code refactor

cmd/utility.go

@@ -81,13 +81,13 @@ func sendTestMail(c *core.CliContext) error {
 		return err
 	}
 
-	if !config.EnableSMTP || mail.Container.Current == nil {
+	if !config.EnableSMTP {
 		return errs.ErrSMTPServerNotEnabled
 	}
 
 	toAddress := c.String("to")
 
-	err = mail.Container.Current.SendMail(&mail.MailMessage{
+	err = mail.Container.SendMail(&mail.MailMessage{
 		To:      toAddress,
 		Subject: "ezBookkeeping test e-mail",
 		Body:    "This is a test e-mail",

cmd/webserver.go

@@ -79,7 +79,7 @@ func startWebServer(c *core.CliContext) error {
 		return err
 	}
 
-	serverInfo := fmt.Sprintf("current server id is %d, current instance id is %d", requestid.Container.Current.GetCurrentServerUniqId(), requestid.Container.Current.GetCurrentInstanceUniqId())
+	serverInfo := fmt.Sprintf("current server id is %d, current instance id is %d", requestid.Container.GetCurrentServerUniqId(), requestid.Container.GetCurrentInstanceUniqId())
 	uuidServerInfo := ""
 	if config.UuidGeneratorType == settings.InternalUuidGeneratorType {
 		uuidServerInfo = fmt.Sprintf(", current uuid server id is %d", config.UuidServerId)

pkg/api/base.go

@@ -23,7 +23,7 @@ type ApiUsingConfig struct {
 
 // CurrentConfig returns the current config
 func (a *ApiUsingConfig) CurrentConfig() *settings.Config {
-	return a.container.Current
+	return a.container.GetCurrentConfig()
 }
 
 // GetTransactionPictureInfoResponse returns the view-object of transaction picture basic info according to the transaction picture model
@@ -53,15 +53,15 @@ func (a *ApiUsingConfig) GetAfterRegisterNotificationContent(userLanguage string
 		language = clientLanguage
 	}
 
-	if !a.container.Current.AfterRegisterNotification.Enabled {
+	if !a.CurrentConfig().AfterRegisterNotification.Enabled {
 		return ""
 	}
 
-	if multiLanguageContent, exists := a.container.Current.AfterRegisterNotification.MultiLanguageContent[language]; exists {
+	if multiLanguageContent, exists := a.CurrentConfig().AfterRegisterNotification.MultiLanguageContent[language]; exists {
 		return multiLanguageContent
 	}
 
-	return a.container.Current.AfterRegisterNotification.DefaultContent
+	return a.CurrentConfig().AfterRegisterNotification.DefaultContent
 }
 
 // GetAfterLoginNotificationContent returns the notification content displayed each time users log in
@@ -72,15 +72,15 @@ func (a *ApiUsingConfig) GetAfterLoginNotificationContent(userLanguage string, c
 		language = clientLanguage
 	}
 
-	if !a.container.Current.AfterLoginNotification.Enabled {
+	if !a.CurrentConfig().AfterLoginNotification.Enabled {
 		return ""
 	}
 
-	if multiLanguageContent, exists := a.container.Current.AfterLoginNotification.MultiLanguageContent[language]; exists {
+	if multiLanguageContent, exists := a.CurrentConfig().AfterLoginNotification.MultiLanguageContent[language]; exists {
 		return multiLanguageContent
 	}
 
-	return a.container.Current.AfterLoginNotification.DefaultContent
+	return a.CurrentConfig().AfterLoginNotification.DefaultContent
 }
 
 // GetAfterOpenNotificationContent returns the notification content displayed each time users open the app
@@ -91,15 +91,15 @@ func (a *ApiUsingConfig) GetAfterOpenNotificationContent(userLanguage string, cl
 		language = clientLanguage
 	}
 
-	if !a.container.Current.AfterOpenNotification.Enabled {
+	if !a.CurrentConfig().AfterOpenNotification.Enabled {
 		return ""
 	}
 
-	if multiLanguageContent, exists := a.container.Current.AfterOpenNotification.MultiLanguageContent[language]; exists {
+	if multiLanguageContent, exists := a.CurrentConfig().AfterOpenNotification.MultiLanguageContent[language]; exists {
 		return multiLanguageContent
 	}
 
-	return a.container.Current.AfterOpenNotification.DefaultContent
+	return a.CurrentConfig().AfterOpenNotification.DefaultContent
 }
 
