// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.

using System;
using System.Collections.Generic;
using System.Composition;
using System.Diagnostics;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.CodeActions;
using Microsoft.CodeAnalysis.CodeRefactorings;
using Microsoft.CodeAnalysis.CSharp.Extensions;
using Microsoft.CodeAnalysis.CSharp.Symbols;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.CSharp.Utilities;
using Microsoft.CodeAnalysis.FindSymbols;
using Microsoft.CodeAnalysis.Formatting;
using Microsoft.CodeAnalysis.Shared.Extensions;
using Microsoft.CodeAnalysis.Simplification;
using Roslyn.Utilities;
using Microsoft.CodeAnalysis;
using ICSharpCode.NRefactory6.CSharp;
using Microsoft.CodeAnalysis.CSharp;
using ICSharpCode.NRefactory6.CSharp.Refactoring;
using MonoDevelop.Core;

namespace MonoDevelop.CSharp.CodeRefactorings.InlineTemporary
{
	[ExportCodeRefactoringProvider(LanguageNames.CSharp, Name = PredefinedCodeRefactoringProviderNames.InlineTemporary), Shared]
	internal partial class InlineTemporaryCodeRefactoringProvider : CodeRefactoringProvider
	{
		internal static readonly SyntaxAnnotation DefinitionAnnotation = new SyntaxAnnotation();
		internal static readonly SyntaxAnnotation ReferenceAnnotation = new SyntaxAnnotation();
		internal static readonly SyntaxAnnotation InitializerAnnotation = new SyntaxAnnotation();
		internal static readonly SyntaxAnnotation ExpressionToInlineAnnotation = new SyntaxAnnotation();

		public override async Task ComputeRefactoringsAsync(CodeRefactoringContext context)
		{
			var document = context.Document;
			var textSpan = context.Span;
			var cancellationToken = context.CancellationToken;

			if (document.Project.Solution.Workspace.Kind == WorkspaceKind.MiscellaneousFiles)
			{
				return;
			}
			var model = await document.GetSemanticModelAsync (cancellationToken).ConfigureAwait (false);
			if (model.IsFromGeneratedCode (cancellationToken))
				return;
			var root = await document.GetCSharpSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
			var token = root.FindToken(textSpan.Start);

			if (!token.Span.Contains(textSpan))
			{
				return;
			}

			var node = token.Parent;

			if (!node.IsKind(SyntaxKind.VariableDeclarator) ||
				!node.IsParentKind(SyntaxKind.VariableDeclaration) ||
				!node.Parent.IsParentKind(SyntaxKind.LocalDeclarationStatement))
			{
				return;
			}

			var variableDeclarator = (VariableDeclaratorSyntax)node;
			var variableDeclaration = (VariableDeclarationSyntax)variableDeclarator.Parent;
			var localDeclarationStatement = (LocalDeclarationStatementSyntax)variableDeclaration.Parent;

			if (variableDeclarator.Identifier != token ||
				variableDeclarator.Initializer == null ||
				variableDeclarator.Initializer.Value.IsMissing ||
				variableDeclarator.Initializer.Value.IsKind(SyntaxKind.StackAllocArrayCreationExpression))
			{
				return;
			}

			if (localDeclarationStatement.ContainsDiagnostics)
			{
				return;
			}

			var references = await GetReferencesAsync(document, variableDeclarator, cancellationToken).ConfigureAwait(false);
			if (!references.Any())
			{
				return;
			}

			context.RegisterRefactoring(
				new DocumentChangeAction(node.Span, DiagnosticSeverity.Info,
					GettextCatalog.GetString ("Inline temporary variable"),
					(c) => this.InlineTemporaryAsync(document, variableDeclarator, c)));
		}

		private async Task<IEnumerable<ReferenceLocation>> GetReferencesAsync(
			Document document,
			VariableDeclaratorSyntax variableDeclarator,
			CancellationToken cancellationToken)
		{
			var semanticModel = await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
			var local = semanticModel.GetDeclaredSymbol(variableDeclarator, cancellationToken);

			if (local != null)
			{
				var findReferencesResult = await SymbolFinder.FindReferencesAsync(local, document.Project.Solution, cancellationToken).ConfigureAwait(false);
				var locations = findReferencesResult.Single(r => r.Definition == local).Locations;
				if (!locations.Any(loc => semanticModel.SyntaxTree.OverlapsHiddenPosition(loc.Location.SourceSpan, cancellationToken)))
				{
					return locations;
				}
			}

