events {
    worker_connections 1024;
}

http {
    upstream api {
        server mm-madam-api:8000;
    }

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

    server {
        listen 80;
        server_name localhost;

        # Security headers
        add_header X-Frame-Options DENY;
        add_header X-Content-Type-Options nosniff;
        add_header X-XSS-Protection "1; mode=block";

        # CORS headers for widget
        location ~* \.(js|css)$ {
            add_header Access-Control-Allow-Origin "*";
            add_header Access-Control-Allow-Methods "GET, OPTIONS";
            add_header Access-Control-Allow-Headers "Content-Type";
            
            # Cache control
            expires 1h;
            add_header Cache-Control "public, immutable";
            
            limit_req zone=widget burst=20 nodelay;
        }

        # Serve chat widget
        location /chat-widget.js {
            root /usr/share/nginx/html;
            try_files $uri =404;
        }

        # Serve demo page
        location / {
            root /usr/share/nginx/html;
            try_files $uri $uri/ /index.html;
        }

        # API proxy
        location /api/ {
            # Rate limiting for API calls
            limit_req zone=chat burst=5 nodelay;
            
            # CORS headers
            add_header Access-Control-Allow-Origin "*";
            add_header Access-Control-Allow-Methods "GET, POST, OPTIONS";
            add_header Access-Control-Allow-Headers "Content-Type, Authorization";
            
            # Handle preflight
            if ($request_method = 'OPTIONS') {
                return 204;
            }
            
            # Proxy settings
            proxy_pass http://api/;
            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;
            
            # Timeouts
            proxy_connect_timeout 60s;
            proxy_send_timeout 60s;
            proxy_read_timeout 60s;
        }

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