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 Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;    

using Newtonsoft.Json.Schema; //https://www.newtonsoft.com/jsonschema/help/html/Introduction.htm

using Newtonsoft.Json.Schema.Generation;

​

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

​

//https://stackoverflow.com/questions/64683083/replace-ref-with-custom-attribute-for-specific-types#64683083

​

    public class Account

    {

        public AccountTypeCode AccountType { get; set; }

        public SomeOtherData SomeOtherData { get; set; }

    }

​

    public class AccountTypeCode { }

​

    public class SomeOtherData { }

​

    public static class ExistingJavaTypeJSchemaGeneratorFactory

    {

        class ExistingJavaTypeSchemaProvider : JSchemaGenerationProvider

        {

            readonly Dictionary<Type, string> existingJavaTypes;

            public ExistingJavaTypeSchemaProvider(Dictionary<Type, string> existingJavaTypes) 

                => this.existingJavaTypes = existingJavaTypes ?? throw new ArgumentNullException(nameof(existingJavaTypes));

            public override JSchema GetSchema(JSchemaTypeGenerationContext context)

                => existingJavaTypes.TryGetValue(context.ObjectType, out var existingJavaType) ? JSchema.Parse(new JObject(new JProperty("existingJavaType", existingJavaType)).ToString()) : null;

​

            public override bool CanGenerateSchema(JSchemaTypeGenerationContext context) 

                => existingJavaTypes.ContainsKey(context.ObjectType);

        }

​

        class ExistingJavaTypeContractResolver : DefaultContractResolver

        {

            readonly Dictionary<Type, string> existingJavaTypes;

            public ExistingJavaTypeContractResolver(Dictionary<Type, string> existingJavaTypes) 

                => this.existingJavaTypes = existingJavaTypes ?? throw new ArgumentNullException(nameof(existingJavaTypes));

​

            protected override JsonContract CreateContract(Type objectType) 

                => existingJavaTypes.ContainsKey(objectType) ? new JsonStringContract(objectType) : base.CreateContract(objectType);

        }

        public static JSchemaGenerator CreateJSchemaGenerator(Dictionary<Type, string> existingJavaTypes)

            => new JSchemaGenerator

               {

                   GenerationProviders = { new ExistingJavaTypeSchemaProvider(existingJavaTypes) },

                   ContractResolver = new ExistingJavaTypeContractResolver(existingJavaTypes),

               };

    }

​

    class TestClass

    {

        public static void Test()

        {

            var generator = ExistingJavaTypeJSchemaGeneratorFactory.CreateJSchemaGenerator(

                new Dictionary<Type, string>

                {

                    {typeof(AccountTypeCode), "com.foo.bar.pojo.AccountTypeCode"}

                });

            generator.DefaultRequired = Required.Default;

            var schema = generator.Generate(typeof(Account));       

            Console.WriteLine(schema);

        }   

    }

​

    public class Program

    {

        public static void Main()

        {

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

            Console.WriteLine("Json.NET version: " + typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine("Json.NET Schema version: " + typeof(Newtonsoft.Json.Schema.JSchema).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.CodeBase.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;

        }

    }

​

#if false

        class DummyConverter<T> : JsonConverter

        {

            public override bool CanConvert(Type objectType) => objectType == typeof(T);

            public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) => throw new NotImplementedException();

            public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer) => throw new NotImplementedException();

        }

        class DummyConverter : JsonConverter

        {

            public DummyConverter(Type type) => this.Type = type ?? throw new ArgumentNullException();

            Type Type { get; }

            public override bool CanConvert(Type objectType) => objectType == Type;

            public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) => throw new NotImplementedException();

            public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer) => throw new NotImplementedException();

        }

#endif