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

events {
    worker_connections 1024;
}

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 100M;

    # Gzip compression
    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;

    # 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 "no-referrer-when-downgrade" always;

    # Server block
    server {
        listen 80;
        server_name _;
        root /usr/share/nginx/html;
        index index.html;

        # Enable CORS for Canvas API (if needed)
        add_header Access-Control-Allow-Origin "*" always;
        add_header Access-Control-Allow-Methods "GET, POST, OPTIONS" always;
        add_header Access-Control-Allow-Headers "DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range" always;

        # Handle SPA routing
        location / {
            try_files $uri $uri/ /index.html;
        }

        # Cache static assets
        location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot|webp)$ {
            expires 1y;
            add_header Cache-Control "public, immutable";
        }

        # Don't cache HTML files
        location ~* \.html$ {
            expires -1;
            add_header Cache-Control "no-store, no-cache, must-revalidate, proxy-revalidate, max-age=0";
        }

        # Handle WebAssembly files (for future image processing)
        location ~* \.wasm$ {
            types { application/wasm wasm; }
            expires 1y;
            add_header Cache-Control "public, immutable";
        }

        # Health check endpoint
        location /health {
            access_log off;
            return 200 "healthy\n";
            add_header Content-Type text/plain;
        }

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