From a9003f82f427b537548e4de257d2db5f9657f5c5 Mon Sep 17 00:00:00 2001
From: Jon Sterling <jon@jonmsterling.com>
Date: Tue, 11 Jun 2024 14:48:54 +0100
Subject: [PATCH] Fixing extremely subtle numbering issues

Closes: https://todo.sr.ht/~jonsterling/forester/58
---
 tree.xsl | 124 ++++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 81 insertions(+), 43 deletions(-)

diff --git a/tree.xsl b/tree.xsl
index f706ff0..ec5dbf1 100644
--- a/tree.xsl
+++ b/tree.xsl
@@ -54,26 +54,46 @@
     </html>
   </xsl:template>
 
-  <xsl:template name="numbered-taxon">
-    <span class="taxon">
-      <xsl:apply-templates select="f:taxon" />
-      <xsl:if test="(not(ancestor-or-self::f:tree[@numbered='false' or @toc='false']) and count(../../f:tree) > 1) or f:number">
-        <xsl:if test="f:taxon">
-          <xsl:text>&#160;</xsl:text>
-        </xsl:if>
+  <xsl:template match="f:tree" mode="tree-taxon-with-number">
+    <xsl:param name="suffix" select="''"/>
+    <xsl:param name="taxon" select="f:frontmatter/f:taxon" />
+    <xsl:param name="number" select="f:frontmatter/f:number" />
+    <xsl:param name="fallback-number"/>
+    <xsl:param name="in-backmatter" select="ancestor::f:backmatter"/>
+
+    <xsl:variable name="tree-is-root" select="not(parent::*)" />
+
+    <xsl:variable name="explicitly-unnumbered" select="boolean(ancestor-or-self::f:tree[@numbered='false' or @toc='false'])"/>
+    <xsl:variable name="implicitly-unnumbered" select="count(../f:tree) = 1 and not(count(f:mainmatter/f:tree) > 1)"/>
+
+    <xsl:variable name="should-number" select="$number != '' or (not($in-backmatter) and not($tree-is-root) and not($explicitly-unnumbered)) and not($implicitly-unnumbered)"/>
+
+    <xsl:if test="$taxon != ''">
+      <xsl:value-of select="$taxon"/>
+      <xsl:if test="$should-number or $fallback-number != ''">
+        <xsl:text>&#160;</xsl:text>
+      </xsl:if>
+    </xsl:if>
+
+    <xsl:choose>
+      <xsl:when test="$should-number">
         <xsl:choose>
-          <xsl:when test="f:number">
-            <xsl:value-of select="f:number" />
+          <xsl:when test="$number != ''">
+            <xsl:value-of select="$number"/>
           </xsl:when>
           <xsl:otherwise>
-            <xsl:number format="1.1" count="f:tree[ancestor::f:tree and not(@toc='false') and not(@numbered='false')]" level="multiple" />
+            <xsl:number format="1.1" count="f:tree[ancestor::f:tree and (not(@toc='false' or @numbered='false'))]" level="multiple" />
           </xsl:otherwise>
         </xsl:choose>
-      </xsl:if>
-      <xsl:if test="f:taxon or (not(ancestor-or-self::f:tree[@numbered='false' or ../@toc='false']) and count(../../f:tree) > 1) or f:number">
-        <xsl:text>.&#160;</xsl:text>
-      </xsl:if>
-    </span>
+      </xsl:when>
+      <xsl:when test="$fallback-number != ''">
+        <xsl:value-of select="$fallback-number"/>
+      </xsl:when>
+    </xsl:choose>
+
+    <xsl:if test="$taxon != '' or $fallback-number != '' or $should-number">
+      <xsl:value-of select="$suffix"/>
+    </xsl:if>
   </xsl:template>
 
