// node --test relay/test/wake.test.mjs   (no dependencies, no database: a fake sql, a fake clock, a fake sleep)
import { test } from 'node:test';
import assert from 'node:assert/strict';
import { waitForChange, RateLimit, validStamp, makeHandler, HOLD_MS_MAX, HOLDS_MAX } from '../lib/wake.mjs';

// a clock that only moves when something sleeps on it
function clock(start = 1_000_000) {
  let t = start;
  return { now: () => t, sleep: async ms => { t += ms; }, set: v => { t = v; } };
}

// the smallest Neon stand-in: one table relay_wake, newest row first, no table until the first CREATE
function fakeDb() {
  const rows = [];
  let created = false;
  let seq = 0;
  const sql = async (query, params = []) => {
    if (/CREATE TABLE/.test(query)) { created = true; return []; }
    if (!created) throw new Error('relation "relay_wake" does not exist');
    if (/INSERT INTO relay_wake/.test(query)) {
      const [stamp, meta] = params;
      const hit = rows.find(r => r.stamp === stamp);
      if (hit) { hit.at = '2026-10-05 12:00:30+00'; hit.meta = JSON.parse(meta); return [{ stamp, at: hit.at }]; }
      const row = { id: ++seq, stamp, at: '2026-10-05 12:00:00+00', meta: JSON.parse(meta) };
      rows.push(row);
      return [{ stamp, at: row.at }];
    }
    if (/SELECT stamp, at, meta FROM relay_wake/.test(query)) { const r = rows[rows.length - 1]; return r ? [r] : []; }
    throw new Error('unexpected query ' + query);
  };
  return { sql, rows, set: (stamp, added = []) => { rows.push({ id: ++seq, stamp, at: '2026-10-05 12:00:00+00', meta: { added } }); created = true; } };
}

function res() {
  const r = { status: null, headers: {}, body: null };
  r.setHeader = (k, v) => { r.headers[k] = v; };
  r.status = s => { r.code = s; return r; };
  r.end = s => { r.body = s; };
  return r;
}
const json = (r, status, obj) => { r.status(status); r.end(JSON.stringify(obj)); };
const reply = r => ({ code: r.code, ...JSON.parse(r.body) });
const req = (method, query = {}, { headers = {}, body } = {}) => ({ method, query, headers: { 'x-forwarded-for': '203.0.113.9', ...headers }, body });

test('validStamp: the publish stamp shape, nothing else', () => {
  assert.equal(validStamp('2026-10-05T11:02:17Z.5e7b56f5'), true);
  assert.equal(validStamp(''), false);
  assert.equal(validStamp('a b'), false);
  assert.equal(validStamp('x'.repeat(121)), false);
  assert.equal(validStamp(42), false);
  assert.equal(validStamp('has/slash'), false);
});

test('waitForChange: no since answers at once; a different stamp answers at once with changed', async () => {
  const c = clock();
  const r = await waitForChange({ read: async () => ({ stamp: 'A', at: null, added: [] }), since: '', now: c.now, sleep: c.sleep });
  assert.deepEqual([r.stamp, r.changed, r.held_ms], ['A', false, 0]);
  const r2 = await waitForChange({ read: async () => ({ stamp: 'B', at: null, added: [] }), since: 'A', now: c.now, sleep: c.sleep });
  assert.deepEqual([r2.stamp, r2.changed, r2.held_ms], ['B', true, 0]);
});

test('waitForChange: holds in 2 s steps, answers the moment the stamp moves, else the unchanged stamp at the deadline', async () => {
  const c = clock();
  let cur = 'A';
  let reads = 0;
  const read = async () => { reads++; if (c.now() >= 1_000_000 + 7_000) cur = 'B'; return { stamp: cur, at: null, added: [] }; };
  const r = await waitForChange({ read, since: 'A', now: c.now, sleep: c.sleep });
  assert.deepEqual([r.stamp, r.changed, r.held_ms], ['B', true, 8_000]);
  assert.equal(reads, 5);
  const c2 = clock();
  let reads2 = 0;
  const r2 = await waitForChange({ read: async () => { reads2++; return { stamp: 'A', at: null, added: [] }; }, since: 'A', now: c2.now, sleep: c2.sleep });
  assert.deepEqual([r2.stamp, r2.changed, r2.held_ms], ['A', false, HOLD_MS_MAX]);
  assert.equal(reads2, Math.ceil(HOLD_MS_MAX / 2_000) + 1);
  // a hold over the cap is clamped; a zero hold is one read
  const c3 = clock();
  const r3 = await waitForChange({ read: async () => ({ stamp: 'A' }), since: 'A', holdMs: 600_000, now: c3.now, sleep: c3.sleep });
  assert.equal(r3.held_ms, HOLD_MS_MAX);
  const c4 = clock();
  const r4 = await waitForChange({ read: async () => ({ stamp: 'A' }), since: 'A', holdMs: 0, now: c4.now, sleep: c4.sleep });
  assert.equal(r4.held_ms, 0);
});

