import test from "node:test";
import assert from "node:assert/strict";
import { mkdtemp, rm } from "node:fs/promises";
import path from "node:path";
import os from "node:os";
import { spawn } from "node:child_process";
import { once } from "node:events";
import { withFileLock } from "../src/capability-language/file-lock.js";

test("authoring lock excludes concurrent mutations and survives owner death", async (context) => {
  const root = await mkdtemp(path.join(os.tmpdir(), "qx-lock-test-"));
  context.after(() => rm(root, { recursive: true, force: true }));
  const filename = path.join(root, "lock");
  const events: string[] = [];
  let queued: Promise<void>;
  await withFileLock(filename, async () => {
    queued = withFileLock(filename, async () => {
      events.push("second");
    });
    events.push("first");
  });
  await queued!;
  assert.deepEqual(events, ["first", "second"]);
  const module = new URL("../src/capability-language/file-lock.js", import.meta.url).href;
  const owner = spawn(
    process.execPath,
    [
      "--input-type=module",
      "-e",
      `import {withFileLock} from ${JSON.stringify(module)}; await withFileLock(${JSON.stringify(filename)}, async () => {process.stdout.write('ready'); await new Promise(() => {});});`,
    ],
    { stdio: ["ignore", "pipe", "pipe"] },
  );
  context.after(() => owner.kill("SIGKILL"));
  await once(owner.stdout, "data");
  const exited = once(owner, "exit");
  owner.kill("SIGKILL");
  await exited;
  let acquired = false;
  await withFileLock(filename, async () => {
    acquired = true;
  });
  assert.equal(acquired, true);
});