/**
 * @file Tests server/update-scheduler.js — the default interval is an hour
 * (the env override and its 60 s floor still apply), a scheduled tick with no
 * browser connected runs no check, and a browser connecting after that gets
 * one catch-up check (only when the last check is stale). The check, the
 * connection count and the connection event are injected; nothing touches git
 * or the network.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const { describe, it, afterEach } = require("node:test");
const assert = require("node:assert/strict");

delete process.env.DASHBOARD_UPDATE_CHECK;
const { startUpdateScheduler, intervalMs } = require("../update-scheduler");

const wait = (ms) => new Promise((r) => setTimeout(r, ms));

let handle = null;
afterEach(() => {
  handle?.stop();
  handle = null;
  delete process.env.DASHBOARD_UPDATE_CHECK_INTERVAL_MS;
});

function harness(clients) {
  const h = { checks: 0, clients, listeners: [] };
  handle = startUpdateScheduler({
    broadcast: () => {},
    getConnectionCount: () => h.clients,
    onConnection: (fn) => {
      h.listeners.push(fn);
      return () => {};
    },
    getStatus: async () => {
      h.checks++;
      return { update_available: false };
    },
    initialDelayMs: 10,
  });
  h.connect = () => h.listeners.forEach((fn) => fn());
  return h;
}

describe("intervalMs", () => {
  it("defaults to one hour and keeps the override with its floor", () => {
    delete process.env.DASHBOARD_UPDATE_CHECK_INTERVAL_MS;
    assert.equal(intervalMs(), 60 * 60 * 1000);
    process.env.DASHBOARD_UPDATE_CHECK_INTERVAL_MS = "120000";
    assert.equal(intervalMs(), 120000);
    process.env.DASHBOARD_UPDATE_CHECK_INTERVAL_MS = "1000";
    assert.equal(intervalMs(), 60 * 60 * 1000);
  });
});

describe("startUpdateScheduler", () => {
  it("checks on the first tick when a browser is connected", async () => {
    const h = harness(1);
    await wait(40);
    assert.equal(h.checks, 1);
  });

  it("skips the tick with no browser, then checks once when one connects", async () => {
    const h = harness(0);
    await wait(40);
    assert.equal(h.checks, 0);
    h.clients = 1;
    h.connect();
    h.connect(); // a second tab in the same window: still one check
    await wait(3_300);
    assert.equal(h.checks, 1);
    h.connect(); // fresh check: no catch-up
    await wait(3_300);
    assert.equal(h.checks, 1);
  });
});