//*******************************************************************
//
//  Lab 14 Solution
//
//  MagazineList.java
//
//*******************************************************************

public class MagazineList
{
   private MagazineNode list;

   //----------------------------------------------------------------
   //  Sets up an initially empty list of magazines.
   //----------------------------------------------------------------
   public MagazineList()
   {
      list = null;
   }

   //----------------------------------------------------------------
   //  Creates a new MagazineNode object and adds it to the end of
   //  the linked list.
   //----------------------------------------------------------------
   public void addBack (Magazine mag)
   {

      MagazineNode node = new MagazineNode (mag);
      MagazineNode current;

      if (list == null)
         list = node;
      else
      {
         current = list;
         while (current.next != null)
            current = current.next;
         current.next = node;
      }
   }

   //----------------------------------------------------------------
   //  Creates a new MagazineNode object and adds it to the front of
   //  the linked list.
   //----------------------------------------------------------------
   public void addFront (Magazine mag)
   {
      MagazineNode node = new MagazineNode (mag);

      node.next = list;
      list = node;
   }

   //----------------------------------------------------------------
   //  Removes the first MagazineNode from the linked list and returs
   //  the Magazine object.  Return null if list is empty;
   //----------------------------------------------------------------
   public Magazine removeFront()
   {
      if (list == null)
        return null;
      else
      {
         Magazine mag = list.magazine;
         list = list.next;
         return mag;
      }
   }


   //----------------------------------------------------------------
   //  Returns the number of Magazine nodes in the linked list
   //----------------------------------------------------------------
   public int count()
   {
      MagazineNode current = list;
      int count = 0;

      while (current != null)
      {
         count++;
         current = current.next;
      }

      return count;
   }




   //----------------------------------------------------------------
   //  Returns this list of magazines as a string.
   //----------------------------------------------------------------
   public String toString ()
   {
      String result = "";

      MagazineNode current = list;

      if (current == null)
        return ("\n\nThe list is empty.");
      else
         while (current != null)
         {
            result += current.magazine + "\n";
            current = current.next;
         }

      return result;
   }

   //*****************************************************************
   //  An inner class that represents a node in the magazine list.
   //  The public variables are accessed by the MagazineList class.
   //*****************************************************************
   private class MagazineNode
   {
      public Magazine magazine;
      public MagazineNode next;

      //--------------------------------------------------------------
      //  Sets up the node
      //--------------------------------------------------------------
      public MagazineNode (Magazine mag)
      {
         magazine = mag;
         next = null;
      }
   }
}