// 
// TokenNode.cs
//  
// Author:
//       Mike Krüger <mkrueger@novell.com>
// 
// Copyright (c) 2010 Novell, Inc (http://www.novell.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 ICSharpCode.Decompiler.CSharp.OutputVisitor;

namespace ICSharpCode.Decompiler.CSharp.Syntax
{
	/// <summary>
	/// Represents a token in C#. Note that the type of the token is defined through the TokenRole.
	/// </summary>
	/// <remarks>
	/// In all non null c# token nodes the Role of a CSharpToken must be a TokenRole.
	/// </remarks>
	public class CSharpTokenNode : AstNode
	{
		public static new readonly CSharpTokenNode Null = new NullCSharpTokenNode();
		class NullCSharpTokenNode : CSharpTokenNode
		{
			public override bool IsNull {
				get {
					return true;
				}
			}

			public NullCSharpTokenNode() : base(TextLocation.Empty, null)
			{
			}

			public override void AcceptVisitor(IAstVisitor visitor)
			{
				visitor.VisitNullNode(this);
			}

			public override T AcceptVisitor<T>(IAstVisitor<T> visitor)
			{
				return visitor.VisitNullNode(this);
			}

			public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
			{
				return visitor.VisitNullNode(this, data);
			}

			protected internal override bool DoMatch(AstNode other, PatternMatching.Match match)
			{
				return other == null || other.IsNull;
			}
		}

		public override NodeType NodeType {
			get {
				return NodeType.Token;
			}
		}

		TextLocation startLocation;
		public override TextLocation StartLocation {
			get {
				return startLocation;
			}
		}

		int TokenLength {
			get {
				uint tokenRoleIndex = (this.flags >> AstNodeFlagsUsedBits);
				if (Role.GetByIndex(tokenRoleIndex) is TokenRole r)
				{
					return r.Length;
				}
				return 0;
			}
		}

		public override TextLocation EndLocation {
			get {
				return new TextLocation(StartLocation.Line, StartLocation.Column + TokenLength);
			}
		}

		public CSharpTokenNode(TextLocation location, TokenRole role)
		{
			this.startLocation = location;
			if (role != null)
				this.flags |= role.Index << AstNodeFlagsUsedBits;
		}

		public override string ToString(CSharpFormattingOptions formattingOptions)
		{
			uint tokenRoleIndex = (this.flags >> AstNodeFlagsUsedBits);
			if (Role.GetByIndex(tokenRoleIndex) is TokenRole r)
			{
				return r.Token;
			}
			return string.Empty;
		}

		public override void AcceptVisitor(IAstVisitor visitor)
		{
			visitor.VisitCSharpTokenNode(this);
		}

		public override T AcceptVisitor<T>(IAstVisitor<T> visitor)
		{
			return visitor.VisitCSharpTokenNode(this);
		}

		public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
		{
			return visitor.VisitCSharpTokenNode(this, data);
		}

		protected internal override bool DoMatch(AstNode other, PatternMatching.Match match)
		{
			CSharpTokenNode o = other as CSharpTokenNode;
			return o != null && !o.IsNull && !(o is CSharpModifierToken);
		}
	}
}
