dev: CSharp language highlight.

YaeBlog.Core/Processors/CodeBlockPostRenderProcessor.cs

@@ -1,11 +1,12 @@
 using AngleSharp;
 using AngleSharp.Dom;
+using Microsoft.Extensions.Logging;
 using YaeBlog.Core.Abstractions;
 using YaeBlog.Core.Models;
 
 namespace YaeBlog.Core.Processors;
 
-public class CodeBlockPostRenderProcessor : IPostRenderProcessor
+public class CodeBlockPostRenderProcessor(ILogger<CodeBlockPostRenderProcessor> logger) : IPostRenderProcessor
 {
     public async Task<BlogEssay> ProcessAsync(BlogEssay essay)
     {
@@ -20,10 +21,34 @@ public class CodeBlockPostRenderProcessor : IPostRenderProcessor
         foreach (IElement element in preElements)
         {
             element.ClassList.Add("p-3 text-bg-secondary rounded-1");
+
+            IEnumerable<IElement> codeElements = from e in element.Children
+                where e.LocalName == "code"
+                    select e;
+
+            foreach (IElement code in codeElements)
+            {
+                string? language = (from c in code.ClassList
+                    where c.StartsWith("language-")
+                    select c[9..].ToLower()).FirstOrDefault();
+
+                if (language is null)
+                {
+                    continue;
+                }
+
+                logger.LogDebug("Detect code block of language {}.", language);
+                code.InnerHtml = HighLightCode(code.InnerHtml, language);
+            }
         }
 
         return essay.WithNewHtmlContent(document.DocumentElement.OuterHtml);
     }
 
     public string Name => nameof(CodeBlockPostRenderProcessor);
+
+    private static string HighLightCode(string code, string language)
+    {
+        return code;
+    }
 }

YaeBlog.Core/Processors/Scanners/CSharpScanner.cs

@@ -0,0 +1,9 @@
+using static LanguageExt.Prelude;
+
+
+namespace YaeBlog.Core.Processors.Scanners;
+
+public class CSharpScanner
+{
+
+}