public static bool TryGetCommonRootDirectory(List <DirectoryPathAbsolute> listOfPaths, out DirectoryPathAbsolute commonRootDirectory)
{
commonRootDirectory = DirectoryPathAbsolute.Empty;
if (listOfPaths == null)
{
return(false);
}
if (listOfPaths.Count == 0)
{
return(false);
}
// If the list contains a path null or empty -> no commonRootDirectory
foreach (DirectoryPathAbsolute path in listOfPaths)
{
if (PathHelper.IsNullOrEmpty(path))
{
return(false);
}
}
if (listOfPaths.Count == 1)
{
commonRootDirectory = listOfPaths[0];
return(true);
}
//
// Case where all paths are identical
//
bool allPathsAreIdentical = true;
for (int i = 1; i < listOfPaths.Count; i++)
{
if (!listOfPaths[0].Equals(listOfPaths[i]))
{
allPathsAreIdentical = false;
break;
}
}
if (allPathsAreIdentical)
{
commonRootDirectory = listOfPaths[0];
return(true);
}
//
// Case where some paths are not on the same drive
//
for (int i = 1; i < listOfPaths.Count; i++)
{
if (string.Compare(listOfPaths[0].Drive, listOfPaths[i].Drive, true) != 0)
{
return(false);
}
}
//
// Build listOfSplittedPaths
//
List <string[]> listOfSplittedPaths = new List <string[]>();
int maxDeepForRootDir = int.MaxValue;
foreach (DirectoryPathAbsolute path in listOfPaths)
{
string[] pathSplitted = path.Path.Split(new char[] { Path.DirectorySeparatorChar });
if (pathSplitted.Length < maxDeepForRootDir)
{
maxDeepForRootDir = pathSplitted.Length;
}
listOfSplittedPaths.Add(pathSplitted);
}
//
// Compute commonRootDirPath from listOfSplittedPaths
//
string commonRootDirPath = string.Empty;
for (int i = 0; i < maxDeepForRootDir; i++)
{
string current = listOfSplittedPaths[0][i];
foreach (string[] pathSplitted in listOfSplittedPaths)
{
if (string.Compare(pathSplitted[i], current, true) != 0)
{
commonRootDirectory = new DirectoryPathAbsolute(commonRootDirPath);
return(true);
}
}
if (i == 0)
{
commonRootDirPath += current;
}
else
{
commonRootDirPath += Path.DirectorySeparatorChar + current;
}
}
commonRootDirectory = new DirectoryPathAbsolute(commonRootDirPath);
return(true);
}