			return SpecializedCollections.EmptyEnumerable<ReferenceLocation>();
		}

		private static bool HasConflict(IdentifierNameSyntax identifier, VariableDeclaratorSyntax variableDeclarator)
		{
			// TODO: Check for more conflict types.
			if (identifier.SpanStart < variableDeclarator.SpanStart)
			{
				return true;
			}

			var identifierNode = identifier
				.Ancestors()
				.TakeWhile(n => n.Kind() == SyntaxKind.ParenthesizedExpression || n.Kind() == SyntaxKind.CastExpression)
				.LastOrDefault();

			if (identifierNode == null)
			{
				identifierNode = identifier;
			}

			if (identifierNode.IsParentKind(SyntaxKind.Argument))
			{
				var argument = (ArgumentSyntax)identifierNode.Parent;
				if (argument.RefOrOutKeyword.Kind() != SyntaxKind.None)
				{
					return true;
				}
			}
			else if (identifierNode.Parent.IsKind(
				SyntaxKind.PreDecrementExpression,
				SyntaxKind.PreIncrementExpression,
				SyntaxKind.PostDecrementExpression,
				SyntaxKind.PostIncrementExpression,
				SyntaxKind.AddressOfExpression))
			{
				return true;
			}
			else if (identifierNode.Parent is AssignmentExpressionSyntax)
			{
				var binaryExpression = (AssignmentExpressionSyntax)identifierNode.Parent;
				if (binaryExpression.Left == identifierNode)
				{
					return true;
				}
			}

			return false;
		}

		private static SyntaxAnnotation CreateConflictAnnotation()
		{
			return ConflictAnnotation.Create(GettextCatalog.GetString ("Conflict(s) detected."));
		}

		private async Task<Document> InlineTemporaryAsync(Document document, VariableDeclaratorSyntax declarator, CancellationToken cancellationToken)
		{
			var workspace = document.Project.Solution.Workspace;

			// Annotate the variable declarator so that we can get back to it later.
			var updatedDocument = await document.ReplaceNodeAsync(declarator, declarator.WithAdditionalAnnotations(DefinitionAnnotation), cancellationToken).ConfigureAwait(false);
			var semanticModel = await updatedDocument.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);

			var variableDeclarator = await FindDeclaratorAsync(updatedDocument, cancellationToken).ConfigureAwait(false);

			// Create the expression that we're actually going to inline.
			var expressionToInline = await CreateExpressionToInlineAsync(variableDeclarator, updatedDocument, cancellationToken).ConfigureAwait(false);

			// Collect the identifier names for each reference.
			var local = (ILocalSymbol)semanticModel.GetDeclaredSymbol(variableDeclarator, cancellationToken);
			var symbolRefs = await SymbolFinder.FindReferencesAsync(local, updatedDocument.Project.Solution, cancellationToken).ConfigureAwait(false);
			var references = symbolRefs.Single(r => r.Definition == local).Locations;
			var syntaxRoot = await updatedDocument.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);

			// Collect the topmost parenting expression for each reference.
			var nonConflictingIdentifierNodes = references
				.Select(loc => (IdentifierNameSyntax)syntaxRoot.FindToken(loc.Location.SourceSpan.Start).Parent)
				.Where(ident => !HasConflict(ident, variableDeclarator));

			// Add referenceAnnotions to identifier nodes being replaced.
			updatedDocument = await updatedDocument.ReplaceNodesAsync(
				nonConflictingIdentifierNodes,
				(o, n) => n.WithAdditionalAnnotations(ReferenceAnnotation),
				cancellationToken).ConfigureAwait(false);

			semanticModel = await updatedDocument.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
			variableDeclarator = await FindDeclaratorAsync(updatedDocument, cancellationToken).ConfigureAwait(false);

			// Get the annotated reference nodes.
			nonConflictingIdentifierNodes = await FindReferenceAnnotatedNodesAsync(updatedDocument, cancellationToken).ConfigureAwait(false);

			var topmostParentingExpressions = nonConflictingIdentifierNodes
				.Select(ident => GetTopMostParentingExpression(ident))
				.Distinct();

			var originalInitializerSymbolInfo = semanticModel.GetSymbolInfo(variableDeclarator.Initializer.Value, cancellationToken);

