// Platform decode capabilities and browser-sink §4.7's choice, in a browser
// (extensions/platform-decode.md, extensions/browser-sink.md).
//
// Build the page's bundle first, from wai/wai-web:
//
//   cargo build --release --target wasm32-unknown-unknown --features platform_decode
//   wasm-bindgen --target web --out-dir demo/pkg-platform --out-name wai_platform_decode \
//     target/wasm32-unknown-unknown/release/wai_web.wasm
//
// then, with Playwright installed under PLAYWRIGHT_HOST:
//
//   [WAI_PLATFORM_BROWSER_CHANNEL=chrome] PLAYWRIGHT_HOST=<dir with node_modules/playwright>/ \
//     node wai/wai-web/demo/verify_platform_decode.mjs
//
// It serves wai-web/demo and wai/pack-conformance on 127.0.0.1, lists the AV1 floor
// objects of the packaging corpus (WAI1 envelopes of wai.video.av1) as objects.json,
// opens platform_decode.html in a headless browser and prints the page's report. It fails
// on a page error, on an AV1 object that does not decode every temporal unit through
// WebCodecs with the configuration the reference's query gives, on an HEVC stream the
// platform's encoder wrote that does not decode back with the derived configuration, and
// on a choice that is not the one the ranks give: the learned alternative without a figure
// last and AV1 chosen; with the synthetic figure, the learned alternative ranked classical
// and the first in the order chosen.
import http from "node:http";
import fs from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { createRequire } from "node:module";

const HERE = path.dirname(fileURLToPath(import.meta.url));
const PACKS = path.resolve(HERE, "../../pack-conformance");
const PORT = Number(process.env.PORT || 8798);
const { chromium } = createRequire(process.env.PLAYWRIGHT_HOST || HERE + "/")("playwright");

/// The AV1 floor objects: WAI1 envelopes ("WAI1", a u32 manifest length, the manifest)
/// whose manifest's capability is wai.video.av1.
function av1Objects() {
  const out = [];
  const packs = path.join(PACKS, "packs");
  for (const p of fs.readdirSync(packs).sort()) {
    const dir = path.join(packs, p, "package", "objects");
    if (!fs.existsSync(dir)) continue;
    for (const f of fs.readdirSync(dir).sort()) {
      const b = fs.readFileSync(path.join(dir, f));
      if (b.length < 8 || b.toString("latin1", 0, 4) !== "WAI1") continue;
      const m = JSON.parse(b.toString("utf8", 8, 8 + b.readUInt32LE(4)));
      if (m.model_requirement && m.model_requirement.capability === "wai.video.av1") out.push(`/pack-conformance/packs/${p}/package/objects/${f}`);
    }
  }
  return out;
}

const objects = av1Objects();
const ROOTS = { "/pack-conformance/": PACKS, "/demo/": HERE };
const MIME = { ".js": "text/javascript", ".wasm": "application/wasm", ".html": "text/html", ".json": "application/json" };
const server = http.createServer((req, res) => {
  const url = decodeURIComponent(req.url.split("?")[0]);
  if (url === "/demo/objects.json") {
    res.writeHead(200, { "content-type": "application/json" });
    return res.end(JSON.stringify(objects));
  }
  const prefix = Object.keys(ROOTS).find((p) => url.startsWith(p));
  const root = prefix && ROOTS[prefix];
  const f = root && path.resolve(root, "." + url.slice(prefix.length - 1));
  if (!f || !f.startsWith(root + path.sep) || !fs.existsSync(f) || !fs.statSync(f).isFile()) {
    res.writeHead(404);
    return res.end("not found");
  }
  res.writeHead(200, { "content-type": MIME[path.extname(f)] || "application/octet-stream" });
  fs.createReadStream(f).pipe(res);
});

let browser;
try {
  if (!fs.existsSync(path.join(HERE, "pkg-platform", "wai_platform_decode.js"))) {
    console.error("no pkg-platform/wai_platform_decode.js; build it as this file's header says");
    process.exit(2);
  }
  if (objects.length === 0) {
    console.error("no AV1 floor object found under pack-conformance/packs");
    process.exit(2);
  }
  await new Promise((r) => server.listen(PORT, "127.0.0.1", r));
  const channel = process.env.WAI_PLATFORM_BROWSER_CHANNEL || undefined;
  browser = await chromium.launch({ channel, args: process.platform === "darwin" ? ["--use-angle=metal"] : [] });
  console.log(`browser: ${channel || "chromium"} ${browser.version()}`);
  const page = await browser.newPage();
  const errs = [];
  page.on("pageerror", (e) => errs.push(String(e)));
  await page.goto(`http://127.0.0.1:${PORT}/demo/platform_decode.html`, { waitUntil: "domcontentloaded", timeout: 30000 });
  await page.waitForFunction(() => window.platformDecode && window.platformDecode.done === true, null, { timeout: 5 * 60 * 1000, polling: 500 });
  const report = await page.evaluate(() => window.platformDecode.report);
  console.log(report);
  for (const e of errs) console.log(`page error: ${e}`);
  const lines = report.split("\n");
  const fail = [];
  if (errs.length || /page error/.test(report)) fail.push("a page error");
  const objs = lines.filter((l) => l.startsWith("platform av1 object:"));
  if (objs.length !== objects.length) fail.push(`${objs.length} AV1 objects reported, ${objects.length} served`);
  for (const l of objs) {
    const m = / decoded=(\d+)\/(\d+) /.exec(l);
    if (!m || m[1] !== m[2] || / error=/.test(l)) fail.push(`not every unit decoded: ${l}`);
  }
  const hevc = lines.find((l) => l.startsWith("platform hevc encoder:"));
  if (!hevc) fail.push("no HEVC line");
  else if (!/not supported/.test(hevc)) {
    const m = / decoded=(\d+)\/(\d+)/.exec(hevc);
    if (!m || m[1] !== m[2] || / error=/.test(hevc) || !/ no-preference=true /.test(hevc)) fail.push(`the derived HEVC configuration did not decode the stream back: ${hevc}`);
  }
  const parse = (l) => { const m = / order=(\[.*?\]) ranks=(\[.*?\]) chosen=(\S+)$/.exec(l || ""); return m && { order: JSON.parse(m[1]), ranks: JSON.parse(m[2]), chosen: m[3] }; };
  const plain = parse(lines.find((l) => l.startsWith("platform choose: ")));
  if (!plain || plain.order[1] !== "int_hyper" || plain.ranks[1] !== "learned-without-budget" || plain.chosen !== "av1") fail.push(`without a figure the learned alternative was not last, or AV1 was not chosen: ${JSON.stringify(plain)}`);
  const fig = parse(lines.find((l) => l.startsWith("platform choose with a synthetic figure:")));
  const learnedAt = fig ? fig.order.indexOf("int_hyper") : -1;
  if (!fig || learnedAt < 0 || fig.ranks[learnedAt] !== "classical" || fig.chosen !== fig.order[0]) fail.push(`with the synthetic figure the learned alternative was not ranked classical, or the first in the order was not chosen: ${JSON.stringify(fig)}`);
  for (const f of fail) console.log(`FAIL ${f}`);
  if (fail.length) process.exitCode = 1;
} finally {
  if (browser) await browser.close();
  server.close();
}