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jellyfin/src/Jellyfin.Extensions/Json/Converters/JsonDefaultStringEnumConver...

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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);
}
}