// GfxEd8
// 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.IO;
using System.Xml;
using System.Xml.Serialization;
using System.Reflection;
using System.Collections;
using System.Collections.Specialized;
using GfxEdInterface;
using System.Diagnostics;

namespace GfxEd8
{
	/// <summary>
	/// Controls the plugins for the editor
	/// </summary>
	public class PluginControl
	{
		// -------------------------------------------
		// PUBLIC
		// -------------------------------------------

		/// <summary>
		/// Creates the plugins
		/// </summary>
		/// <param name="config">The XML config file</param>
		public static void Initialise(string config)
		{
			XmlDocument xml=new XmlDocument();
			
			xml.PreserveWhitespace=false;
			
			//Debugger.Break();
			
			xml.Load(config);
			
			XmlNode node=xml.FirstChild;
			
			if (node.Name!="Config")
			{
				throw new Exception("Illegal element " + node.Name + " in config");
			}
			
			m_names=new StringCollection();
			m_interface=new Hashtable();
			
			foreach (XmlNode n in node.ChildNodes)
			{
				if (n.Name!="Import")
				{
					throw new Exception("Illegal element " + node.Name + " in config");
				}

				PluginData plg=new PluginData();
				
				XmlNode dll=n.Attributes.GetNamedItem("dll");
				XmlNode name=n.Attributes.GetNamedItem("name");
				
				if (dll==null || name==null)
				{
					throw new Exception("Missing attributes in Import config");
				}
				
				string path=Path.GetFullPath(dll.Value);
				
				try
				{
					plg.asm=Assembly.LoadFile(path);
				}
				catch (System.Security.SecurityException)
				{
					throw new Exception("Do not have permission to load:\n"+path);
				}
				catch (Exception)
				{
					throw new Exception("Could not load plugin:\n"+path);
				}
				
				try
				{
					plg.iface=(IPlugin)plg.asm.CreateInstance(name.Value);
				}
				catch (InvalidCastException)
				{
					throw new Exception("The plugin " + dll.Value+" is incorrect");
				}
				
				Validate(plg.iface,path);
				
				m_names.Add(plg.iface.ShortName);
				m_interface[plg.iface.ShortName]=plg;
			}
		}
		
		
		public static StringCollection Names
		{
			get {return m_names;}
		}
		
		public static IPlugin Get(string name)
		{
			PluginData d=(PluginData)m_interface[name];

			if (d!=null)
			{
				return d.iface;
			}
			else
			{
				return null;
			}
		}
		
		public static Assembly GetAssembly(string name)
		{
			PluginData d=(PluginData)m_interface[name];
			
			if (d!=null)
			{
				return d.asm;
			}
			else
			{
				return null;
			}
		}
		
		public static string Version(string name)
		{
			Assembly a=GetAssembly(name);
			
			if (a==null)
			{
				return "0.0";
			}
			
			AssemblyName n=a.GetName();
			
			return n.Version.Major.ToString()+"."+n.Version.Minor.ToString();
		}
		
		// -------------------------------------------
		// PRIVATE
		// -------------------------------------------
		private static StringCollection		m_names=null;
		private static Hashtable			m_interface=null;
		
		private class PluginData
		{
			public PluginData()
			{
				asm=null;
				iface=null;
			}
			
			public Assembly	asm;
			public IPlugin	iface;
		}
		
		private static void Validate(IPlugin p, string path)
		{
			foreach (SpriteSize s in p.AllowedSizes)
			{
				if (s==null)
				{
					throw new Exception("Sprite Sizes incorrecly defined in\n"+path);
				}
			}

			foreach (Colour c in p.Palette)
			{
				if (c==null)
				{
					throw new Exception("Sprite Sizes incorrecly defined in\n"+path);
				}
			}
			
			if (p.Palette.Length<p.MaxColours)
			{
				throw new Exception("Not enough colours defined in\n"+path);
			}

			if (p.SprPalEditable.Length!=p.MaxColours)
			{
				throw new Exception("Wrong editable colour indicators in\n"+path);
			}

			if (p.SprPalCommon.Length!=p.MaxColours)
			{
				throw new Exception("Wrong common colour indicators in\n"+path);
			}
		}
		
		private PluginControl()
		{
		}
	}
}