# WhatsApp Gateway - Arquitectura Profesional

## 🏗️ Arquitectura del Sistema

```
┌──────────────────────────────┐
│        Manager Web           │
│     (React + TypeScript)     │
│  - QR Display                │
│  - Status Dashboard          │
│  - Control Interface         │
└──────────────┬───────────────┘
               │ HTTP/WebSocket
┌──────────────▼───────────────┐
│   WhatsApp Gateway (Node)    │
│         Baileys              │
│  - Session Management        │
│  - QR Generation             │
│  - Message Handling         │
│  - WebSocket Events          │
└──────────────┬───────────────┘
               │ REST API
┌──────────────▼───────────────┐
│       Core API Layer        │
│  - Send Messages            │
│  - Bulk Operations          │
│  - Status Monitoring        │
│  - Health Checks            │
└──────────────┬───────────────┘
               │
┌──────────────▼───────────────┐
│      File Storage           │
│  - Session Credentials      │
│  - Auth Information         │
└──────────────────────────────┘
```

## 🚀 Inicio Rápido

### 1. Instalar Dependencias

```bash
# Gateway (Backend)
cd gateway
npm install

# Manager Web (Frontend)
cd ../manager
npm install
```

### 2. Configurar Variables de Entorno

```bash
# gateway/.env
PORT=3001
NODE_ENV=production
SESSION_ID=default
LOG_LEVEL=info
```

### 3. Iniciar Servicios

```bash
# Terminal 1: Gateway
cd gateway
npm run dev

# Terminal 2: Manager Web
cd manager
npm run dev
```

### 4. Acceder a la Interfaz

- **Manager Web**: http://localhost:3002
- **API Gateway**: http://localhost:3001
- **WebSocket**: ws://localhost:3003

## 📡 API Endpoints

### Enviar Mensaje
```http
POST /api/send
Content-Type: application/json

{
  "jid": "1234567890@s.whatsapp.net",
  "content": "Hola desde el Gateway!",
  "type": "text"
}
```

### Enviar Mensajes Masivos
```http
POST /api/send/bulk
Content-Type: application/json

{
  "messages": [
    {
      "jid": "1234567890@s.whatsapp.net",
      "content": "Mensaje 1",
      "type": "text"
    },
    {
      "jid": "0987654321@s.whatsapp.net",
      "content": "Mensaje 2",
      "type": "text"
    }
  ]
}
```

### Ver Estado
```http
GET /api/status
```

### Health Check
```http
GET /api/health
```

## 🔧 Configuración para VPS

### Systemd Service (Gateway)

```ini
# /etc/systemd/system/whatsapp-gateway.service
[Unit]
Description=WhatsApp Gateway Service
After=network.target

[Service]
Type=simple
User=whatsapp
WorkingDirectory=/opt/whatsapp-gateway
ExecStart=/usr/bin/node dist/index.js
Restart=always
RestartSec=10
Environment=NODE_ENV=production
Environment=PORT=3001

[Install]
WantedBy=multi-user.target
```

### Nginx Reverse Gateway

```nginx
# /etc/nginx/sites-available/whatsapp-gateway
server {
    listen 80;
    server_name tu-dominio.com;

    # Manager Web
    location / {
        proxy_pass http://localhost:3002;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }

    # API Gateway
    location /api/ {
        proxy_pass http://localhost:3001;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }

    # WebSocket
    location /ws {
        proxy_pass http://localhost:3003;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $host;
    }
}
```

### Docker Compose

```yaml
# docker-compose.yml
version: '3.8'

services:
  whatsapp-gateway:
    build: ./gateway
    ports:
      - "3001:3001"
      - "3003:3003"
    volumes:
      - ./auth_info:/app/auth_info
    environment:
      - NODE_ENV=production
      - PORT=3001
    restart: unless-stopped

  whatsapp-manager:
    build: ./manager
    ports:
      - "3002:3002"
    depends_on:
      - whatsapp-gateway
    restart: unless-stopped

  nginx:
    image: nginx:alpine
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - ./nginx.conf:/etc/nginx/nginx.conf
    depends_on:
      - whatsapp-gateway
      - whatsapp-manager
    restart: unless-stopped
```

## 🔐 Seguridad

### 1. Variables de Entorno
```bash
# Nunca exponer credenciales en el código
SESSION_ID=unique-session-id
API_KEY=your-api-key-here
WEBHOOK_SECRET=webhook-secret
```

### 2. CORS Configurado
```typescript
// Solo dominios confiables
cors({
  origin: ['https://tu-dominio.com', 'https://manager.tu-dominio.com'],
  credentials: true
})
```

### 3. Rate Limiting
```bash
# Nginx rate limiting
limit_req_zone $binary_remote_addr zone=api:10m rate=10r/s;
```

## 📈 Monitoreo

### Logs Estructurados
```bash
# Ver logs en tiempo real
tail -f /var/log/whatsapp-gateway.log | jq '.'
```

### Métricas de Salud
```bash
# Health check endpoint
curl http://localhost:3001/api/health
```

### Uso de Recursos
```bash
# Monitorear memoria y CPU
htop
docker stats
```

## 🚀 Despliegue en VPS

### 1. Preparar Servidor
```bash
# Actualizar sistema
sudo apt update && sudo apt upgrade -y

# Instalar Node.js 18+
curl -fsSL https://deb.nodesource.com/setup_18.x | sudo -E bash -
sudo apt-get install -y nodejs

# Instalar PM2
sudo npm install -g pm2
```

### 2. Clonar y Configurar
```bash
# Clonar repositorio
git clone <tu-repo> whatsapp-gateway
cd whatsapp-gateway

# Instalar dependencias
cd gateway && npm install
cd ../manager && npm install
```

### 3. Iniciar con PM2
```bash
# Gateway
pm2 start gateway/dist/index.js --name whatsapp-gateway

# Manager Web (opcional, puede servir con nginx)
pm2 start "cd manager && npm run build && serve -s dist -l 3002" --name whatsapp-manager

# Guardar configuración
pm2 save
pm2 startup
```

### 4. Configurar Firewall
```bash
# Solo puertos necesarios
sudo ufw allow 22    # SSH
sudo ufw allow 80    # HTTP
sudo ufw allow 443   # HTTPS
sudo ufw enable
```

## 🔄 Integración con n8n

### Webhook Configuration
```json
{
  "method": "POST",
  "path": "/webhook",
  "webhookId": "whatsapp-events",
  "responseMode": "onReceived"
}
```

### n8n Node Example
```javascript
// Enviar mensaje desde n8n
const response = await fetch('http://localhost:3001/api/send', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    jid: $input.first().json.phone + '@s.whatsapp.net',
    content: $input.first().json.message,
    type: 'text'
  })
});
```

## 🛠️ Troubleshooting

### Problemas Comunes

1. **QR no aparece**
   - Verificar conexión WebSocket
   - Revisar logs del Gateway

2. **Conexión se cae**
   - Checar persistencia de sesión
   - Verificar archivo de credenciales

3. **Mensajes no se envían**
   - Validar formato JID
   - Verificar estado de conexión

### Debug Mode
```bash
# Habilitar logs detallados
LOG_LEVEL=debug npm run dev
```

## 📝 Licencia

Este proyecto es para uso personal y educativo.