   <xsl:template match="f:tree" mode="toc">
@@ -105,7 +125,12 @@
           <xsl:text>■</xsl:text>
         </a>
         <span class="link local" data-target="#tree-{f:anchor}">
-          <xsl:call-template name="numbered-taxon" />
+          <span class="taxon">
+            <xsl:apply-templates select=".." mode="tree-taxon-with-number">
+              <xsl:with-param name="suffix">.&#160;</xsl:with-param>
+            </xsl:apply-templates>
+          </span>
+
           <xsl:apply-templates select="f:title" />
         </span>
       </xsl:for-each>
@@ -150,7 +175,12 @@
   <xsl:template match="f:frontmatter">
     <header>
       <h1>
-        <xsl:call-template name="numbered-taxon" />
+        <span class="taxon">
+          <xsl:apply-templates select=".." mode="tree-taxon-with-number">
+            <xsl:with-param name="suffix">.&#160;</xsl:with-param>
+          </xsl:apply-templates>
+        </span>
+
         <xsl:apply-templates select="f:title" />
         <xsl:text>&#032;</xsl:text>
         <xsl:apply-templates select="f:addr" />
@@ -177,18 +207,24 @@
     </header>
   </xsl:template>
 
-  <xsl:template match="f:tree" mode="tree-number">
-    <xsl:choose>
-      <xsl:when test="f:frontmatter/f:number">
-        <xsl:value-of select="f:frontmatter/f:number" />
-      </xsl:when>
-      <xsl:otherwise>
-        <xsl:number format="1.1" count="f:tree[ancestor::f:tree and not(@toc='false' or @numbered='false')]" level="multiple" />
-      </xsl:otherwise>
-    </xsl:choose>
-  </xsl:template>
-
   <xsl:template match="f:ref">
+    <xsl:variable name="fallback-number">
+      <xsl:text>[</xsl:text>
+      <xsl:value-of select="@addr"/>
+      <xsl:text>]</xsl:text>
+    </xsl:variable>
+
+    <xsl:variable name="taxon">
+      <xsl:choose>
+        <xsl:when test="@taxon">
+          <xsl:value-of select="@taxon"/>
+        </xsl:when>
+        <xsl:otherwise>
+          <xsl:text>§</xsl:text>
+        </xsl:otherwise>
+      </xsl:choose>
+    </xsl:variable>
+
     <a class="link local">
       <xsl:attribute name="href">
         <xsl:choose>
@@ -203,23 +239,25 @@
       </xsl:attribute>
 
       <xsl:choose>
-        <xsl:when test="@taxon">
-          <xsl:value-of select="@taxon" />
-        </xsl:when>
-        <xsl:otherwise>§</xsl:otherwise>
-      </xsl:choose>
-      <xsl:text>&#160;</xsl:text>
-      <xsl:choose>
-        <xsl:when test="@number">
-          <xsl:value-of select="@number" />
-        </xsl:when>
-        <xsl:when test="key('tree-with-addr',current()/@addr)[not(@numbered='false' or @toc='false')]">
-          <xsl:apply-templates select="key('tree-with-addr',current()/@addr)[1]" mode="tree-number" />
+        <xsl:when test="key('tree-with-addr', current()/@addr)">
+          <xsl:apply-templates select="key('tree-with-addr', current()/@addr)" mode="tree-taxon-with-number">
+            <xsl:with-param name="in-backmatter" select="boolean(ancestor::f:backmatter)" />
+            <xsl:with-param name="number" select="@number"/>
+            <xsl:with-param name="fallback-number" select="$fallback-number"/>
+            <xsl:with-param name="taxon" select="$taxon"/>
+          </xsl:apply-templates>
         </xsl:when>
         <xsl:otherwise>
-          <xsl:text>[</xsl:text>
-          <xsl:value-of select="@addr" />
-          <xsl:text>]</xsl:text>
+          <xsl:value-of select="$taxon"/>
+          <xsl:text>&#160;</xsl:text>
+          <xsl:choose>
+            <xsl:when test="@number">
+              <xsl:value-of select="@number"/>
+            </xsl:when>
+            <xsl:otherwise>
+              <xsl:value-of select="$fallback-number"/>
+            </xsl:otherwise>
+          </xsl:choose>
         </xsl:otherwise>
       </xsl:choose>
     </a>
-- 
2.51.2