upstream bcards_backend {
    server 141.148.162.114:8080;
    server 129.146.116.218:8080;
    
    # Health check settings
    keepalive 32;
}

server {
    listen 80;
    server_name bcards.site www.bcards.site;
    
    # Redirect HTTP to HTTPS
    return 301 https://$server_name$request_uri;
}

server {
    listen 443 ssl http2;
    server_name bcards.site www.bcards.site;
    
    # SSL Configuration
    ssl_certificate /etc/letsencrypt/live/bcards.site/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/bcards.site/privkey.pem;
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384;
    ssl_prefer_server_ciphers off;
    ssl_session_cache shared:SSL:10m;
    ssl_session_timeout 10m;
    
    # Security headers
    add_header X-Frame-Options DENY;
    add_header X-Content-Type-Options nosniff;
    add_header X-XSS-Protection "1; mode=block";
    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
    
    # Gzip compression
    gzip on;
    gzip_vary on;
    gzip_min_length 1024;
    gzip_types text/plain text/css text/xml text/javascript application/javascript application/xml+rss application/json;
    
    # Load balancer configuration
    location / {
        proxy_pass http://bcards_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;
        
        # Connection settings
        proxy_connect_timeout 30s;
        proxy_send_timeout 30s;
        proxy_read_timeout 30s;
        
        # Buffer settings
        proxy_buffering on;
        proxy_buffer_size 4k;
        proxy_buffers 8 4k;
        
        # Health check
        proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
        proxy_next_upstream_tries 2;
        proxy_next_upstream_timeout 30s;
    }
    
    # Health check endpoint
    location /health {
        access_log off;
        proxy_pass http://bcards_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;
    }
    
    # Static files (if any)
    location /static {
        proxy_pass http://bcards_backend;
        proxy_cache_valid 200 1h;
        expires 1h;
        add_header Cache-Control "public, immutable";
    }
    
    # Logging
    access_log /var/log/nginx/bcards_access.log;
    error_log /var/log/nginx/bcards_error.log;
}