events {
    worker_connections 1024;
}

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

    # Hide nginx version
    server_tokens off;

    # Log format
    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;
    error_log   /var/log/nginx/error.log;

    sendfile        on;
    tcp_nopush      on;
    tcp_nodelay     on;
    keepalive_timeout  65;
    types_hash_max_size 2048;

    # Include additional configuration files
    include /etc/nginx/conf.d/*.conf;

    # Server block
    server {
        listen       80;
        server_name  localhost;

        # Handle preflight requests for CORS
        location / {
            # Handle preflight requests
            if ($request_method = 'OPTIONS') {
                add_header 'Access-Control-Allow-Origin' '*' always;
                add_header 'Access-Control-Allow-Methods' 'GET, POST, PUT, DELETE, OPTIONS' always;
                add_header 'Access-Control-Allow-Headers' 'DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range,Authorization' always;
                add_header 'Access-Control-Max-Age' 1728000 always;
                add_header 'Content-Type' 'text/plain; charset=utf-8' always;
                add_header 'Content-Length' 0 always;
                return 204;
            }
            
            root   /usr/share/nginx/html;
            index  index.html index.htm;
            
            # Try to serve file, if not found, serve index.html (for SPA routing)
            try_files $uri $uri/ /index.html;
            
            # Add CORS headers for all responses
            add_header 'Access-Control-Allow-Origin' '*' always;
            add_header 'Access-Control-Allow-Credentials' 'true' always;
            add_header 'Access-Control-Allow-Methods' 'GET, POST, PUT, DELETE, OPTIONS' always;
            add_header 'Access-Control-Allow-Headers' 'DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range,Authorization' always;
            
            # Add security headers
            add_header X-Frame-Options "SAMEORIGIN" always;
            add_header X-XSS-Protection "1; mode=block" always;
            add_header X-Content-Type-Options "nosniff" always;
        }

        # Error pages
        error_page  404              /404.html;
        location = /404.html {
            internal;
        }

        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            internal;
        }
    }
}