// 
// IntroduceConstantAction.cs
//  
// Author:
//       Mike Krüger <mkrueger@xamarin.com>
// 
// Copyright (c) 2012 Xamarin <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;

using System.Collections.Generic;

namespace ICSharpCode.NRefactory.CSharp.Refactoring
{
	[ContextAction("Introduce constant", Description = "Creates a constant for a non constant primitive expression.")]
	public class IntroduceConstantAction : CodeActionProvider
	{
		public override IEnumerable<CodeAction> GetActions(RefactoringContext context)
		{
			var pexpr = context.GetNode<PrimitiveExpression>();
			if (pexpr == null)
				yield break;

			var visitor = new DeclareLocalVariableAction.SearchNodeVisitior(pexpr);

			if (pexpr.Parent is VariableInitializer) {
				var varDec = pexpr.Parent.Parent as VariableDeclarationStatement;
				if (varDec != null && (varDec.Modifiers & Modifiers.Const) != 0)
					yield break;
				var fieldDecl = pexpr.Parent.Parent as FieldDeclaration;
				if (fieldDecl != null && (fieldDecl.Modifiers & Modifiers.Const) != 0)
					yield break;
			}

			var node = context.GetNode <BlockStatement>();
			if (node != null)
				node.AcceptVisitor(visitor);

			var resolveResult = context.Resolve(pexpr);
			var statement = context.GetNode<Statement>();
			if (statement != null) {
				yield return new CodeAction(context.TranslateString("Create local constant"), script => {
					string name = CreateMethodDeclarationAction.CreateBaseName(pexpr, resolveResult.Type);
					var service = (NamingConventionService)context.GetService(typeof(NamingConventionService));
					if (service != null)
						name = service.CheckName(context, name, AffectedEntity.LocalConstant);
					
					var initializer = new VariableInitializer(name, pexpr.Clone());
					var decl = new VariableDeclarationStatement() {
						Type = context.CreateShortType(resolveResult.Type),
						Modifiers = Modifiers.Const,
						Variables = { initializer }
					};
					
					script.InsertBefore(statement, decl);
					var variableUsage = new IdentifierExpression(name);
					script.Replace(pexpr, variableUsage);
					script.Link(initializer.NameToken, variableUsage);
				}, pexpr);
			}
			
			yield return new CodeAction(context.TranslateString("Create constant field"), script => {
				string name = CreateMethodDeclarationAction.CreateBaseName(pexpr, resolveResult.Type);
				var service = (NamingConventionService)context.GetService(typeof(NamingConventionService));
				if (service != null)
					name = service.CheckName(context, name, AffectedEntity.ConstantField);
				
				var initializer = new VariableInitializer(name, pexpr.Clone());
				
				var decl = new FieldDeclaration() {
					ReturnType = context.CreateShortType(resolveResult.Type),
					Modifiers = Modifiers.Const,
					Variables = { initializer }
				};
				
				var variableUsage = new IdentifierExpression(name);
				script.Replace(pexpr, variableUsage);
				//				script.Link(initializer.NameToken, variableUsage);
				script.InsertWithCursor(context.TranslateString("Create constant"), Script.InsertPosition.Before, decl);
			}, pexpr);

			if (visitor.Matches.Count > 1) {
				yield return new CodeAction(string.Format(context.TranslateString("Create local constant (replace '{0}' occurrences)"), visitor.Matches.Count), script => {
					string name = CreateMethodDeclarationAction.CreateBaseName(pexpr, resolveResult.Type);
					var service = (NamingConventionService)context.GetService(typeof(NamingConventionService));
					if (service != null)
						name = service.CheckName(context, name, AffectedEntity.LocalConstant);
					
					var initializer = new VariableInitializer(name, pexpr.Clone());
					var decl = new VariableDeclarationStatement() {
						Type = context.CreateShortType(resolveResult.Type),
						Modifiers = Modifiers.Const,
						Variables = { initializer }
					};
					
					script.InsertBefore(statement, decl);

					var linkedNodes = new List<AstNode>();
					linkedNodes.Add(initializer.NameToken);
					for (int i = 0; i < visitor.Matches.Count; i++) {
						var identifierExpression = new IdentifierExpression(name);
						linkedNodes.Add(identifierExpression);
						script.Replace(visitor.Matches [i], identifierExpression);
					}
					script.Link(linkedNodes.ToArray ());
				}, pexpr);
				
				yield return new CodeAction(string.Format(context.TranslateString("Create constant field (replace '{0}' occurrences)"), visitor.Matches.Count), script => {
					string name = CreateMethodDeclarationAction.CreateBaseName(pexpr, resolveResult.Type);
					var service = (NamingConventionService)context.GetService(typeof(NamingConventionService));
					if (service != null)
						name = service.CheckName(context, name, AffectedEntity.ConstantField);
					
					var initializer = new VariableInitializer(name, pexpr.Clone());
					
					var decl = new FieldDeclaration() {
						ReturnType = context.CreateShortType(resolveResult.Type),
						Modifiers = Modifiers.Const,
						Variables = { initializer }
					};
					
					var linkedNodes = new List<AstNode>();
					linkedNodes.Add(initializer.NameToken);
					for (int i = 0; i < visitor.Matches.Count; i++) {
						var identifierExpression = new IdentifierExpression(name);
						linkedNodes.Add(identifierExpression);
						script.Replace(visitor.Matches [i], identifierExpression);
					}
					script.InsertWithCursor(context.TranslateString("Create constant"), Script.InsertPosition.Before, decl);
				}, pexpr);
			}
		}
	}
}

