Add home hero with intro and buttons from the body, next-event card and page tiles

Elternbeirat.Web/Features/Home/HomeTile.cs

@@ -0,0 +1,39 @@
+using Elternbeirat.Contracts;
+using Elternbeirat.Web.Features.Layout;
+using Elternbeirat.Web.Shared;
+
+namespace Elternbeirat.Web.Features.Home;
+
+/// <summary>
+///     One tile on the home page, leading to a section of the site.
+/// </summary>
+/// <param name="Href">Target URL of the page.</param>
+/// <param name="Title">The page's title.</param>
+/// <param name="Description">
+///     The first sentence of the page's body, or an empty string, in which case the
+///     tile shows only the title.
+/// </param>
+/// <param name="Icon">The icon name, see <see cref="TileIcons"/>.</param>
+public sealed record HomeTile(string Href, string Title, string Description, string Icon)
+{
+    /// <summary>
+    ///     Builds one tile per header page except the home page itself.
+    /// </summary>
+    /// <param name="pages">All public pages.</param>
+    /// <returns>The tiles, in menu order.</returns>
+    /// <remarks>
+    ///     The tiles mirror the header menu (<see cref="NavBuilder.HeaderPages"/>), so a
+    ///     page an editor puts into the header appears here too, without any code. The
+    ///     home page is left out: a tile leading to the page it sits on would be useless.
+    /// </remarks>
+    public static IReadOnlyList<HomeTile> From(IReadOnlyList<Page> pages) =>
+    [
+        .. NavBuilder.HeaderPages(pages)
+            .Where(page => !Page.IsHomeSlug(page.Slug))
+            .Select(page => new HomeTile(
+                NavBuilder.HrefFor(page.Slug),
+                page.Title,
+                Markdown.FirstSentence(page.Body),
+                TileIcons.For(page.Slug))),
+    ];
+}