using System;

 using System.Collections.Generic;

 using System.ComponentModel;

 using System.IO;

 using System.Linq;

 using System.Text;

 using System.Threading.Tasks;

 using System.Runtime.Serialization;

 using System.Runtime.Serialization.Json;

 using System.Globalization;

 namespace SharpLib.Utils

 {

     /// <summary>

     /// Allow serialization into JSON.

     /// Most useful to be able to save complex settings for instance.

     /// Usage:

     /// ...

     /// [TypeConverter(typeof(TypeConverterJson<PersistantObject>))]

     /// [DataContract]

     /// public class PersistantObject

     /// ...

     /// </summary>

     /// <typeparam name="T"></typeparam>

     public class TypeConverterJson<T> : TypeConverter where T : class

     {

         public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)

         {

             if (sourceType == typeof(string))

                 return true;

             else

                 return base.CanConvertFrom(context, sourceType);

         }

         /// <summary>

         /// Internalize

         /// </summary>

         /// <param name="context"></param>

         /// <param name="culture"></param>

         /// <param name="value"></param>

         /// <returns></returns>

         public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)

         {

             string stringValue = value as string;

             if (stringValue != null)

             {

                 //try

                 //{

                     //Load object form JSON string

                     byte[] byteArray = Encoding.UTF8.GetBytes(stringValue);

                     MemoryStream stream = new MemoryStream(byteArray);

                     DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(T),

                         new DataContractJsonSerializerSettings()

                         {

                             UseSimpleDictionaryFormat = true

                         });

                     T settings = (T)ser.ReadObject(stream);

                     return settings;

                 //}

                 //catch (Exception ex)

                 //{

                     //That's not helping with partial loading

                 //    Trace.WriteLine("WARNING: Internalize exception -" + ex.ToString() );

                 //    return null;

                 //}

             }

             else

             {

                 return base.ConvertFrom(context, culture, value);

             }

         }

         /// <summary>

         /// Externalize

         /// </summary>

         /// <param name="context"></param>

         /// <param name="culture"></param>

         /// <param name="value"></param>

         /// <param name="destinationType"></param>

         /// <returns></returns>

         public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)

         {

             if (destinationType == typeof(string))

             {

                 //Save settings into JSON string

                 MemoryStream stream = new MemoryStream();

                 DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(T), new DataContractJsonSerializerSettings()

                 {

                     UseSimpleDictionaryFormat = true

                 });

                 ser.WriteObject(stream, value);

                 // convert stream to string

                 stream.Position = 0;

                 StreamReader reader = new StreamReader(stream);

                 string text = reader.ReadToEnd();

                 return text;

             }

             else

             {

                 return base.ConvertTo(context,culture,value,destinationType);

             }

         }

     }

 }