' 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
Imports Microsoft.CodeAnalysis.Text
Imports Microsoft.VisualStudio.Text
Imports Microsoft.VisualStudio.Text.Editor
Imports Microsoft.VisualStudio.Text.Editor.OptionsExtensionMethods
Imports Microsoft.VisualStudio.Text.Operations
 
Namespace Microsoft.CodeAnalysis.Editor.VisualBasic.EndConstructGeneration
    Friend Class SpitLinesResult
        Inherits AbstractEndConstructResult
 
        Private ReadOnly _lines As String()
        Private ReadOnly _startOnCurrentLine As Boolean
 
        Public Sub New(lines As IEnumerable(Of String),
                       Optional startOnCurrentLine As Boolean = False)
            _lines = lines.ToArray()
 
            ' At least one line must be blank for us to know where the caret should land
            Contract.ThrowIfFalse(_lines.Any(Function(line) String.IsNullOrWhiteSpace(line)))
 
            _startOnCurrentLine = startOnCurrentLine
        End Sub
 
        Public Overrides Sub Apply(textView As ITextView,
                                   subjectBuffer As ITextBuffer,
                                   caretPosition As Integer,
                                   smartIndentationService As ISmartIndentationService,
                                   undoHistoryRegistry As ITextUndoHistoryRegistry,
                                   editorOperationsFactoryService As IEditorOperationsFactoryService)
 
            Dim current = subjectBuffer.CurrentSnapshot
            Dim document = current.GetOpenDocumentInCurrentContextWithChanges()
            If document Is Nothing Then
                Return
            End If
 
            Dim bufferNewLine = textView.Options.GetNewLineCharacter()
            Dim currentLine = current.GetLineFromPosition(caretPosition)
 
            ' Join the lines together. As long as we aren't starting this text on the current line, we add a newline at
            ' the front, as we will be inserting this text before the newline of the line the caret is currently on.
            ' This is to guarantee that our _lines array is properly put in the next line, even if we're on the last in
            ' in the buffer
            Dim joinedLines = If(_startOnCurrentLine, "", bufferNewLine) + String.Join(bufferNewLine, _lines)
 
            subjectBuffer.ApplyChange(New TextChange(New TextSpan(caretPosition, 0), joinedLines))
 
            SetIndentForFirstBlankLine(textView, subjectBuffer, smartIndentationService, currentLine)
        End Sub
 
    End Class
End Namespace