using System.Collections.Generic;

using System.Linq;



namespace NHibernate.Envers.Tools

{

	public class DictionaryComparer<K, V> : IEqualityComparer<IDictionary<K, V>>

	{

		public bool Equals(IDictionary<K, V> x, IDictionary<K, V> y)

		{

			if (x.Count != y.Count)

				return false;

			foreach (var xKeyValue in x)

			{

				V yValue;

				if (y.TryGetValue(xKeyValue.Key, out yValue))

				{

					if (!xKeyValue.Value.Equals(yValue))

						return false;

				}

				else

				{

					return false;

				}

			}

			return true;

		}



		public int GetHashCode(IDictionary<K, V> obj)

		{

			return obj.Aggregate(123, (current, keyValue) => current + (keyValue.GetHashCode()*31));

		}

	}

}