' Licensed to the .NET Foundation under one or more agreements.
' The .NET Foundation licenses this file to you under the MIT license.
' See the LICENSE file in the project root for more information.
 
Imports System.Collections.Immutable
Imports System.Composition
Imports System.Diagnostics.CodeAnalysis
Imports System.Threading
Imports Microsoft.CodeAnalysis.CodeActions
Imports Microsoft.CodeAnalysis.CodeFixes
Imports Microsoft.CodeAnalysis.Diagnostics
Imports Microsoft.CodeAnalysis.Editing
Imports Microsoft.CodeAnalysis.UseIsNullCheck
Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
 
Namespace Microsoft.CodeAnalysis.VisualBasic.UseIsNotExpression
    <ExportCodeFixProvider(LanguageNames.VisualBasic, Name:=PredefinedCodeFixProviderNames.UseIsNotExpression), [Shared]>
    Friend Class VisualBasicUseIsNotExpressionCodeFixProvider
        Inherits SyntaxEditorBasedCodeFixProvider
 
        <ImportingConstructor>
        <SuppressMessage("RoslynDiagnosticsReliability", "RS0033:Importing constructor should be [Obsolete]", Justification:="Used in test code: https://github.com/dotnet/roslyn/issues/42814")>
        Public Sub New()
        End Sub
 
        Public Overrides ReadOnly Property FixableDiagnosticIds As ImmutableArray(Of String) = ImmutableArray.Create(IDEDiagnosticIds.UseIsNotExpressionDiagnosticId)
 
        Public Overrides Function RegisterCodeFixesAsync(context As CodeFixContext) As Task
            RegisterCodeFix(context, VisualBasicAnalyzersResources.Use_IsNot_expression, NameOf(VisualBasicAnalyzersResources.Use_IsNot_expression))
            Return Task.CompletedTask
        End Function
 
        Protected Overrides Function FixAllAsync(
                document As Document,
                diagnostics As ImmutableArray(Of Diagnostic),
                editor As SyntaxEditor,
                cancellationToken As CancellationToken) As Task
 
            For Each diagnostic In diagnostics
                cancellationToken.ThrowIfCancellationRequested()
                ProcessDiagnostic(editor, diagnostic, cancellationToken)
            Next
 
            Return Task.CompletedTask
        End Function
 
        Private Shared Sub ProcessDiagnostic(
                editor As SyntaxEditor,
                diagnostic As Diagnostic,
                cancellationToken As CancellationToken)
            Dim notExpressionLocation = diagnostic.AdditionalLocations(0)
 
            Dim notExpression = DirectCast(notExpressionLocation.FindNode(getInnermostNodeForTie:=True, cancellationToken), UnaryExpressionSyntax)
            Dim operand = notExpression.Operand
 
            Dim replacement As ExpressionSyntax
            If operand.IsKind(SyntaxKind.IsExpression) Then
                Dim isExpression = DirectCast(operand, BinaryExpressionSyntax)
                replacement = SyntaxFactory.IsNotExpression(
                    isExpression.Left,
                    SyntaxFactory.Token(SyntaxKind.IsNotKeyword).WithTriviaFrom(isExpression.OperatorToken),
                    isExpression.Right)
            Else
                Contract.ThrowIfFalse(operand.IsKind(SyntaxKind.TypeOfIsExpression))
                Dim typeOfIsExpression = DirectCast(operand, TypeOfExpressionSyntax)
                replacement = SyntaxFactory.TypeOfIsNotExpression(
                    typeOfIsExpression.TypeOfKeyword,
                    typeOfIsExpression.Expression,
                    SyntaxFactory.Token(SyntaxKind.IsNotKeyword).WithTriviaFrom(typeOfIsExpression.OperatorToken),
                    typeOfIsExpression.Type)
            End If
 
            editor.ReplaceNode(
                notExpression,
                replacement.WithPrependedLeadingTrivia(notExpression.GetLeadingTrivia()))
        End Sub
    End Class
End Namespace