upstream backend {
    server backend:8000;
}

# Servidor HTTPS (SSL/TLS)
# NOTA: Solo se expone puerto 443. No hay redirección HTTP->HTTPS
# Los usuarios DEBEN acceder directamente vía HTTPS
server {
    listen 443 ssl http2;
    server_name localhost;
    client_max_body_size 100M;

    # Certificados SSL
    # NOTA: Debes generar estos certificados o usar Let's Encrypt
    # Para desarrollo/pruebas locales, usa certificados autofirmados
    # Para producción, usa certificados reales de Let's Encrypt o una CA
    ssl_certificate /etc/nginx/ssl/cert.pem;
    ssl_certificate_key /etc/nginx/ssl/key.pem;

    # Configuración SSL moderna y segura
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers 'ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384';
    ssl_prefer_server_ciphers off;

    # HSTS (HTTP Strict Transport Security)
    # Obliga al navegador a usar HTTPS por 1 año
    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;

    # Seguridad adicional
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-XSS-Protection "1; mode=block" always;
    add_header Referrer-Policy "no-referrer-when-downgrade" always;

    # Sesión SSL
    ssl_session_cache shared:SSL:10m;
    ssl_session_timeout 10m;

    # OCSP Stapling
    ssl_stapling on;
    ssl_stapling_verify on;

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

    # Frontend - Servir archivos estáticos de React
    location / {
        root /usr/share/nginx/html;
        index index.html index.htm;
        try_files $uri $uri/ /index.html;
    }

    # API Backend - Proxy al backend Django
    location /api/ {
        proxy_pass http://backend;
        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 https;
        proxy_set_header X-Forwarded-Ssl on;
        proxy_redirect off;

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

    # Admin de Django
    location /admin/ {
        proxy_pass http://backend;
        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 https;
        proxy_set_header X-Forwarded-Ssl on;
        proxy_redirect off;

        # Timeouts extendidos para importaciones/exportaciones de archivos grandes
        proxy_connect_timeout 300s;
        proxy_send_timeout 300s;
        proxy_read_timeout 300s;
    }

    # Archivos estáticos de Django
    location /static/ {
        alias /app/staticfiles/;
        expires 30d;
        add_header Cache-Control "public, immutable";
    }

    # Archivos media de Django
    location /media/ {
        alias /app/media/;
        expires 30d;
        add_header Cache-Control "public";
    }

    # Configuración de gzip
    gzip on;
    gzip_vary on;
    gzip_proxied any;
    gzip_comp_level 6;
    gzip_types text/plain text/css text/xml text/javascript
               application/json application/javascript application/xml+rss
               application/rss+xml font/truetype font/opentype
               application/vnd.ms-fontobject image/svg+xml;
}