using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.IO;

using System.Globalization;

​

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;    

​

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

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//https://stackoverflow.com/questions/77024669/newtonsoft-json-custom-serialization-for-property-values-to-become-json-field-na

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    public class FaactRecordDifferences

    {

        public string Id { get; set; }

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        public int Year { get; set; }

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        [JsonConverter(typeof(FieldDifferenceListConverter))]

        public List<FieldDifference> Fields { get; set; }

    }

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    public class FieldDifference

    {

        public string FieldName { get; set; }

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        public string FieldValue { get; set; }

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        public Type type { get; set; }

    }

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    public class FieldDifferenceListConverter : JsonConverter<List<FieldDifference>>

    {

        public override void WriteJson(JsonWriter writer, List<FieldDifference> value, JsonSerializer serializer)

        {

            writer.WriteStartObject();

            foreach (var field in value)

            {

                writer.WritePropertyName(field.FieldName);

                if (field.type == typeof(string))

                    writer.WriteValue(field.FieldValue);

                else

                    writer.WriteRawValue(field.FieldValue);

            }

            writer.WriteEndObject();

        }

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

        {

            var list = existingValue ?? (List<FieldDifference>)serializer.ContractResolver.ResolveContract(objectType).DefaultCreator();

            //Skip comments via MoveToContentAndAssert():

            switch (reader.MoveToContentAndAssert().TokenType)

            {

                case JsonToken.Null:

                    return null;

                case JsonToken.StartObject:

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

                    {

                        var name = reader.TokenType == JsonToken.PropertyName ? (string)reader.Value : throw new JsonSerializationException($"Expected PropertyName but got {reader.TokenType}");

                        FieldDifference field = reader.ReadToContentAndAssert().TokenType switch

                        {

                            JsonToken.String => new FieldDifference { FieldName = name, FieldValue = (string)reader.Value, type = typeof(string) },

                            JsonToken.Integer => new FieldDifference { FieldName = name, FieldValue = Convert.ToString(reader.Value, CultureInfo.InvariantCulture), type = typeof(int)},

                            JsonToken.Float => new FieldDifference { FieldName = name, FieldValue = Convert.ToString(reader.Value, CultureInfo.InvariantCulture), type = typeof(double)},

                            JsonToken.Boolean => new FieldDifference { FieldName = name, FieldValue = JsonConvert.ToString((bool)reader.Value), type = typeof(bool)},

                            JsonToken.Null => new FieldDifference { FieldName = name, FieldValue = null, type = typeof(string)},

                            JsonToken.Date => new FieldDifference { FieldName = name, FieldValue = JsonConvert.SerializeObject(reader.Value), type = reader.ValueType},

                            _ => new FieldDifference { FieldName = name, FieldValue = reader.ReadOuterJson(Formatting.None, DateParseHandling.None), type = typeof(object) },

                        };

                        list.Add(field);

                    }

                    break;

                default:

                    throw new JsonSerializationException($"Unknown token {reader.TokenType}");

            }

            return list;

        }

    }

​

    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();

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        public static JsonReader MoveToContentAndAssert(this JsonReader reader)

        {

            ArgumentNullException.ThrowIfNull(reader);

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

                reader.ReadAndAssert();

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

                reader.ReadAndAssert();

            return reader;

        }

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        public static JsonReader ReadAndAssert(this JsonReader reader)

        {

            ArgumentNullException.ThrowIfNull(reader);

            if (!reader.Read())

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

            return reader;

        }

        public static string ReadOuterJson(this JsonReader reader, Formatting formatting = Formatting.None, DateParseHandling? dateParseHandling = null, FloatParseHandling? floatParseHandling = null)

        {

            // If you would prefer a null JSON value to return an empty string, remove this line:

            if (reader.TokenType == JsonToken.Null)

                return null;

            var oldDateParseHandling = reader.DateParseHandling;

            var oldFloatParseHandling = reader.FloatParseHandling;

            try

            {

                if (dateParseHandling != null)

                    reader.DateParseHandling = dateParseHandling.Value;

                if (floatParseHandling != null)

                    reader.FloatParseHandling = floatParseHandling.Value;

                using (var sw = new StringWriter(CultureInfo.InvariantCulture))

                using (var jsonWriter = new JsonTextWriter(sw) { Formatting = formatting })

                {

                    jsonWriter.WriteToken(reader);

                    return sw.ToString();

                }

            }

            finally

            {

                reader.DateParseHandling = oldDateParseHandling;

                reader.FloatParseHandling = oldFloatParseHandling;

            }

        }       

    }

    class TestClass

    {

        public static void Test()

        {

            var model = new FaactRecordDifferences

            {

                Id = "1010101",

                Year = 2023,

                Fields = new()

                {

                    new() { FieldName = "SomeFirstField", FieldValue = "1200.21", type = typeof(double) },

                    new() { FieldName = "AnotherTestField", FieldValue = "SomeStringValue", type = typeof(string) },

                    new() { FieldName = "SomeFirstField", FieldValue = "6120.40", type = typeof(double) },

                    new() { FieldName = "SomeBoolField", FieldValue = "true", type = typeof(bool) },

                    new() { FieldName = "SomeDateTimeField", FieldValue = JsonConvert.ToString(new DateTime(2023, 1, 1)), type = typeof(DateTime) },

                    new() { FieldName = "SomeIntField", FieldValue = "11011", type = typeof(int) },

                },

            };

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

            Console.WriteLine(json);

            var model2 = JsonConvert.DeserializeObject<FaactRecordDifferences>(json);

            var json2 = JsonConvert.SerializeObject(model2, Formatting.Indented);

            Console.WriteLine("Deserialized and re-serialized {0}:", model2);

            Console.WriteLine(json2);

            Assert.That(JToken.DeepEquals(JToken.Parse(json), JToken.Parse(json2)));

        }   

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: {0} ({1}), {2}", System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , Environment.Version, Environment.OSVersion);

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

            Console.WriteLine();

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            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

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

                Console.WriteLine(ex);

                throw;

            }

        }

    }

​