using System;
using System.Collections;

namespace OPWLibrary
{
   /// <summary>
   /// A NHibernate.Collection.Bag is basically an Arraylist. You can iterate
   /// through it and can access items by index. There is however no key on
   /// it. We are forced by NH to use them because only Bags and Sets can
   /// be used in bidirectional relationships - ie relationships where the
   /// child can see the parent. This class will provide a wrapper for our
   /// Bags. Part of this will give a method to find a record by the key
   /// </summary>
   abstract public class clsGenericBagWrapper : ArrayList, iOPWObject, iOPWCollection
   {
      #region Private Variables
         private Hashtable   _HashedCollection;
      #endregion
      public clsGenericBagWrapper(IList Listn) : base(List)
      {
         _application = Application;
         LoadHashedCollection();
         SaveChecksumState();
      }

      /// <summary>
      /// So that we can look up these items by their key, load them into a hashtable
      /// using their key
      /// </summary>
      /// <param name="ChildType"></param>
      private void LoadHashedCollection()
      {
         _HashedCollection = new Hashtable();
         foreach (iOPWObject_NHLoaded o in this)
         {
            _HashedCollection.Add(o.Key,o);
         }
      }


      #region iOPWCollection Members

      /// <summary>
      /// One limitation of NH is that you can't use an IDictionary in
      /// a bidirectional relationship. You have to use a 'bag' or a 'set'.
      /// This sort of sucks, because, if you want to look up an item by the
      /// key, Going to try copying them into a hashtable to see if that helps..
      /// </summary>
      virtual public object ItemByKey(object key)
      {
            return this._HashedCollection[key];
      }

      #endregion
   }
}

namespace OPWLibrary
{
   /// <summary>
   /// Interface for each object that we use as a collection or
   /// collection base
   /// </summary>
   public interface iOPWCollection
   {
      object ItemByKey(object key);
   }
}