/// <summary>
/// Splits the specified repository by creating a new repository containing only specified directories.
/// </summary>
/// <param name="repository">Directory path for the repository to split.</param>
public void Split(string repository)
{
#region Pre-Verifications
// TODO: Consider moving these into directory helper
// verify repository directory exists
if (!Directory.Exists(repository))
{
throw new DirectoryNotFoundException(repository);
}
// verify we have a name for the new repository
if (string.IsNullOrWhiteSpace(SplitRepositoryName))
{
throw new Exception("The new repository name is invalid.");
}
// verify we know which directories to split into the new repository
if (DirectoriesToRetain == null || DirectoriesToRetain.Count() == 0)
{
throw new Exception("No directories will be included in the new repository.");
}
string parentDirectory = Directory.GetParent(repository).FullName;
string newRepository = string.Format("{0}\\{1}", parentDirectory, SplitRepositoryName);
// verify new repository directory does not already exist
if (Directory.Exists(newRepository))
{
throw new Exception("The new repository directory already exists.");
}
#endregion Pre-Verifications
// clone existing repository into to-be new repository
Git.WorkingDirectory = parentDirectory;
Git.Execute(string.Format("clone {0} {1}", repository, newRepository));
// protect existing repository from changes
Git.WorkingDirectory = newRepository;
Git.Execute("remote rm origin");
// identify directories to remove
var directoriesToRemove = GetDirectoriesToRemove(newRepository);
// remove all directories except for the the directories to include
// TODO: Consider offering alternative filter-branch options (e.g. besides index-filter)
Git.Execute(string.Format("filter-branch --index-filter \"git rm -r --cached --ignore-unmatch {0}\" --prune-empty -f -- --all", directoriesToRemove.Implode(" ")));
Git.Execute("for-each-ref --format=\" % (refname)\" refs/original/ | xargs -n 1 git update-ref -d");
// add each removed subdirectory into .gitignore
// TODO: Ensure each directory is on its own line in .gitignore
File.AppendAllLines(string.Format("{0}\\.gitignore", newRepository), directoriesToRemove.Select(sdr => DirectoryHelper.AppendDirectorySeparatorChar(sdr, true)));
// commit removal and invoke git garbage collection
// TODO: Support custom commit message
Git.Execute("commit -a -m \"Removed unnecessary directories from git history and added them to .gitignore\"");
Git.Execute("gc");
// TODO: Support removal of directories that were split into new repository from original repository
}
/// <summary>
/// Gets the directories, including subdirectories if IncludeSubdirectories is true, to remove from the new repository.
/// </summary>
/// <param name="newRepository">The path to the new repository.</param>
/// <returns></returns>
public IEnumerable <string> GetDirectoriesToRemove(string newRepository)
{
// get all directories for removal, and exclude git directories, as well as directories (and their subdirectories) to retain
var directories = new List <string>(DirectoryHelper.GetDirectories(newRepository, "*", true ? SearchOption.AllDirectories : SearchOption.TopDirectoryOnly));
directories.RemoveAll(d => d.StartsWith(".git")); // always retain git directories
directories.RemoveAll(d => DirectoriesToRetain.Any(dtr => d == dtr || d.StartsWith(dtr + Path.AltDirectorySeparatorChar)));
// ensure parent directories for directories to retain are also retained
// TODO: Refactor this into a directory helper
foreach (var directory in DirectoriesToRetain)
{
string path;
int index = directory.LastIndexOf(Path.AltDirectorySeparatorChar);
while (index > 0)
{
path = directory.Substring(0, index);
if (directories.Contains(path))
{
directories.Remove(path);
}
index = path.LastIndexOf(Path.AltDirectorySeparatorChar);
}
}
// for all directories to remove, their subdirectories will automatically be removed,
// so no need to duplicate the effort by including them in the filter-branch match
// TODO: Refactor this into directory helper and for better performance
bool keepGoing = true;
List <string> alreadyScanned = new List <string>();
var directoriesCopy = directories.ToList();
while (keepGoing)
{
keepGoing = false;
foreach (var dc in directoriesCopy)
{
if (!DirectoriesToRetain.Any(dtr => dtr.StartsWith(dc)))
{
directories.RemoveAll(d => d.StartsWith(dc + Path.AltDirectorySeparatorChar));
alreadyScanned.Add(dc);
keepGoing = true;
break;
}
}
if (keepGoing)
{
directoriesCopy = directories.ToList();
directoriesCopy.RemoveAll(d => alreadyScanned.Contains(d));
}
}
return(directories);
}
