# Allows the usage of $CORS_ALLOWED_DOMAIN
map $http_x_cors_allowed_domain $CORS_ALLOWED_DOMAIN {
    default "*";
}

server {
    server_name $VIRTUAL_HOST;
    listen 443;
    location / {
        # Set the Access-Control-Allow-Origin header to allow specific domain(s) for CORS
        add_header 'Access-Control-Allow-Origin' $CORS_ALLOWED_DOMAIN;
        # Specify the allowed HTTP methods for CORS requests
        add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
        # Define the allowed request headers for CORS requests
        add_header 'Access-Control-Allow-Headers' 'DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range';
        # Specify the response headers that are accessible by the client (browser)
        add_header 'Access-Control-Expose-Headers' 'Content-Length,Content-Range';
        # Set the maximum age (in seconds) for the CORS preflight request cache in the client (browser)
        add_header 'Access-Control-Max-Age' 1728000;

        # Handle CORS preflight (OPTIONS) requests
        if ($request_method = 'OPTIONS') {
            # Set the response content type and charset for the preflight request
            add_header 'Content-Type' 'text/plain; charset=utf-8';
            # Set the response content length to 0 for the preflight request
            add_header 'Content-Length' 0;
            # Return a 204 No Content status for the preflight request
            return 204;
        }
    }
}