# Configuração Nginx para o projeto Integra GPL
# Atualizado em: 07/12/2025
# Contexto: Hardening de segurança baseado no padrão 'cloud' e otimização de buffers.
# Autor: Gemini (Thought Partner)

upstream integra_gpl_backend {
    # Backend da aplicação (Python/Node)
    server 172.16.9.101:8000;
    
    # Mantém conexões abertas para performance
    keepalive 32;
}

# Servidor HTTP (Redirecionamento HTTPS)
server {
    listen 80;
    listen [::]:80;
    server_name integra.grupopralog.com.br;

    # Segurança: Ocultar versão do Nginx
    server_tokens off;

    location /.well-known/acme-challenge/ {
        root /var/www/html;
    }

    location / {
        return 301 https://$host$request_uri;
    }
}

# Servidor HTTPS Principal
server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    server_name integra.grupopralog.com.br;

    # Segurança: Ocultar versão do Nginx
    server_tokens off;

    # Limite de Upload (Ajustado conforme padrão do cloud, útil para importações grandes)
    client_max_body_size 10M;

    # ----------------------------------------------------------------------
    # Logs
    # ----------------------------------------------------------------------
    access_log /var/log/nginx/integra.grupopralog.com.br.access.log detailed_proxy;
    error_log /var/log/nginx/integra.grupopralog.com.br.error.log warn;

    # ----------------------------------------------------------------------
    # Configuração SSL/TLS (Hardening Avançado)
    # ----------------------------------------------------------------------
    ssl_certificate /etc/letsencrypt/live/integra.grupopralog.com.br/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/integra.grupopralog.com.br/privkey.pem;

    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_prefer_server_ciphers on;
    
    # Ciphers Modernos e Seguros (Padrão Mozilla Intermediate)
    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;
    
    # Curvas Elípticas e DHParam (Extraído do arquivo 'cloud')
    ssl_ecdh_curve X25519:secp256r1:secp384r1;
    ssl_dhparam /etc/nginx/dhparam.pem;

    # Sessão SSL Otimizada
    ssl_session_timeout 1d;
    ssl_session_cache shared:MozSSL:10m;
    ssl_session_tickets off;

    # OCSP Stapling
    ssl_stapling on;
    ssl_stapling_verify on;
    resolver 8.8.8.8 8.8.4.4 valid=300s;
    resolver_timeout 5s;

    # ----------------------------------------------------------------------
    # Headers de Segurança (Hardening 'cloud')
    # ----------------------------------------------------------------------
    # HSTS Preload (2 anos - garante HTTPS estrito)
    add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload" always;
    
    # Proteção de Frame e Content Type
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header Referrer-Policy "no-referrer-when-downgrade" always;

    # ----------------------------------------------------------------------
    # Buffers e Timeouts (Evita erro 502 em cargas altas)
    # ----------------------------------------------------------------------
    client_body_buffer_size 128M;
    proxy_buffer_size 512k;
    proxy_buffers 32 256k;
    proxy_busy_buffers_size 512k;
    proxy_temp_file_write_size 512k;

    # Timeouts elevados para processamentos longos de integração
    proxy_connect_timeout 120s;
    proxy_send_timeout 1200s;
    proxy_read_timeout 1200s;

    # ----------------------------------------------------------------------
    # Compressão (Lista expandida do 'cloud')
    # ----------------------------------------------------------------------
    brotli on;
    brotli_comp_level 6;
    brotli_types application/atom+xml application/javascript application/json application/ld+json application/manifest+json application/rss+xml application/vnd.ms-fontobject application/x-font-opentype application/x-font-truetype application/x-javascript application/xhtml+xml application/xml font/eot font/opentype font/otf font/truetype font/woff font/woff2 image/svg+xml image/x-icon text/css text/javascript text/plain text/xml;

    gzip on;
    gzip_vary on;
    gzip_proxied any;
    gzip_comp_level 6;
    gzip_types application/atom+xml application/javascript application/json application/ld+json application/manifest+json application/rss+xml application/vnd.ms-fontobject application/x-font-opentype application/x-font-truetype application/x-javascript application/xhtml+xml application/xml font/eot font/opentype font/otf font/truetype font/woff font/woff2 image/svg+xml image/x-icon text/css text/javascript text/plain text/xml;

    # ----------------------------------------------------------------------
    # Cache de Arquivos Estáticos (Otimização do 'cloud')
    # ----------------------------------------------------------------------
    location ~* \.(?:css|js|mjs|svg|gif|png|jpg|jpeg|ico|wasm|woff|woff2|ttf|otf)$ {
        proxy_pass http://integra_gpl_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 $scheme;

        # Otimização de buffer para download de assets
        proxy_buffering on;

        # Cache de 1 ano (Immutable)
        expires 1y;
        add_header Cache-Control "public, immutable";
        
        # Performance: desativa log para assets
        access_log off;
        log_not_found off;
    }

    # ----------------------------------------------------------------------
    # Aplicação Principal
    # ----------------------------------------------------------------------
    location / {
        proxy_pass http://integra_gpl_backend;
        
        # Headers de Proxy
        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;

        # WebSockets (Essencial para apps modernos)
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";

        # Buffering
        proxy_buffering on;
        proxy_request_buffering off;
    }
}