using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using Newtonsoft.Json;

namespace Essgee.Utilities
{
	public class HexadecimalJsonConverter : JsonConverter
	{
		public override bool CanConvert(Type objectType)
		{
			// TODO: maybe actually check things?
			return true;
		}

		public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
		{
			switch (Type.GetTypeCode(value.GetType()))
			{
				case TypeCode.Byte:
				case TypeCode.SByte:
					writer.WriteValue($"0x{value:X2}");
					break;
				case TypeCode.UInt16:
				case TypeCode.Int16:
					writer.WriteValue($"0x{value:X4}");
					break;
				case TypeCode.UInt32:
				case TypeCode.Int32:
					writer.WriteValue($"0x{value:X8}");
					break;
				case TypeCode.UInt64:
				case TypeCode.Int64:
					writer.WriteValue($"0x{value:X16}");
					break;
				default:
					throw new JsonSerializationException();
			}
		}

		public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
		{
			if ((reader.Value is string value) && value.StartsWith("0x"))
				return Convert.ChangeType(Convert.ToUInt64(value, 16), objectType);
			else
				throw new JsonSerializationException();
		}
	}
}