D Secret Santa Challenge

import std.stdio;
import std.algorithm;
import std.array;
import std.random;

class SecretSanta {

   private string[string] santa;

   private string[] LIST = [
      "David Jason",
      "Claire Jason",
      "Vicky Pollard",
      "Keith Pollard",
      "Ian Smith",
      "Maria Osawa",
      "Mark Kelly",
      "Sarah Kelly"
  ];

   string[string] givePresents(){
      assign;
      while(hasUnassigned){
        assign;
      }
      return santa;
   }

private  bool hasUnassigned(){
    return canFind(santa.values,"unknown");
  }

  private void assign(){
     writeln("attempting to assign");
      foreach (name; LIST) {
        string[] list = LIST.filter!(n => n != name)
                              .filter!(n => !canFind(n.split()[$-1],name))
                              .filter!(n => !canFind(santa.values,n)).array;

        string randomName = list.length == 0 ? "unknown" : list[uniform(0,$)];

         santa[name] = randomName;
      }
  }

}


void main(){
  SecretSanta secretSanta = new SecretSanta();
  writeln(secretSanta.givePresents());
}