			// Make each topmost parenting statement or Equals Clause Expressions semantically explicit.
			updatedDocument = await updatedDocument.ReplaceNodesAsync(topmostParentingExpressions, (o, n) => Simplifier.Expand(n, semanticModel, workspace, cancellationToken: cancellationToken), cancellationToken).ConfigureAwait(false);
			semanticModel = await updatedDocument.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
			var semanticModelBeforeInline = semanticModel;

			variableDeclarator = await FindDeclaratorAsync(updatedDocument, cancellationToken).ConfigureAwait(false);
			var scope = GetScope(variableDeclarator);

			var newScope = ReferenceRewriter.Visit(semanticModel, scope, variableDeclarator, expressionToInline, cancellationToken);

			updatedDocument = await updatedDocument.ReplaceNodeAsync(scope, newScope, cancellationToken).ConfigureAwait(false);
			semanticModel = await updatedDocument.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);

			variableDeclarator = await FindDeclaratorAsync(updatedDocument, cancellationToken).ConfigureAwait(false);
			newScope = GetScope(variableDeclarator);
			var conflicts = newScope.GetAnnotatedNodesAndTokens(ConflictAnnotation.Kind);
			var declaratorConflicts = variableDeclarator.GetAnnotatedNodesAndTokens(ConflictAnnotation.Kind);

			// Note that we only remove the local declaration if there weren't any conflicts,
			// unless those conflicts are inside the local declaration.
			if (conflicts.Count() == declaratorConflicts.Count())
			{
				// Certain semantic conflicts can be detected only after the reference rewriter has inlined the expression
				var newDocument = await DetectSemanticConflicts(updatedDocument,
					semanticModel,
					semanticModelBeforeInline,
					originalInitializerSymbolInfo,
					cancellationToken).ConfigureAwait(false);

				if (updatedDocument == newDocument)
				{
					// No semantic conflicts, we can remove the definition.
					updatedDocument = await updatedDocument.ReplaceNodeAsync(newScope, RemoveDeclaratorFromScope(variableDeclarator, newScope), cancellationToken).ConfigureAwait(false);
				}
				else
				{
					// There were some semantic conflicts, don't remove the definition.
					updatedDocument = newDocument;
				}
			}

			return updatedDocument;
		}

		private static async Task<VariableDeclaratorSyntax> FindDeclaratorAsync(Document document, CancellationToken cancellationToken)
		{
			return await FindNodeWithAnnotationAsync<VariableDeclaratorSyntax>(document, DefinitionAnnotation, cancellationToken).ConfigureAwait(false);
		}

		private static async Task<ExpressionSyntax> FindInitializerAsync(Document document, CancellationToken cancellationToken)
		{
			return await FindNodeWithAnnotationAsync<ExpressionSyntax>(document, InitializerAnnotation, cancellationToken).ConfigureAwait(false);
		}

		private static async Task<T> FindNodeWithAnnotationAsync<T>(Document document, SyntaxAnnotation annotation, CancellationToken cancellationToken)
			where T : SyntaxNode
		{
			var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
			return root
				.GetAnnotatedNodesAndTokens(annotation)
				.Single()
				.AsNode() as T;
		}

		private static async Task<IEnumerable<IdentifierNameSyntax>> FindReferenceAnnotatedNodesAsync(Document document, CancellationToken cancellationToken)
		{
			var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
			return FindReferenceAnnotatedNodes(root);
		}

		private static IEnumerable<IdentifierNameSyntax> FindReferenceAnnotatedNodes(SyntaxNode root)
		{
			var annotatedNodesAndTokens = root.GetAnnotatedNodesAndTokens(ReferenceAnnotation);
			foreach (var nodeOrToken in annotatedNodesAndTokens)
			{
				if (nodeOrToken.IsNode && nodeOrToken.AsNode().IsKind(SyntaxKind.IdentifierName))
				{
					yield return (IdentifierNameSyntax)nodeOrToken.AsNode();
				}
			}
		}

		private SyntaxNode GetScope(VariableDeclaratorSyntax variableDeclarator)
		{
			var variableDeclaration = (VariableDeclarationSyntax)variableDeclarator.Parent;
			var localDeclaration = (LocalDeclarationStatementSyntax)variableDeclaration.Parent;
			var scope = localDeclaration.Parent;

			while (scope.IsKind(SyntaxKind.LabeledStatement))
			{
				scope = scope.Parent;
			}