 // ApiUsingDuplicateChecker represents an api that need to use duplicate checker

pkg/api/exchange_rates.go

@@ -30,13 +30,7 @@ var (
 
 // LatestExchangeRateHandler returns latest exchange rate data
 func (a *ExchangeRatesApi) LatestExchangeRateHandler(c *core.WebContext) (any, *errs.Error) {
-	dataSource := exchangerates.Container.Current
-
-	if dataSource == nil {
-		return nil, errs.ErrInvalidExchangeRatesDataSource
-	}
-
-	exchangeRateResponse, err := dataSource.GetLatestExchangeRates(c, c.GetCurrentUid(), a.container.Current)
+	exchangeRateResponse, err := exchangerates.Container.GetLatestExchangeRates(c, c.GetCurrentUid(), a.CurrentConfig())
 
 	if err != nil {
 		return nil, errs.Or(err, errs.ErrOperationFailed)

pkg/avatars/avatar_provider_container.go

@@ -9,7 +9,7 @@ import (
 
 // AvatarProviderContainer contains the current user avatar provider
 type AvatarProviderContainer struct {
-	Current AvatarProvider
+	current AvatarProvider
 }
 
 // Initialize a user avatar provider container singleton instance
@@ -20,13 +20,13 @@ var (
 // InitializeAvatarProvider initializes the current user avatar provider according to the config
 func InitializeAvatarProvider(config *settings.Config) error {
 	if config.AvatarProvider == core.USER_AVATAR_PROVIDER_INTERNAL {
-		Container.Current = NewInternalStorageAvatarProvider(config)
+		Container.current = NewInternalStorageAvatarProvider(config)
 		return nil
 	} else if config.AvatarProvider == core.USER_AVATAR_PROVIDER_GRAVATAR {
-		Container.Current = NewGravatarAvatarProvider()
+		Container.current = NewGravatarAvatarProvider()
 		return nil
 	} else if config.AvatarProvider == "" {
-		Container.Current = NewNullAvatarProvider()
+		Container.current = NewNullAvatarProvider()
 		return nil
 	}
 
@@ -35,5 +35,9 @@ func InitializeAvatarProvider(config *settings.Config) error {
 
 // GetAvatarUrl returns the avatar url by the current user avatar provider
 func (p *AvatarProviderContainer) GetAvatarUrl(user *models.User) string {
-	return p.Current.GetAvatarUrl(user)
+	if p.current == nil {
+		return ""
+	}
+
+	return p.current.GetAvatarUrl(user)
 }

pkg/cli/base.go

@@ -9,5 +9,5 @@ type CliUsingConfig struct {
 
 // CurrentConfig returns the current config
 func (l *CliUsingConfig) CurrentConfig() *settings.Config {
-	return l.container.Current
+	return l.container.GetCurrentConfig()
 }

pkg/cron/cron_container_test.go

@@ -95,7 +95,7 @@ func TestCronJobSchedulerContainerRepeatRun(t *testing.T) {
 		InMemoryDuplicateCheckerCleanupIntervalDuration: 60 * time.Second,
 	})
 
-	duplicatechecker.Container.Current = checker
+	duplicatechecker.SetDuplicateChecker(checker)
 
 	container := &CronJobSchedulerContainer{
 		allJobsMap:       make(map[string]*CronJob),

pkg/cron/cron_job.go

@@ -22,7 +22,7 @@ func (j *CronJob) doRun() {
 	start := time.Now()
 	c := core.NewCronJobContext(j.Name, j.Period.GetInterval())
 
-	if duplicatechecker.Container.Current != nil {
+	if duplicatechecker.Container.IsEnabled() {
 		localAddr, err := utils.GetLocalIPAddressesString()
 
 		if err != nil {

pkg/duplicatechecker/duplicate_checker_container.go

@@ -9,7 +9,7 @@ import (
 
 // DuplicateCheckerContainer contains the current duplicate checker
 type DuplicateCheckerContainer struct {
-	Current DuplicateChecker
+	current DuplicateChecker
 }
 
 // Initialize a duplicate checker container singleton instance
@@ -21,7 +21,7 @@ var (
 func InitializeDuplicateChecker(config *settings.Config) error {
 	if config.DuplicateCheckerType == settings.InMemoryDuplicateCheckerType {
 		checker, err := NewInMemoryDuplicateChecker(config)
-		Container.Current = checker
+		Container.current = checker
 
 		return err
 	}
@@ -29,37 +29,75 @@ func InitializeDuplicateChecker(config *settings.Config) error {
 	return errs.ErrInvalidDuplicateCheckerType
 }
 
