// Noddybox.DOOM - DOOM WAD Wrapper
// Copyright (C) 2004  Ian Cowburn
// 
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
//
// $Id$
//
using System;
using System.Collections;

namespace Noddybox.DOOM
{
	/// <summary>
	/// Performs operations on a collection of WADs
	/// </summary>
	public class WADCollection : IEnumerable, IEnumerator
	{
		// ====================================
		// PUBLIC
		// ====================================
		
		/// <summary>
		/// Delegate for WAD added event
		/// </summary>
		public delegate void WadAddedEvent(WADCollection collection, WAD wad);
		
		/// <summary>
		/// Delegate for WAD removed event
		/// </summary>
		public delegate void WadRemovedEvent(WADCollection collection);
		
		/// <summary>
		/// Create an empty collection of WADs
		/// </summary>
		public WADCollection()
		{
			m_wads=new ArrayList();
			m_iter_index=-1;
		}
		
		/// <summary>
		/// Add a WAD to the collection
		/// </summary>
		/// <param name="w">The WAD</param>
		public void AddWad(WAD w)
		{
			m_wads.Add(w);
			
			if (WadAdded!=null)
			{
				WadAdded(this,w);
			}
		}
		
		/// <summary>
		/// Remove a WAD from the collection
		/// </summary>
		/// <param name="w">The WAD</param>
		public void RemoveWad(WAD w)
		{
			m_wads.Remove(w);
			
			if (WadRemoved!=null)
			{
				WadRemoved(this);
			}
		}
		
		
		/// <summary>
		/// Get the first palette (PLAYPAL) lump from the WAD files
		/// </summary>
		/// <returns>The lump containing the palette, or null if not found</returns>
		public WADEntry GetPalette()
		{
			return QueryDirectory("PLAYPAL");
		}
		
		
		/// <summary>
		/// Queries the WAD directories for the named lump.  Note it searches
		/// back from the last loaded WAD as DOOM does.
		/// </summary>
		/// <param name="name">The lump name</param>
		/// <returns>The lump, or null if it doesn't exist</returns>
		public WADEntry QueryDirectory(string name)
		{
			for(int f=m_wads.Count-1;f>=0;f--)
			{
				WAD w=(WAD)m_wads[f];
				
				WADEntry e=w.FindEntry("PLAYPAL");
				
				if (e!=null)
				{
					return e;
				}
			}
			
			return null;
		}

		/// <summary>
		/// Called when a WAD is added to the collection
		/// </summary>
		public event WadAddedEvent 		WadAdded;
		
		/// <summary>
		/// Called when a WAD is removed from the collection
		/// </summary>
		public event WadRemovedEvent	WadRemoved;

		/// <summary>
		/// Returns the number of WADs in the collection
		/// </summary>
		public int Count
		{
			get {return m_wads.Count;}
		}
		
		/// <summary>
		/// Index into the WADs 
		/// </summary>
		public WAD this[int index]
		{
			get {return (WAD)m_wads[index];}
		}
		
		/// <summary>
		/// Gets an enumerator
		/// </summary>
		/// <returns>The enumerator</returns>
		public IEnumerator GetEnumerator()
		{
			Reset();
			return this;
		}
		
		/// <summary>
		/// Get the current object from the enumerator
		/// </summary>
		public object Current
		{
			get
			{
				if (m_iter_index==-1)
				{
					throw new InvalidOperationException();
				}
				
				return m_wads[m_iter_index];
			}
		}

		/// <summary>
		/// Reset the enumerator to the start of the collection.
		/// </summary>
		public void Reset()
		{
			m_iter_index=-1;
		}

		/// <summary>
		/// Move the enumerator to the next item.
		/// </summary>
		/// <returns>True if there are more objects to enumerate over</returns>
		public bool MoveNext()
		{
			m_iter_index++;
			
			if (m_iter_index>=m_wads.Count)
			{
				m_iter_index=-1;
			}
			
			return m_iter_index!=-1;
		}


		// ====================================
		// PRIVATE
		// ====================================
		private ArrayList	m_wads;
		private int			m_iter_index;
	}
}