import puppeteer, { PaperFormat } from "puppeteer";

import { env } from "../config/env.js";

interface PdfOptions {
  format?: PaperFormat;
  width?: string;
  height?: string;
  margin?: { top?: string; right?: string; bottom?: string; left?: string };
}

export async function renderPdf(html: string, options?: PdfOptions) {
  const browser = await puppeteer.launch({
    executablePath: env.PUPPETEER_EXECUTABLE_PATH,
    headless: true,
    args: ["--no-sandbox", "--disable-setuid-sandbox", "--disable-dev-shm-usage"],
  });

  try {
    const page = await browser.newPage();
    await page.setContent(html, { waitUntil: "networkidle0" });

    const pdf = await page.pdf({
      format: options?.width || options?.height ? undefined : (options?.format || "A4"),
      width: options?.width,
      height: options?.height,
      margin: options?.margin,
      printBackground: true,
      preferCSSPageSize: true,
    });

    // Normalize Puppeteer's Uint8Array output to a Node Buffer so Express sends a valid PDF payload.
    return Buffer.from(pdf);
  } finally {
    await browser.close();
  }
}