import { test, expect } from "vitest";
import { existsSync, mkdtempSync, rmSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { MaintenanceBarrier } from "../src/runtime/maintenance-gate.js";

test("activation waits for an in-flight admission lease and rejects later admissions", async () => {
  const gate = new MaintenanceBarrier();
  const release = gate.acquire();
  expect(release).toBeTypeOf("function");
  let acknowledged = false;
  const activation = gate.activate().then(() => { acknowledged = true; });
  await Promise.resolve();
  expect(acknowledged).toBe(false);
  expect(gate.acquire()).toBeUndefined();
  release?.();
  await activation;
  expect(acknowledged).toBe(true);
  expect(gate.status()).toEqual({ active: true, admissions: 0 });
  gate.deactivate();
  expect(gate.acquire()).toBeTypeOf("function");
});

test("durable activation survives recreation and deactivation removes the marker first", async () => {
  const directory = mkdtempSync(join(tmpdir(), "tht-maintenance-gate-"));
  const marker = join(directory, "maintenance.json");
  try {
    const first = new MaintenanceBarrier(marker);
    const release = first.acquire();
    expect(release).toBeTypeOf("function");
    const activation = first.activate();
    expect(existsSync(marker)).toBe(true);
    expect(first.acquire()).toBeUndefined();
    expect(first.status()).toEqual({ active: true, admissions: 1 });
    release?.();
    await activation;
    expect(first.status()).toEqual({ active: true, admissions: 0 });

    const recreated = new MaintenanceBarrier(marker);
    expect(recreated.status()).toEqual({ active: true, admissions: 0 });
    recreated.deactivate();
    expect(existsSync(marker)).toBe(false);
    expect(recreated.status()).toEqual({ active: false, admissions: 0 });
  } finally {
    rmSync(directory, { recursive: true, force: true });
  }
});