epaper-display/display/middleware/src/api/routes/mqtt-topics.ts

import { Router } from 'express';
import {
  getTopicsForBroker,
  updateTopic,
  startDiscovery,
  addManualTopic,
} from '../../modules/mqtt/topic-discovery';
import { createDatapointFromMqtt, getDatapointByTopicId } from '../../modules/datapoints/datapoint-manager';
import { getConnection } from './../../modules/mqtt/broker-manager';
import { getDb } from '../../db/index';

const router = Router({ mergeParams: true });

// GET /api/mqtt/brokers/:brokerId/topics?search=grid&selected=1&limit=50&offset=0
router.get('/', (req, res): void => {
  try {
    const brokerId = parseInt(req.params.brokerId);
    const search = req.query.search as string | undefined;
    const selectedOnly = req.query.selected === '1';
    const limit = parseInt(req.query.limit as string) || 50;
    const offset = parseInt(req.query.offset as string) || 0;
    res.json(getTopicsForBroker(brokerId, { search, selectedOnly, limit, offset }));
  } catch (err) {
    res.status(500).json({ error: (err as Error).message });
  }
});

// PUT /api/mqtt/brokers/:brokerId/topics/:id
router.put('/:id', (req, res): void => {
  try {
    const topicId = parseInt(req.params.id);
    const topicRow = getDb().prepare('SELECT * FROM mqtt_topics WHERE id = ?').get(topicId) as any;
    if (!topicRow) { res.status(404).json({ error: 'Topic not found' }); return; }

    const topic = updateTopic(topicId, req.body);

    // If selecting a topic, auto-create a datapoint
    if (req.body.selected === 1 || req.body.selected === true) {
      const existing = getDatapointByTopicId(topicId);
      if (!existing) {
        createDatapointFromMqtt(topicRow.broker_id, topicId, topicRow.topic);
      }
      // Subscribe to the topic on the broker connection
      const client = getConnection(topicRow.broker_id);
      if (client?.connected) client.subscribe(topicRow.topic);
    }

    res.json(topic);
  } catch (err) {
    res.status(500).json({ error: (err as Error).message });
  }
});

// POST /api/mqtt/brokers/:brokerId/topics/discover
router.post('/discover', (req, res): void => {
  const brokerId = parseInt(req.params.brokerId);
  const { prefix } = req.body;

  res.json({ message: 'Discovery started', brokerId, prefix: prefix ?? null });

  // Run in background
  startDiscovery(brokerId, prefix).catch((err) => {
    console.error('Discovery error:', (err as Error).message);
  });
});

// POST /api/mqtt/brokers/:brokerId/topics/manual
router.post('/manual', (req, res): void => {
  try {
    const brokerId = parseInt(req.params.brokerId);
    const { topic } = req.body;
    if (!topic) { res.status(400).json({ error: 'topic is required' }); return; }
    res.status(201).json(addManualTopic(brokerId, topic));
  } catch (err) {
    res.status(500).json({ error: (err as Error).message });
  }
});

export default router;