[otp] fix lint issues

Author: capcom6

internal/config/config.go

@@ -88,7 +88,7 @@ type PubSub struct {
 }
 
 type OTP struct {
-	TTL     uint16 `yaml:"ttl" envconfig:"OTP__TTL"`
+	TTL     uint16 `yaml:"ttl"     envconfig:"OTP__TTL"`
 	Retries uint8  `yaml:"retries" envconfig:"OTP__RETRIES"`
 }
 

internal/sms-gateway/otp/config.go

@@ -7,7 +7,7 @@ import (
 
 // Config configures the OTP service.
 type Config struct {
-	TTL     time.Duration `yaml:"ttl" envconfig:"OTP__TTL"`
+	TTL     time.Duration `yaml:"ttl"     envconfig:"OTP__TTL"`
 	Retries int           `yaml:"retries" envconfig:"OTP__RETRIES"`
 }
 

internal/sms-gateway/otp/domain.go

@@ -2,7 +2,7 @@ package otp
 
 import "time"
 
-// Code is a one-time user authorization code
+// Code is a one-time user authorization code.
 type Code struct {
 	Code       string
 	ValidUntil time.Time

internal/sms-gateway/otp/module.go

@@ -10,10 +10,13 @@ func Module() fx.Option {
 	return fx.Module(
 		"otp",
 		logger.WithNamedLogger("otp"),
-		fx.Provide(func(factory cache.Factory) (cache.Cache, error) {
-			return factory.New("otp")
-
-		}, NewStorage, fx.Private),
+		fx.Provide(
+			func(factory cache.Factory) (cache.Cache, error) {
+				return factory.New("otp")
+			},
+			NewStorage,
+			fx.Private,
+		),
 		fx.Provide(NewService),
 	)
 }

internal/sms-gateway/otp/service.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/android-sms-gateway/server/pkg/cache"
+	"github.com/samber/lo"
 	"go.uber.org/zap"
 )
 
@@ -51,19 +52,29 @@ func NewService(cfg Config, storage *Storage, logger *zap.Logger) (*Service, err
 //
 // The generated code is stored with a TTL of the configured duration.
 func (s *Service) Generate(ctx context.Context, userID string) (*Code, error) {
+	const maxValue = 999999
+	const bytesLength = 3
+
 	var code string
 	var err error
 
-	b := make([]byte, 3)
+	b := make([]byte, bytesLength)
 	validUntil := time.Now().Add(s.cfg.TTL)
 
 	for range s.cfg.Retries {
 		if _, err = rand.Read(b); err != nil {
 			s.logger.Warn("failed to read random bytes", zap.Error(err))
 			continue
 		}
-		num := (int(b[0]) << 16) | (int(b[1]) << 8) | int(b[2])
-		code = fmt.Sprintf("%06d", num%1000000)
+
+		num := lo.Reduce(
+			b,
+			func(agg uint64, item byte, _ int) uint64 {
+				return (agg << 8) | uint64(item) //nolint:mnd // bits in byte
+			},
+			0,
+		)
+		code = fmt.Sprintf("%06d", num%(maxValue+1))
 
 		if err = s.storage.SetOrFail(ctx, code, userID, cache.WithValidUntil(validUntil)); err != nil {
 			s.logger.Warn("failed to store code", zap.Error(err))

internal/sms-gateway/otp/storage.go

@@ -2,32 +2,40 @@ package otp
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/android-sms-gateway/server/pkg/cache"
 )
 
-// Storage wraps the cache interface for string values
+// Storage wraps the cache interface for string values.
 type Storage struct {
 	cache cache.Cache
 }
 
-// NewStorage creates a new CodesCache with the underlying cache
+// NewStorage creates a new CodesCache with the underlying cache.
 func NewStorage(c cache.Cache) *Storage {
 	return &Storage{cache: c}
 }
 
-// SetOrFail is like Set, but returns an error if the key already exists
+// SetOrFail is like Set, but returns an error if the key already exists.
 func (s *Storage) SetOrFail(ctx context.Context, key string, value string, opts ...cache.Option) error {
-	return s.cache.SetOrFail(ctx, key, []byte(value), opts...)
+	if err := s.cache.SetOrFail(ctx, key, []byte(value), opts...); err != nil {
+		return fmt.Errorf("failed to set cache item: %w", err)
+	}
+
+	return nil
 }
 
-// GetAndDelete retrieves and deletes a string value
+// GetAndDelete retrieves and deletes a string value.
 func (s *Storage) GetAndDelete(ctx context.Context, key string) (string, error) {
 	data, err := s.cache.GetAndDelete(ctx, key)
 	return string(data), err
 }
 
-// Cleanup removes expired items
+// Cleanup removes expired items.
 func (s *Storage) Cleanup(ctx context.Context) error {
-	return s.cache.Cleanup(ctx)
+	if err := s.cache.Cleanup(ctx); err != nil {
+		return fmt.Errorf("failed to cleanup cache: %w", err)
+	}
+	return nil
 }