' 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 Microsoft.CodeAnalysis.Text
Imports Microsoft.CodeAnalysis.VisualBasic.Symbols
Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
'-----------------------------------------------------------------------------
' Contains the definition of the BlockContext
'-----------------------------------------------------------------------------
 
Namespace Microsoft.CodeAnalysis.VisualBasic.Syntax.InternalSyntax
 
    Friend NotInheritable Class DoLoopBlockContext
        Inherits ExecutableStatementContext
 
        Friend Sub New(statement As StatementSyntax, prevContext As BlockContext)
            MyBase.New(If(DirectCast(statement, DoStatementSyntax).WhileOrUntilClause Is Nothing,
                          SyntaxKind.SimpleDoLoopBlock,
                          SyntaxKind.DoWhileLoopBlock),
                       statement,
                       prevContext)
        End Sub
 
        Friend Overrides Function CreateBlockSyntax(statement As StatementSyntax) As VisualBasicSyntaxNode
            Dim doStmt As DoStatementSyntax = Nothing
            Dim loopStmt As LoopStatementSyntax = DirectCast(statement, LoopStatementSyntax)
 
            GetBeginEndStatements(doStmt, loopStmt)
 
            Dim kind As SyntaxKind = BlockKind
 
            If kind = SyntaxKind.DoWhileLoopBlock AndAlso
               loopStmt.WhileOrUntilClause IsNot Nothing Then
 
                Dim whileUntilClause = loopStmt.WhileOrUntilClause
 
                ' Error: the loop has a condition in both header and trailer.
                Dim keyword = Parser.ReportSyntaxError(whileUntilClause.WhileOrUntilKeyword, ERRID.ERR_LoopDoubleCondition)
                Dim errors = whileUntilClause.GetDiagnostics
 
                whileUntilClause = SyntaxFactory.WhileOrUntilClause(whileUntilClause.Kind, DirectCast(keyword, KeywordSyntax), whileUntilClause.Condition)
 
                If errors IsNot Nothing Then
                    whileUntilClause = DirectCast(whileUntilClause.SetDiagnostics(errors), WhileOrUntilClauseSyntax)
                End If
 
                loopStmt = SyntaxFactory.LoopStatement(loopStmt.Kind, loopStmt.LoopKeyword, whileUntilClause)
            End If
 
            If kind = SyntaxKind.SimpleDoLoopBlock AndAlso loopStmt.WhileOrUntilClause IsNot Nothing Then
                ' Set the Do Loop kind now that the bottom is known.
                kind = If(loopStmt.Kind = SyntaxKind.LoopWhileStatement, SyntaxKind.DoLoopWhileBlock, SyntaxKind.DoLoopUntilBlock)
            ElseIf doStmt.WhileOrUntilClause IsNot Nothing Then
                kind = If(doStmt.Kind = SyntaxKind.DoWhileStatement, SyntaxKind.DoWhileLoopBlock, SyntaxKind.DoUntilLoopBlock)
            End If
 
            Dim result = SyntaxFactory.DoLoopBlock(kind, doStmt, Body(), loopStmt)
 
            FreeStatements()
 
            Return result
        End Function
 
        Friend Overrides Function KindEndsBlock(kind As SyntaxKind) As Boolean
            Select Case kind
                Case SyntaxKind.SimpleLoopStatement,
                     SyntaxKind.LoopWhileStatement,
                     SyntaxKind.LoopUntilStatement
                    Return True
                Case Else
                    Return False
            End Select
        End Function
 
    End Class
 
End Namespace