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.Threading;

​

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/75081574/cosmos-db-save-documents-with-interface-properties-net-sdk-v3-how-do-i-save-a

​

    public interface IMyCommand

    {

    }

​

    public class MyCommand1 : IMyCommand

    {

    }

​

    public class MyCommand2 : IMyCommand

    {

    }

​

    //partition key is CompanyId

    [JsonConverter(typeof(MyCommandSerializationBinderSettingConverter))] // Add this

    public class MyClass

    {

        [JsonProperty("id")]

        public Guid Id { get; set; }

​

        public string CompanyId { get; set; }

        [JsonProperty(ItemTypeNameHandling = TypeNameHandling.Auto)] // Add this

        public List<IMyCommand> Commands { get; set; }

​

        public MyClass(string partitionKey)

        {

            CompanyId = partitionKey;

        }

    }

​

    internal class MyCommandSerializationBinderSettingConverter : KnownTypesJsonConverter<object>

    {

        public MyCommandSerializationBinderSettingConverter() : base(new KeyValuePair<string, Type>[] 

            {

                new(nameof(MyCommand1), typeof(MyCommand1)),

                new(nameof(MyCommand2), typeof(MyCommand2)),

            }) { }

    }

​

    public class KnownTypesJsonConverter<TValue> : RecursiveConverterBase<TValue>

    {

        readonly ISerializationBinder binder;

        public KnownTypesJsonConverter(IEnumerable<KeyValuePair<string, Type>> namesToTypes) => this.binder = new KnownTypesSerializationBinder(namesToTypes);

        public KnownTypesJsonConverter(ISerializationBinder binder) => this.binder = binder;

​

        protected override void WriteJsonWithDefault(JsonWriter writer, TValue value, JsonSerializer serializer)

        {

            var old = serializer.SerializationBinder;

            try

            {

                serializer.SerializationBinder = binder;

                base.WriteJsonWithDefault(writer, value, serializer);

            }

            finally

            {

                serializer.SerializationBinder = old;

            }

        }

        protected override TValue ReadJsonWithDefault(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) 

        {

            var old = serializer.SerializationBinder;

            try

            {

                serializer.SerializationBinder = binder;

                return base.ReadJsonWithDefault(reader, objectType, existingValue, serializer);

            }

            finally

            {

                serializer.SerializationBinder = old;

            }

        }

    }

    public abstract class RecursiveConverterBase<TValue> : JsonConverter

    {

        static readonly ThreadLocal<Stack<Type>> typeStack = new (() => new Stack<Type>());

​

        bool IsSuspended => typeStack.IsValueCreated && typeStack.Value.TryPeek(out var type) && type == GetType();

​

        public override bool CanRead => !IsSuspended;

        public override bool CanWrite => !IsSuspended;

​

        public override bool CanConvert(Type objectType) => !IsSuspended && typeof(TValue).IsAssignableFrom(objectType); // Or typeof(TValue) == objectType if you prefer.

​

        protected virtual void WriteJsonWithDefault(JsonWriter writer, TValue value, JsonSerializer serializer)

        {

            Console.WriteLine(value);

            serializer.Serialize(writer, value, typeof(TValue));

        }

​

        public sealed override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)

        {

            using (var pushValue = typeStack.Value.PushUsing(GetType()))

            {

                WriteJsonWithDefault(writer, (TValue)value, serializer);

            }

        }

​

        protected virtual TValue ReadJsonWithDefault(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) => (TValue)serializer.Deserialize(reader, objectType);

​

        public sealed override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)

        {

            using (var pushValue = typeStack.Value.PushUsing(GetType()))

            {

                return ReadJsonWithDefault(reader, objectType, existingValue, serializer);

            }

        }

    }

​

    public static class StackExtensions

    {

        public class PushValue<T> : IDisposable

        {

            readonly Stack<T> stack;

            readonly int count;

​

            public PushValue(T value, Stack<T> stack)

            {

                this.stack = stack;

                this.count = stack.Count;

                stack.Push(value);

            }

​

            // By using a disposable struct we avoid the overhead of allocating and freeing an instance of a finalizable class.

            public void Dispose()

            {

                if (stack != null)

                {

                    while (stack.Count > count)

                        stack.Pop();

                }

            }

        }

​

        public static PushValue<T> PushUsing<T>(this Stack<T> stack, T value)

        {

            if (stack == null)

                throw new ArgumentNullException();

            return new PushValue<T>(value, stack);

        }

    }

    public class KnownTypesSerializationBinder : ISerializationBinder

    {

        Dictionary<Type, string> typesToNames;

        Dictionary<string, Type> namesToTypes;

        public KnownTypesSerializationBinder(IEnumerable<KeyValuePair<string, Type>> namesToTypes) =>

            (this.namesToTypes, this.typesToNames) = (namesToTypes.ToDictionary(t => t.Key, t => t.Value), namesToTypes.ToDictionary(t => t.Value, t => t.Key));

        public Type BindToType(string assemblyName, string typeName) => namesToTypes[typeName];

​

        public void BindToName(Type serializedType, out string assemblyName, out string typeName) => (assemblyName, typeName) = (null, typesToNames[serializedType]);

    }

    class TestClass

    {

        public static void Test()

        {

            string partitionKey = "Test";           

            var myclass = new MyClass(partitionKey)

            {

                Id = Guid.NewGuid(),

                Commands = new List<IMyCommand>

                {

                    new MyCommand1(),

                    new MyCommand2()

                }

            };

            var settings = new JsonSerializerSettings

            {

            };

​

            var json = JsonConvert.SerializeObject(myclass, settings);

            Console.WriteLine(json);

            var myclass2 = JsonConvert.DeserializeObject<MyClass>(json, settings);

            var json2 = JsonConvert.SerializeObject(myclass2, settings);

            Console.WriteLine(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();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

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

                Console.WriteLine(ex);

                throw;

            }

        }

    }

​