// The fabric's WebGPU member in a browser, held to the CPU reference's pins.
//
// The native members are checked by scripts/wai-quantum-webgpu-member.sh. This
// checks the browser's: the same WGSL kernel compiled by the browser's own WGSL
// compiler, run in a worker by wai-web/demo/quantum_webgpu.html with the bundle
// built by
//
//   cd wai/wai-web
//   cargo build --locked --release --target wasm32-unknown-unknown --features quantum_webgpu
//   wasm-bindgen --target web --out-dir demo/pkg-webgpu --out-name wai_quantum_webgpu \
//     target/wasm32-unknown-unknown/release/wai_web.wasm
//
// It serves wai-web/demo and quantum-conformance on 127.0.0.1, opens the page in
// Playwright's headless browser and requires:
//
// - an adapter opened as a member, its arithmetic probed in the page, running the
//   implementation fabric/expected.json names;
// - the four certificates fabric/expected.json lists (both gatesets, random-v1 and
//   fabric-v1), each bit-exact, on that member, for that implementation, over the
//   listed number of cases, with the pinned corpus digest;
// - every vector of vectors/ and v2/vectors/ run on the member to its manifest's
//   statevector hash;
// - the same adapter running the tile implementation fabric/expected.json names
//   (tile runs: the browser's WGSL compiler holds its barrier to the uniformity
//   rules, which the native translator does not check), with the same four
//   certificates and every vector;
// - every file of reject/ refused with its listed class (`WQC parse (<class>): ...`);
// - a circuit one qubit wider than the member holds refused: as too-wide, or as
//   too-many-qubits where the member holds the reference's maximum; and, with the
//   same adapter offering only the WebGPU default buffer limits, a member holding
//   25 qubits that refuses 26 as too-wide.
//
// On success it prints
//
//   browser webgpu: member=<id> class=<c> certified bit-exact 4 of 4; tiles certified bit-exact 4 of 4; vectors <n> of <n>; tile vectors <n> of <n>; rejects <m> of <m>
//
// With no adapter it prints `browser webgpu: no adapter (<why>)`, which is a
// failure when WAI_QUANTUM_WEBGPU_REQUIRE=1 and not otherwise.
//
//   [WAI_QUANTUM_WEBGPU_REQUIRE=1] [PLAYWRIGHT_HOST=<dir with node_modules/playwright>] \
//     node wai/quantum-conformance/browser_webgpu.mjs
//
// Headless, a page is offered no hardware adapter unless the browser draws through
// the platform's GPU interface: on macOS that is `--use-angle=metal`, kept below.
// WAI_QUANTUM_WEBGPU_BROWSER_ARGS (space-separated) replaces the launch arguments.
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 DEMO = path.resolve(HERE, "../wai-web/demo");
const PLAYWRIGHT_HOST = process.env.PLAYWRIGHT_HOST ||
  "/Users/dcharlot/data-share/vibe-coding/joulesperbit/";
const REQUIRE = process.env.WAI_QUANTUM_WEBGPU_REQUIRE === "1";
const PORT = Number(process.env.PORT || 8795);
// The certificates take the longest: a few hundred circuits per gateset, each run
// on the device and read back.
const TIMEOUT_MS = Number(process.env.WAI_QUANTUM_WEBGPU_TIMEOUT_MS || 30 * 60 * 1000);
const ARGS = process.env.WAI_QUANTUM_WEBGPU_BROWSER_ARGS !== undefined
  ? process.env.WAI_QUANTUM_WEBGPU_BROWSER_ARGS.split(/\s+/).filter(Boolean)
  : process.platform === "darwin" ? ["--use-angle=metal"] : [];

const { chromium } = createRequire(PLAYWRIGHT_HOST)("playwright");

const readJson = (p) => JSON.parse(fs.readFileSync(p, "utf8"));

// What the page must report, read from the committed corpus.
const EXPECTED = readJson(path.join(HERE, "fabric", "expected.json"));
const VECTORS = {};
for (const prefix of ["", "v2/"]) {
  for (const [file, e] of Object.entries(readJson(path.join(HERE, prefix, "expected_hashes.json")))) {
    VECTORS[prefix + file] = e.statevector_hash;
  }
}
const REJECTS = Object.fromEntries(
  Object.entries(readJson(path.join(HERE, "reject", "reject.json"))).map(([file, kind]) => ["reject/" + file, kind]));
const MAX_QUBITS = 26; // wai::quantum::MAX_QUBITS
const DEFAULT_LIMITS_QUBITS = 25; // two planes of 2^25 u32 in a 128 MiB binding

