// 
// GenerateSwitchLabels.cs
//  
// Author:
//       Mike Krüger <mkrueger@novell.com>
// 
// Copyright (c) 2011 Mike Krüger <mkrueger@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 System;
using ICSharpCode.NRefactory.TypeSystem;

namespace ICSharpCode.NRefactory.CSharp.Refactoring
{
	public class GenerateSwitchLabels : IContextAction
	{
		public bool IsValid (RefactoringContext context)
		{
			var switchStatement = GetSwitchStatement (context);
			if (switchStatement == null)
				return false;
			var result = context.Resolve (switchStatement.Expression);
			if (result == null)
				return false;
			return result.Type.IsEnum ();
		}
		
		public void Run (RefactoringContext context)
		{
			var switchStatement = GetSwitchStatement (context);
			
			var result = context.Resolve (switchStatement.Expression);
			var type = result.Type;
			var newSwitch = (SwitchStatement)switchStatement.Clone ();
			
			var target = new TypeReferenceExpression (context.CreateShortType (result.Type.Resolve (context.TypeResolveContext)));
			foreach (var field in type.GetFields (context.TypeResolveContext)) {
				if (field.IsSynthetic || !field.IsConst)
					continue;
				newSwitch.SwitchSections.Add (new SwitchSection () {
					CaseLabels = {
						new CaseLabel (new MemberReferenceExpression (target.Clone (), field.Name))
					},
					Statements = {
						new BreakStatement ()
					}
				});
			}
			
			newSwitch.SwitchSections.Add (new SwitchSection () {
				CaseLabels = {
					new CaseLabel ()
				},
				Statements = {
					new ThrowStatement (new ObjectCreateExpression (context.CreateShortType ("System", "ArgumentOutOfRangeException")))
				}
			});
			
			using (var script = context.StartScript ()) {
				script.Replace (switchStatement, newSwitch);
			}
		}
		
		static SwitchStatement GetSwitchStatement (RefactoringContext context)
		{
			var switchStatment = context.GetNode<SwitchStatement> ();
			if (switchStatment != null && switchStatment.SwitchSections.Count == 0)
				return switchStatment;
			return null;
		}
	}
}