//
// ConvertNullCoalescingToConditionalExpressionAction.cs
//
// Author:
//       Mike Krüger <mkrueger@xamarin.com>
//
// Copyright (c) 2013 Xamarin Inc. (http://xamarin.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 System;

namespace ICSharpCode.NRefactory.CSharp.Refactoring
{
	[ContextAction("Convert '??' to '?:'",
	               Description = "Convert '??' to '?:'")]
	public class ConvertNullCoalescingToConditionalExpressionAction : SpecializedCodeAction<BinaryOperatorExpression>
	{
		protected override CodeAction GetAction(RefactoringContext ctx, BinaryOperatorExpression node)
		{
			if (node.Operator != BinaryOperatorType.NullCoalescing || !node.OperatorToken.Contains(ctx.Location))
				return null;
			return new CodeAction(
				ctx.TranslateString("Replace with '?:' expression"),
				script => {
					Expression expr = new ConditionalExpression (
						new BinaryOperatorExpression(node.Left.Clone(), BinaryOperatorType.InEquality, new NullReferenceExpression ()),
						node.Left.Clone(),
						node.Right.Clone()
					);
					script.Replace(node, expr);
				},
				node
			);
		}

	}
}