using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Runtime.Serialization.Formatters;

using System.IO;

using System.Data;

using System.ComponentModel.DataAnnotations;

using System.Globalization;

using System.Reflection;

using System.Collections.ObjectModel;

​

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;    

​

using NUnit.Framework; // Throws NUnit.Framework.AssertionException

​

//https://stackoverflow.com/questions/68069271/how-to-get-this-json-in-c

​

    public class KeyValueListAsObjectConverter<TValue> : JsonConverter<List<KeyValuePair<string, TValue>>>

    {

        public override List<KeyValuePair<string, TValue>> ReadJson(JsonReader reader, Type objectType, List<KeyValuePair<string, TValue>> existingValue, bool hasExistingValue, JsonSerializer serializer)

        {

            if (reader.MoveToContentAndAssert().TokenType == JsonToken.Null)

                return null;

            reader.AssertTokenType(JsonToken.StartObject);

            var list = existingValue ?? (List<KeyValuePair<string, TValue>>)serializer.ContractResolver.ResolveContract(objectType).DefaultCreator();

            while (reader.ReadToContentAndAssert().TokenType != JsonToken.EndObject)

            {

                var name = (string)reader.AssertTokenType(JsonToken.PropertyName).Value;

                var value = serializer.Deserialize<TValue>(reader.ReadToContentAndAssert());

                list.Add(new KeyValuePair<string, TValue>(name, value));

            }

            return list;

        }

​

        public override void WriteJson(JsonWriter writer, List<KeyValuePair<string, TValue>> value, JsonSerializer serializer)

        {

            writer.WriteStartObject();

            foreach (var pair in value)

            {

                writer.WritePropertyName(pair.Key);

                serializer.Serialize(writer, pair.Value);

            }

            writer.WriteEndObject();

        }

    }

​

    public static partial class JsonExtensions

    {

        public static JsonReader AssertTokenType(this JsonReader reader, JsonToken tokenType) => 

            reader.TokenType == tokenType ? reader : throw new JsonSerializationException(string.Format("Unexpected token {0}, expected {1}", reader.TokenType, tokenType));

        public static JsonReader ReadToContentAndAssert(this JsonReader reader) =>

            reader.ReadAndAssert().MoveToContentAndAssert();

​

        public static JsonReader MoveToContentAndAssert(this JsonReader reader)

        {

            if (reader == null)

                throw new ArgumentNullException();

            if (reader.TokenType == JsonToken.None)       // Skip past beginning of stream.

                reader.ReadAndAssert();

            while (reader.TokenType == JsonToken.Comment) // Skip past comments.

                reader.ReadAndAssert();

            return reader;

        }

​

        public static JsonReader ReadAndAssert(this JsonReader reader)

        {

            if (reader == null)

                throw new ArgumentNullException();

            if (!reader.Read())

                throw new JsonReaderException("Unexpected end of JSON stream.");

            return reader;

        }

    }

​

    public class Model

    {

        [JsonConverter(typeof(KeyValueListAsObjectConverter<string>))]

        public List<KeyValuePair<string, string>> data { get; } = new ();

    }

​

    public class Model2

    {

        public List<KeyValuePair<string, string>> data { get; } = new ();

    }

​

    class TestClass

    {

        public static void Test()

        {

            var jsonString = GetJson();

            var model = JsonConvert.DeserializeObject<Model>(jsonString);

            var json2 = JsonConvert.SerializeObject(model, Formatting.Indented);

            Console.WriteLine("Re-serialized {0}:", model);

            Console.WriteLine(json2);

            // Can't use JToken.DeepEquals or JToken.Parse with duplicated property names.

            Assert.AreEqual(jsonString.Replace(" ", "").Trim(), json2.Replace(" ", "").Trim());

            var model2 = new Model2();

            model2.data.AddRange(model.data);

            var jsonAlternate = JsonConvert.SerializeObject(model2, Formatting.Indented);

            Console.WriteLine("JSON in an equivalent format:");

            Console.WriteLine(jsonAlternate);

        }   

        static string GetJson()

        {

            return @"{

    ""data"": {

        ""a"": ""4"",

        ""b"": ""2"",

        ""c"": ""3"",

        ""a"": ""444""

    }

}

";

        }

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: {0} ({1})", System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , GetNetCoreVersion());

            Console.WriteLine("{0} version: {1}", typeof(JsonSerializer).Assembly.GetName().Name,  typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Failed with unhandled exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

        public static string GetNetCoreVersion()

        {

            //https://techblog.dorogin.com/how-to-detect-net-core-version-in-runtime-ecd65ad695be

            //

            var assembly = typeof(System.Runtime.GCSettings).GetTypeInfo().Assembly;

            var assemblyPath = assembly.Location.Split(new[] { '/', '\\' }, StringSplitOptions.RemoveEmptyEntries);

            int netCoreAppIndex = Array.IndexOf(assemblyPath, "Microsoft.NETCore.App");

            if (netCoreAppIndex > 0 && netCoreAppIndex < assemblyPath.Length - 2)

                return assemblyPath[netCoreAppIndex + 1];

            return null;

        }

    }

​