feat: 添加内容热重载指令 (#4)

Reviewed-on: #4

YaeBlog/Commands/Binders/BlogOptionsBinder.cs

@@ -0,0 +1,36 @@
+using System.CommandLine.Binding;
+using System.Text.Json;
+using Microsoft.Extensions.Options;
+using YaeBlog.Core.Models;
+
+namespace YaeBlog.Commands.Binders;
+
+public sealed class BlogOptionsBinder : BinderBase<IOptions<BlogOptions>>
+{
+    protected override IOptions<BlogOptions> GetBoundValue(BindingContext bindingContext)
+    {
+        bindingContext.AddService<IOptions<BlogOptions>>(_ =>
+        {
+            FileInfo settings = new(Path.Combine(Environment.CurrentDirectory, "appsettings.json"));
+            if (!settings.Exists)
+            {
+                throw new InvalidOperationException("Failed to load YaeBlog configurations.");
+            }
+
+            using StreamReader reader = settings.OpenText();
+            using JsonDocument document = JsonDocument.Parse(reader.ReadToEnd());
+            JsonElement root = document.RootElement;
+            JsonElement optionSection = root.GetProperty(BlogOptions.OptionName);
+
+            BlogOptions? result = optionSection.Deserialize<BlogOptions>();
+            if (result is null)
+            {
+                throw new InvalidOperationException("Failed to load YaeBlog configuration in appsettings.json.");
+            }
+
+            return new OptionsWrapper<BlogOptions>(result);
+        });
+
+        return bindingContext.GetRequiredService<IOptions<BlogOptions>>();
+    }
+}