user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;

events {
    worker_connections 1024;
    use epoll;
    multi_accept on;
}

http {
    include /etc/nginx/mime.types;
    default_type application/octet-stream;

    # Logging
    log_format main '$remote_addr - $remote_user [$time_local] "$request" '
                    '$status $body_bytes_sent "$http_referer" '
                    '"$http_user_agent" "$http_x_forwarded_for"';
    access_log /var/log/nginx/access.log main;

    # Performance
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    client_max_body_size 10M;

    # Gzip compression
    gzip on;
    gzip_vary on;
    gzip_min_length 1000;
    gzip_comp_level 6;
    gzip_types
        text/plain
        text/css
        text/xml
        text/javascript
        application/json
        application/javascript
        application/xml+rss
        application/atom+xml
        image/svg+xml;

    # Rate limiting
    limit_req_zone $binary_remote_addr zone=api:10m rate=10r/m;
    limit_req_zone $binary_remote_addr zone=general:10m rate=100r/m;

    # Upstream servers
    upstream ai_town_server {
        server ai-town-server:8080;
        keepalive 32;
    }

    upstream ai_town_admin {
        server ai-town-server:8081;
        keepalive 8;
    }

    # Main server block
    server {
        listen 80;
        server_name _;
        
        # 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;

        # Static files (Web client)
        location / {
            root /usr/share/nginx/html;
            index index.html;
            try_files $uri $uri/ /index.html;
            
            # Cache static assets
            location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot)$ {
                expires 1y;
                add_header Cache-Control "public, immutable";
                add_header Vary "Accept-Encoding";
            }
            
            # Cache HTML files for shorter time
            location ~* \.(html)$ {
                expires 1h;
                add_header Cache-Control "public, must-revalidate";
            }
        }

        # WebSocket proxy
        location /ws {
            proxy_pass http://ai_town_server;
            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;
            
            # WebSocket specific settings
            proxy_read_timeout 86400;
            proxy_send_timeout 86400;
            proxy_connect_timeout 10s;
        }

        # Admin API (restricted access)
        location /api {
            # Rate limiting
            limit_req zone=api burst=5 nodelay;
            
            # IP whitelist (uncomment and configure for production)
            # allow 192.168.1.0/24;
            # allow 10.0.0.0/8;
            # deny all;
            
            proxy_pass http://ai_town_admin;
            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;
            
            # Timeout settings
            proxy_connect_timeout 10s;
            proxy_send_timeout 30s;
            proxy_read_timeout 30s;
        }

        # Health check endpoint
        location /health {
            proxy_pass http://ai_town_server/health;
            access_log off;
        }

        # Admin interface
        location /admin {
            proxy_pass http://ai_town_admin;
            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;
        }

        # Security: Hide nginx version
        server_tokens off;

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

    # HTTPS server (uncomment for SSL)
    # server {
    #     listen 443 ssl http2;
    #     server_name your-domain.com;
    #     
    #     ssl_certificate /etc/nginx/ssl/cert.pem;
    #     ssl_certificate_key /etc/nginx/ssl/key.pem;
    #     
    #     ssl_protocols TLSv1.2 TLSv1.3;
    #     ssl_ciphers ECDHE-RSA-AES256-GCM-SHA512:DHE-RSA-AES256-GCM-SHA512:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES256-GCM-SHA384;
    #     ssl_prefer_server_ciphers off;
    #     ssl_session_cache shared:SSL:10m;
    #     ssl_session_timeout 10m;
    #     
    #     # Include the same location blocks as HTTP server
    # }
}