1 files changed, 133 insertions, 0 deletions
diff --git a/src/marlin.core/functional/GitBinaryClient.cs b/src/marlin.core/functional/GitBinaryClient.cs
new file mode 100644
index 0000000..001f2c8
--- /dev/null
+++ b/src/marlin.core/functional/GitBinaryClient.cs
@@ -0,0 +1,133 @@
+namespace marlin.core.functional;
+
+using System.Diagnostics;
+
+public class GitBinaryClient : IGitClient
+{
+    private readonly IGitCredential? _credential;
+
+    public GitBinaryClient(IGitCredential? credential = null)
+    {
+        this._credential = credential;
+    }
+
+    public async Task<Dictionary<string, string>> GetRemoteRefs(string remote)
+    {
+        string stdout = await this.RunAsync(
+            authenticate: true,
+            "ls-remote", "--heads", "--tags", remote);
+
+        return ParseRefs(stdout);
+    }
+
+    public async Task Init(string repoPath)
+    {
+        Directory.CreateDirectory(repoPath);
+        await this.RunAsync(authenticate: false, "init", "--bare", repoPath);
+    }
+
+    public async Task FetchTrees(string repoPath, string remote, IEnumerable<string> refs, bool skipBlobs = false)
+    {
+        var refList = refs as IReadOnlyCollection<string> ?? refs.ToArray();
+        if (refList.Count == 0)
+            return;
+
+        var args = new List<string> { "-C", repoPath, "fetch" };
+        if (skipBlobs)
+            args.Add("--filter=blob:none");
+        args.Add(remote);
+        args.AddRange(refList);
+
+        await this.RunAsync(authenticate: true, args.ToArray());
+    }
+
+    public async Task<string[]> ListTree(string repoPath, string hash, string filterPath = ".")
+    {
+        string stdout = await this.RunAsync(
+            authenticate: false,
+            "-C", repoPath, "ls-tree", "-r", "--name-only", hash, "--", filterPath);
+
+        return stdout.Split('\n', StringSplitOptions.RemoveEmptyEntries);
+    }
+
+    public Task<byte[]> CatFile(string repoPath, string hash, string fileName)
+    {
+        return this.RunRawAsync(
+            authenticate: false,
+            "-C", repoPath, "show", $"{hash}:{fileName}");
+    }
+
+    private Task<string> RunAsync(bool authenticate, params string[] arguments) =>
+        this.RunAsync(authenticate, async stream =>
+        {
+            using var reader = new StreamReader(stream);
+            return await reader.ReadToEndAsync();
+        }, arguments);
+
+    private Task<byte[]> RunRawAsync(bool authenticate, params string[] arguments) =>
+        this.RunAsync(authenticate, async stream =>
+        {
+            using var buffer = new MemoryStream();
+            await stream.CopyToAsync(buffer);
+            return buffer.ToArray();
+        }, arguments);
+
+    private async Task<T> RunAsync<T>(bool authenticate, Func<Stream, Task<T>> readStdout, string[] arguments)
+    {
+        var psi = new ProcessStartInfo("git")
+        {
+            RedirectStandardOutput = true,
+            RedirectStandardError = true,
+            UseShellExecute = false,
+            CreateNoWindow = true,
+        };
+
+        foreach (string arg in arguments)
+            psi.ArgumentList.Add(arg);
+        
+        psi.Environment["GIT_TERMINAL_PROMPT"] = "0";
+
+        IAsyncDisposable? credentialScope = authenticate && this._credential != null
+            ? await this._credential.ApplyAsync(psi)
+            : null;
+
+        try
+        {
+            using var process = Process.Start(psi)
+                ?? throw new InvalidOperationException("Failed to start git process.");
+
+            Task<T> stdoutTask = readStdout(process.StandardOutput.BaseStream);
+            Task<string> stderrTask = process.StandardError.ReadToEndAsync();
+
+            await process.WaitForExitAsync();
+            T stdout = await stdoutTask;
+            string stderr = await stderrTask;
+
+            if (process.ExitCode != 0)
+                throw new GitCommandException(string.Join(' ', arguments), process.ExitCode, stderr);
+
+            return stdout;
+        }
+        finally
+        {
+            if (credentialScope != null)
+                await credentialScope.DisposeAsync();
+        }
+    }
+
+    private static Dictionary<string, string> ParseRefs(string stdout)
+    {
+        var result = new Dictionary<string, string>();
+
+        foreach (string line in stdout.Split('\n', StringSplitOptions.RemoveEmptyEntries))
+        {
+            string[] parts = line.Split('\t');
+            if (parts.Length != 2)
+                continue; // ignore a malformed line rather than throw over one bad entry
+
+            result[parts[1]] = parts[0];
+        }
+
+        return result;
+    }
+}