Questionable/Questionable.Model/Common/Converter/EnumConverter.cs

42 lines
1.4 KiB
C#

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text.Json;
using System.Text.Json.Serialization;
namespace Questionable.Model.Common.Converter;
public abstract class EnumConverter<T> : JsonConverter<T>
where T : Enum
{
private readonly ReadOnlyDictionary<T, string> _enumToString;
private readonly ReadOnlyDictionary<string, T> _stringToEnum;
protected EnumConverter(IReadOnlyDictionary<T, string> values)
{
_enumToString = values is IDictionary<T, string> dict
? new ReadOnlyDictionary<T, string>(dict)
: new ReadOnlyDictionary<T, string>(values.ToDictionary(x => x.Key, x => x.Value));
_stringToEnum = new ReadOnlyDictionary<string, T>(_enumToString.ToDictionary(x => x.Value, x => x.Key));
}
public override T? Read(ref Utf8JsonReader reader, Type typeToConvert,
JsonSerializerOptions options)
{
if (reader.TokenType != JsonTokenType.String)
throw new JsonException();
string? str = reader.GetString();
if (str == null)
throw new JsonException();
return _stringToEnum.TryGetValue(str, out T? value) ? value : throw new JsonException();
}
public override void Write(Utf8JsonWriter writer, T value, JsonSerializerOptions options)
{
writer.WriteStringValue(_enumToString[value]);
}
}