feat(lib/store): implement valkey backend

Signed-off-by: Xe Iaso <me@xeiaso.net>

lib/store/valkey/valkey.go

@@ -0,0 +1,49 @@
+package valkey
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/TecharoHQ/anubis/lib/store"
+	valkey "github.com/redis/go-redis/v9"
+)
+
+type Store struct {
+	rdb *valkey.Client
+}
+
+func (s *Store) Delete(ctx context.Context, key string) error {
+	n, err := s.rdb.Del(ctx, key).Result()
+	if err != nil {
+		return fmt.Errorf("can't delete from valkey: %w", err)
+	}
+
+	switch n {
+	case 0:
+		return fmt.Errorf("%w: %d key(s) deleted", store.ErrNotFound, n)
+	default:
+		return nil
+	}
+}
+
+func (s *Store) Get(ctx context.Context, key string) ([]byte, error) {
+	result, err := s.rdb.Get(ctx, key).Result()
+	if err != nil {
+		if valkey.HasErrorPrefix(err, "redis: nil") {
+			return nil, fmt.Errorf("%w: %w", store.ErrNotFound, err)
+		}
+
+		return nil, fmt.Errorf("can't fetch from valkey: %w", err)
+	}
+
+	return []byte(result), nil
+}
+
+func (s *Store) Set(ctx context.Context, key string, value []byte, expiry time.Duration) error {
+	if _, err := s.rdb.Set(ctx, key, string(value), expiry).Result(); err != nil {
+		return fmt.Errorf("can't set %q in valkey: %w", key, err)
+	}
+
+	return nil
+}