' 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.Threading
Imports Microsoft.CodeAnalysis.PooledObjects
Imports Microsoft.CodeAnalysis.Structure
Imports Microsoft.CodeAnalysis.Text
Imports Microsoft.CodeAnalysis.VisualBasic.Syntax

Namespace Microsoft.CodeAnalysis.VisualBasic.Structure
    Friend Class CompilationUnitStructureProvider
        Inherits AbstractSyntaxNodeStructureProvider(Of CompilationUnitSyntax)

        Protected Overrides Sub CollectBlockSpans(previousToken As SyntaxToken,
                                                  compilationUnit As CompilationUnitSyntax,
                                                  spans As ArrayBuilder(Of BlockSpan),
                                                  options As BlockStructureOptions,
                                                  cancellationToken As CancellationToken)
            CollectCommentsRegions(compilationUnit, spans, options)

            If Not compilationUnit.Imports.IsEmpty Then
                Dim startPos = compilationUnit.Imports.First().SpanStart
                Dim endPos = compilationUnit.Imports.Last().Span.End

                Dim span = TextSpan.FromBounds(startPos, endPos)
                spans.AddIfNotNull(CreateBlockSpan(
                    span, span, bannerText:="Imports" & SpaceEllipsis,
                    autoCollapse:=True, type:=BlockTypes.Imports, isCollapsible:=True,
                    isDefaultCollapsed:=options.CollapseImportsWhenFirstOpened))
            End If

            CollectCommentsRegions(compilationUnit.EndOfFileToken.LeadingTrivia, spans)
        End Sub
    End Class
End Namespace