using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

​

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/76276372/json-deserialize-in-one-data-as-array-and-in-one-as-json-object-coming-tricky-no

​

    public class TestClass

    {

        public List<Variant> variants { get; set; } = new ();

    }

​

    public class Variant

    {

        public string name { get; set; }

        public string description { get; set; }

        [JsonConverter(typeof(JsonSingleOrEmptyArrayConverter<Dictionary<string, List<Image>>>))]

        public Dictionary<string, List<Image>> images { get; set; } = new ();

    }

​

    public class Image

    {

        public string id { get; set; }

        public string product_id { get; set; }

    }

​

    public class JsonSingleOrEmptyArrayConverter<T> : JsonConverter where T : class

    {

        // Copied from this answer https://stackoverflow.com/a/53219877

        // To https://stackoverflow.com/questions/53219668/cannot-deserialize-the-current-json-object-empty-array

        public override bool CanConvert(Type objectType)

        {

            return typeof(T).IsAssignableFrom(objectType);

        }

​

        public override bool CanWrite { get { return false; } }

​

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

        {

            var contract = serializer.ContractResolver.ResolveContract(objectType);

            // Allow for dictionary contracts as well as objects contracts, since both are represented by 

            // an unordered set of name/value pairs that begins with { (left brace) and ends with } (right brace).

            if (!(contract is Newtonsoft.Json.Serialization.JsonObjectContract 

                  || contract is Newtonsoft.Json.Serialization.JsonDictionaryContract))

            {

                throw new JsonSerializationException(string.Format("Unsupported objectType {0} at {1}.", objectType, reader.Path));

            }

​

            switch (reader.SkipComments().TokenType)

            {

                case JsonToken.StartArray:

                    {

                        int count = 0;

                        while (reader.Read())

                        {

                            switch (reader.TokenType)

                            {

                                case JsonToken.Comment:

                                    break;

                                case JsonToken.EndArray:

                                    // You might want to allocate an empty object here if existingValue is null

                                    // If so, do

                                    // return existingValue ?? contract.DefaultCreator();

                                    return existingValue;

                                default:

                                    {

                                        count++;

                                        if (count > 1)

                                            throw new JsonSerializationException(string.Format("Too many objects at path {0}.", reader.Path));

                                        existingValue = existingValue ?? contract.DefaultCreator();

                                        serializer.Populate(reader, existingValue);

                                    }

                                    break;

                            }

                        }

                        // Should not come here.

                        throw new JsonSerializationException(string.Format("Unclosed array at path {0}.", reader.Path));

                    }

​

                case JsonToken.Null:

                    return null;

​

                case JsonToken.StartObject:

                    existingValue = existingValue ?? contract.DefaultCreator();

                    serializer.Populate(reader, existingValue);

                    return existingValue;

​

                default:

                    throw new InvalidOperationException("Unexpected token type " + reader.TokenType.ToString());

            }

        }

​

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

        {

            throw new NotImplementedException();

        }

    }

​

    public static partial class JsonExtensions

    {

        public static JsonReader SkipComments(this JsonReader reader)

        {

            while (reader.TokenType == JsonToken.Comment && reader.Read())

                ;

            return reader;

        }

    }

​

    class TestHarness

    {

        public static void Test()

        {

            var json = GetJson();

            Console.WriteLine("Input JSON:");

            Console.WriteLine(JToken.Parse(GetJson()));

            var root = JsonConvert.DeserializeObject<TestClass>(json);

​

            var json2 = JsonConvert.SerializeObject(root, Formatting.Indented);

​

            foreach (var variant in root.variants)

            {

                Console.WriteLine($"Images for {variant.name}:");

                foreach (var pair in variant.images)

                {

                    Console.WriteLine($"  For color {pair.Key}:");

                    foreach (var image in pair.Value)

                        Console.WriteLine($"    id = {image.id}");

                }

            }

            Console.WriteLine("Re-serialized {0}:", root);

            Console.WriteLine(json2);

        }   

        static string GetJson() =>

"""

{ "variants": [

                {

                    "name": "test1",

                    "description": "test1",

                    "images": []

                },

               {

                    "name": "test2",

                    "description": "test2",

                    "images": {

                        "WHITE": [

                            {

                                "id": "ttest",

                                "product_id": "ttest",

                            }

                        ]

                    }

               }

            ]

}

""";

    }

​

    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

            {

                TestHarness.Test();

            }

            catch (Exception ex)

            {

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

                Console.WriteLine(ex);

                throw;

            }

        }

    }

​