using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var test = new SomeEnumerable

        {

            SomeCollection = new List<SomeEntity>

            { 

                new SomeEntity

                {

                    Id = 1, Value = "Test1", Name = "SomeName1WithEmail", ContactType = ContactPointType.Email, IsDefault = false, IsDeleted = false

                },

                new SomeEntity

                {

                    Id = 1, Value = "Test1", Name = "SomeName1WithPhone", ContactType = ContactPointType.Phone, IsDefault = false, IsDeleted = false

                },

                new SomeEntity

                {

                    Id = 2, Value = "Test2", Name = "SomeName2", ContactType = ContactPointType.Email, IsDefault = false, IsDeleted = false

                }

            }

        };

        var samples = test.SomeCollection.Where(s => !s.IsDeleted && s.Id == 1)// hard-coded for intents and purposes

            .Select(s => new SomeTargetClassType

                    {

                        Id = s.Id,

                        Name = s.Name,

                        //Address left out for brevity

                        //Country also left out

                        Email = s.GetContactPoint(ContactPointType.Email),

                        Phone = s.GetContactPoint(ContactPointType.Phone)

                    }).ToList();

        samples.ForEach(s => Console.WriteLine(s.Name + " ID --" + s.Id + " Email -- " + s.Email + " Phone -- " + s.Phone));

        var testInterface = new SomeOtherEntity{ Value = "It works!", ContactType = ContactPointType.Email};

        var result = (from SomeEntity sample in test.SomeCollection where !string.IsNullOrEmpty(sample.GetContactPoint(testInterface.ContactType))

                                                                                                select new SomeTargetClassType

                                                                                                {

                                                                                                    Email = sample.GetContactPoint(ContactPointType.Email),

                                                                                                    Phone = sample.GetContactPoint(ContactPointType.Phone)

                                                                                                }).ToList();

        Console.WriteLine("");

        result.ForEach(s => Console.WriteLine("Interface yielded: Email -- " + s.Email + "  Phone -- " + s.Phone));

    }

}

​

public class SomeEnumerable

{

    public List<SomeEntity> SomeCollection{get; set;}   

}

​

public interface IContactable

{

    ContactPointType GetContactType();

    string GetValue();

}

​

public class SomeEntity : IContactable

{

    public int Id { get; set; }

    public string Name{get;set;}

    public bool IsDeleted{get;set;}

    //Address intentionally left out of here for brevity's sake

    public string Value { get; set; }

    public ContactPointType ContactType { get; set; }

    public bool IsDefault { get; set; } 

    public ContactPointType GetContactType()

    {

        return this.ContactType;    

    }

    public string GetValue()

    {

        return this.Value;  

    }

}

​

public class SomeOtherEntity : IContactable

{

    public ContactPointType ContactType {get; set;}

    public string Value{get; set;}

    public ContactPointType GetContactType()

    {

        return this.ContactType;    

    }

    public string GetValue()

    {

        return this.Value;  

    }

}

​

public enum ContactPointType

{

    Email = 0,

    Phone = 1   

}

​

public class SomeTargetClassType

{

    public int Id {get;set;}

    public string Name {get;set;}

    public string Address{get;set;}

    public string Country {get;set;}

    public string Email{get;set;}

    public string Phone{get;set;}

}

​

​

public static class Extensions

{

    public static string GetContactPoint(this IContactable src, ContactPointType contactType)

    {

        return src.GetContactType() == contactType ? src.GetValue() : "";

    }

}