refactor: isolate SSE setup

api/prisma/migrations/20250609203423_notify_sse/migration.sql

@@ -0,0 +1,26 @@
+-- Create function and trigger to notify SSE on planilla changes
+CREATE OR REPLACE FUNCTION notify_planilla_change() RETURNS trigger AS $$
+DECLARE
+  payload TEXT;
+BEGIN
+  payload := json_build_object(
+    'table', TG_TABLE_NAME,
+    'operation', TG_OP,
+    'old', row_to_json(OLD),
+    'new', row_to_json(NEW)
+  )::text;
+  PERFORM pg_notify('sse_events', payload);
+  IF TG_OP = 'DELETE' THEN
+    RETURN OLD;
+  ELSE
+    RETURN NEW;
+  END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+DROP TRIGGER IF EXISTS planilla_notify_trigger ON "Planilla";
+CREATE TRIGGER planilla_notify_trigger
+  AFTER INSERT OR UPDATE OR DELETE ON "Planilla"
+  DEFERRABLE INITIALLY DEFERRED
+  FOR EACH ROW
+  EXECUTE PROCEDURE notify_planilla_change();

api/server.js

@@ -2,6 +2,7 @@ import express from 'express';
 import { PrismaClient } from './prisma/generated/client/index.js';
 import { Decimal } from '@prisma/client/runtime/library.js';
 import cors from 'cors';
+import { registerSse } from './sse/index.js';
 
 // Import new routers
 import empleadosRouter from './routes/empleados/empleados.js';
@@ -48,6 +49,9 @@ app.use(cors({
   origin: ['http://localhost:5173', 'https://planilla.interno.com'],
   credentials: true
 }));
+
+// --------- Server Sent Events setup ---------
+registerSse(app);
 // Mount new routers
 app.use('/api/empleados', empleadosRouter);
 app.use('/api/asistencias', asistenciasRouter);

api/sse/index.js

@@ -0,0 +1,39 @@
+import pg from 'pg';
+
+export function registerSse(app) {
+  const sseClients = [];
+
+  app.get('/events', (req, res) => {
+    res.set({
+      'Content-Type': 'text/event-stream',
+      'Cache-Control': 'no-cache',
+      Connection: 'keep-alive'
+    });
+    res.flushHeaders();
+    res.write(':\n\n');
+    sseClients.push(res);
+
+    res.on('close', () => {
+      const idx = sseClients.indexOf(res);
+      if (idx !== -1) sseClients.splice(idx, 1);
+      res.end();
+    });
+  });
+
+  const broadcast = (data) => {
+    const payload = `data: ${data}\n\n`;
+    sseClients.forEach((client) => client.write(payload));
+  };
+
+  const { Client: PgClient } = pg;
+  const pgClient = new PgClient({ connectionString: process.env.DATABASE_URL });
+  pgClient.connect()
+    .then(() => pgClient.query('LISTEN sse_events'))
+    .then(() => console.log('🛎️  Listening to Postgres channel sse_events'))
+    .catch((err) => console.error('PG listen error', err));
+
+  pgClient.on('notification', (msg) => {
+    console.log('Notificación Postgres:', msg.payload);
+    broadcast(msg.payload);
+  });
+}