# HTTP server - redirect to HTTPS (uncomment in production with SSL)
# server {
#     listen 80;
#     server_name your-domain.com;
#     return 301 https://$server_name$request_uri;
# }

# Main server configuration
server {
    listen 80;
    # listen 443 ssl http2;  # Uncomment for HTTPS
    server_name localhost;

    # SSL configuration (uncomment in production)
    # ssl_certificate /etc/nginx/ssl/fullchain.pem;
    # ssl_certificate_key /etc/nginx/ssl/privkey.pem;
    # ssl_session_timeout 1d;
    # ssl_session_cache shared:SSL:50m;
    # ssl_session_tickets off;
    # ssl_protocols TLSv1.2 TLSv1.3;
    # ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256;
    # ssl_prefer_server_ciphers off;

    # Security headers
    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 "strict-origin-when-cross-origin" always;

    # Client body size limit
    client_max_body_size 10M;

    # API endpoints
    location /api/ {
        # Rate limiting
        limit_req zone=api_limit burst=20 nodelay;
        limit_conn conn_limit 10;

        # Proxy settings
        proxy_pass http://api_servers;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        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_cache_bypass $http_upgrade;

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

    # Health check endpoint
    location /health {
        proxy_pass http://api_servers;
        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;
    }

    # API documentation
    location /api-docs {
        proxy_pass http://api_servers;
        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;
    }

    # Static file uploads
    location /uploads/ {
        proxy_pass http://api_servers;
        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 static files
        proxy_cache_valid 200 1d;
        expires 1d;
        add_header Cache-Control "public, immutable";
    }

    # Deny access to hidden files
    location ~ /\. {
        deny all;
        access_log off;
        log_not_found off;
    }

    # Error pages
    error_page 500 502 503 504 /50x.html;
    location = /50x.html {
        root /usr/share/nginx/html;
        internal;
    }
}