/// <exception cref="FileNotFoundException">If no files are available.</exception>
/// <exception cref="DirectoryNotFoundException">If the PDF directory is missing or could not be read (e. g. due to network issues).</exception>"
private string GetNextFileName(bool includeCurrentFile = false)
{
IEnumerable <string> availableFiles = repository.ListAllFiles();
if (availableFiles == null)
{
// connection lost or
currentFile = null;
throw new DirectoryNotFoundException("Could not read directory.");
}
if (!availableFiles.Any())
{
currentFile = null;
throw new FileNotFoundException("No files available!");
}
if (currentFile != null)
{
// determine which files come alphabetically after currentFile
IEnumerable <string> alphabeticallyNextFiles;
if (includeCurrentFile)
{
// ">=" ensures that currentFile itself is included if available
alphabeticallyNextFiles = availableFiles.Where(f => f.CompareTo(currentFile) >= 0);
}
else
{
alphabeticallyNextFiles = availableFiles.Where(f => f.CompareTo(currentFile) > 0);
}
if (alphabeticallyNextFiles.Any())
{
// if there are any files after currentFile, use the next file (i.e. the file that comes first in the alphabet)
currentFile = alphabeticallyNextFiles.Min();
}
else
{
// otherwise, take the first file (i.e. roll over to the beginning)
currentFile = availableFiles.Min();
}
}
else
{
// First Call -> return first file name in the culture-dependent alphabet
currentFile = availableFiles.Min();
}
return(currentFile);
}
