using System;

using System.Collections.Generic;

using System.Text.Json;

using System.Text.Json.Serialization;

​

namespace ConsoleApp6

{

    class Program

    {

        static void Main(string[] args)

        {

            var refHandler = new MyRefHandler();

            var opts = new JsonSerializerOptions

            {

                ReferenceHandler = refHandler

            };

​

            var refResolver = new MyRefResolver();

            refHandler.Resolver = refResolver;

​

            var employee = new Employee() { Name = "Bob" };

​

            refResolver.AddReference("1", employee);

​

            string json = @"{""$ref"":""1""}";

            Employee deserializedObject = JsonSerializer.Deserialize<Employee>(json, opts);

​

            json = JsonSerializer.Serialize(deserializedObject);

            Console.WriteLine(json);

        }

    }

​

    class MyRefHandler : ReferenceHandler

    {

        public ReferenceResolver Resolver { get; set; }

​

        public override ReferenceResolver CreateResolver() => Resolver;

    }

​

    class MyRefResolver : ReferenceResolver

    {

        private uint _referenceCount;

        private readonly Dictionary<string, object> _referenceIdToObjectMap = new();

        private readonly Dictionary<object, string> _objectToReferenceIdMap = new();

​

        public override void AddReference(string referenceId, object value)

        {

            if (!_referenceIdToObjectMap.TryAdd(referenceId, value))

            {

                throw new JsonException();

            }

        }

​

        public override string GetReference(object value, out bool alreadyExists)

        {

            if (_objectToReferenceIdMap.TryGetValue(value, out string referenceId))

            {

                alreadyExists = true;

            }

            else

            {

                _referenceCount++;

                referenceId = _referenceCount.ToString();

                _objectToReferenceIdMap.Add(value, referenceId);

                alreadyExists = false;

            }

​

            return referenceId;

        }

​

        public override object ResolveReference(string referenceId)

        {

            if (!_referenceIdToObjectMap.TryGetValue(referenceId, out object value))

            {

                throw new JsonException();

            }

​

            return value;

        }

    }

​

    class Employee

    {

        public string Name { get; set; }

    }

}

​