test('waitForChange: an empty store answers the empty stamp (the app then waits its own floor)', async () => {
  const c = clock();
  const r = await waitForChange({ read: async () => null, since: 'A', now: c.now, sleep: c.sleep });
  assert.deepEqual([r.stamp, r.changed, r.held_ms], ['', true, 0]);
});

test('RateLimit: the window, the reset, independent keys', () => {
  const c = clock();
  const rl = new RateLimit({ perMinute: 3, now: c.now });
  assert.equal(rl.take('a'), null); assert.equal(rl.take('a'), null); assert.equal(rl.take('a'), null);
  assert.equal(rl.take('a'), 60);
  assert.equal(rl.take('b'), null);
  c.set(c.now() + 59_000);
  assert.equal(rl.take('a'), 1);
  c.set(c.now() + 1_000);
  assert.equal(rl.take('a'), null);
});

test('handler: GET before any POST answers the empty stamp; POST needs auth and a stamp; GET then sees it', async () => {
  const db = fakeDb();
  const c = clock();
  const h = makeHandler({ sql: db.sql, authed: r => r.headers['x-relay-token'] === 'T' ? 'token' : null, readJson: async r => r.body || {}, json, now: c.now, sleep: c.sleep });
  let r = res(); await h(req('GET', {}), r);
  assert.deepEqual(reply(r), { code: 200, ok: true, stamp: '', at: null, added: [], changed: false, held_ms: 0 });
  r = res(); await h(req('POST', {}, { body: { stamp: 'S1' } }), r);
  assert.equal(reply(r).code, 401);
  r = res(); await h(req('POST', {}, { headers: { 'x-relay-token': 'T' }, body: { stamp: '' } }), r);
  assert.equal(reply(r).code, 400);
  r = res(); await h(req('POST', {}, { headers: { 'x-relay-token': 'T' }, body: { stamp: 'S1', added: ['run-1', 7, ''] } }), r);
  assert.deepEqual(reply(r), { code: 200, ok: true, stamp: 'S1', at: '2026-10-05T12:00:00.000Z', added: ['run-1', '7'] });
  r = res(); await h(req('GET', { since: 'S0' }), r);
  assert.deepEqual(reply(r), { code: 200, ok: true, stamp: 'S1', at: '2026-10-05T12:00:00.000Z', added: ['run-1', '7'], changed: true, held_ms: 0 });
  r = res(); await h(req('PUT', {}), r);
  assert.equal(reply(r).code, 405);
  // the stamp may also come as ?stamp= with the token in the path (the /r/<token>/wake rewrite)
  r = res(); await h(req('POST', { token: 'T', stamp: 'S2' }, { headers: { 'x-relay-token': 'T' }, body: {} }), r);
  assert.equal(reply(r).stamp, 'S2');
});

test('handler: a held GET answers when a POST lands, with the held time', async () => {
  const db = fakeDb();
  db.set('S1');
  const c = clock();
  const h = makeHandler({ sql: db.sql, authed: () => 'token', readJson: async r => r.body || {}, json, now: c.now, sleep: async ms => { c.sleep(ms); if (c.now() >= 1_000_000 + 6_000 && !db.rows.some(x => x.stamp === 'S2')) db.set('S2', ['job-9']); } });
  const r = res(); await h(req('GET', { since: 'S1' }), r);
  const j = reply(r);
  assert.deepEqual([j.stamp, j.changed, j.added, j.held_ms], ['S2', true, ['job-9'], 6_000]);
});

test('handler: the rate limit answers 429 with Retry-After and never holds; over the hold cap the answer is immediate', async () => {
  const db = fakeDb();
  db.set('S1');
  const c = clock();
  const h = makeHandler({ sql: db.sql, authed: () => null, readJson: async () => ({}), json, limiter: new RateLimit({ perMinute: 1, now: c.now }), now: c.now, sleep: c.sleep });
  let r = res(); await h(req('GET', { since: 'S1', hold: 2 }), r);
  assert.equal(reply(r).held_ms, 2_000);
  r = res(); await h(req('GET', { since: 'S1' }), r);
  assert.deepEqual([reply(r).code, reply(r).error, r.headers['Retry-After']], [429, 'rate limited', '58']);
  const h2 = makeHandler({ sql: db.sql, authed: () => null, readJson: async () => ({}), json, holds: { n: HOLDS_MAX }, now: c.now, sleep: c.sleep });
  r = res(); await h2(req('GET', { since: 'S1' }), r);
  assert.deepEqual([reply(r).code, reply(r).held_ms], [200, 0]);
});

test('handler: a database error is a 500 with its message, not a hang', async () => {
  const c = clock();
  const h = makeHandler({ sql: async () => { throw new Error('connection refused'); }, authed: () => 'token', readJson: async () => ({ stamp: 'S1' }), json, now: c.now, sleep: c.sleep });
  const r = res(); await h(req('GET', { since: 'S1' }), r);
  assert.deepEqual([reply(r).code, reply(r).error], [500, 'connection refused']);
});