<?xml version='1.0'?>
<!DOCTYPE xsl:stylesheet SYSTEM "../../../lib/xml/xsl.dtd" >
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="3.0" xmlns:s="http://schemas.openxmlformats.org/spreadsheetml/2006/main" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:e="http://markup.co.uk/excel" exclude-result-prefixes="xs s e xf" xmlns="http://markup.co.uk/excel" xmlns:xf="http://www.w3.org/2005/xpath-functions">
 <xsl:param name="sheet-number"/>
 <xsl:param name="xlDir"/>
 
 <xsl:include href="a2n.xsl"/>

  <xsl:variable name="pat1">("[^"]*")|(\{[^}]+})|(,)|([^=\-+*/();:,.$&lt;>^!]+(?:\.[^=\-+*/();:,.$&lt;>^!]+)*\()|([)])|(^=|\()|((?:(?:'[^']+')|(?:\[[0-9]+\][^!]*)|(?:[a-zA-Z_][a-zA-Z0-9._]*)!))|(\$?[A-Z]+\$?[0-9]+)|([a-zA-Z_\\][a-zA-Z0-9._]*)|(.)</xsl:variable>
 <xsl:param name="pat" select="$pat1"/><!-- xsl:param for refinement debugging by passing in the pattern -->
 
 <xsl:variable name="workbook" select="document(concat($xlDir,'/workbook.xml'))/*"/>
 <xsl:variable name="sheet-name" select="$workbook/s:sheets/s:sheet[@sheetId=$sheet-number]/@name"/>
 
 <xsl:function name="e:lookup" as="xs:string*">
  <xsl:param name="name" as="xs:string" required="yes"/>
  <xsl:variable name="defn" select="$workbook/s:definedNames/s:definedName[@name=$name]"/>
  <xsl:sequence select="let $prefix := concat($sheet-name,'!')
                   return if ($defn and
                              starts-with($defn,$prefix))
                           then substring-after($defn,$prefix)
                           else ()"/>
 </xsl:function>

 <xsl:function name="e:tokenise" as="element(*)*">
  <!-- Tokenise a formula, recursively wrt variables
       Output is composed of e:* as follows:
       c: A list (function parameter) separator
       e: An external (variable, cell or range) reference
       f: A function name followed by an opening parenthesis
       l: The beginning of the formula or an opening paren
       m: A constant matrix
       p: A close-paren
       q: A text (delimited by double quotes) 
       r: A range reference
       s: A single-cell reference
       v: A variable name [should only occur inside e]
       x: Amalgamated single characters not matched by anything else
 -->
  <xsl:param name="formula" as="xs:string" required="yes"/>
  <!-- The row and column number of the cell whence the formula came -->
  <xsl:param name="row" required="yes" as="xs:int"/>
  <xsl:param name="col" required="yes" as="xs:int"/>
  <xsl:sequence select="
     let $tokens := analyze-string($formula,$pat)/xf:match/xf:group
        return e:tok1($tokens,count($tokens),1,$row,$col,())"/>
 </xsl:function>
 
 <xsl:function name="e:tok1" as="element(*)*">
  <xsl:param name="tokens" as="element(xf:group)*" required="yes"/>
  <xsl:param name="n" required="yes" as="xs:int"/>
  <xsl:param name="i" required="yes" as="xs:int"/>
  <xsl:param name="row" required="yes" as="xs:int"/>
  <xsl:param name="col" required="yes" as="xs:int"/>
  <xsl:param name="soFar" required="yes" as="element(*)*"/>
  <xsl:sequence select="
    if ($i gt $n)
          then $soFar
          else 
            let $next := e:expand($tokens,$i,true(),$row,$col),
                $j := $next?1,
                $res := $next?2 return
            e:tok1($tokens,$n,$j,$row,$col,($soFar,$res))"/>
 </xsl:function>
 
 <xsl:function name="e:expand" as="element(*)*">
  <xsl:param name="tokens" required="yes" as="element(xf:group)*"/>
  <xsl:param name="i" required="yes" as="xs:int"/>
  <xsl:param name="local" required="yes" as="xs:boolean"/>
  <xsl:param name="row" required="yes" as="xs:int"/>
  <xsl:param name="col" required="yes" as="xs:int"/>
  <xsl:sequence select="
    let $t := $tokens[$i],
        $r := $tokens[$i + 1] return
     if ($t/@nr=1) then e:exp1($i,'q',string($t))
     else if ($t/@nr=2) then e:exp1($i,'m',string($t))
     else if ($t/@nr=3) then e:exp1($i,'c',',')
     else if ($t/@nr=4) then e:exp1($i,'f',string($t))
     else if ($t/@nr=5) then e:exp1($i,'p',')')
     else if ($t/@nr=6) then e:exp1($i,'l',string($t))
     else if ($t/@nr=7)
       then if (substring-before($t,'!')=('[0]',$sheet-name))
              then (: it's a local reference after all :)
               e:expand($tokens,$i+1,true(),$row,$col)
              else let $ext := e:expand($tokens,$i+1,false(),$row,$col) return
                    [$ext?1,e:external($ext?2)]
     else if ($t/@nr=10) then e:amalgamate($tokens,$i+1,string($t))
     else if ($r[@nr=10 and .=':'])
       then (: a range, takes priority :)
          e:range($tokens,$i,$ext,$row,$col)
     else if ($t/@nr=8) then e:single($i,$ext,string($t))
     else if ($t/@nr=9)
       then if ($ext) then (: can't expand :) e:exp1($i,'v',string($t))
       else e:tokenise(e:lookup(string($t)),$row,$col)
     else (-- shouldn't ever get here --) ()"/>
 </xsl:function>
 
 <xsl:function name="e:exp1" as="array(*)">
  <xsl:param name="i" as="xs:int"/>
  <xsl:param name="name" as="xs:string"/>
  <xsl:param name="val" as="xs:string"/>
  <xsl:variable name="elt">
   <xsl:element name="{$name}" namespace="http://markup.co.uk/excel">
    <xsl:value-of select="$val"/>
   </xsl:element>
  </xsl:variable>
  <xsl:sequence select="[$i+1,$elt]"/>
 </xsl:function>
 
 <xsl:function name="e:single" as="element(*)">
  <xsl:param name="group" as="element(xf:group)"/>
  <xsl:param name="row" as="xs:integer"/>
  <xsl:param name="col" as="xs:integer"/>
  <xsl:param name="external" as="xs:boolean"/>
  <xsl:variable name="val" select="if ($group/@nr=9) then e:lookup($group)
                                             else string($group)"/>
  <xsl:choose>
   <xsl:when test="count($val)>0 or not($external)">
    <xsl:sequence select="e:cr($val,$row,$col)"/>
   </xsl:when>
   <xsl:otherwise>
    <v><xsl:value-of select="$group"/></v>
   </xsl:otherwise>
  </xsl:choose>  
 </xsl:function>
 
 <xsl:function name="e:range" as="element(e:r)">
  <xsl:param name="l" as="element(e:s)" required="yes"/>
  <xsl:param name="r" as="element(e:s)" required="yes"/>
  <r><xsl:copy-of select="$l"/><xsl:copy-of select="$r"/></r>
 </xsl:function>
 
 <xsl:function name="e:external" as="element(e:e)">
  <xsl:param name="source" as="element(xf:group)" required="yes"/>
  <xsl:param name="ref" as="element(*)" required="yes"/>
  <e s="{$source}"><xsl:sequence select="$ref"/></e>
 </xsl:function>
</xsl:stylesheet>