using System;

using System.Linq;

using System.Collections.Generic;

using System.Globalization;

using Newtonsoft.Json;

using Newtonsoft.Json.Converters;

​

public class Program

{

    public static void Main()

    {

        string jsonInput = @"[

  {0:24, 1:74, 2:5, 8:5},

  {0:45, 1:857, 10:7, 2:42, 3:8, 5:89, 55:98},

  [103, null, null, 195],

  null,

  null,

  null,

  {0:84, 5:854, 6:425},

  {6:8, 7:578},

  [0, 1],

  {8:8, 9:9},

  [0, 1, 2, 3]

]";

        var fireBaseResult = FireBaseResult.FromJson(jsonInput);

        foreach(var row in fireBaseResult){

            row.InnerArray.Dump();

        }

    }

    public class FireBaseResult

    {

        public static List<FireBaseResultElement> FromJson(string json) => JsonConvert.DeserializeObject<List<FireBaseResultElement>>(json, Converter.Settings);

    }

​

    public partial struct FireBaseResultElement

    {

        public long?[] InnerArray;

        public static implicit operator FireBaseResultElement(long?[]  Items) => new FireBaseResultElement{InnerArray = Items};

    }

​

    internal static class Converter

    {

        public static readonly JsonSerializerSettings Settings =

            new JsonSerializerSettings{MetadataPropertyHandling = MetadataPropertyHandling.Ignore, DateParseHandling = DateParseHandling.None, 

                                       Converters = {new FireBaseResultElementConverter(), new IsoDateTimeConverter{DateTimeStyles = DateTimeStyles.AssumeUniversal}}, };

    }

​

    internal class FireBaseResultElementConverter : JsonConverter

    {

        public override bool CanConvert(Type t) => t == typeof(FireBaseResultElement) || t == typeof(FireBaseResultElement? );

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

        {

            switch (reader.TokenType)

            {

                case JsonToken.Null:

                    return new FireBaseResultElement{};

                case JsonToken.StartObject:

                    var objectValue = serializer.Deserialize<Dictionary<string, long?>>(reader);

                    return new FireBaseResultElement{InnerArray=objectValue.Values.ToArray()};

                case JsonToken.StartArray:

                    var arrayValue = serializer.Deserialize<long?[]>(reader);

                    return new FireBaseResultElement{InnerArray=arrayValue};

            }

​

            throw new Exception("Cannot unmarshal type FireBaseResultElement");

        }

​

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

        {

            throw new Exception("Cannot marshal type FireBaseResultElement");

        }

    }

}