using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Data;

using System.Globalization;

​

using System.Text.Json;

using System.Text.Json.Serialization;

using System.Text.Json.Serialization.Metadata;

using System.Text.Json.Nodes;

​

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

​

//https://stackoverflow.com/questions/77437559/system-text-json-serialize-an-object/

​

#nullable enable

​

    public class MyDataClass : IJsonOnDeserialized

    {

        //Some properties correctly serialized and deserialized

        public string [] Property1 { get; set; } = Array.Empty<string>();

        public DateTime Property2 { get; set; }

​

        //The Value I need to deserialize to the correct type, and its format.

        public Int32 Format { get; set; } // Shouldn't this be a FormatTypeBase enum rather than an integer?

        public required Object? Value { get; set;}

        // A callback to convert the deserialized JsonElement to the correct primitive.

        void IJsonOnDeserialized.OnDeserialized() 

        {

            if (Value is JsonElement e)

            {

                Value = FormatHelper.GetObjectValue(Format, e.ValueKind == JsonValueKind.String ? e.GetString() : e.GetRawText());

            }

        }

    }       

​

    public enum FormatTypeBase

    {

        Boolean = 1,

        Numeric = 2,

        String = 3,

    }

​

    public class FormatHelper

    {

        public static Object? GetObjectValue(Int32 formatType, String? value)

        {

            if (value == null)

                return null;  // Or throw an exception?

            Object? result = null;

            switch ((FormatTypeBase)formatType)

            {

                case FormatTypeBase.Boolean:

                    result = value == "1" || value.Equals("true", StringComparison.OrdinalIgnoreCase); // TODO: check for invalid non-Boolean string values.

                    break;

                case FormatTypeBase.Numeric:

                    result = Double.Parse(value, CultureInfo.InvariantCulture);

                    break;

                case FormatTypeBase.String:

                    result = value;

                    break;

                //...

                default:

                    throw new NotImplementedException(((FormatTypeBase)formatType).ToString());

            }

            return result;

        }       

    }

​

    class TestClass

    {

        public static void Test()

        {

            var list = new List<MyDataClass>()

            {

                new() { Property1 = new [] { "some value 1"} , Property2 = DateTime.Today.AddHours(1), Format = (int)FormatTypeBase.Boolean, Value = true },

                new() { Property1 = new [] { "some value 2" }, Property2 = DateTime.Today.AddHours(2), Format = (int)FormatTypeBase.String, Value = "hello" },

                new() { Property1 = new [] { "some value 3" }, Property2 = DateTime.Today.AddHours(3), Format = (int)FormatTypeBase.Numeric, Value = Math.PI },

                new() { Property1 = new [] { "some value 4"} , Property2 = DateTime.Today.AddHours(4), Format = (int)FormatTypeBase.Boolean, Value = false },

            };

            var options = new JsonSerializerOptions

            {

                WriteIndented = true,

            };

            var json = JsonSerializer.Serialize(list, options);

            Console.WriteLine(json);

            var list2 = JsonSerializer.Deserialize<List<MyDataClass>>(json);

            Assert.That(list.Select(i => i.Value?.GetType()).SequenceEqual(list2!.Select(i => i.Value?.GetType())), "types not identical");

            var json2 = JsonSerializer.Serialize(list2, options);

            Assert.AreEqual(json, json2);

            Assert.That(list.SelectMany(i => i.Property1).SequenceEqual(list2!.SelectMany(i => i.Property1)));

            Assert.That(list.Select(i => i.Property2).SequenceEqual(list2!.Select(i => i.Property2)));

        }   

    }

​

    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("System.Text.Json version: " + typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

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

                Console.WriteLine(ex);

                throw;

            }

        }

    }

​