/**
 * @file Tests server/lib/backoff-poll.js — the poll that runs at its base pace
 * while passes find work (or fail) and slows to its idle pace after a pass
 * that resolved `false`, returning to the base pace once work shows up again.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const { describe, it } = require("node:test");
const assert = require("node:assert/strict");
const { startBackoffPoll, idleDefault } = require("../lib/backoff-poll");

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

describe("startBackoffPoll", () => {
  it("slows down after idle passes and speeds up again on work", async () => {
    const answers = [true, false, false, true, "x"];
    const at = [];
    const t0 = Date.now();
    const poll = startBackoffPoll(
      () => {
        at.push(Date.now() - t0);
        const a = answers.shift();
        if (a === "x") throw new Error("boom");
        return a;
      },
      { baseMs: 10, idleMs: 80 }
    );
    await wait(260);
    poll.stop();
    assert.ok(at.length >= 5, `ran ${at.length} times`);
    const gaps = at.slice(1).map((t, i) => t - at[i]);
    assert.ok(gaps[0] < 60, "work → base pace");
    assert.ok(gaps[1] >= 75, "idle → idle pace");
    assert.ok(gaps[2] >= 75, "still idle");
    assert.ok(gaps[3] < 60, "work again → base pace");
  });

  it("idles at a minute by default, never faster than the base pace", () => {
    assert.equal(idleDefault(15_000), 60_000);
    assert.equal(idleDefault(120_000), 120_000);
  });
});