feat(lib/store): add bbolt store implementation

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

lib/store/bbolt/factory.go

@@ -0,0 +1,100 @@
+package bbolt
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/TecharoHQ/anubis/lib/store"
+	"go.etcd.io/bbolt"
+)
+
+var (
+	ErrMissingPath     = errors.New("bbolt: path is missing from config")
+	ErrCantWriteToPath = errors.New("bbolt: can't write to path")
+)
+
+func init() {
+	store.Register("bbolt", Factory{})
+}
+
+type Factory struct{}
+
+func (Factory) Build(ctx context.Context, data json.RawMessage) (store.Interface, error) {
+	var config Config
+	if err := json.Unmarshal([]byte(data), &config); err != nil {
+		return nil, fmt.Errorf("%w: %w", store.ErrBadConfig, err)
+	}
+
+	if err := config.Valid(); err != nil {
+		return nil, fmt.Errorf("%w: %w", store.ErrBadConfig, err)
+	}
+
+	if config.Bucket == "" {
+		config.Bucket = "anubis"
+	}
+
+	bdb, err := bbolt.Open(config.Path, 0600, nil)
+	if err != nil {
+		return nil, fmt.Errorf("can't open bbolt database %s: %w", config.Path, err)
+	}
+
+	if err := bdb.Update(func(tx *bbolt.Tx) error {
+		if _, err := tx.CreateBucketIfNotExists([]byte(config.Bucket)); err != nil {
+			return err
+		}
+
+		return nil
+	}); err != nil {
+		return nil, fmt.Errorf("can't create bbolt bucket %q: %w", config.Bucket, err)
+	}
+
+	result := &Store{
+		bdb:    bdb,
+		bucket: []byte(config.Bucket),
+	}
+
+	go result.cleanupThread(ctx)
+
+	return result, nil
+}
+
+func (Factory) Valid(data json.RawMessage) error {
+	var config Config
+	if err := json.Unmarshal([]byte(data), &config); err != nil {
+		return fmt.Errorf("%w: %w", store.ErrBadConfig, err)
+	}
+
+	if err := config.Valid(); err != nil {
+		return fmt.Errorf("%w: %w", store.ErrBadConfig, err)
+	}
+
+	return nil
+}
+
+type Config struct {
+	Path   string `json:"path"`
+	Bucket string `json:"bucket,omitempty"`
+}
+
+func (c Config) Valid() error {
+	var errs []error
+
+	if c.Path == "" {
+		errs = append(errs, ErrMissingPath)
+	} else {
+		dir := filepath.Dir(c.Path)
+		if err := os.WriteFile(filepath.Join(dir, ".test-file"), []byte(""), 0600); err != nil {
+			errs = append(errs, ErrCantWriteToPath)
+		}
+	}
+
+	if len(errs) != 0 {
+		return errors.Join(errs...)
+	}
+
+	return nil
+}