/**
 * Render every page of the diagnostic PDF using Chromium's built-in PDF viewer
 * and the pdf.js `applicationOptions` to size the viewport properly.
 */
import puppeteer from "puppeteer-core";
import { readFileSync, mkdirSync, readdirSync } from "fs";
import { join } from "path";

const CHROME = "/Applications/Google Chrome.app/Contents/MacOS/Google Chrome";
const PDF = "/tmp/rjbulk-pdfs/customer-delivery-diag.pdf";
const OUT_DIR = "/tmp/rjbulk-pdf-images";

mkdirSync(OUT_DIR, { recursive: true });

const browser = await puppeteer.launch({
  executablePath: CHROME,
  headless: "new",
  args: ["--no-sandbox", "--disable-gpu"],
});

// We embed the PDF in an <embed> on a blank HTML page so we can use the
// `#page=N` URL fragment which Chromium's PDF viewer honours.
const html = `<!doctype html><html><body style="margin:0;padding:0">
<embed src="file://${PDF}" type="application/pdf" width="100%" height="1200" id="pdf"/>
</body></html>`;
const hostPath = "/tmp/rjbulk-pdfs/_host.html";
const { writeFileSync } = await import("fs");
writeFileSync(hostPath, html);

const page = await browser.newPage();
await page.setViewport({ width: 900, height: 1300 });
await page.goto(`file://${hostPath}`, { waitUntil: "networkidle2", timeout: 30000 });
await new Promise((r) => setTimeout(r, 1500));

// 1/6 means 6 pages — read it from the toolbar
const totalPages = await page.evaluate(() => {
  const m = document.body.innerText.match(/\/\s*(\d+)/);
  return m ? parseInt(m[1], 10) : 1;
});
console.log(`Total pages: ${totalPages}`);

for (let i = 1; i <= totalPages; i++) {
  await page.goto(`file://${PDF}#page=${i}&zoom=100`, { waitUntil: "networkidle2" });
  await new Promise((r) => setTimeout(r, 600));
  await page.screenshot({ path: join(OUT_DIR, `diag-page-${String(i).padStart(2, "0")}.png`) });
  console.log(`  ✓ page ${i}`);
}

await browser.close();