// Two roots, at the paths they have under wai/, so the page's default corpus
// location (../../quantum-conformance/) holds here as it does under any static
// server run from wai/.
const ROOTS = { "/wai-web/demo/": DEMO, "/quantum-conformance/": HERE };
const MIME = { ".js": "text/javascript", ".mjs": "text/javascript", ".wasm": "application/wasm", ".html": "text/html", ".json": "application/json" };
const server = http.createServer((req, res) => {
  const url = decodeURIComponent(req.url.split("?")[0]);
  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;
let fail = 0;
const report = (label, problem) => {
  if (problem) {
    fail++;
    console.log(`FAIL ${label}: ${problem}`);
  } else {
    console.log(`PASS ${label}`);
  }
};

process.on("unhandledRejection", (e) => { console.error("UNHANDLED:", e); process.exitCode = 1; });

try {
  if (!fs.existsSync(path.join(DEMO, "pkg-webgpu", "wai_quantum_webgpu.js"))) {
    console.error(`no pkg-webgpu/wai_quantum_webgpu.js under ${DEMO}; build it as this file's header says`);
    process.exit(2);
  }
  await new Promise((r) => server.listen(PORT, "127.0.0.1", r));
  browser = await chromium.launch({ args: ARGS });
  const page = await browser.newPage();
  const errs = [];
  page.on("console", (m) => { if (m.type() === "error") errs.push(m.text()); });
  page.on("pageerror", (e) => errs.push(String(e)));
  // domcontentloaded, never networkidle: the page's work runs in a worker after
  // load, and networkidle stalls on some hosts.
  await page.goto(`http://127.0.0.1:${PORT}/wai-web/demo/quantum_webgpu.html`, { waitUntil: "domcontentloaded", timeout: 30000 });
  await page.waitForFunction(() => window.quantumWebGpu && window.quantumWebGpu.done === true, null, { timeout: TIMEOUT_MS, polling: 1000 });
  const messages = await page.evaluate(() => window.quantumWebGpu.messages);

  const of = (type, limits) => messages.filter((m) => m.type === type && (limits === undefined || m.limits === limits));
  for (const m of messages.filter((m) => m.type === "error" || m.type === "refused")) {
    report(`the page (${m.type})`, m.error || m.why);
  }
  const none = of("no-adapter")[0];
  const member = of("member", "offered")[0];
  if (!member) {
    const why = none ? none.why : "the page reported no member and no reason";
    console.log(`browser webgpu: no adapter (${why})`);
    if (REQUIRE || !none || fail) process.exitCode = 1;
  } else {
    // The member.
    console.log(`member ${member.id}: ${member.detail}`);
    report(`member ${member.id} (class ${member.class})`,
      !/^local\/(gpu|swgpu)-webgpu-[0-9a-f]{12}$/.test(member.id) ? "not a WebGPU member id"
        : (member.class === "cpu") !== member.id.startsWith("local/swgpu-") ? "its class and id disagree"
          : null);
    report("the probe passed in the page", member.detail.includes("probe passed in this process") ? null : `detail: ${member.detail}`);
    report(`implementation ${member.implementation}`,
      member.implementation === EXPECTED.implementation ? null : `fabric/expected.json pins ${EXPECTED.implementation}`);

    // The tile member: the same adapter, the pinned tile implementation.
    const tiled = of("tiled")[0];
    report(`the tile member runs ${EXPECTED.tile_implementation}`,
      !tiled ? "not reported" : tiled.error ? `refused: ${tiled.error}`
        : tiled.id !== member.id ? `member ${tiled.id}`
          : tiled.implementation !== EXPECTED.tile_implementation ? `implementation ${tiled.implementation}`
            : null);

