#!/usr/bin/env node
/**
 * Exports the evidence report to PDF, headlessly.
 *
 * Uses the Chromium that Playwright already installed, so there is no new
 * dependency and no need to open a browser by hand. The browser's own
 * File > Print also works and produces the same layout; this exists so the
 * export can be scripted, and so CI can attach a PDF to a build.
 *
 *   node scripts/report-pdf.mjs               everything
 *   node scripts/report-pdf.mjs --summary     summary plus the narrated scenarios only
 *   node scripts/report-pdf.mjs --out x.pdf   write somewhere else
 */

import { existsSync, mkdirSync, statSync } from 'node:fs';
import { dirname, isAbsolute, join, resolve } from 'node:path';
import { fileURLToPath, pathToFileURL } from 'node:url';

import { chromium } from '@playwright/test';

const E2E = resolve(dirname(fileURLToPath(import.meta.url)), '..');
const REPORT_DIR = join(E2E, 'evidence-report');
const SOURCE = join(REPORT_DIR, 'index.html');

const args = process.argv.slice(2);
const summaryOnly = args.includes('--summary');

const outFlag = args.indexOf('--out');
const requested = outFlag !== -1 ? args[outFlag + 1] : undefined;
const OUT = requested
  ? isAbsolute(requested)
    ? requested
    : resolve(process.cwd(), requested)
  : join(REPORT_DIR, summaryOnly ? 'TravelHub-test-report-summary.pdf' : 'TravelHub-test-report.pdf');

if (!existsSync(SOURCE)) {
  console.error(
    `No report found at ${SOURCE}\n` + 'Run the suite first:  npm run test:e2e',
  );
  process.exit(1);
}

const browser = await chromium.launch();

try {
  const page = await browser.newPage();
  await page.goto(pathToFileURL(SOURCE).href, { waitUntil: 'load' });

  const counts = await page.evaluate(async (opts) => {
    if (opts.summaryOnly) {
      // Drop scenarios that carry only a screenshot, then any area left empty.
      for (const el of document.querySelectorAll('.scenario')) {
        if (el.dataset.facts === '0') {
          el.remove();
        }
      }
      for (const area of document.querySelectorAll('.area')) {
        if (!area.querySelector('.scenario')) {
          area.remove();
        }
      }
    }

    // A collapsed <details> would print as a one-line summary.
    for (const details of document.querySelectorAll('details')) {
      details.open = true;
    }

    // Lazy images never load off-screen, and the PDF renderer does not scroll.
    // Only the screenshots: the lightbox holds an empty <img> that never loads.
    const images = [...document.querySelectorAll('img.shot')];
    for (const img of images) {
      img.loading = 'eager';
    }
    await Promise.all(
      images.map((img) =>
        img.complete
          ? null
          : new Promise((done) => {
              img.addEventListener('load', done, { once: true });
              img.addEventListener('error', done, { once: true });
            }),
      ),
    );

    return {
      scenarios: document.querySelectorAll('.scenario').length,
      images: images.length,
      unloaded: images.filter((i) => i.naturalWidth === 0).length,
    };
  }, { summaryOnly });

  if (counts.unloaded > 0) {
    console.warn(`  warning: ${counts.unloaded} screenshot(s) failed to load`);
  }

  await page.emulateMedia({ media: 'print' });

  const foot =
    '<div style="width:100%;font-size:8pt;color:#9ca3af;padding:0 12mm;' +
    'font-family:Segoe UI,Helvetica,Arial,sans-serif;display:flex;justify-content:space-between">' +
    '<span>TravelHub — test execution report</span>' +
    '<span>Page <span class="pageNumber"></span> of <span class="totalPages"></span></span>' +
    '</div>';

  mkdirSync(dirname(OUT), { recursive: true });

  await page.pdf({
    path: OUT,
    format: 'A4',
    printBackground: true,
    displayHeaderFooter: true,
    headerTemplate: '<div></div>', // suppress Chromium's default header
    footerTemplate: foot,
    margin: { top: '14mm', bottom: '16mm', left: '12mm', right: '12mm' },
  });

  const mb = (statSync(OUT).size / 1024 / 1024).toFixed(1);
  console.log(
    `PDF written: ${OUT}\n` +
      `  ${counts.scenarios} scenarios · ${counts.images} screenshots · ${mb} MB` +
      (summaryOnly ? '  (summary: narrated scenarios only)' : ''),
  );
} finally {
  await browser.close();
}