xquery version "1.0";

module namespace mpdl-text = "http://www.mpiwg-berlin.mpg.de/ns/mpdl/text"; 

declare namespace text = "http://exist-db.org/xquery/text";
declare namespace util = "http://exist-db.org/xquery/util";
declare namespace local = "http://www.mpiwg-berlin.mpg.de/ns/mpdl/local";

declare function mpdl-text:indexTerms($document, $indexTermsStartStr, $pn as xs:int, $pageSize as xs:int) as node()* {
  let $index := $document/archimedes/text
  let $language := $document/archimedes/info/lang
  let $from := ($pn * $pageSize) - $pageSize + 1
  let $to := $pn * $pageSize
  let $maxTo := 10000
  let $callback := util:function(QName("http://www.mpiwg-berlin.mpg.de/ns/mpdl/local", "local:termEntries"), 2)
  let $indexResult := text:index-terms($index, $indexTermsStartStr, $callback, $maxTo)
  let $count := count($indexResult)
  let $pages := 
    if ($count = 0)
    then 0
    else $count idiv $pageSize + 1
  let $resultEntries := 
    for $entry at $pos in $indexResult
    where $pos >= $from and $pos <= $to
    return $entry

  let $result :=
      <index-terms>
        <start-string>{$indexTermsStartStr}</start-string>
        <size>{$count}</size>
        <pages>{$pages}</pages>
        <pn>{$pn}</pn>
        {$resultEntries}
      </index-terms>
  return $result
};

declare function local:termEntries($term as xs:string, $data as xs:int+) {
  let $result := 
    <entry>  
       <term>{$term}</term>  
       <frequency>{$data[1]}</frequency>  
       <documents>{$data[2]}</documents>  
       <position>{$data[3]}</position>  
       <rank>{$data[4]}</rank>  
     </entry>  
  return $result
};