Add MediaStreamProtocol enum (#10153)

* Add MediaStreamProtocol enum

* Add default handling for enum during deserialization

---------

Co-authored-by: Cody Robibero <cody@robibe.ro>

1 files changed, 49 insertions, 0 deletions

diff --git a/src/Jellyfin.Extensions/Json/Converters/JsonDefaultStringEnumConverter.cs b/src/Jellyfin.Extensions/Json/Converters/JsonDefaultStringEnumConverter.cs
new file mode 100644
index 000000000..06ecfc558
--- /dev/null
+++ b/src/Jellyfin.Extensions/Json/Converters/JsonDefaultStringEnumConverter.cs
@@ -0,0 +1,49 @@
+using System;
+using System.ComponentModel;
+using System.Reflection;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace Jellyfin.Extensions.Json.Converters;
+
+/// <summary>
+/// Json unknown enum converter.
+/// </summary>
+/// <typeparam name="T">The type of enum.</typeparam>
+public class JsonDefaultStringEnumConverter<T> : JsonConverter<T>
+    where T : struct, Enum
+{
+    private readonly JsonConverter<T> _baseConverter;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="JsonDefaultStringEnumConverter{T}"/> class.
+    /// </summary>
+    /// <param name="baseConverter">The base json converter.</param>
+    public JsonDefaultStringEnumConverter(JsonConverter<T> baseConverter)
+    {
+        _baseConverter = baseConverter;
+    }
+
+    /// <inheritdoc />
+    public override T Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+    {
+        if (reader.IsNull() || reader.IsEmptyString())
+        {
+            var customValueAttribute = typeToConvert.GetCustomAttribute<DefaultValueAttribute>();
+            if (customValueAttribute?.Value is null)
+            {
+                throw new InvalidOperationException($"Default value not set for '{typeToConvert.Name}'");
+            }
+
+            return (T)customValueAttribute.Value;
+        }
+
+        return _baseConverter.Read(ref reader, typeToConvert, options);
+    }
+
+    /// <inheritdoc />
+    public override void Write(Utf8JsonWriter writer, T value, JsonSerializerOptions options)
+    {
+        _baseConverter.Write(writer, value, options);
+    }
+}