Add ::: team block rendering board members as person cards with initials avatars

Elternbeirat.Web/Shared/Markdown.cs

@@ -1,6 +1,7 @@
 using System.Text;
 using System.Text.RegularExpressions;
 using Markdig;
+using Markdig.Extensions.CustomContainers;
 using Markdig.Renderers.Html;
 using Markdig.Syntax;
 using Markdig.Syntax.Inlines;
@@ -20,8 +21,8 @@ namespace Elternbeirat.Web.Shared;
 ///                 <b>Custom containers</b> (<c>::: name</c> … <c>:::</c>) turn a block
 ///                 into <c>&lt;div class="name"&gt;</c>. That is how editors use the
 ///                 design blocks (<c>kennzahlen</c>, <c>aufruf</c>, <c>kacheln</c>,
-///                 <c>hinweis</c>) without writing HTML. An unknown name just yields a
-///                 div without styling, so a typo never breaks a page.
+///                 <c>hinweis</c>, <c>team</c>) without writing HTML. An unknown name
+///                 just yields a div without styling, so a typo never breaks a page.
 ///             </description>
 ///         </item>
 ///         <item>
@@ -45,8 +46,14 @@ namespace Elternbeirat.Web.Shared;
 ///         the text around an element), but the stylesheet needs exactly that to show a
 ///         lone <c>mailto:</c> link as a button and a lone PDF link as a file card.
 ///     </para>
+///     <para>
+///         The list items of a <c>::: team</c> block become person cards
+///         (<see cref="TeamMember"/>): the initials avatar and the split into name,
+///         role and duties need the text itself, which CSS cannot read.
+///     </para>
 /// </remarks>
 /// <seealso cref="IconSet"/>
+/// <seealso cref="TeamMember"/>
 public static partial class Markdown
 {
     /// <summary>
@@ -183,22 +190,24 @@ public static partial class Markdown
         Markdig.Markdown.Parse(markdown, Pipeline);
 
     /// <summary>
-    ///     Renders a document from <see cref="Parse"/> to HTML, marking lone links on
-    ///     the way, exactly as <see cref="ToHtml"/> does.
+    ///     Renders a document from <see cref="Parse"/> to HTML, building the team cards
+    ///     and marking lone links on the way, exactly as <see cref="ToHtml"/> does.
     /// </summary>
     /// <param name="document">The parsed document; changed in place.</param>
     /// <returns>The rendered HTML.</returns>
     internal static string Render(MarkdownDocument document) =>
-        Markdig.Markdown.ToHtml(MarkLoneLinks(document), Pipeline);
+        Markdig.Markdown.ToHtml(MarkLoneLinks(BuildTeamCards(document)), Pipeline);
 
     /// <summary>
     ///     Flattens inline Markdown to the text a reader sees: emphasis and link
     ///     markup dropped, link text kept, images left out, whitespace collapsed.
     /// </summary>
-    /// <param name="inline">The inline content, e.g. of a paragraph or heading.</param>
+    /// <param name="inlines">
+    ///     The inline content, e.g. of a paragraph or heading, or a part of it.
+    /// </param>
     /// <returns>The visible text, trimmed.</returns>
-    internal static string PlainText(ContainerInline inline) =>
-        Whitespace().Replace(AppendText(new StringBuilder(), inline).ToString(), " ").Trim();
+    internal static string PlainText(IEnumerable<Inline> inlines) =>
+        Whitespace().Replace(inlines.Aggregate(new StringBuilder(), AppendText).ToString(), " ").Trim();
 
     /// <summary>
     ///     Whether an inline carries no visible content (whitespace or a line break).
@@ -279,6 +288,35 @@ public static partial class Markdown
     [GeneratedRegex(@"\s+")]
     private static partial Regex Whitespace();
 
+    /// <summary>
+    ///     Turns the list items of every <c>::: team</c> block into person cards.
+    /// </summary>
+    /// <param name="document">The parsed document; changed in place.</param>
+    /// <returns>The same <paramref name="document"/>, for chaining.</returns>
+    /// <remarks>
+    ///     Only lists directly in the block count; a nested list inside a card stays a
+    ///     list. <c>::: team gross</c> adds the class
+    ///     <see cref="TeamMember.LargeModifier"/> to the block, because Markdig only
+    ///     turns the block name into a class, not the words after it.
+    /// </remarks>
+    private static MarkdownDocument BuildTeamCards(MarkdownDocument document)
+    {
+        foreach (var team in document.Descendants<CustomContainer>().Where(TeamMember.IsTeam).ToList())
+        {
+            if (TeamMember.IsLarge(team))
+            {
+                team.GetAttributes().AddClass(TeamMember.LargeModifier);
+            }
+
+            foreach (var item in team.OfType<ListBlock>().SelectMany(list => list.OfType<ListItemBlock>()))
+            {
+                TeamMember.ToCard(item);
+            }
+        }
+
+        return document;
+    }
+
     /// <summary>
     ///     Adds <see cref="LoneLinkClass"/> to every paragraph that holds nothing but
     ///     one link.