			var parentExpressions = scope.AncestorsAndSelf().OfType<ExpressionSyntax>();
			if (parentExpressions.Any())
			{
				scope = parentExpressions.LastOrDefault().Parent;
			}

			return scope;
		}

		private VariableDeclaratorSyntax FindDeclarator(SyntaxNode node)
		{
			var annotatedNodesOrTokens = node.GetAnnotatedNodesAndTokens(DefinitionAnnotation).ToList();

			return (VariableDeclaratorSyntax)annotatedNodesOrTokens.First().AsNode();
		}

		private SyntaxTriviaList GetTriviaToPreserve(SyntaxTriviaList syntaxTriviaList)
		{
			return ShouldPreserve(syntaxTriviaList) ? syntaxTriviaList : default(SyntaxTriviaList);
		}

		private static bool ShouldPreserve(SyntaxTriviaList trivia)
		{
			return trivia.Any(
				t => t.Kind() == SyntaxKind.SingleLineCommentTrivia ||
				t.Kind() == SyntaxKind.MultiLineCommentTrivia ||
				t.IsDirective);
		}

		private SyntaxNode RemoveDeclaratorFromVariableList(VariableDeclaratorSyntax variableDeclarator, VariableDeclarationSyntax variableDeclaration)
		{
			Debug.Assert(variableDeclaration.Variables.Count > 1);
			Debug.Assert(variableDeclaration.Variables.Contains(variableDeclarator));

			var localDeclaration = (LocalDeclarationStatementSyntax)variableDeclaration.Parent;
			var scope = GetScope(variableDeclarator);

			var newLocalDeclaration = localDeclaration.RemoveNode(variableDeclarator, SyntaxRemoveOptions.KeepNoTrivia)
				.WithAdditionalAnnotations(Formatter.Annotation);

			return scope.ReplaceNode(localDeclaration, newLocalDeclaration);
		}

		private SyntaxNode RemoveDeclaratorFromScope(VariableDeclaratorSyntax variableDeclarator, SyntaxNode scope)
		{
			var variableDeclaration = (VariableDeclarationSyntax)variableDeclarator.Parent;

			// If there is more than one variable declarator, remove this one from the variable declaration.
			if (variableDeclaration.Variables.Count > 1)
			{
				return RemoveDeclaratorFromVariableList(variableDeclarator, variableDeclaration);
			}

			var localDeclaration = (LocalDeclarationStatementSyntax)variableDeclaration.Parent;

			// There's only one variable declarator, so we'll remove the local declaration
			// statement entirely. This means that we'll concatenate the leading and trailing
			// trivia of this declaration and move it to the next statement.
			var leadingTrivia = localDeclaration
				.GetLeadingTrivia()
				.Reverse()
				.SkipWhile(t => t.MatchesKind(SyntaxKind.WhitespaceTrivia))
				.Reverse()
				.ToSyntaxTriviaList();

			var trailingTrivia = localDeclaration
				.GetTrailingTrivia()
				.SkipWhile(t => t.MatchesKind(SyntaxKind.WhitespaceTrivia, SyntaxKind.EndOfLineTrivia))
				.ToSyntaxTriviaList();

			var newLeadingTrivia = leadingTrivia.Concat(trailingTrivia);

			var nextToken = localDeclaration.GetLastToken().GetNextTokenOrEndOfFile();
			var newNextToken = nextToken.WithPrependedLeadingTrivia(newLeadingTrivia)
				.WithAdditionalAnnotations(Formatter.Annotation);

			var newScope = scope.ReplaceToken(nextToken, newNextToken);

			var newLocalDeclaration = (LocalDeclarationStatementSyntax)FindDeclarator(newScope).Parent.Parent;

			// If the local is parented by a label statement, we can't remove this statement. Instead,
			// we'll replace the local declaration with an empty expression statement.
			if (newLocalDeclaration.IsParentKind(SyntaxKind.LabeledStatement))
			{
				var labeledStatement = (LabeledStatementSyntax)newLocalDeclaration.Parent;
				var newLabeledStatement = labeledStatement.ReplaceNode(newLocalDeclaration, SyntaxFactory.ParseStatement(""));

				return newScope.ReplaceNode(labeledStatement, newLabeledStatement);
			}

			return newScope.RemoveNode(newLocalDeclaration, SyntaxRemoveOptions.KeepNoTrivia);
		}

