'use strict';

/**
 * Drives the shell's alerts through its HTTP API and shell stream: the
 * defaults, every refusal, raise → `alert` frame → timeout → `alert-clear`
 * frame, replacement on a channel, an early clear, text tidying, the
 * channel list riding along in a saved layout, the admin colour save (and
 * its `alerts-config` frame, and what lands in proddash.json), and the admin
 * test flash.
 *
 *   node tools/alerts.test.js
 *
 * Plain Node, no dependencies. Starts server.js on a spare port with a
 * temporary data directory, talks to it over HTTP, exits non-zero on the
 * first failure and always stops the server it started.
 */

const assert = require('node:assert/strict');
const { spawn } = require('node:child_process');
const fs = require('node:fs');
const http = require('node:http');
const net = require('node:net');
const os = require('node:os');
const path = require('node:path');

const ROOT = path.join(__dirname, '..');

function freePort() {
  return new Promise((resolve, reject) => {
    const probe = net.createServer();
    probe.listen(0, '127.0.0.1', () => {
      const { port } = probe.address();
      probe.close(() => resolve(port));
    });
    probe.on('error', reject);
  });
}

async function waitFor(url, ms = 15000) {
  const deadline = Date.now() + ms;
  let last = '';
  while (Date.now() < deadline) {
    try {
      const r = await fetch(url);
      if (r.ok) return;
      last = 'HTTP ' + r.status;
    } catch (err) {
      last = err.message;
    }
    await new Promise((r) => setTimeout(r, 200));
  }
  throw new Error('server did not come up: ' + last);
}

/** A bare SSE reader for /api/events: collects { event, data } frames and waits for one. */
function openEvents(url) {
  const frames = [];
  const waiters = [];
  const req = http.get(url, { headers: { accept: 'text/event-stream' } }, (res) => {
    let buf = '';
    res.setEncoding('utf8');
    res.on('data', (chunk) => {
      buf += chunk;
      let i;
      while ((i = buf.indexOf('\n\n')) >= 0) {
        const block = buf.slice(0, i);
        buf = buf.slice(i + 2);
        let event = 'message';
        const data = [];
        for (const line of block.split('\n')) {
          if (line.startsWith('event:')) event = line.slice(6).trim();
          else if (line.startsWith('data:')) data.push(line.slice(5).replace(/^ /, ''));
        }
        if (!data.length) continue;
        let parsed = null;
        try { parsed = JSON.parse(data.join('\n')); } catch { parsed = data.join('\n'); }
        const frame = { event, data: parsed };
        frames.push(frame);
        for (const w of [...waiters]) {
          if (w.match(frame)) {
            waiters.splice(waiters.indexOf(w), 1);
            w.resolve(frame);
          }
        }
      }
    });
  });
  return {
    frames,
    /** The next frame (already seen or still to come) that `match` accepts. */
    next(match, ms = 5000, label = 'frame') {
      const seen = frames.find(match);
      if (seen) {
        frames.splice(frames.indexOf(seen), 1);
        return Promise.resolve(seen);
      }
      return new Promise((resolve, reject) => {
        const w = { match, resolve: (f) => { clearTimeout(timer); frames.splice(frames.indexOf(f), 1); resolve(f); } };
        const timer = setTimeout(() => {
          waiters.splice(waiters.indexOf(w), 1);
          reject(new Error(`no ${label} within ${ms} ms`));
        }, ms);
        waiters.push(w);
      });
    },
    close() { req.destroy(); },
  };
}

(async () => {
  const dataDir = fs.mkdtempSync(path.join(os.tmpdir(), 'proddash-alerts-test-'));
  const port = await freePort();
  const child = spawn(process.execPath, ['server.js'], {
    cwd: ROOT,
    env: { ...process.env, PRODDASH_DATA_DIR: dataDir, PORT: String(port), PRODDASH_NO_REMOTE_CHECK: '1', PRODDASH_LAUNCHER: '1' },
    stdio: ['ignore', 'pipe', 'pipe'],
  });
  let log = '';
  child.stdout.on('data', (d) => { log += d; });
  child.stderr.on('data', (d) => { log += d; });

  const base = `http://127.0.0.1:${port}`;
  const api = async (p, init = {}) => {
    const r = await fetch(base + p, { headers: { 'Content-Type': 'application/json' }, ...init });
    return { status: r.status, body: await r.json().catch(() => ({})) };
  };
  const raise = (alert) => api('/api/alerts', { method: 'POST', body: JSON.stringify(alert) });
  let events = null;
  let failed = false;

  try {
    await waitFor(base + '/api/alerts');
    events = openEvents(base + '/api/events');

