xquery version "3.0";

declare option exist:serialize "method=xml media-type=text/xml indent=yes";

declare function local:config() {
    <data>{
            for $headers in collection('/db/apps/iskkan/data')//header
            
            return
                <result> {
                for $header in $headers
                let $lang := $header/lang,
                    $engine := $header/engine/@abbreviation
            
                return (
                    $header/timestamp,
                    $header/lang,
                    $header/testtype,
                    <engine>{$engine}</engine>,
                    $header/lexicon,
                    $header/document,
                    $header/truefalsesummary,
                    $header/suggestionsummary)
                }</result>
        }
    </data>
};

local:config()