// Copyright (c) 2010-2013 AlphaSierraPapa for the SharpDevelop Team
// 
// 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 ICSharpCode.Decompiler.CSharp.Resolver;
using ICSharpCode.Decompiler.Semantics;
using ICSharpCode.Decompiler.TypeSystem;

namespace ICSharpCode.Decompiler.CSharp.TypeSystem
{
	/// <summary>
	/// Looks up an alias (identifier in front of :: operator).
	/// </summary>
	/// <remarks>
	/// The member lookup performed by the :: operator is handled
	/// by <see cref="MemberTypeOrNamespaceReference"/>.
	/// </remarks>
	[Serializable]
	public sealed class AliasNamespaceReference : TypeOrNamespaceReference, ISupportsInterning
	{
		readonly string identifier;

		public AliasNamespaceReference(string identifier)
		{
			if (identifier == null)
				throw new ArgumentNullException(nameof(identifier));
			this.identifier = identifier;
		}

		public string Identifier {
			get { return identifier; }
		}

		public override ResolveResult Resolve(CSharpResolver resolver)
		{
			return resolver.ResolveAlias(identifier);
		}

		public override IType ResolveType(CSharpResolver resolver)
		{
			// alias cannot refer to types
			return SpecialType.NoType;
		}

		public override string ToString()
		{
			return identifier + "::";
		}

		int ISupportsInterning.GetHashCodeForInterning()
		{
			return identifier.GetHashCode();
		}

		bool ISupportsInterning.EqualsForInterning(ISupportsInterning other)
		{
			AliasNamespaceReference anr = other as AliasNamespaceReference;
			return anr != null && this.identifier == anr.identifier;
		}
	}
}