    // ── defaults ──
    let r = await api('/api/alerts');
    assert.equal(r.status, 200);
    assert.equal(r.body.channels, 6, 'six channels');
    assert.deepEqual(r.body.levels, ['low', 'medium', 'critical']);
    assert.deepEqual(Object.keys(r.body.colors), ['low', 'medium', 'critical'], 'a pair per level');
    for (const pair of Object.values(r.body.colors)) {
      assert.equal(pair.length, 2);
      for (const c of pair) assert.match(c, /^#[0-9a-f]{6}$/, 'colours are #rrggbb');
    }
    assert.deepEqual(r.body.active, [], 'nothing active on a fresh server');
    const defaults = r.body.colors;

    // ── refusals say why ──
    r = await raise({ channel: 7, level: 'low', text: 'x' });
    assert.equal(r.status, 400); assert.match(r.body.error, /channel/);
    r = await raise({ channel: 1, level: 'high', text: 'x' });
    assert.equal(r.status, 400); assert.match(r.body.error, /level/);
    r = await raise({ channel: 1, level: 'low', text: '   ' });
    assert.equal(r.status, 400); assert.match(r.body.error, /text/);
    r = await raise({ channel: 1, level: 'low', text: 'x', duration: -1 });
    assert.equal(r.status, 400); assert.match(r.body.error, /duration/);
    r = await raise({ channel: 1, level: 'low', text: 'x', duration: 'soon' });
    assert.equal(r.status, 400); assert.match(r.body.error, /duration/);
    {
      const plain = await fetch(base + '/api/alerts', { method: 'POST', headers: { 'Content-Type': 'text/plain' }, body: '{}' });
      assert.equal(plain.status, 415, 'a POST that is not application/json is refused');
    }
    r = await fetch(base + '/api/alerts/9', { method: 'DELETE' }).then(async (x) => ({ status: x.status, body: await x.json() }));
    assert.equal(r.status, 400, 'clearing a channel that does not exist is refused');
    r = await api('/api/alerts');
    assert.deepEqual(r.body.active, [], 'a refused alert is not half-raised');

    // ── raise → frame → timeout → clear frame ──
    r = await raise({ channel: 2, level: 'MEDIUM', text: 'Service over by 5:00', duration: 1, source: 'pco-plan' });
    assert.equal(r.status, 200, 'raise: ' + JSON.stringify(r.body));
    const a = r.body.alert;
    assert.equal(a.channel, 2);
    assert.equal(a.level, 'medium', 'level is case-insensitive');
    assert.equal(a.text, 'Service over by 5:00');
    assert.equal(a.source, 'pco-plan', 'the source is kept');
    assert.equal(a.duration, 1);
    assert.ok(a.remainingMs > 0 && a.remainingMs <= 1000, 'remainingMs counts down from the duration');
    let frame = await events.next((f) => f.event === 'alert' && f.data.id === a.id, 5000, '`alert` frame');
    assert.equal(frame.data.text, a.text, 'the frame carries the alert');
    r = await api('/api/alerts');
    assert.equal(r.body.active.length, 1, 'it is active');
    assert.equal(r.body.active[0].id, a.id);
    frame = await events.next((f) => f.event === 'alert-clear' && f.data.channel === 2, 5000, '`alert-clear` frame at timeout');
    assert.equal(frame.data.id, a.id, 'the clear names the alert that ended');
    r = await api('/api/alerts');
    assert.deepEqual(r.body.active, [], 'gone once its time is up');

    // ── defaults for duration; a held alert; replacement; early clear ──
    r = await raise({ channel: 3, level: 'low', text: 'first' });
    assert.equal(r.body.alert.duration, 15, '15 s when omitted');
    r = await raise({ channel: 3, level: 'low', text: 'LTC lost', duration: 0 });
    assert.equal(r.status, 200);
    assert.equal(r.body.alert.endsAt, null, 'duration 0 holds the alert');
    assert.equal(r.body.alert.remainingMs, null);
    const held = r.body.alert;
    r = await api('/api/alerts');
    assert.equal(r.body.active.length, 1, 'one alert per channel — the second replaced the first');
    assert.equal(r.body.active[0].id, held.id);
    r = await raise({ channel: 3, level: 'critical', text: 'replaced', duration: 600 });
    const replaced = r.body.alert;
    assert.equal(replaced.duration, 600, 'the cap is 600 s');
    r = await raise({ channel: 3, level: 'critical', text: 'capped', duration: 9999 });
    assert.equal(r.body.alert.duration, 600, 'longer is clamped to the cap');
    r = await api('/api/alerts');
    assert.equal(r.body.active.length, 1);
    assert.equal(r.body.active[0].text, 'capped');
    r = await fetch(base + '/api/alerts/3', { method: 'DELETE' }).then(async (x) => ({ status: x.status, body: await x.json() }));
    assert.equal(r.status, 200);
    assert.equal(r.body.cleared, true, 'an early clear says it cleared something');
    frame = await events.next((f) => f.event === 'alert-clear' && f.data.channel === 3, 5000, '`alert-clear` frame after DELETE');
    r = await fetch(base + '/api/alerts/3', { method: 'DELETE' }).then(async (x) => ({ status: x.status, body: await x.json() }));
    assert.equal(r.body.cleared, false, 'clearing an empty channel is honest about it');
    r = await api('/api/alerts');
    assert.deepEqual(r.body.active, []);