+// SetDuplicateChecker sets the current duplicate checker
+func SetDuplicateChecker(checker DuplicateChecker) {
+	Container.current = checker
+}
+
+// IsEnabled returns whether the duplicate checker is enabled
+func (c *DuplicateCheckerContainer) IsEnabled() bool {
+	return c.current != nil
+}
+
 // GetSubmissionRemark returns whether the same submission has been processed and related remark by the current duplicate checker
 func (c *DuplicateCheckerContainer) GetSubmissionRemark(checkerType DuplicateCheckerType, uid int64, identification string) (bool, string) {
-	return c.Current.GetSubmissionRemark(checkerType, uid, identification)
+	if c.current == nil {
+		return false, ""
+	}
+
+	return c.current.GetSubmissionRemark(checkerType, uid, identification)
 }
 
 // SetSubmissionRemark saves the identification and remark by the current duplicate checker
 func (c *DuplicateCheckerContainer) SetSubmissionRemark(checkerType DuplicateCheckerType, uid int64, identification string, remark string) {
-	c.Current.SetSubmissionRemark(checkerType, uid, identification, remark)
+	if c.current == nil {
+		return
+	}
+
+	c.current.SetSubmissionRemark(checkerType, uid, identification, remark)
 }
 
 // RemoveSubmissionRemark removes the identification and remark by the current duplicate checker
 func (c *DuplicateCheckerContainer) RemoveSubmissionRemark(checkerType DuplicateCheckerType, uid int64, identification string) {
-	c.Current.RemoveSubmissionRemark(checkerType, uid, identification)
+	if c.current == nil {
+		return
+	}
+
+	c.current.RemoveSubmissionRemark(checkerType, uid, identification)
 }
 
 // GetOrSetCronJobRunningInfo returns the running info when the cron job is running or saves the running info by the current duplicate checker
 func (c *DuplicateCheckerContainer) GetOrSetCronJobRunningInfo(jobName string, runningInfo string, runningInterval time.Duration) (bool, string) {
-	return c.Current.GetOrSetCronJobRunningInfo(jobName, runningInfo, runningInterval)
+	if c.current == nil {
+		return false, ""
+	}
+
+	return c.current.GetOrSetCronJobRunningInfo(jobName, runningInfo, runningInterval)
 }
 
 // RemoveCronJobRunningInfo removes the running info of the cron job by the current duplicate checker
 func (c *DuplicateCheckerContainer) RemoveCronJobRunningInfo(jobName string) {
-	c.Current.RemoveCronJobRunningInfo(jobName)
+	if c.current == nil {
+		return
+	}
+
+	c.current.RemoveCronJobRunningInfo(jobName)
 }
 
 // GetFailureCount returns the failure count of the specified failure key
 func (c *DuplicateCheckerContainer) GetFailureCount(failureKey string) uint32 {
-	return c.Current.GetFailureCount(failureKey)
+	if c.current == nil {
+		return 0
+	}
+
+	return c.current.GetFailureCount(failureKey)
 }
 
 // IncreaseFailureCount increases the failure count of the specified failure key
 func (c *DuplicateCheckerContainer) IncreaseFailureCount(failureKey string) uint32 {
-	return c.Current.IncreaseFailureCount(failureKey)
+	if c.current == nil {
+		return 0
+	}
+
+	return c.current.IncreaseFailureCount(failureKey)
 }

pkg/exchangerates/exchange_rates_datasource_container.go

@@ -1,13 +1,15 @@
 package exchangerates
 
 import (
+	"github.com/mayswind/ezbookkeeping/pkg/core"
 	"github.com/mayswind/ezbookkeeping/pkg/errs"
+	"github.com/mayswind/ezbookkeeping/pkg/models"
 	"github.com/mayswind/ezbookkeeping/pkg/settings"
 )
 
 // ExchangeRatesDataSourceContainer contains the current exchange rates data source
 type ExchangeRatesDataSourceContainer struct {
-	Current ExchangeRatesDataSource
+	current ExchangeRatesDataSource
 }
 
