXECUTABLE_PATH;
  } else {
    launchConfig.headless = true;
  }

  const browser = await puppeteer.launch(launchConfig);

  try {
    const page = await browser.newPage();

    await page.setContent(html, {
      waitUntil: "load",
    });

    // Wait for fonts
    await page.evaluate(() => document.fonts?.ready);

    // Wait for images to fully decode
    await page.evaluate(async () => {
      const images = Array.from(document.images);

      await Promise.all(
        images.map((img) => {
          if (img.complete && img.naturalHeight !== 0) return;

          return new Promise((resolve) => {
            img.onload = resolve;
            img.onerror = resolve;
          });
        }),
      );
    });

    // Force layout + paint
    await page.evaluate(() => document.body.getBoundingClientRect());

    // Extra stability delay (important on servers)
    await new Promise((r) => setTimeout(r, 1000));

    const buffer = await page.pdf({
      format: "A4",
      printBackground: true,
    });

    return buffer;
  } finally {
    await browser.close();
  }
};

module.exports = { generatePDF };