    // The four certificates, per implementation.
    const certify = (tile, implementation) => {
      let certified = 0;
      for (const want of EXPECTED.certificates) {
        const label = `${tile ? "tile " : ""}${want.kernel} ${want.corpus}`;
        const got = of("certificate").find((m) => m.label === label && !!m.tile === tile);
        const c = got && got.got;
        const generator = ` seed=${want.seed} cases=${want.cases}` + (want.corpus === "fabric-v1" ? ` wide=${want.wide}` : "");
        const problem = !got ? "not reported"
          : got.error ? `refused: ${got.error}`
            : c.parity !== "bit-exact" ? `parity ${c.parity}`
              : c.kernel !== want.kernel ? `kernel ${c.kernel}`
                : c.implementation !== implementation ? `implementation ${c.implementation}`
                  : c.member !== member.id ? `issued to ${c.member}`
                    : c.cases !== want.cases_compared ? `${c.cases} cases, not ${want.cases_compared}`
                      : !c.generator.endsWith(generator) ? `generator ${c.generator}`
                        : c.corpus_hex !== want.corpus_hex ? `corpus ${c.corpus_hex}, pinned ${want.corpus_hex}`
                          : null;
        report(`certificate ${label} bit-exact with the pinned digest`, problem);
        if (!problem) certified++;
      }
      return certified;
    };
    const certified = certify(false, member.implementation);
    const tileCertified = certify(true, EXPECTED.tile_implementation);

    // Every vector, per implementation.
    const run = (tile) => {
      let vectors = 0;
      for (const [label, want] of Object.entries(VECTORS)) {
        const got = of("vector").find((m) => m.label === label && !!m.tile === tile);
        const problem = !got ? "not reported" : got.error ? `refused: ${got.error}` : got.got !== want ? `browser=${got.got} corpus=${want}` : null;
        report(`${tile ? "tile " : ""}${label}`, problem);
        if (!problem) vectors++;
      }
      return vectors;
    };
    const vectors = run(false);
    const tileVectors = run(true);

    // Every reject file.
    let rejects = 0;
    for (const [label, kind] of Object.entries(REJECTS)) {
      const got = of("reject").find((m) => m.label === label);
      const m = got && got.error && /^WQC parse \(([a-z-]+)\): /.exec(got.error);
      const problem = !got ? "not reported" : !got.error ? "accepted" : !m || m[1] !== kind ? `refused as: ${got.error}` : null;
      report(`${label} refused as ${kind}`, problem);
      if (!problem) rejects++;
    }

    // One qubit too wide, on the limits offered and on the WebGPU defaults.
    const wide = of("wide", "offered")[0];
    const wantClass = member.max_qubits + 1 > MAX_QUBITS ? "too-many-qubits" : "too-wide";
    report(`${member.max_qubits + 1} qubits on the member refused as ${wantClass}`,
      !wide ? "not reported" : !wide.error ? "accepted" : !wide.error.startsWith(`simulate (${wantClass}): `) ? `refused as: ${wide.error}` : null);
    const capped = of("member", "webgpu-defaults")[0];
    const cappedWide = of("wide", "webgpu-defaults")[0];
    if (capped) console.log(`member ${capped.id} (the same adapter on the WebGPU default limits): ${capped.detail}`);
    report(`on the WebGPU default limits the member holds ${DEFAULT_LIMITS_QUBITS} qubits and refuses ${DEFAULT_LIMITS_QUBITS + 1} as too-wide`,
      !capped ? "no member on the default limits"
        : capped.max_qubits !== DEFAULT_LIMITS_QUBITS ? `it holds ${capped.max_qubits}`
          : !cappedWide ? "not reported"
            : !cappedWide.error ? "accepted"
              : !cappedWide.error.startsWith(`simulate (too-wide): ${DEFAULT_LIMITS_QUBITS + 1} qubits; this member holds at most ${DEFAULT_LIMITS_QUBITS}`) ? `refused as: ${cappedWide.error}`
                : null);

    report("console errors", errs.length ? `${errs.length}\n  ${errs.join("\n  ")}` : null);
    const n = Object.keys(VECTORS).length;
    const r = Object.keys(REJECTS).length;
    if (fail === 0) {
      const k = EXPECTED.certificates.length;
      console.log(`browser webgpu: member=${member.id} class=${member.class} certified bit-exact ${certified} of ${k}; tiles certified bit-exact ${tileCertified} of ${k}; vectors ${vectors} of ${n}; tile vectors ${tileVectors} of ${n}; rejects ${rejects} of ${r}`);
    } else {
      console.log(`browser webgpu: ${fail} checks failed`);
    }
    process.exitCode = fail ? 1 : 0;
  }
} catch (e) {
  console.error("HARNESS ERROR:", e);
  process.exitCode = 1;
} finally {
  if (browser) await browser.close();
  server.close();
}