using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Buffers;

​

using System.Text.Json;

using System.Text.Json.Serialization;

​

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

​

//https://stackoverflow.com/questions/63376873/in-system-text-json-is-it-possible-to-specify-custom-indentation-rules

​

#nullable enable

​

    public class NoIndentationConverter : NoIndentationConverter<object>

    {

        public override bool CanConvert(Type typeToConvert) => true;

    }

    public class NoIndentationConverter<T> : DefaultConverterFactory<T>

    {

        protected override void Write(Utf8JsonWriter writer, T value, JsonSerializerOptions modifiedOptions) 

        {

            // TODO: investigate https://learn.microsoft.com/en-us/dotnet/api/microsoft.toolkit.highperformance.buffers.arraypoolbufferwriter-1

            var bufferWriter = new ArrayBufferWriter<byte>();

            using (var innerWriter = new Utf8JsonWriter(bufferWriter))

                JsonSerializer.Serialize(innerWriter, value, modifiedOptions);

            writer.WriteRawValue(bufferWriter.WrittenSpan, skipInputValidation : true);

        }

​

        protected override JsonSerializerOptions ModifyOptions(JsonSerializerOptions options) { (options = base.ModifyOptions(options)).WriteIndented = false; return options; }

    }

​

    public abstract class DefaultConverterFactory<T> : JsonConverterFactory

    {

        // Adapted from this answer https://stackoverflow.com/a/65430421/3744182

        // To https://stackoverflow.com/questions/65430420/how-to-use-default-serialization-in-a-custom-system-text-json-jsonconverter

        class DefaultConverter : JsonConverter<T> 

        {

            readonly JsonSerializerOptions modifiedOptions;

            readonly DefaultConverterFactory<T> factory;

​

            public DefaultConverter(JsonSerializerOptions modifiedOptions, DefaultConverterFactory<T> factory) => (this.modifiedOptions, this.factory) = (modifiedOptions, factory);

​

            public override void Write(Utf8JsonWriter writer, T value, JsonSerializerOptions options) => factory.Write(writer, value, modifiedOptions);

            public override T? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) => factory.Read(ref reader, typeToConvert, modifiedOptions);

            public override bool CanConvert(Type typeToConvert) => typeof(T).IsAssignableFrom(typeToConvert);

        }

​

        protected virtual JsonSerializerOptions ModifyOptions(JsonSerializerOptions options) 

            => options.CopyAndRemoveConverter(this.GetType());

​

        protected virtual T? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions modifiedOptions)

            => (T?)JsonSerializer.Deserialize(ref reader, typeToConvert, modifiedOptions);

​

        protected virtual void Write(Utf8JsonWriter writer, T value, JsonSerializerOptions modifiedOptions) 

            => JsonSerializer.Serialize(writer, value, modifiedOptions);

​

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

​

        public sealed override JsonConverter CreateConverter(Type typeToConvert, JsonSerializerOptions options) => new DefaultConverter(ModifyOptions(options), this);

    }

​

    public static class JsonSerializerExtensions

    {

        public static JsonSerializerOptions CopyAndRemoveConverter(this JsonSerializerOptions options, Type converterType)

        {

            var copy = new JsonSerializerOptions(options);

            for (var i = copy.Converters.Count - 1; i >= 0; i--)

                if (copy.Converters[i].GetType() == converterType)

                    copy.Converters.RemoveAt(i);

            return copy;

        }

    }

​

    public partial class Root

    {

        [JsonPropertyName("TILESET")]

        public string Tileset { get; set; }

​

        [JsonPropertyName("TILES")]

        public Tiles Tiles { get; set; }

    }

​

    public partial class Tiles

    {

        [JsonPropertyName("TILE_1")]

        public Tile1 Tile1 { get; set; }

    }

​

    public partial class Tile1

    {

        [JsonPropertyName("NAME")]

        public string Name { get; set; }

​

        [JsonPropertyName("TEXTURE_BOUNDS")]

        public List<long> TextureBounds { get; set; }

​

        [JsonPropertyName("SCREEN_BOUNDS")]

        public List<long> ScreenBounds { get; set; }

    }

​

    class TestClass

    {

        public static void Test()

        {

            var originalJson = GetJson();

            var options = new JsonSerializerOptions

            {

                Converters = { new NoIndentationConverter<List<long>>() },

                WriteIndented = true,

            };

            var root = JsonSerializer.Deserialize<Root>(originalJson, options);

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

            Console.WriteLine("Serialized {0}: ", root);

            Console.WriteLine(json2);

        }   

        static string GetJson()

        {

            return @"{

      ""TILESET"": ""tilesets/HOW_TO_GET_TILESET_NAME_?"",

      ""TILES"": {

            ""TILE_1"": {

          ""NAME"": ""auto_tile_18"",

          ""TEXTURE_BOUNDS"": [

            304,

            16,

            16,

            16

          ],

          ""SCREEN_BOUNDS"": [

            485,

            159,

            64,

            64

          ]

        }

      }

    }";

        }

    }

​

    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;

            }

        }

    }

​