feat(attachments): data layer for task file attachments

TaskAttachmentEntity (+config, cascade FK), TaskAttachmentRepository, and an AttachmentStore that writes files under ~/.todo-app/attachments/<taskId>/ with a path-traversal guard and a 5 MB cap. TaskPromptComposer gains an optional read-only 'Reference files' section. Migration AddTaskAttachments.
2026-06-26 16:11:48 +02:00
parent 5231ad6b86
commit 3f9f047955
12 changed files with 1249 additions and 1 deletions
@@ -0,0 +1,73 @@
+namespace ClaudeDo.Data;
+
+public sealed class AttachmentStore
+{
+    private const long MaxBytes = 5 * 1024 * 1024; // 5 MB
+
+    private readonly string _root;
+
+    public AttachmentStore(string? root = null)
+        => _root = root ?? Paths.Expand("~/.todo-app/attachments");
+
+    public string TaskDir(string taskId)
+        => Path.Combine(_root, taskId);
+
+    public async Task<long> SaveAsync(string taskId, string fileName, Stream content, CancellationToken ct = default)
+    {
+        if (Path.GetFileName(fileName) != fileName)
+            throw new ArgumentException("fileName must not contain path separators or '..'.", nameof(fileName));
+
+        var dir = TaskDir(taskId);
+        var resolvedPath = Path.GetFullPath(Path.Combine(dir, fileName));
+
+        // Containment guard: resolved path must stay inside TaskDir
+        var resolvedDir = Path.GetFullPath(dir);
+        if (!resolvedPath.StartsWith(resolvedDir + Path.DirectorySeparatorChar, StringComparison.Ordinal)
+            && !resolvedPath.Equals(resolvedDir, StringComparison.Ordinal))
+            throw new ArgumentException("fileName resolves outside the task directory.", nameof(fileName));
+
+        Directory.CreateDirectory(dir);
+
+        // Buffer up to MaxBytes + 1 to detect oversize without reading fully
+        await using var fs = new FileStream(resolvedPath, FileMode.Create, FileAccess.Write, FileShare.None,
+            bufferSize: 81920, useAsync: true);
+
+        var buffer = new byte[81920];
+        long total = 0;
+        int read;
+        while ((read = await content.ReadAsync(buffer, ct)) > 0)
+        {
+            total += read;
+            if (total > MaxBytes)
+            {
+                fs.Close();
+                try { File.Delete(resolvedPath); } catch { }
+                throw new InvalidOperationException($"Attachment exceeds the 5 MB size limit.");
+            }
+            await fs.WriteAsync(buffer.AsMemory(0, read), ct);
+        }
+
+        return total;
+    }
+
+    public void DeleteFile(string taskId, string fileName)
+    {
+        if (Path.GetFileName(fileName) != fileName)
+            return; // traversal attempt — ignore silently
+
+        var dir = TaskDir(taskId);
+        var resolvedPath = Path.GetFullPath(Path.Combine(dir, fileName));
+        var resolvedDir = Path.GetFullPath(dir);
+        if (!resolvedPath.StartsWith(resolvedDir + Path.DirectorySeparatorChar, StringComparison.Ordinal)
+            && !resolvedPath.Equals(resolvedDir, StringComparison.Ordinal))
+            return; // containment violation — ignore silently
+
+        try { File.Delete(resolvedPath); } catch (DirectoryNotFoundException) { } catch (FileNotFoundException) { }
+    }
+
+    public void DeleteTaskDir(string taskId)
+    {
+        var dir = TaskDir(taskId);
+        try { Directory.Delete(dir, recursive: true); } catch (DirectoryNotFoundException) { } catch (IOException) { }
+    }
+}