import java.util.ArrayList;
import java.util.Collection;
import java.util.Map;
import java.util.HashMap;

public class IDs
{
   /** Static *****************************************************************/
   private static final Map<String, IDs> FROM_XML;
   private static final Collection<IDs> ALL_IDS;
   private static int next_id;

   static
   {
      next_id = 0;

      FROM_XML = new HashMap<String, IDs>();
      ALL_IDS = new ArrayList<IDs>();
   }


   public static IDs get_id_from_xml_id
   (
      final String xml_id,
      final String type
   )
   {
      IDs result;

      result = FROM_XML.get(xml_id);

      if (result == null)
      {
         result = generate_new_id(type);

         FROM_XML.put(xml_id, result);
      }
      else if ((result.type == null) && (type != null))
      {
         /* This allows us to get an ID from a simple reference. */
         /* TODO: Don't forget to report any (type == null) at the end. */
         result.type = type;
      }

      return result;
   }

   public static IDs generate_new_id
   (
      final String type
   )
   {
      final IDs result;

      result = new IDs(type);

      ALL_IDS.add(result);

      /* TODO: remove, it's for debug. */
      if (type != null)
      {
         System.out.println
         (
            "[ID] ("
            + result.get_type()
            + " "
            + result.get_value()
            + ")"
         );
      }

      return result;
   }

   /** Non-Static *************************************************************/
   private final int value;
   private String type;

   private IDs (final String type)
   {
      this.type = type;

      value = IDs.next_id;

      IDs.next_id += 1;
   }

   public String get_type ()
   {
      return type;
   }

   public int get_value ()
   {
      return value;
   }
}