		private ExpressionSyntax SkipRedundantExteriorParentheses(ExpressionSyntax expression)
		{
			while (expression.IsKind(SyntaxKind.ParenthesizedExpression))
			{
				var parenthesized = (ParenthesizedExpressionSyntax)expression;
				if (parenthesized.Expression == null ||
					parenthesized.Expression.IsMissing)
				{
					break;
				}

				if (parenthesized.Expression.IsKind(SyntaxKind.ParenthesizedExpression) ||
					parenthesized.Expression.IsKind(SyntaxKind.IdentifierName))
				{
					expression = parenthesized.Expression;
				}
				else
				{
					break;
				}
			}

			return expression;
		}

		public static IEnumerable<SyntaxTrivia> SkipInitialWhitespace(SyntaxTriviaList triviaList)
		{
			return triviaList.SkipWhile(t => t.Kind() == SyntaxKind.WhitespaceTrivia);
		}

		private async Task<ExpressionSyntax> CreateExpressionToInlineAsync(
			VariableDeclaratorSyntax variableDeclarator,
			Document document,
			CancellationToken cancellationToken)
		{
			var updatedDocument = document;

			var expression = SkipRedundantExteriorParentheses(variableDeclarator.Initializer.Value);
			var semanticModel = await updatedDocument.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
			var localSymbol = (ILocalSymbol)semanticModel.GetDeclaredSymbol(variableDeclarator, cancellationToken);
			var newExpression = InitializerRewriter.Visit(expression, localSymbol, semanticModel);

			// If this is an array initializer, we need to transform it into an array creation
			// expression for inlining.
			if (newExpression.Kind() == SyntaxKind.ArrayInitializerExpression)
			{
				var arrayType = (ArrayTypeSyntax)localSymbol.Type.GenerateTypeSyntax();
				var arrayInitializer = (InitializerExpressionSyntax)newExpression;

				// Add any non-whitespace trailing trivia from the equals clause to the type.
				var equalsToken = variableDeclarator.Initializer.EqualsToken;
				if (equalsToken.HasTrailingTrivia)
				{
					var trailingTrivia = SkipInitialWhitespace(equalsToken.TrailingTrivia);
					if (trailingTrivia.Any())
					{
						arrayType = arrayType.WithTrailingTrivia(trailingTrivia);
					}
				}

				newExpression = SyntaxFactory.ArrayCreationExpression(arrayType, arrayInitializer);
			}

			newExpression = newExpression.WithAdditionalAnnotations(InitializerAnnotation);

			updatedDocument = await updatedDocument.ReplaceNodeAsync(variableDeclarator.Initializer.Value, newExpression, cancellationToken).ConfigureAwait(false);
			semanticModel = await updatedDocument.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
			newExpression = await FindInitializerAsync(updatedDocument, cancellationToken).ConfigureAwait(false);
			var newVariableDeclarator = await FindDeclaratorAsync(updatedDocument, cancellationToken).ConfigureAwait(false);
			localSymbol = (ILocalSymbol)semanticModel.GetDeclaredSymbol(newVariableDeclarator, cancellationToken);

			bool wasCastAdded;
			var explicitCastExpression = newExpression.CastIfPossible(localSymbol.Type, newVariableDeclarator.SpanStart, semanticModel, out wasCastAdded);

			if (wasCastAdded)
			{
				updatedDocument = await updatedDocument.ReplaceNodeAsync(newExpression, explicitCastExpression, cancellationToken).ConfigureAwait(false);
				semanticModel = await updatedDocument.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
				newVariableDeclarator = await FindDeclaratorAsync(updatedDocument, cancellationToken).ConfigureAwait(false);
			}

			// Now that the variable declarator is normalized, make its initializer
			// value semantically explicit.
			newExpression = await Simplifier.ExpandAsync(newVariableDeclarator.Initializer.Value, updatedDocument, cancellationToken: cancellationToken).ConfigureAwait(false);
			return newExpression.WithAdditionalAnnotations(ExpressionToInlineAnnotation);
		}

		private static SyntaxNode GetTopMostParentingExpression(ExpressionSyntax expression)
		{
			return expression.AncestorsAndSelf().OfType<ExpressionSyntax>().Last();
		}

		private static async Task<Document> DetectSemanticConflicts(
			Document inlinedDocument,
			SemanticModel newSemanticModelForInlinedDocument,
			SemanticModel semanticModelBeforeInline,
			SymbolInfo originalInitializerSymbolInfo,
			CancellationToken cancellationToken)
		{
			// In this method we detect if inlining the expression introduced the following semantic change:
			// The symbol info associated with any of the inlined expressions does not match the symbol info for original initializer expression prior to inline.

