fix: move implementation to "internal" package

internal/service/random_generator.go

@@ -0,0 +1,54 @@
+package service
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"spend-sparrow/internal/log"
+	"spend-sparrow/internal/types"
+
+	"github.com/google/uuid"
+)
+
+type Random interface {
+	Bytes(size int) ([]byte, error)
+	String(size int) (string, error)
+	UUID() (uuid.UUID, error)
+}
+
+type RandomImpl struct {
+}
+
+func NewRandom() *RandomImpl {
+	return &RandomImpl{}
+}
+
+func (r *RandomImpl) Bytes(size int) ([]byte, error) {
+	b := make([]byte, 32)
+	_, err := rand.Read(b)
+	if err != nil {
+		log.Error("Error generating random bytes: %v", err)
+		return []byte{}, types.ErrInternal
+	}
+
+	return b, nil
+}
+
+func (r *RandomImpl) String(size int) (string, error) {
+	bytes, err := r.Bytes(size)
+	if err != nil {
+		log.Error("Error generating random string: %v", err)
+		return "", types.ErrInternal
+	}
+
+	return base64.StdEncoding.EncodeToString(bytes), nil
+}
+
+func (r *RandomImpl) UUID() (uuid.UUID, error) {
+	id, err := uuid.NewRandom()
+	if err != nil {
+		log.Error("Error generating random UUID: %v", err)
+		return uuid.Nil, types.ErrInternal
+	}
+
+	return id, nil
+}