// Boot benchmark: time from navigation to a guest's exit, and the peak resident memory
// of the whole browser (every process, so the page, its workers and the SW count),
// sampled from `ps` every 10ms. Also prints the wire size of each dist/runtime/ asset.
// Usage: node scripts/bench-boot.mjs [page=/demo/index.html] [runs=7]
// Needs the dev server (npm run serve) on :8931.
import { chromium } from "@playwright/test";
import { execFileSync } from "node:child_process";
import { readdirSync, readFileSync, statSync } from "node:fs";
import { brotliCompressSync, gzipSync } from "node:zlib";

const PAGE = process.argv[2] ?? "/demo/index.html";
const RUNS = Number(process.argv[3] ?? 7);
const BASE = process.env.BASE ?? "http://localhost:8931";

function treeRssKB(root) {
  const rows = execFileSync("ps", ["-A", "-o", "pid=,ppid=,rss="], { encoding: "utf8" })
    .trim().split("\n").map((l) => l.trim().split(/\s+/).map(Number));
  const kids = new Map();
  for (const [pid, ppid] of rows) (kids.get(ppid) ?? kids.set(ppid, []).get(ppid)).push(pid);
  const rss = new Map(rows.map(([pid, , r]) => [pid, r]));
  let sum = 0;
  const stack = [root];
  while (stack.length) { const p = stack.pop(); sum += rss.get(p) ?? 0; stack.push(...(kids.get(p) ?? [])); }
  return sum;
}

const server = await chromium.launchServer();
const browser = await chromium.connect(server.wsEndpoint());
const pid = server.process().pid;
const rows = [];
for (let i = 0; i < RUNS; i++) {
  const ctx = await browser.newContext();
  const page = await ctx.newPage();
  await page.goto(BASE + "/demo/demo.css"); // settle a renderer first so its baseline is not counted as boot
  const base = treeRssKB(pid);
  let peak = base;
  let sampling = true;
  const sampler = (async () => {
    while (sampling) { peak = Math.max(peak, treeRssKB(pid)); await new Promise((r) => setTimeout(r, 10)); }
  })();
  const t0 = performance.now();
  await page.goto(BASE + PAGE);
  await page.waitForFunction(() => { const t = document.getElementById("exit")?.textContent; return t && t !== "…"; }, null, { timeout: 60_000, polling: 5 });
  const ms = Math.round(performance.now() - t0);
  await new Promise((r) => setTimeout(r, 200));
  sampling = false;
  await sampler;
  rows.push({ ms, peakMB: Math.round((peak - base) / 1024), exit: await page.locator("#exit").textContent() });
  await ctx.close();
}
await browser.close();
await server.close();

const med = (k) => rows.map((r) => r[k]).sort((a, b) => a - b)[Math.floor(rows.length / 2)];
console.log(rows.map((r) => `${r.ms}ms/${r.peakMB}MB/exit ${r.exit}`).join("  "));
console.log(`median boot→exit ${med("ms")}ms · peak RSS over baseline ${med("peakMB")}MB`);
for (const f of readdirSync("dist/runtime")) {
  if (!statSync(`dist/runtime/${f}`).isFile()) continue;
  const b = readFileSync(`dist/runtime/${f}`);
  console.log(`  ${f.padEnd(14)} ${String(Math.round(b.length / 1024)).padStart(6)}KB raw ${String(Math.round(gzipSync(b, { level: 9 }).length / 1024)).padStart(6)}KB gz ${String(Math.round(brotliCompressSync(b).length / 1024)).padStart(6)}KB br`);
}