using System;

using System.Collections.Generic;

using Newtonsoft.Json;

using AutoMapper;

public class Program

{

    public static void Main()

    {

        MapperConfiguration _config = new MapperConfiguration(cfg =>

                                                              {

                                                                  cfg.CreateMap<UserModel, UserDefinition>()

                                                                    .ForMember(d => d.Id, o => o.Ignore()) 

                                                                    .ForMember(d => d.UserName, o => o.MapFrom(s => s.Username))

                                                                    .ForMember(d => d.Contacts, o => o.MapFrom(new UserContactDefinitionListResolver())); 

                                                              });

        IMapper _mapper = _config.CreateMapper();

        UserModel src = new UserModel

        {

            PhoneNumber = "12345",

            ContactEmail = "abc@email.com"

        };

        UserDefinition dst = _mapper.Map<UserDefinition>(src);

        Console.WriteLine(JsonConvert.SerializeObject(dst, Formatting.Indented));

    }

}

public class UserContactDefinitionListResolver : IValueResolver<UserModel, UserDefinition, List<UserContactDefinition>>

{

    public List<UserContactDefinition> Resolve(UserModel src, UserDefinition dst, List<UserContactDefinition> dstMember, ResolutionContext ctx)

    {

        dstMember = new List<UserContactDefinition>();

        if (!string.IsNullOrWhiteSpace(src.PhoneNumber))

            dstMember.Add(new UserContactDefinition

            {

                Type = ContactType.Phone,

                IsPrimary = true,

                Label = src.PhoneType,

                Value = src.PhoneNumber

            });

        if (!string.IsNullOrWhiteSpace(src.ContactEmail))

            dstMember.Add(new UserContactDefinition

            {

                Type = ContactType.Email,

                IsPrimary = true,

                Label = src.EmailType,

                Value = src.ContactEmail

            });

        return dstMember;

    }

}

public class UserModel

{

    public int Id { get; set; } 

    public string Username { get; set; }

    public string PhoneType { get; set; }

    public string PhoneNumber { get; set; }

    public string EmailType { get; set; }

    public string ContactEmail { get; set; }

}

public class UserDefinition

{

    public int Id { get; set; } 

    public string UserName { get; set; }

    public List<UserContactDefinition> Contacts { get; set; }      

}

public class UserContactDefinition

{

    public ContactType Type { get; set; }

    public bool IsPrimary { get; set; }

    public string Label { get; set; }

    public string Value { get; set; }

}       

​

public enum ContactType

{

    Phone,

    Email

}