'use strict';

const test = require('node:test');
const assert = require('node:assert/strict');

const DashboardApi = require('../../src/specificClass.js');
const handlers = require('../../src/commands/handlers.js');

function makeCtx(sends, nodeId = 'dApi-1') {
  return {
    node: { id: nodeId },
    RED: { nodes: { getNode: () => null } },
    send: (m) => sends.push(m),
    logger: null,
  };
}

function makeChildPayload(id, softwareType = 'measurement') {
  return {
    config: {
      general: { id, name: id },
      functionality: { softwareType, positionVsParent: 'downstream' },
    },
  };
}

test('recordChild caches child source by id; subsequent ones replace by id', () => {
  const api = new DashboardApi({});
  api.recordChild(makeChildPayload('a'));
  api.recordChild(makeChildPayload('b'));
  api.recordChild(makeChildPayload('a')); // replace
  assert.equal(api.cachedChildSources().length, 2);
});

test('regenerate-dashboard with no cached children is a no-op (no msgs emitted)', async () => {
  const api = new DashboardApi({});
  const sends = [];
  await handlers.regenerateDashboard(api, { topic: 'regenerate-dashboard', payload: {} }, makeCtx(sends));
  assert.equal(sends.length, 0);
});

test('regenerate-dashboard re-emits for each cached child, bypassing diff', async () => {
  const api = new DashboardApi({});
  // Pre-populate cache as if two children had registered.
  api.recordChild(makeChildPayload('m-1'));
  api.recordChild(makeChildPayload('m-2'));

  // Set a diff that says nothing changed — registerChild would skip, but
  // regenerateDashboard should ignore the predicate.
  api.lastFlowsStartedDiff = { added: [], changed: [], removed: [], rewired: [] };

  const sends = [];
  await handlers.regenerateDashboard(api, { topic: 'regenerate-dashboard', payload: {} }, makeCtx(sends));
  // Each child yields at least one dashboard message (the root for the child's view).
  assert.ok(sends.length >= 2, `expected ≥2 emitted msgs, got ${sends.length}`);
  // Every emitted msg carries trigger: 'manual' in meta.
  for (const m of sends) assert.equal(m.meta?.trigger, 'manual');
});

test('child.register stamps trigger: child.register in emitted msg meta', async () => {
  const api = new DashboardApi({});
  api.lastFlowsStartedDiff = null; // cold-start → always regen
  const sends = [];
  await handlers.registerChild(api, { topic: 'child.register', payload: makeChildPayload('m-3') }, makeCtx(sends));
  assert.ok(sends.length >= 1);
  for (const m of sends) assert.equal(m.meta?.trigger, 'child.register');
});

test('command registry exposes regenerate-dashboard with regen alias', () => {
  const registry = require('../../src/commands/index.js');
  const entry = registry.find((e) => e.topic === 'regenerate-dashboard');
  assert.ok(entry, 'topic registered');
  assert.deepEqual(entry.aliases, ['regen']);
  assert.equal(typeof entry.handler, 'function');
});