Json response transformed into new json format c#

I would personally use AutoMapper in this case.

My answer will be written using .NET 6 Web API model (with AutoMapper package obviously installed first).

I generated the C# classes with the tool you provided for my example.

Let’s assume I have a Request.cs file as :

using System.Text.Json.Serialization;
namespace Something.Requests
{
    // Root myDeserializedClass = JsonSerializer.Deserialize<Root>(myJsonResponse);
    public class ByDirection
    {
        [JsonPropertyName("heading")]
        public string heading { get; set; }

        [JsonPropertyName("total")]
        public Total total { get; set; }
    }

    public class ByHour
    {
        [JsonPropertyName("edges")]
        public List<Edge> edges { get; set; }
    }

    public class Data
    {
        [JsonPropertyName("trafficData")]
        public TrafficData trafficData { get; set; }
    }

    public class Edge
    {
        [JsonPropertyName("node")]
        public Node node { get; set; }
    }

    public class Node
    {
        [JsonPropertyName("from")]
        public DateTime from { get; set; }

        [JsonPropertyName("to")]
        public DateTime to { get; set; }

        [JsonPropertyName("byDirection")]
        public List<ByDirection> byDirection { get; set; }
    }

    public class Request
    {
        [JsonPropertyName("data")]
        public Data data { get; set; }
    }

    public class Total
    {
        [JsonPropertyName("volumeNumbers")]
        public VolumeNumbers volumeNumbers { get; set; }
    }

    public class TrafficData
    {
        [JsonPropertyName("volume")]
        public Volume volume { get; set; }
    }

    public class Volume
    {
        [JsonPropertyName("byHour")]
        public ByHour byHour { get; set; }
    }

    public class VolumeNumbers
    {
        [JsonPropertyName("volume")]
        public int volume { get; set; }
    }
}

Using your tool, I also created a Response.cs like this :

using System.Text.Json.Serialization;

namespace Something.Answers
{
    public class Datum
    {
        [JsonPropertyName("from")]
        public DateTime from { get; set; }

        [JsonPropertyName("to")]
        public DateTime to { get; set; }

        [JsonPropertyName("heading")]
        public string heading { get; set; }

        [JsonPropertyName("volume")]
        public int volume { get; set; }
    }

    public class Result
    {
        [JsonPropertyName("data")]
        public List<Datum> data { get; set; }
    }
}

In order to handle mapping between the two type of objects, I would create a MappingConfiguration like so :

namespace Something.Mapper
{
    public class MappingConfiguration : Profile
    {
        public MappingConfiguration()
        {
            // TEST
            CreateMap<Something.Requests.Node, Something.Answers.Datum>()
                .ForMember(datum => datum.from, opt => opt.MapFrom(node => node.from))
                .ForMember(datum => datum.to, opt => opt.MapFrom(node => node.to))
                .ForMember(datum => datum.heading, opt => opt.MapFrom(node => node.byDirection.FirstOrDefault().heading))
                .ForMember(datum => datum.volume, opt => opt.MapFrom(node => node.byDirection.FirstOrDefault().total.volumeNumbers))
                .ReverseMap();
        }
    }
}

In my Program.cs, I would then Dependency Inject my MappingConfiguration with code below, before my "builder.Build()" :

var mappingConfig = new MapperConfiguration(mc =>
{
    mc.AddProfile(new MappingConfiguration());
});

IMapper mapper = mappingConfig.CreateMapper();
builder.Services.AddSingleton(mapper);

Finally, within my business class, I can do something like this:

var jsonRequest = "{rn  "data": {rn    "trafficData": {rn      "volume": {rn        "byHour": {rn          "edges": [rn            {rn              "node": {rn                "from": "2019-10-24T12:00:00+02:00",rn                "to": "2019-10-24T13:00:00+02:00",rn                "byDirection": [rn                  {rn                    "heading": "North",rn                    "total": {rn                      "volumeNumbers": {rn                        "volume": 696rn                      }rn                    }rn                  },rn                  {rn                    "heading": "South",rn                    "total": {rn                      "volumeNumbers": {rn                        "volume": 726rn                      }rn                    }rn                  }rn                ]rn              }rn            },rn            {rn              "node": {rn                "from": "2019-10-24T13:00:00+02:00",rn                "to": "2019-10-24T14:00:00+02:00",rn                "byDirection": [rn                  {rn                    "heading": "North",rn                    "total": {rn                      "volumeNumbers": {rn                        "volume": 805rn                      }rn                    }rn                  },rn                  {rn                    "heading": "South",rn                    "total": {rn                      "volumeNumbers": {rn                        "volume": 751rn                      }rn                    }rn                  }rn                ]rn              }rn            }rn          ]rn        }rn      }rn    }rn  }rn}";
Something.Requests.Request myRequest = JsonSerializer.Deserialize<Something.Requests.Request>(jsonRequest);

List<Something.Answers.Datum> data= new List<Something.Answers.Datum>();

foreach(var edge in myRequest.data.trafficData.volume.byHour.edges)
{
     var tmp = _mapper.Map<Something.Requests.Node>(edge.node);
}
var jsonAnswer = JsonSerializer.Serialize(data);

Hope this gives you an alternative.