// Drives spike/gpu.html in headless Chromium: is a WebGL-backed CanvasKit
// surface fast enough to replace the CPU raster path (which measured 3.2s for a
// single 12MP tone pass in Node)? Run:
//   node spike/gpu-bench.mjs
import http from 'node:http';
import fs from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';
import { chromium } from 'playwright-core';

const here = path.dirname(fileURLToPath(import.meta.url));
const webRoot = path.resolve(here, '..');
const SAMPLES = process.env.W0_SAMPLES ?? '/tmp/w0';
const CK_BIN = path.join(webRoot, 'node_modules/canvaskit-wasm/bin');

const routes = [
  { prefix: '/bin/', dir: CK_BIN },
  { prefix: '/samples/', dir: SAMPLES },
  { prefix: '/', dir: path.join(webRoot, 'spike') },
];
const MIME = { '.js': 'text/javascript', '.wasm': 'application/wasm', '.html': 'text/html', '.jpg': 'image/jpeg', '.png': 'image/png' };

const server = http.createServer((req, res) => {
  const url = decodeURIComponent(req.url.split('?')[0]);
  const route = routes.find((r) => url.startsWith(r.prefix));
  if (!route) { res.writeHead(404).end(); return; }
  const rel = url.slice(route.prefix.length) || 'gpu.html';
  const file = path.join(route.dir, rel);
  fs.readFile(file, (err, data) => {
    if (err) { res.writeHead(404).end(String(err)); return; }
    res.writeHead(200, { 'content-type': MIME[path.extname(file)] ?? 'application/octet-stream' });
    res.end(data);
  });
});

await new Promise((r) => server.listen(0, '127.0.0.1', r));
const port = server.address().port;
console.log(`serving on ${port}`);

const browser = await chromium.launch({
  // The cached playwright build is chromium-1228 while playwright-core wants
  // 1243; point straight at the cached binary instead of downloading one.
  executablePath: process.env.CHROME_PATH ??
    '/home/locpham/.cache/ms-playwright/chromium-1228/chrome-linux64/chrome',
  args: ['--use-gl=angle', '--use-angle=swiftshader', '--enable-unsafe-swiftshader', '--no-sandbox'],
});
const page = await browser.newPage();
page.on('console', (m) => console.log('[browser]', m.text()));
page.on('pageerror', (e) => console.log('[pageerror]', e.message));
await page.goto(`http://127.0.0.1:${port}/gpu.html`, { waitUntil: 'load' });
await page.waitForFunction(() => document.title === 'done' || document.title === 'error', null, { timeout: 180000 });
console.log(await page.textContent('#out').catch(() => '(no output element)'));
const results = await page.evaluate(() => window.__results ?? null);
console.log('\njson:', JSON.stringify(results));
await browser.close();
server.close();