<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<!-- ********************************************************************
     ********************************************************************
	 Copyright 2008, Regina Obe
     License: BSD
	 Purpose: This is an xsl transform that generates PostgreSQL COMMENT ON FUNCTION ddl
	 statements from postgis xml doc reference
     ******************************************************************** -->
	<xsl:output method="text" />

	<!-- We deal only with the reference chapter -->
        <xsl:template match="/">
                <xsl:apply-templates select="/book/chapter[@id='reference']" />
        </xsl:template>

        <xsl:template match="chapter">
		<xsl:variable name="ap"><xsl:text>'</xsl:text></xsl:variable>
<!-- Pull out the purpose section for each ref entry and strip whitespace and put in a variable to be tagged unto each function comment  -->
		<xsl:for-each select="sect1[@id='reference_sfcgal']/refentry">
		  <xsl:variable name='plaincomment'>
		  	<xsl:value-of select="normalize-space(translate(translate(refnamediv/refpurpose,'&#x0d;&#x0a;', ' '), '&#09;', ' '))"/>
		  </xsl:variable>
<!-- Replace apostrophes with 2 apostrophes needed for escaping in SQL -->
		<xsl:variable name='comment'>
			<xsl:call-template name="globalReplace">
				<xsl:with-param name="outputString" select="$plaincomment"/>
				<xsl:with-param name="target" select="$ap"/>
				<xsl:with-param name="replacement" select="''"/>
			</xsl:call-template>
		</xsl:variable>
<!-- For each function prototype generate the DDL comment statement
	If its input is a geometry set - we know it is an aggregate function rather than a regular function 
	Do not output OUT params since they define output rather than act as input and do not put a comma after argument just before an OUT parameter -->
		<xsl:for-each select="refsynopsisdiv/funcsynopsis/funcprototype">
COMMENT ON <xsl:choose><xsl:when test="contains(paramdef/type,'geometry set')">AGGREGATE</xsl:when><xsl:otherwise>FUNCTION</xsl:otherwise></xsl:choose><xsl:text> </xsl:text> <xsl:value-of select="funcdef/function" />(<xsl:for-each select="paramdef"><xsl:choose><xsl:when test="count(parameter) &gt; 0"> 
<xsl:choose><xsl:when test="contains(parameter,'OUT')"></xsl:when><xsl:when test="contains(type,'geometry set')">geometry</xsl:when><xsl:otherwise><xsl:value-of select="type" /></xsl:otherwise></xsl:choose><xsl:if test="position()&lt;last() and not(contains(parameter,'OUT')) and not(contains(following-sibling::paramdef[1],'OUT'))"><xsl:text>, </xsl:text></xsl:if></xsl:when>
</xsl:choose></xsl:for-each>) IS '<xsl:call-template name="listparams"><xsl:with-param name="func" select="." /></xsl:call-template> <xsl:value-of select='$comment' />';
			</xsl:for-each>
		</xsl:for-each>
	</xsl:template>
	
<!--General replace macro hack to make up for the fact xsl 1.0 does not have a built in one.  
	Not needed for xsl 2.0 lifted from http://www.xml.com/pub/a/2002/06/05/transforming.html -->
	<xsl:template name="globalReplace">
	  <xsl:param name="outputString"/>
	  <xsl:param name="target"/>
	  <xsl:param name="replacement"/>
	  <xsl:choose>
		<xsl:when test="contains($outputString,$target)">
		  <xsl:value-of select=
			"concat(substring-before($outputString,$target),
				   $replacement)"/>
		  <xsl:call-template name="globalReplace">
			<xsl:with-param name="outputString" 
				 select="substring-after($outputString,$target)"/>
			<xsl:with-param name="target" select="$target"/>
			<xsl:with-param name="replacement" 
				 select="$replacement"/>
		  </xsl:call-template>
		</xsl:when>
		<xsl:otherwise>
		  <xsl:value-of select="$outputString"/>
		</xsl:otherwise>
	  </xsl:choose>
	</xsl:template>

	<!--macro to pull out function parameter names so we can provide a pretty arg list prefix for each function.  -->
	<xsl:template name="listparams">
		<xsl:param name="func" />
		<xsl:for-each select="$func">
			<xsl:if test="count(paramdef/parameter) &gt; 0">args: </xsl:if>
			<xsl:for-each select="paramdef">
				<xsl:choose>
					<xsl:when test="count(parameter) &gt; 0"> 
						<xsl:value-of select="parameter" />
					</xsl:when>
				</xsl:choose>
				<xsl:if test="position()&lt;last()"><xsl:text>, </xsl:text></xsl:if>
			</xsl:for-each>
			<xsl:if test="count(paramdef/parameter) &gt; 0"> - </xsl:if>
		</xsl:for-each>	
	</xsl:template>

</xsl:stylesheet>
