ConfigManager: Test write access for config paths

Filesystem/File.vb

@@ -24,6 +24,8 @@ Public Class File
     Private ReadOnly _logger As Logger
     Private ReadOnly _logConfig As LogConfig
 
+    Private Const FILE_NAME_ACCESS_TEST = "accessTest.txt"
+
     Public Sub New(LogConfig As LogConfig)
         _logConfig = LogConfig
         _logger = LogConfig.GetLogger()
@@ -94,6 +96,55 @@ Public Class File
         IO.File.Move(FilePath, Path.Combine(Directory, oFileInfo.Name))
     End Sub
 
+    ''' <summary>
+    ''' Tries to create a directory and returns its path.
+    ''' Returns a temp path if `DirectoryPath` can not be created or written to.
+    ''' </summary>
+    ''' <param name="DirectoryPath">The directory to create</param>
+    ''' <param name="TestWriteAccess">Should a write access test be performed?</param>
+    ''' <returns>The used path</returns>
+    Public Function CreateDirectory(DirectoryPath As String, Optional TestWriteAccess As Boolean = True) As String
+        Dim oFinalPath As String
+        If Directory.Exists(DirectoryPath) Then
+            _logger.Debug("Directory {0} already exists. Skipping.", DirectoryPath)
+            oFinalPath = DirectoryPath
+        Else
+            Try
+                Directory.CreateDirectory(DirectoryPath)
+                oFinalPath = DirectoryPath
+            Catch ex As Exception
+                _logger.Error(ex)
+                _logger.Warn("Directory {0} could not be created. Temp path will be used instead.", DirectoryPath)
+                oFinalPath = Path.GetTempPath()
+            End Try
+        End If
+
+        If TestWriteAccess AndAlso Not TestPathIsWritable(DirectoryPath) Then
+            _logger.Warn("Directory {0} is not writable. Temp path will be used instead.", DirectoryPath)
+            oFinalPath = Path.GetTempPath()
+        Else
+            oFinalPath = DirectoryPath
+        End If
+
+        _logger.Debug("Using path {0}", oFinalPath)
+
+        Return oFinalPath
+    End Function
+
+    Public Function TestPathIsWritable(DirectoryPath As String) As Boolean
+        Try
+            Dim fileAccessPath = Path.Combine(DirectoryPath, FILE_NAME_ACCESS_TEST)
+            Using fs As FileStream = IO.File.Create(fileAccessPath)
+                fs.WriteByte(0)
+            End Using
+
+            IO.File.Delete(fileAccessPath)
+            Return True
+        Catch ex As Exception
+            Return False
+        End Try
+    End Function
+
     Public Function TestPathIsDirectory(Path As String) As Boolean
         If Not Directory.Exists(Path) Then
             Return False

Filesystem/Filesystem.vbproj

@@ -79,7 +79,9 @@
     <Compile Include="DocumentObject.vb" />
     <Compile Include="FileContainer.vb" />
     <Compile Include="Encryption.vb" />
-    <Compile Include="File.vb" />
+    <Compile Include="File.vb">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Compile>
     <Compile Include="FileContainerInner.vb" />
     <Compile Include="FileWatcher.vb" />
     <Compile Include="FileWatcherFilters.vb" />