<?xml version="1.0" encoding="UTF-8"?>
<!--
  (C) PDFlib GmbH 2008 www.pdflib.com

  Purpose: generate font and glyph statistics from TETML input

  Expected input: TETML in "glyph" or "wordplus" mode.

  Stylesheet parameters: none

  Version: $Id: fontstat.xsl,v 1.2 2008/11/19 10:37:32 stm Exp $
-->

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:tet="http://www.pdflib.com/XML/TET3/TET-3.0"
  >
  <xsl:output method="text" />

  <!-- Index the Glyph element by their font ids -->
  <xsl:key name="glyphs" match="tet:TET/tet:Document/tet:Pages//tet:Glyph" use="@font" />

  <xsl:variable name="total-glyph-count" select="count(/tet:TET/tet:Document/tet:Pages//tet:Glyph)" />

  <xsl:template match="/">
    <!-- Make sure that font information is present in the input TETML. -->
    <xsl:if test="tet:TET/tet:Document/tet:Pages//tet:Content[not(@font = 'true')]">
      <xsl:message terminate="yes">
        <xsl:text>Stylesheet fontstat.xsl processing TETML for document '</xsl:text>
        <xsl:value-of select="tet:TET/tet:Document/@filename" />
        <xsl:text>': this stylesheet requires font info in TETML. </xsl:text>
        <xsl:text>Create the input in page mode "glyph" or "wordplus".</xsl:text>
      </xsl:message>
    </xsl:if>

    <xsl:value-of select="$total-glyph-count" />
    <xsl:text> total glyphs in the document; breakdown by font:&#xa;&#xa;</xsl:text>

    <xsl:apply-templates select="tet:TET/tet:Document/tet:Pages//tet:Font">
      <!-- Sort descending by number of Glyph elements that refer to the Font element. -->
      <xsl:sort select="count(key('glyphs', @id))" data-type="number" order="descending" />
    </xsl:apply-templates>
  </xsl:template>

  <!-- Iterate over all fonts in the document. -->
  <xsl:template match="tet:Font">
    <!-- Compute the total number of references to the font -->
    <xsl:variable name="count" select="count(key('glyphs', @id))" />

    <!-- Print the percentage, font name, and glyph count, with two digits after the decimal point. -->
    <xsl:value-of select="round($count div $total-glyph-count * 10000) div 100" />
    <xsl:text>% </xsl:text>

    <xsl:value-of select="@name" />
    <xsl:text>: </xsl:text>

    <!-- Emit the total number of glyphs in this font -->
    <xsl:value-of select="$count" />
    <xsl:text> glyphs</xsl:text>

    <!-- Determine the number of unknown glyphs for this font,
         i .e. those without proper Unicode mapping.
    -->
    <xsl:variable name="unknown-glyph-count" select="count(key('glyphs', @id)[@unknown = 'true'])" />
    <xsl:if test="$unknown-glyph-count > 0">
      <xsl:text> (</xsl:text>
      <xsl:value-of select="$unknown-glyph-count" />
      <xsl:text> unknown)</xsl:text> 
    </xsl:if>

    <!-- Determine the number of ligatures for this font,
         i.e. Glyph elements with more than one character.
    -->

    <xsl:variable name="ligatures" select="key('glyphs', @id)[string-length() > 1]" />		
    <xsl:variable name="ligature-count" select="count($ligatures)" />
    <xsl:if test="$ligature-count > 0">
      <xsl:text>, </xsl:text>
      <xsl:value-of select="$ligature-count" />
      <xsl:text> uses of ligatures: </xsl:text>

      <xsl:for-each select="$ligatures[not(. = preceding::tet:Glyph[@font=current()/@id])]">
        <xsl:value-of select="." />
        <xsl:text> </xsl:text>
      </xsl:for-each>
    </xsl:if>

    <xsl:text>&#xa;</xsl:text>
  </xsl:template>
</xsl:stylesheet>