using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using Castle.MicroKernel.Resolvers.SpecializedResolvers;
using Castle.Windsor;

public static class Extensions
{
	/// <summary>
	/// Determines whether the specified type is a generic collection.
	/// </summary>
	/// <param name="type">The type.</param>
	public static bool IsGenericCollection(this Type type)
	{
		if (type == null)
		{
			throw new ArgumentNullException("type");
		}
		return type.GetInterfaces().Where(@interface => @interface.IsGenericType).Any(@interface => @interface.GetGenericTypeDefinition() == typeof(ICollection<>));
	}

	/// <summary>
	/// Adds the CollectionResolver to the container.
	/// </summary>
	/// <param name="container">The container.</param>
	/// <param name="allowEmptyCollections">if set to <c>true</c> [allow empty collections].</param>
	public static void AddCollectionResolver(this IWindsorContainer container, bool allowEmptyCollections)
	{
		container.Kernel.Resolver.AddSubResolver(new CollectionResolver(container.Kernel, allowEmptyCollections));
		_useCollectionResolver = true;
	}

	/// <summary>
	/// I havent found an easy way to check if a SubResolver was added to the kerner, so just register it through our extension method and
	/// use a static bool variable to do the check
	/// </summary>
	private static bool _useCollectionResolver;

	public static void ResolveDependencies(this IWindsorContainer container, object objToConfigure)
	{
		// get all the properties through reflection
		PropertyInfo[] props = objToConfigure.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance);
		foreach (var info in props)
		{
			object o = info.GetValue(objToConfigure, null);
			// skip the object is it already contains a value of any sort
			if (o != null) continue;
			if (_useCollectionResolver && info.PropertyType.IsGenericCollection())
			{
				o = container.ResolveAll(info.PropertyType.GetGenericArguments()[0]);
			}
			else if ((info.PropertyType.IsInterface) || (info.PropertyType.IsClass))
			{
				// try to resolve the related type if the component knows it
				if (container.Kernel.HasComponent(info.PropertyType))
					o = container.Resolve(info.PropertyType);
			}
			if (o != null)
				info.SetValue(objToConfigure, o, null);
		}
	}

	public static void ReleaseDependencies(this IWindsorContainer container, object objToConfigure)
	{
		// get all the properties through reflection
		PropertyInfo[] props = objToConfigure.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance);
		foreach (var info in props)
		{
			object o = info.GetValue(objToConfigure, null);
			if (o == null) continue;
			if (info.PropertyType.IsGenericCollection())
			{
				ICollection c = o as ICollection;
				if (c != null)
					foreach (var obj in c)
						container.Release(obj);
			}
			else if ((info.PropertyType.IsInterface) || (info.PropertyType.IsClass))
			{
				container.Release(o);
			}
		}
	}
}