fix: resolve rebase conflicts, fix errcheck issues, implement FetchAndDecryptBlob

internal/vaultik/blob_fetch_stub.go

@@ -1,15 +1,12 @@
 package vaultik
 
-// TODO: These are stub implementations for methods referenced but not yet
-// implemented. They allow the package to compile for testing.
-// Remove once the real implementations land.
-
 import (
 	"context"
 	"fmt"
 	"io"
 
 	"filippo.io/age"
+	"git.eeqj.de/sneak/vaultik/internal/blobgen"
 )
 
 // FetchAndDecryptBlobResult holds the result of fetching and decrypting a blob.
@@ -19,10 +16,40 @@ type FetchAndDecryptBlobResult struct {
 
 // FetchAndDecryptBlob downloads a blob, decrypts it, and returns the plaintext data.
 func (v *Vaultik) FetchAndDecryptBlob(ctx context.Context, blobHash string, expectedSize int64, identity age.Identity) (*FetchAndDecryptBlobResult, error) {
-	return nil, fmt.Errorf("FetchAndDecryptBlob not yet implemented")
+	rc, _, err := v.FetchBlob(ctx, blobHash, expectedSize)
+	if err != nil {
+		return nil, err
+	}
+	defer func() { _ = rc.Close() }()
+
+	reader, err := blobgen.NewReader(rc, identity)
+	if err != nil {
+		return nil, fmt.Errorf("creating blob reader: %w", err)
+	}
+	defer func() { _ = reader.Close() }()
+
+	data, err := io.ReadAll(reader)
+	if err != nil {
+		return nil, fmt.Errorf("reading blob data: %w", err)
+	}
+
+	return &FetchAndDecryptBlobResult{Data: data}, nil
 }
 
 // FetchBlob downloads a blob and returns a reader for the encrypted data.
 func (v *Vaultik) FetchBlob(ctx context.Context, blobHash string, expectedSize int64) (io.ReadCloser, int64, error) {
-	return nil, 0, fmt.Errorf("FetchBlob not yet implemented")
+	blobPath := fmt.Sprintf("blobs/%s/%s/%s", blobHash[:2], blobHash[2:4], blobHash)
+
+	rc, err := v.Storage.Get(ctx, blobPath)
+	if err != nil {
+		return nil, 0, fmt.Errorf("downloading blob %s: %w", blobHash[:16], err)
+	}
+
+	info, err := v.Storage.Stat(ctx, blobPath)
+	if err != nil {
+		_ = rc.Close()
+		return nil, 0, fmt.Errorf("stat blob %s: %w", blobHash[:16], err)
+	}
+
+	return rc, info.Size, nil
 }