using System;

using System.Collections.Generic;

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

public class Program

{

    public static void Main()

    {

        string json = @"

            {

              ""event_id"": 123,

              ""event_name"": ""event1"",

              ""start_date"": ""2018-11-30"",

              ""end_date"": ""2018-12-04"",

              ""participants"": {

                ""guests"": [

                  {

                    ""guest_id"": 143,

                    ""first_name"": ""John"",

                    ""last_name"": ""Smith""

                  },

                  {

                    ""guest_id"": 189,

                    ""first_name"": ""Bob"",

                    ""last_name"": ""Duke""

                  }

                ]

              }

            }";

​

        string json2 = @"

            {

              ""name"": ""event2"",

              ""from"": ""2017-05-05"",

              ""to"": ""2017-05-09"",

              ""city"": ""Some other city"",

              ""country"": ""US"",

              ""guests"": [

                {

                  ""email"": ""jane@smith.com"",

                  ""firstName"": ""Jane"",

                  ""lastName"": ""Smith"",

                  ""telephone"": ""1-369-81891""

                }

              ]

            }";

​

        var settings = new JsonSerializerSettings

        {

            Converters = new List<JsonConverter>

            {

                new EventConverter(),

                new GuestConverter()

            }

        };

​

        Console.WriteLine("----- Event deserialized from JSON format #1 -----");

        var evt = JsonConvert.DeserializeObject<Event>(json, settings);

        DumpEvent(evt);

​

        Console.WriteLine("----- Event deserialized from JSON format #2 -----");

        evt = JsonConvert.DeserializeObject<Event>(json2, settings);

        DumpEvent(evt);

    }

​

    private static void DumpEvent(Event evt)

    {

        Console.WriteLine("Event ID: " + evt.EventId);

        Console.WriteLine("Event Name: " + evt.EventName);

        Console.WriteLine("Start Date: " + evt.StartDate.ToShortDateString());

        Console.WriteLine("End Date: " + evt.EndDate.ToShortDateString());

        Console.WriteLine("  -- Guest List --");

        foreach (var guest in evt.Guests)

        {

            Console.WriteLine("  Guest ID: " + guest.GuestId);

            Console.WriteLine("  First Name: " + guest.FirstName);

            Console.WriteLine("  Last Name: " + guest.LastName);

            Console.WriteLine("  Email: " + guest.Email);

            Console.WriteLine();

        }

        Console.WriteLine();

    }

}

​

public class Event

{

    public int EventId { get; set; }

    public string EventName { get; set; }

    public DateTime StartDate { get; set; }

    public DateTime EndDate { get; set; }

    public List<Guest> Guests { get; set; }

}

​

public class Guest

{

    public string GuestId { get; set; }

    public string FirstName { get; set; }

    public string LastName { get; set; }

    public string Email { get; set; }

}

​

public class EventConverter : JsonConverter

{

    public override bool CanConvert(Type objectType)

    {

        return objectType == typeof(Event);

    }

​

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

    {

        Event evt = new Event();

        JObject obj = JObject.Load(reader);

        if (obj["event_id"] != null)

        {

            // JSON format #1

            evt.EventId = (int)obj["event_id"];

            evt.EventName = (string)obj["event_name"];

            evt.StartDate = (DateTime)obj["start_date"];

            evt.EndDate = (DateTime)obj["end_date"];

            evt.Guests = obj.SelectToken("participants.guests").ToObject<List<Guest>>(serializer);

        }

        else if (obj["name"] != null)

        {

            // JSON format #2

            evt.EventName = (string)obj["name"];

            evt.StartDate = (DateTime)obj["from"];

            evt.EndDate = (DateTime)obj["to"];

            evt.Guests = obj["guests"].ToObject<List<Guest>>(serializer);

        }

        else

        {

            throw new JsonException("Unknown format for Event");

        }

        return evt;

    }

​

    public override bool CanWrite

    {

        get { return false; }

    }

​

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

    {

        throw new NotImplementedException();

    }

}

​

public class GuestConverter : JsonConverter

{

    public override bool CanConvert(Type objectType)

    {

        return objectType == typeof(Guest);

    }

​

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

    {

        Guest guest = new Guest();

        JObject obj = JObject.Load(reader);

        if (obj["guest_id"] != null)

        {

            // JSON format #1

            guest.GuestId = (string)obj["guest_id"];

            guest.FirstName = (string)obj["first_name"];

            guest.LastName = (string)obj["last_name"];

        }

        else if (obj["email"] != null)

        {

            // JSON format #2

            guest.FirstName = (string)obj["firstName"];

            guest.LastName = (string)obj["lastName"];

            guest.Email = (string)obj["email"];

        }

        else

        {

            throw new JsonException("Unknown format for Guest");

        }

        return guest;

    }

​

    public override bool CanWrite

    {

        get { return false; }

    }

​

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

    {

        throw new NotImplementedException();

    }

}

​