    // ── text is tidied: control characters out, whitespace collapsed, 80 chars at most ──
    r = await raise({ channel: 4, level: 'low', text: '  SPL\n\t 102 dB\u0007 —   over ' + 'x'.repeat(100), duration: 60 });
    assert.equal(r.status, 200);
    assert.equal(r.body.alert.text.length, 80, 'cut at 80');
    assert.ok(r.body.alert.text.startsWith('SPL 102 dB — over x'), 'whitespace collapsed, control characters gone');
    assert.equal(r.body.alert.source, 'api', 'no source given → api');
    r = await raise({ channel: 4, level: 'low', text: 'bad source', duration: 60, source: 'not a module id!' });
    assert.equal(r.body.alert.source, 'api', 'a malformed source → api');
    await fetch(base + '/api/alerts/4', { method: 'DELETE' });

    // ── the channel list rides along in a saved layout ──
    const tile = { id: 't1', module: 'clock', x: 0, y: 0, w: 2, h: 1, settings: {} };
    r = await api('/api/layouts/Stage', { method: 'PUT', body: JSON.stringify({ layout: { tiles: [tile], alertChannels: [3, 1, '2', 1, 9, 'x'] } }) });
    assert.equal(r.status, 200, 'save: ' + JSON.stringify(r.body));
    r = await api('/api/layouts/Stage');
    assert.deepEqual(r.body.layout.alertChannels, [1, 2, 3], 'channels come back whole, deduplicated, sorted, 1–6 only');
    r = await api('/api/layouts/Plain', { method: 'PUT', body: JSON.stringify({ layout: { tiles: [tile] } }) });
    r = await api('/api/layouts/Plain');
    assert.equal('alertChannels' in r.body.layout, false, 'a layout saved without the list does not grow one');

    // ── admin: colours (admin is open here — a fresh data directory has no PIN) ──
    r = await api('/api/admin/alerts', {
      method: 'POST',
      body: JSON.stringify({ colors: { low: ['#112233', 'nonsense'], critical: ['#ABCDEF', '#000000'], bogus: ['#111111', '#222222'] } }),
    });
    assert.equal(r.status, 200, 'colour save: ' + JSON.stringify(r.body));
    assert.deepEqual(r.body.colors.low, ['#112233', defaults.low[1]], 'a malformed colour takes the default');
    assert.deepEqual(r.body.colors.medium, defaults.medium, 'a level left out keeps the default');
    assert.deepEqual(r.body.colors.critical, ['#abcdef', '#000000'], 'colours are lower-cased');
    assert.equal('bogus' in r.body.colors, false, 'an unknown level is dropped');
    frame = await events.next((f) => f.event === 'alerts-config', 5000, '`alerts-config` frame');
    assert.deepEqual(frame.data.colors, r.body.colors, 'open dashboards hear the new colours');
    r = await api('/api/alerts');
    assert.deepEqual(r.body.colors.low, ['#112233', defaults.low[1]], 'GET reflects the save');
    const settings = JSON.parse(fs.readFileSync(path.join(dataDir, 'proddash.json'), 'utf8'));
    assert.deepEqual(settings.alerts.colors.critical, ['#abcdef', '#000000'], 'saved under alerts.colors in proddash.json');

    // ── admin: the test flash ──
    r = await api('/api/admin/alerts/test', { method: 'POST', body: JSON.stringify({ level: 'critical', channel: 5 }) });
    assert.equal(r.status, 200, 'test: ' + JSON.stringify(r.body));
    assert.equal(r.body.alert.channel, 5);
    assert.equal(r.body.alert.level, 'critical');
    assert.equal(r.body.alert.source, 'admin');
    assert.match(r.body.alert.text, /^Test — critical alert$/);
    assert.equal(r.body.alert.duration, 8, 'a test flash is short');
    r = await api('/api/admin/alerts/test', { method: 'POST', body: JSON.stringify({ level: 'nope', channel: 5 }) });
    assert.equal(r.status, 400, 'a bad test level is refused like any other');
    await fetch(base + '/api/alerts/5', { method: 'DELETE' });

    console.log('alerts: every check passed');
  } catch (err) {
    failed = true;
    console.error('FAIL:', err.message);
    console.error('--- last of the server log ---\n' + log.slice(-2000));
  } finally {
    try { events?.close(); } catch { /* already closed */ }
    child.kill('SIGTERM');
    await new Promise((r) => setTimeout(r, 400));
    fs.rmSync(dataDir, { recursive: true, force: true });
  }
  process.exit(failed ? 1 : 0);
})();