# Upstream para el backend API
upstream api_backend {
    server api:3000;
    keepalive 32;
}

# Upstream para el frontend
upstream frontend_app {
    server frontend:80;
    keepalive 16;
}

# Configuración del servidor principal
server {
    listen 80;
    server_name localhost;

    # Logs
    access_log /var/log/nginx/access.log;
    error_log /var/log/nginx/error.log;

    # Health check endpoint
    location /health {
        access_log off;
        return 200 "healthy\n";
        add_header Content-Type text/plain;
    }

    # API REST endpoints
    location /api {
        # Reescribir la URL quitando el prefijo /api
        rewrite ^/api/(.*)$ /$1 break;

        proxy_pass http://api_backend;
        proxy_http_version 1.1;

        # Headers
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header Connection "";

        # Timeouts
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;

        # Buffering
        proxy_buffering on;
        proxy_buffer_size 4k;
        proxy_buffers 8 4k;
        proxy_busy_buffers_size 8k;

        # CORS headers (si es necesario)
        add_header Access-Control-Allow-Origin * always;
        add_header Access-Control-Allow-Methods "GET, POST, PUT, DELETE, OPTIONS" always;
        add_header Access-Control-Allow-Headers "Authorization, Content-Type" always;

        if ($request_method = 'OPTIONS') {
            return 204;
        }
    }

    # WebSocket endpoint
    location /ws {
        proxy_pass http://api_backend;
        proxy_http_version 1.1;

        # WebSocket upgrade headers
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";

        # Headers estándar
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;

        # Timeouts más largos para WebSocket
        proxy_connect_timeout 7d;
        proxy_send_timeout 7d;
        proxy_read_timeout 7d;

        # Deshabilitar buffering para WebSocket
        proxy_buffering off;
    }

    # Socket.io endpoint
    location /socket.io/ {
        proxy_pass http://api_backend;
        proxy_http_version 1.1;

        # WebSocket upgrade headers
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";

        # Headers estándar
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;

        # Timeouts más largos para WebSocket
        proxy_connect_timeout 7d;
        proxy_send_timeout 7d;
        proxy_read_timeout 7d;

        # Deshabilitar buffering para WebSocket
        proxy_buffering off;
    }

    # Frontend - SPA con fallback para React Router
    location / {
        proxy_pass http://frontend_app;
        proxy_http_version 1.1;

        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;

        # Cache de activos estáticos
        location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot)$ {
            proxy_pass http://frontend_app;
            expires 1y;
            add_header Cache-Control "public, immutable";
        }
    }

    # Denegar acceso a archivos ocultos
    location ~ /\. {
        deny all;
        access_log off;
        log_not_found off;
    }
}

# Configuración HTTPS (descomentar cuando tengas certificados)
# server {
#     listen 443 ssl http2;
#     server_name localhost;
#
#     ssl_certificate /etc/nginx/ssl/cert.pem;
#     ssl_certificate_key /etc/nginx/ssl/key.pem;
#     ssl_protocols TLSv1.2 TLSv1.3;
#     ssl_ciphers HIGH:!aNULL:!MD5;
#     ssl_prefer_server_ciphers on;
#
#     # Incluir las mismas configuraciones de location que arriba
#     # ...
# }

# Redirección HTTP a HTTPS (descomentar cuando tengas HTTPS configurado)
# server {
#     listen 80;
#     server_name localhost;
#     return 301 https://$server_name$request_uri;
# }