using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Dynamic;
using System.Linq;
using System.Reflection;

namespace NotifyWrapper_Test
{
	public class NotifyWrapper : DynamicObject, INotifyPropertyChanged
	{
		object obj;
		Dictionary<string, Tuple<PropertyInfo, bool>> properties;	// <name, <info, has_setter>>
		Dictionary<string, EventHandler> events;					// <name, delegate>
		public event PropertyChangedEventHandler PropertyChanged;

		// Tのインスタンスをnew()で作成して使用
		public static NotifyWrapper Create<T>() where T : new() { return Create<T>(new T()); }

		// Tのインスタンスを指定して使用
		public static NotifyWrapper Create<T>(T instance) { return new NotifyWrapper(instance, typeof(T)); }

		NotifyWrapper(object instance, Type type)
		{
			obj = instance;
			properties = type.GetProperties()
				.ToDictionary(i => i.Name, i => new Tuple<PropertyInfo, bool>(i, i.GetSetMethod() != null));
			// プロパティ名Changed という名前のイベントを自動生成
			events = properties
				.Where(i => i.Value.Item2)
				.ToDictionary(i => i.Key + "Changed", i => new EventHandler(delegate { })); // チェック面倒なので空のデリゲートを...
		}

		public override bool TryGetMember(GetMemberBinder binder, out object result)
		{
			Tuple<PropertyInfo, bool> pi;
			EventHandler ev;
			result =
				properties.TryGetValue(binder.Name, out pi) ? pi.Item1.GetValue(obj, null) :
				events.TryGetValue(binder.Name, out ev) ? ev :
				null;
			return (result != null);
		}

		public override bool TrySetMember(SetMemberBinder binder, object value)
		{
			Tuple<PropertyInfo, bool> pi;
			if (properties.TryGetValue(binder.Name, out pi))
			{
				if (pi.Item2 == false)
					return false;
				pi.Item1.SetValue(obj, value, null);
				events[binder.Name + "Changed"](obj, EventArgs.Empty);
				if (PropertyChanged != null)
					PropertyChanged(obj, new PropertyChangedEventArgs(binder.Name));
				return true;
			}
			var ev = value as EventHandler;
			if (ev != null && events.ContainsKey(binder.Name))
			{
				events[binder.Name] = ev;
				return true;
			}
			return false;
		}

		// 必須じゃないけどとりあえず
		public override IEnumerable<string> GetDynamicMemberNames()
		{
			return properties.Select(i => i.Key)
				.Concat(events.Select(i => i.Key))
				.OrderBy(i => i);
		}

	}

	class Foo
	{
		public string Name { get; set; }
		public Foo()
		{
			Name = "Hoge";
		}
	}

	class Program
	{
		static void Main(string[] args)
		{
			dynamic item = NotifyWrapper.Create<Foo>();

			// メンバー名を取得してみる
			Console.WriteLine("DynamicMembers:");
			((NotifyWrapper)item).GetDynamicMemberNames().Run(Console.WriteLine);

			// イベント設定
			((INotifyPropertyChanged)item).PropertyChanged += (_,e) => Console.WriteLine("PropertyChanged: {0}", e.PropertyName);
			var name_changed = new EventHandler((_, __) => Console.WriteLine("Name Changed"));
			item.NameChanged += name_changed;

			// 読み書きテスト
			Console.WriteLine(item.Name);	// Hogeのはず
			item.Name = "Foo";				// イベントが発動するはず
			Console.WriteLine(item.Name);	// Fooのはず

			// イベント解除してテスト
			item.NameChanged -= name_changed;
			item.Name = "ほえー";
		}

	}
}