//
// ChainedExtension.cs
//
// Author:
//       Lluis Sanchez Gual <lluis@xamarin.com>
//
// Copyright (c) 2014 Xamarin, Inc (http://www.xamarin.com)
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
using System;
using System.Reflection;
using System.Linq;
using System.Collections.Generic;

namespace MonoDevelop.Projects
{
	public class ChainedExtension: IDisposable
	{
		ChainedExtension nextInChain;
		ExtensionChain chain;

		internal static T CreateChain<T> (ChainedExtension next) where T:ChainedExtension, new()
		{
			var first = new T ();
			first.nextInChain = ChainedExtension.FindNextImplementation<T> (next);
			return first;
		}

		internal protected static T FindNextImplementation<T> (ChainedExtension next) where T : ChainedExtension
		{
			return (T)FindNextImplementation(typeof (T), next, out _);
		}

		internal static ChainedExtension FindNextImplementation (Type type, ChainedExtension next, out int position)
		{
			position = -1;
			return FindNextImplementation_Internal (type, next, ref position);
		}

		static ChainedExtension FindNextImplementation_Internal (Type type, ChainedExtension next, ref int position)
		{
			if (next == null) {
				return null;
			}

			position++;
			if (!type.IsInstanceOfType (next))
				return FindNextImplementation_Internal (type, next.nextInChain, ref position);

			// Maybe it would make sense to cache these, but not sure if we should.
			foreach (var method in type.GetMethods (BindingFlags.DeclaredOnly | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance)) {
				if (method != null && method.IsVirtual && method.Name != "InitializeChain") {
					var paramArray = method.GetParameters ();
					var paramTypeArray = new Type [paramArray.Length];
					for (int i = 0; i < paramArray.Length; ++i)
						paramTypeArray [i] = paramArray [i].ParameterType;

					var tm = next.GetType ().GetMethod (method.Name, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance, null, paramTypeArray, null);
					if (tm == null)
						continue;
					if (tm.DeclaringType != type)
						return next;
				}
			}

			// Serializable fields and properties
			foreach (var m in next.GetType ().GetMembers (BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance)) {
				if (m.IsDefined (typeof (MonoDevelop.Core.Serialization.ItemPropertyAttribute)))
					return next;
			}

			return FindNextImplementation_Internal (type, next.nextInChain, ref position);
		}

		internal void InitChain (ExtensionChain chain, ChainedExtension next)
		{
			this.chain = chain;
			nextInChain = next;

			InitializeChain (next);
		}

		internal protected virtual void InitializeChain (ChainedExtension next)
		{
		}

		internal ChainedExtension Next {
			get { return nextInChain; }
		}

		internal void DisposeChain ()
		{
			Dispose ();
			if (nextInChain != null)
				nextInChain.DisposeChain ();
		}

		public virtual void Dispose ()
		{
			if (chain != null)
				chain.RemoveExtension (this);
		}
	}
}