From 031314d66299855d312bda8bff9322ce628a2a50 Mon Sep 17 00:00:00 2001
From: josedario87 <71241187+josedario87@users.noreply.github.com>
Date: Mon, 9 Jun 2025 15:16:02 -0600
Subject: [PATCH] refactor: isolate SSE setup

---
 README.md                                     | 14 +++++++
 .../20250609203423_notify_sse/migration.sql   | 26 +++++++++++++
 api/server.js                                 |  4 ++
 api/sse/index.js                              | 39 +++++++++++++++++++
 ui/src/main.js                                | 13 ++++---
 ui/src/stores/usePlanillas.js                 | 19 +++++++++
 6 files changed, 110 insertions(+), 5 deletions(-)
 create mode 100644 api/prisma/migrations/20250609203423_notify_sse/migration.sql
 create mode 100644 api/sse/index.js

diff --git a/README.md b/README.md
index 33338dc..a653664 100644
--- a/README.md
+++ b/README.md
@@ -132,6 +132,20 @@ docker compose down --remove-orphans
 * Arranca en puerto **80** internamente.
 * Código fuente en `ui/src/`, configuración en `vite.config.js`.
 
+### Notificaciones en tiempo real (SSE)
+
+El backend expone un endpoint `/events` que utiliza **Server-Sent Events**. La
+base de datos PostgreSQL emite mensajes mediante triggers y el servidor los
+reenvía a los navegadores conectados.
+
+```javascript
+const source = new EventSource('http://localhost:4000/events');
+source.onmessage = (e) => {
+  const data = JSON.parse(e.data);
+  console.log('Evento recibido', data);
+};
+```
+
 #### Card Animation
 The data cards implemented in `ui/src/components/ui/NucleoDataCard.vue` now feature a subtle growing animation when hovered over. This animation is implemented purely with CSS using keyframes and transitions defined within the component's `<style scoped>` section, ensuring the styles are encapsulated and don't affect other elements.
 
diff --git a/api/prisma/migrations/20250609203423_notify_sse/migration.sql b/api/prisma/migrations/20250609203423_notify_sse/migration.sql
new file mode 100644
index 0000000..cb8f6ee
--- /dev/null
+++ b/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();
diff --git a/api/server.js b/api/server.js
index 799f0e1..e6cd6ff 100644
--- a/api/server.js
+++ b/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);
diff --git a/api/sse/index.js b/api/sse/index.js
new file mode 100644
index 0000000..be9a908
--- /dev/null
+++ b/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);
+  });
+}
diff --git a/ui/src/main.js b/ui/src/main.js
index cf50243..101a662 100644
--- a/ui/src/main.js
+++ b/ui/src/main.js
@@ -1,6 +1,7 @@
 import { createApp } from 'vue'
 import { createPinia } from 'pinia'
 import router from './router'
+import { usePlanillasStore } from './stores/usePlanillas'
 
 import App from './App.vue'
 import './style.css'          // Tailwind o tus estilos globales
@@ -8,12 +9,14 @@ import './style.css'          // Tailwind o tus estilos globales
 
 // console.log(`API_BASE_URL: ${API_BASE_URL}`);
 
-const app = 
-createApp(App)
+const app = createApp(App)
 
-
-
-app.use(createPinia())
+const pinia = createPinia()
+app.use(pinia)
 app.use(router)
 
+// iniciar suscripción SSE cuando la app monte
+const store = usePlanillasStore(pinia)
+store.subscribeToEvents()
+
 app.mount('#app')
diff --git a/ui/src/stores/usePlanillas.js b/ui/src/stores/usePlanillas.js
index c56fc0c..06d6bea 100644
--- a/ui/src/stores/usePlanillas.js
+++ b/ui/src/stores/usePlanillas.js
@@ -17,6 +17,7 @@ export const usePlanillasStore = defineStore('planillas', {
   state: () => ({
     planillas: [],
     currentPlanilla: getDefaultCurrentPlanilla(),
+    _sse: null,
   }),
 
   actions: {
@@ -82,5 +83,23 @@ export const usePlanillasStore = defineStore('planillas', {
     clearCurrentPlanilla() {
       this.currentPlanilla = getDefaultCurrentPlanilla()
     },
+
+    subscribeToEvents() {
+      if (this._sse) return
+      this._sse = new EventSource('/events')
+      this._sse.onmessage = (e) => {
+        try {
+          const payload = JSON.parse(e.data)
+          if (payload.table === 'Planilla') {
+            this.fetchPlanillas()
+          }
+        } catch (err) {
+          console.error('Error procesando SSE', err)
+        }
+      }
+      this._sse.onerror = () => {
+        console.warn('SSE connection lost, reloading...')
+      }
+    },
   },
 })