Repo Migrate Folder With History

RepoMigrate.cs

void Main()
{
	var originalRepo = "git@github.com:_**_/_**_.git";
	var originalRepoBranch = "master";
	var newRepo = "git@github.com:_**_/_**_.git";
	var newRepoBranch = "master";
	var workInProgressDir = @"C:\Temp\RepoCopy";
	var relativeFolderToMigrate = "src/path";
	MigrateRepo(originalRepo, originalRepoBranch, newRepo, newRepoBranch, workInProgressDir, relativeFolderToMigrate);
}

private void MigrateRepo(string originalRepo, string originalRepoBranch, string newRepo, string newRepoBranch, string workInProgressDir, string relativeFolderToMigrate)
{
	var runId = Guid.NewGuid().ToString();
	Console.WriteLine("-----------------------------");
	Console.WriteLine($"RunId: {runId}");
	var runDirectory = Path.Combine(workInProgressDir, runId);
	var fromRepoPath = Path.Combine(runDirectory, "FromRepo");
	var fromRepoCleanUpPath = Path.Combine(runDirectory, "FromRepoCleanUp");
	var toRepoPath = Path.Combine(runDirectory, "ToRepo");

	EnsureDirectoryClean(runDirectory);

	Console.WriteLine("-----------------------------");
	Console.WriteLine($"Creating filtered version of {originalRepo}");
	RunGit(workInProgressDir, $"clone {originalRepo} {fromRepoPath}");		
	RunGit(fromRepoPath, "remote rm origin");
	RunGit(fromRepoPath, $"checkout {originalRepoBranch}");
	RunGit(fromRepoPath, $"filter-branch --subdirectory-filter {relativeFolderToMigrate} -- --all");

	Console.WriteLine("-----------------------------");
	Console.WriteLine($"Moving {fromRepoPath} content back into the relative folder of {relativeFolderToMigrate}");

	var subDirs = Directory.GetDirectories(fromRepoPath);
	var subFiles = Directory.GetFiles(fromRepoPath);

	var newLocationRoot = Path.Combine(fromRepoPath, relativeFolderToMigrate);
	Console.WriteLine($"Creating Dir: {newLocationRoot}"); 
	Directory.CreateDirectory(newLocationRoot);

	foreach (var subDir in subDirs)
	{
		if(subDir.EndsWith(".git")) continue;
		var relativeSubDir = subDir.Replace(fromRepoPath, "").Substring(1);		
		var newLocation = Path.Combine(fromRepoPath, relativeFolderToMigrate, relativeSubDir);
		Console.WriteLine($"Moving Dir: {subDir} -> {newLocation}");
		Directory.Move(subDir, newLocation);
	}

	foreach (var subFile in subFiles)
	{
		var relativeSubFile = subFile.Replace(fromRepoPath, "").Substring(1);		
		var newLocation = Path.Combine(fromRepoPath, relativeFolderToMigrate, relativeSubFile);
		Console.WriteLine($"Moving File: {subFile} -> {newLocation}");
		File.Move(subFile, newLocation);
	}
	
	RunGit(fromRepoPath, $"add .");
	RunGit(fromRepoPath, $"commit -m \"Revert folder structure post filter\"");
	
	Console.WriteLine("-----------------------------");
	Console.WriteLine($"Merging filtered version of {originalRepo} into {newRepo}");
	RunGit(workInProgressDir, $"clone {newRepo} {toRepoPath}");
	RunGit(toRepoPath, $"remote add FromRepo {fromRepoPath}");
	RunGit(toRepoPath, $"pull FromRepo {originalRepoBranch}", true);
	RunGit(toRepoPath, $"branch feature/RepoMigrate origin/{newRepoBranch}");
	RunGit(toRepoPath, "checkout feature/RepoMigrate");
	RunGit(toRepoPath, $"merge FromRepo/{originalRepoBranch} --allow-unrelated-histories");
	RunGit(toRepoPath, "remote rm FromRepo");	
	RunGit(toRepoPath, "push origin feature/RepoMigrate");
	
	Console.WriteLine("-----------------------------");
	Console.WriteLine($"Cleaning {originalRepo}");
	RunGit(workInProgressDir, $"clone {originalRepo} {fromRepoCleanUpPath}");
	RunGit(fromRepoCleanUpPath, "branch feature/RepoMigrate");
	RunGit(fromRepoCleanUpPath, "checkout feature/RepoMigrate");
	Directory.Delete(Path.Combine(fromRepoCleanUpPath, relativeFolderToMigrate), true);
	RunGit(fromRepoCleanUpPath, $"add .");
	RunGit(fromRepoCleanUpPath, $"commit -a -m \"Remove migrated folder {relativeFolderToMigrate} as moved to {newRepo}\"");
	RunGit(fromRepoCleanUpPath, "push origin feature/RepoMigrate");
}

private void RunGit(string workingDirectory, string args, bool ignoreError = false)
{
	RunCommand(workingDirectory, "git", args, ignoreError);
}

private void RunCommand(string workingDirectory, string fileName, string args, bool ignoreError = false)
{
	Process process = new Process();
	Console.WriteLine("-----------------------------");
	Console.WriteLine($"WorkingDirectory: {workingDirectory}");
	Console.WriteLine($"Exec: {fileName} {args}");
	
	try
	{
		process.StartInfo.FileName = fileName;
		process.StartInfo.WorkingDirectory = workingDirectory;
		process.StartInfo.Arguments = args;
		process.StartInfo.RedirectStandardError = true;
		process.StartInfo.RedirectStandardOutput = true;
		process.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
		process.StartInfo.CreateNoWindow = true;
		process.StartInfo.UseShellExecute = false;
		process.EnableRaisingEvents = false;
		process.OutputDataReceived += (sender, eventArgs) => WriteConsoleOutput("stdOut", eventArgs);
		process.ErrorDataReceived += (sender, eventArgs) => WriteConsoleOutput("stdErr", eventArgs);
		process.Start();
		process.BeginOutputReadLine();
		process.BeginErrorReadLine();
		process.WaitForExit();
		
		if(process.ExitCode == 0)
		{
			Console.WriteLine($"SUCCESS: Process exited with code of {process.ExitCode}");
		}
		else if (ignoreError)
		{
			Console.WriteLine($"WARN: Process exited with code of {process.ExitCode}");
		}
		else
		{
			Console.WriteLine($"ERROR: Process exited with code of {process.ExitCode}");
			throw new Exception($"Process exited with non-zero exit code of {process.ExitCode}");
		}
	}
	finally
	{
		process.Close();
	}
}

private void WriteConsoleOutput(string type, DataReceivedEventArgs eventArgs)
{
	if (eventArgs.Data != null)
	{
		Console.WriteLine($"{type} : {eventArgs.Data}");
	}
}

private void EnsureDirectoryClean(string path)
{
	if (Directory.Exists(path))
	{
		Console.WriteLine("-----------------------------");
		Console.WriteLine($"Directory {path} already exists, delete manually");
		Console.WriteLine("Press enter to continue");
		Console.ReadLine();
		Directory.CreateDirectory(path);
	}
	else
	{
		Directory.CreateDirectory(path);
	}
}