// Run one guest on the fixture page and print its stdio as it arrives, for debugging a
// guest that hangs. Needs `npm run serve`. Usage:
//   node scripts/probe-guest.mjs <guest.cjs> [stdin text] [--keep-open] [--timeout=ms]
//   node scripts/probe-guest.mjs <guest.cjs> --pty=80x24 [--keys='["a","\\r"]'] [--timeout=ms]
// With --pty the guest runs on a terminal; each of --keys (JSON) is typed 100 ms apart, and
// stdout is printed JSON-quoted so control sequences show.
import { readFileSync } from "node:fs";
import { basename } from "node:path";
import { chromium } from "@playwright/test";

const args = process.argv.slice(2);
const file = args[0];
const stdin = args[1] && !args[1].startsWith("--") ? args[1] : "";
const keepOpen = args.includes("--keep-open");
const timeout = Number(args.find((a) => a.startsWith("--timeout="))?.slice(10) ?? 5000);
const repeat = Number(args.find((a) => a.startsWith("--repeat-stdin="))?.slice(15) ?? 1);
const ptyArg = args.find((a) => a.startsWith("--pty="))?.slice(6);
const pty = ptyArg ? { cols: Number(ptyArg.split("x")[0]), rows: Number(ptyArg.split("x")[1]) } : null;
const keys = JSON.parse(args.find((a) => a.startsWith("--keys="))?.slice(7) ?? "[]");

const browser = await chromium.launch();
const page = await browser.newPage();
page.on("console", (m) => console.log(`[page:${m.type()}]`, m.text()));
page.on("pageerror", (e) => console.log("[pageerror]", e.message));
page.on("exposebinding", () => {});
await page.exposeFunction("report", (stream, text) => process.stdout.write(`[${stream}] ${text}`));
await page.goto("http://localhost:8931/demo/fixture.html");
await page.waitForFunction(() => window.__runtime !== undefined, undefined, { timeout: 20_000 });
const name = `/app/${basename(file)}`;
const started = Date.now();
console.log("page ready");
const result = await Promise.race([
  page.evaluate(async ({ name, source, stdin, keepOpen, pty, keys }) => {
    const runtime = window.__runtime;
    runtime.writeTree({ [name]: source });
    if (pty) {
      const proc = runtime.exec(name, { pty });
      const dec = new TextDecoder();
      void proc.stdout.pipeTo(new WritableStream({ write(c) { window.report("pty", `${JSON.stringify(dec.decode(c))}\n`); } }));
      void (async () => {
        for (const key of keys) {
          await new Promise((r) => setTimeout(r, 100));
          proc.pty.write(key);
        }
      })();
      return { code: await proc.exited, signal: await proc.signal };
    }
    const proc = runtime.exec(name);
    const dec = new TextDecoder();
    void proc.stdout.pipeTo(new WritableStream({ write(c) { window.report("stdout", dec.decode(c)); } }));
    void proc.stderr.pipeTo(new WritableStream({ write(c) { window.report("stderr", dec.decode(c)); } }));
    const writer = proc.stdin.getWriter();
    if (stdin) void writer.write(new TextEncoder().encode(stdin));
    if (!keepOpen) void writer.close();
    return { code: await proc.exited, signal: await proc.signal };
  }, { name, source: readFileSync(file, "utf8"), stdin: stdin.repeat(repeat), keepOpen, pty, keys }),
  new Promise((r) => setTimeout(() => r("timeout"), timeout)),
]);
console.log("\nresult", JSON.stringify(result), `after ${Date.now() - started} ms`);
await browser.close();
console.log(`closed after ${Date.now() - started} ms`);