4 files changed, 130 insertions, 13 deletions
diff --git a/src/marlin.agents.shell/BlobArtifactStore.cs b/src/marlin.agents.shell/BlobArtifactStore.cs
new file mode 100644
index 0000000..e447c5a
--- /dev/null
+++ b/src/marlin.agents.shell/BlobArtifactStore.cs
@@ -0,0 +1,102 @@
+namespace marlin.agents.shell;
+
+using System.Security.Cryptography;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using core.util;
+using Microsoft.Extensions.FileSystemGlobbing;
+using Microsoft.Extensions.FileSystemGlobbing.Abstractions;
+
+public class BlobArtifactStore : IArtifactStore
+{
+    private static readonly string _storeDir = Path.Combine(CommonPaths.AgentRoot, "store");
+    private static readonly string _blobDir = Path.Combine(_storeDir, "blob");
+    private static readonly string _manifestFile = Path.Combine(_storeDir, "manifest.json");
+
+    private Dictionary<ArtifactManifestKey, ArtifactManifestEntry[]> _manifest
+    {
+        get => field != null ? field : throw new InvalidOperationException("Init not run, cannot access manifest");
+        set;
+    }
+
+    public void Init()
+    {
+        Directory.CreateDirectory(_storeDir);
+        Directory.CreateDirectory(_blobDir);
+
+        if (File.Exists(_manifestFile))
+        {
+            _manifest = JsonSerializer.Deserialize<Dictionary<ArtifactManifestKey, ArtifactManifestEntry[]>>(
+                File.ReadAllText(_manifestFile))
+                ?? throw new InvalidOperationException("Could not read manifest, possibly corrupted");
+        }
+        else
+            _manifest = new();
+    }
+    
+    public async Task Stow(Guid jobId, string stepId, string artifactId, string basePath, string glob)
+    {
+        var key = new ArtifactManifestKey { JobId = jobId, StepId = stepId, ArtifactId = artifactId };
+        var entries = new List<ArtifactManifestEntry>();
+
+        Matcher matcher = new();
+        matcher.AddInclude(glob);
+        var globMatches = matcher.Execute(new DirectoryInfoWrapper(new DirectoryInfo(basePath)));
+        
+        foreach (var globMatch in globMatches.Files)
+        {
+            var fullPath = Path.Join(basePath, globMatch.Path);
+            var entry = new ArtifactManifestEntry
+            {
+                RelativePath = globMatch.Path,
+                Hash = ComputeFileHash(fullPath)
+            };
+            
+            var targetPath = Path.Join(_blobDir, entry.Hash);
+            
+            if (!File.Exists(targetPath))
+                File.Move(fullPath, targetPath);
+            else
+                File.Delete(fullPath);
+            
+            entries.Add(entry);
+        }
+
+        _manifest[key] = entries.ToArray();
+        await File.WriteAllTextAsync(_manifestFile, JsonSerializer.Serialize(this._manifest));
+    }
+    
+    public async Task<IArtifactAccessHandle> Access(Guid jobId, string stepId, string artifactId)
+    {
+        throw new NotImplementedException();
+    }
+
+    private static string ComputeFileHash(string filePath)
+    {
+        using var stream = File.OpenRead(filePath);
+        byte[] hash = SHA256.HashData(stream);
+        return Convert.ToHexStringLower(hash);
+    }
+}
+
+public class BlobArtifactAccessHandle : IArtifactAccessHandle
+{
+    public string Path { get; }
+    
+    public void Dispose() => Directory.Delete(Path, true);
+}
+
+public class ArtifactManifestKey
+{
+    public required Guid JobId { get; init; }
+    public required string StepId { get; init; }
+    public required string ArtifactId { get; init; }
+
+    public override int GetHashCode() => HashCode.Combine(JobId.GetHashCode(), StepId.GetHashCode(), ArtifactId.GetHashCode());
+}
+
+public class ArtifactManifestEntry
+{
+    public required string RelativePath { get; init; }
+    public required string Hash { get; init; }
+}
+\ No newline at end of file
diff --git a/src/marlin.agents.shell/IArtifactStore.cs b/src/marlin.agents.shell/IArtifactStore.cs
new file mode 100644
index 0000000..2d6338c
--- /dev/null
+++ b/src/marlin.agents.shell/IArtifactStore.cs
@@ -0,0 +1,15 @@
+namespace marlin.agents.shell;
+
+public interface IArtifactStore
+{
+    /// Extracts given artifacts into shared flat blob storage
+    Task Stow(Guid jobId, string stepId, string artifactId, string basePath, string glob);
+    
+    /// Constructs virtual directory structure to access a given artifact
+    Task<IArtifactAccessHandle> Access(Guid jobId, string stepId, string artifactId);
+}
+
+public interface IArtifactAccessHandle : IDisposable
+{
+    public string Path { get; }
+}
+\ No newline at end of file
diff --git a/src/marlin.agents.shell/LocalInstanceService.cs b/src/marlin.agents.shell/LocalInstanceService.cs
new file mode 100644
index 0000000..d0d2521
--- /dev/null
+++ b/src/marlin.agents.shell/LocalInstanceService.cs
@@ -0,0 +1,13 @@
+using marlin.core.contracts;
+using ProtoBuf.Grpc;
+
+public class LocalInstanceService : IInstanceService
+{
+    public async Task SendLogEvent(LogEventRequest request, CallContext context = default)
+    {
+        TextWriter writer = request.Error ? Console.Error : Console.Out;
+        await writer.WriteLineAsync(request.Message);
+    }
+    
+    public Task SendStatusUpdate(StatusUpdateRequest request, CallContext context = default) => Task.CompletedTask;
+}
+\ No newline at end of file
diff --git a/src/marlin.agents.shell/Program.cs b/src/marlin.agents.shell/Program.cs
index c895e8d..1a3e97f 100644
--- a/src/marlin.agents.shell/Program.cs
+++ b/src/marlin.agents.shell/Program.cs
@@ -2,13 +2,11 @@ using System.Runtime.InteropServices;
 using System.Threading.Channels;
 using Grpc.Net.Client;
 using marlin.agents.shell;
-using marlin.core.contracts;
 using marlin.core.functional;
 using marlin.core.models;
 using marlin.core.models.meta;
 using marlin.core.models.plan;
 using marlin.core.util;
-using ProtoBuf.Grpc;
 using ProtoBuf.Grpc.Client;
 
 DotNetEnv.Env.NoClobber().TraversePath().Load();
@@ -25,15 +23,4 @@ else
 
     JobUnitOfWork uow = new(new LocalInstanceService(), repoPath, recipe);
     await uow.Run();
-}
-
-public class LocalInstanceService : IInstanceService
-{
-    public async Task SendLogEvent(LogEventRequest request, CallContext context = default)
-    {
-        TextWriter writer = request.Error ? Console.Error : Console.Out;
-        await writer.WriteLineAsync(request.Message);
-    }
-    
-    public Task SendStatusUpdate(StatusUpdateRequest request, CallContext context = default) => Task.CompletedTask;
 }
 \ No newline at end of file