' 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.Composition
Imports System.Threading
Imports Microsoft.CodeAnalysis.Highlighting
Imports Microsoft.CodeAnalysis.Host.Mef
Imports Microsoft.CodeAnalysis.Text
Imports Microsoft.CodeAnalysis.VisualBasic.Syntax

Namespace Microsoft.CodeAnalysis.VisualBasic.KeywordHighlighting
    <ExportHighlighter(LanguageNames.VisualBasic), [Shared]>
    Friend Class EnumBlockHighlighter
        Inherits AbstractKeywordHighlighter(Of SyntaxNode)

        <ImportingConstructor>
        <Obsolete(MefConstruction.ImportingConstructorMessage, True)>
        Public Sub New()
        End Sub

        Protected Overloads Overrides Sub AddHighlights(node As SyntaxNode, highlights As List(Of TextSpan), cancellationToken As CancellationToken)
            Dim endBlockStatement = TryCast(node, EndBlockStatementSyntax)
            If endBlockStatement IsNot Nothing Then
                If endBlockStatement.Kind <> SyntaxKind.EndEnumStatement Then
                    Return
                End If
            End If

            Dim enumBlock = node.GetAncestor(Of EnumBlockSyntax)()
            If enumBlock Is Nothing Then
                Return
            End If

            With enumBlock
                With .EnumStatement
                    Dim firstKeyword = If(.Modifiers.Count > 0, .Modifiers.First(), .EnumKeyword)
                    highlights.Add(TextSpan.FromBounds(firstKeyword.SpanStart, .EnumKeyword.Span.End))
                End With

                highlights.Add(.EndEnumStatement.Span)
            End With
        End Sub
    End Class
End Namespace