using System;

using System.Linq;

using System.Collections.Generic;

using System.Text.RegularExpressions;

​

public class Program

{

    public static void Main()

    {

        var str = ",fhzg.jfh/fdsg,example.com/xy/*, xy.com/b, , xy.com/x";

        var domainsDict = str.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries).Where(w => w.Contains("/")).Select(a => 

            {

                var y = a.Trim().Split(new char[] { '/' }, StringSplitOptions.RemoveEmptyEntries).ToList();

                return new{ 

                    Domain = string.Join("/", y.Take(y.Count-1)),

                    Tenant = y.Last()

                };

            }

        )

        .Where(d => d.Domain.Length > 0 && d.Tenant.Length > 0)

        .GroupBy(g => g.Domain)

        .Select(s => s.Last())

        .ToDictionary(g => g.Domain, g => g.Tenant);

            //;

        //.GroupBy(g => g.Tenant).Select(s => s.First())

        foreach(var di in domainsDict){

            Console.WriteLine($"Key:{di.Key}  Value:{di.Value}");

        }

        Console.WriteLine($"---------------------------\n\n");

        /*

            foreach(var di in domainsDict){

            Console.WriteLine($"Key:{di.Domain}  Value:{di.Tenant}");

        }

        */

        var toAdd = "ghfbd";

        var tenant = "c";

        var domains = str.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries).Select(a => 

            {

                var y = a.Trim().Split(new char[] { '/' }, StringSplitOptions.RemoveEmptyEntries).ToList();

                return new{ 

                    Domain = string.Join("/", y.Take(y.Count-1)),

                    Tenant = y.Last()

                };

            }

        )

        .Where(d => d.Tenant != tenant)

        .Where(d => d.Domain.Length > 0 && d.Tenant.Length > 0)

        .ToList();  

        if(toAdd.Length > 2){

            domains.Add(new{ 

                Domain = toAdd,

                Tenant = tenant

            }); 

        }

        var newDomains = string.Join(",",domains.Select(d => $"{d.Domain}/{d.Tenant}"));

        Console.WriteLine(newDomains);

    }

}