			// If any semantic changes were introduced by inlining, we update the document with conflict annotations.
			// Otherwise we return the given inlined document without any changes.

			var syntaxRootBeforeInline = await semanticModelBeforeInline.SyntaxTree.GetRootAsync(cancellationToken).ConfigureAwait(false);

			// Get all the identifier nodes which were replaced with inlined expression.
			var originalIdentifierNodes = FindReferenceAnnotatedNodes(syntaxRootBeforeInline).ToList ();

			if (!originalIdentifierNodes.Any())
			{
				// No conflicts
				return inlinedDocument;
			}

			// Get all the inlined expression nodes.
			var syntaxRootAfterInline = await inlinedDocument.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
			var inlinedExprNodes = syntaxRootAfterInline.GetAnnotatedNodesAndTokens(ExpressionToInlineAnnotation).ToList ();
			Debug.Assert(originalIdentifierNodes.Count() == inlinedExprNodes.Count());

			Dictionary<SyntaxNode, SyntaxNode> replacementNodesWithChangedSemantics = null;
			using (var originalNodesEnum = originalIdentifierNodes.GetEnumerator())
			{
				using (var inlinedNodesOrTokensEnum = inlinedExprNodes.GetEnumerator())
				{
					while (originalNodesEnum.MoveNext())
					{
						inlinedNodesOrTokensEnum.MoveNext();
						var originalNode = originalNodesEnum.Current;

						// expressionToInline is Parenthesized prior to replacement, so get the parenting parenthesized expression.
						var inlinedNode = (ExpressionSyntax)inlinedNodesOrTokensEnum.Current.Parent;
						Debug.Assert(inlinedNode.IsKind(SyntaxKind.ParenthesizedExpression));

						// inlinedNode is the expanded form of the actual initializer expression in the original document.
						// We have annotated the inner initializer with a special syntax annotation "InitializerAnnotation".
						// Get this annotated node and compute the symbol info for this node in the inlined document.
						var innerInitializerInInlineNodeorToken = inlinedNode.GetAnnotatedNodesAndTokens(InitializerAnnotation).First();

						ExpressionSyntax innerInitializerInInlineNode = (ExpressionSyntax)(innerInitializerInInlineNodeorToken.IsNode ?
							innerInitializerInInlineNodeorToken.AsNode() :
							innerInitializerInInlineNodeorToken.AsToken().Parent);
						var newInializerSymbolInfo = newSemanticModelForInlinedDocument.GetSymbolInfo(innerInitializerInInlineNode, cancellationToken);

						// Verification: The symbol info associated with any of the inlined expressions does not match the symbol info for original initializer expression prior to inline.
						if (!SpeculationAnalyzer.SymbolInfosAreCompatible(originalInitializerSymbolInfo, newInializerSymbolInfo, performEquivalenceCheck: true))
						{
							newInializerSymbolInfo = newSemanticModelForInlinedDocument.GetSymbolInfo(inlinedNode, cancellationToken);
							if (!SpeculationAnalyzer.SymbolInfosAreCompatible(originalInitializerSymbolInfo, newInializerSymbolInfo, performEquivalenceCheck: true))
							{
								if (replacementNodesWithChangedSemantics == null)
								{
									replacementNodesWithChangedSemantics = new Dictionary<SyntaxNode, SyntaxNode>();
								}

								replacementNodesWithChangedSemantics.Add(inlinedNode, originalNode);
							}
						}
					}
				}
			}

			if (replacementNodesWithChangedSemantics == null)
			{
				// No conflicts.
				return inlinedDocument;
			}

			// Replace the conflicting inlined nodes with the original nodes annotated with conflict annotation.
			Func<SyntaxNode, SyntaxNode, SyntaxNode> conflictAnnotationAdder =
				(SyntaxNode oldNode, SyntaxNode newNode) =>
				newNode.WithAdditionalAnnotations(ConflictAnnotation.Create(GettextCatalog.GetString ("Conflict(s) detected.")));

			return await inlinedDocument.ReplaceNodesAsync(replacementNodesWithChangedSemantics.Keys, conflictAnnotationAdder, cancellationToken).ConfigureAwait(false);
		}
	}
}