 // Initialize a exchange rates data source container singleton instance
@@ -18,60 +20,69 @@ var (
 // InitializeExchangeRatesDataSource initializes the current exchange rates data source according to the config
 func InitializeExchangeRatesDataSource(config *settings.Config) error {
 	if config.ExchangeRatesDataSource == settings.ReserveBankOfAustraliaDataSource {
-		Container.Current = newCommonHttpExchangeRatesDataSource(&ReserveBankOfAustraliaDataSource{})
+		Container.current = newCommonHttpExchangeRatesDataSource(&ReserveBankOfAustraliaDataSource{})
 		return nil
 	} else if config.ExchangeRatesDataSource == settings.BankOfCanadaDataSource {
-		Container.Current = newCommonHttpExchangeRatesDataSource(&BankOfCanadaDataSource{})
+		Container.current = newCommonHttpExchangeRatesDataSource(&BankOfCanadaDataSource{})
 		return nil
 	} else if config.ExchangeRatesDataSource == settings.CzechNationalBankDataSource {
-		Container.Current = newCommonHttpExchangeRatesDataSource(&CzechNationalBankDataSource{})
+		Container.current = newCommonHttpExchangeRatesDataSource(&CzechNationalBankDataSource{})
 		return nil
 	} else if config.ExchangeRatesDataSource == settings.DanmarksNationalbankDataSource {
-		Container.Current = newCommonHttpExchangeRatesDataSource(&DanmarksNationalbankDataSource{})
+		Container.current = newCommonHttpExchangeRatesDataSource(&DanmarksNationalbankDataSource{})
 		return nil
 	} else if config.ExchangeRatesDataSource == settings.EuroCentralBankDataSource {
-		Container.Current = newCommonHttpExchangeRatesDataSource(&EuroCentralBankDataSource{})
+		Container.current = newCommonHttpExchangeRatesDataSource(&EuroCentralBankDataSource{})
 		return nil
 	} else if config.ExchangeRatesDataSource == settings.NationalBankOfGeorgiaDataSource {
-		Container.Current = newCommonHttpExchangeRatesDataSource(&NationalBankOfGeorgiaDataSource{})
+		Container.current = newCommonHttpExchangeRatesDataSource(&NationalBankOfGeorgiaDataSource{})
 		return nil
 	} else if config.ExchangeRatesDataSource == settings.CentralBankOfHungaryDataSource {
-		Container.Current = newCommonHttpExchangeRatesDataSource(&CentralBankOfHungaryDataSource{})
+		Container.current = newCommonHttpExchangeRatesDataSource(&CentralBankOfHungaryDataSource{})
 		return nil
 	} else if config.ExchangeRatesDataSource == settings.BankOfIsraelDataSource {
-		Container.Current = newCommonHttpExchangeRatesDataSource(&BankOfIsraelDataSource{})
+		Container.current = newCommonHttpExchangeRatesDataSource(&BankOfIsraelDataSource{})
 		return nil
 	} else if config.ExchangeRatesDataSource == settings.CentralBankOfMyanmarDataSource {
-		Container.Current = newCommonHttpExchangeRatesDataSource(&CentralBankOfMyanmarDataSource{})
+		Container.current = newCommonHttpExchangeRatesDataSource(&CentralBankOfMyanmarDataSource{})
 		return nil
 	} else if config.ExchangeRatesDataSource == settings.NorgesBankDataSource {
-		Container.Current = newCommonHttpExchangeRatesDataSource(&NorgesBankDataSource{})
+		Container.current = newCommonHttpExchangeRatesDataSource(&NorgesBankDataSource{})
 		return nil
 	} else if config.ExchangeRatesDataSource == settings.NationalBankOfPolandDataSource {
-		Container.Current = newCommonHttpExchangeRatesDataSource(&NationalBankOfPolandDataSource{})
+		Container.current = newCommonHttpExchangeRatesDataSource(&NationalBankOfPolandDataSource{})
 		return nil
 	} else if config.ExchangeRatesDataSource == settings.NationalBankOfRomaniaDataSource {
-		Container.Current = newCommonHttpExchangeRatesDataSource(&NationalBankOfRomaniaDataSource{})
+		Container.current = newCommonHttpExchangeRatesDataSource(&NationalBankOfRomaniaDataSource{})
 		return nil
 	} else if config.ExchangeRatesDataSource == settings.BankOfRussiaDataSource {
-		Container.Current = newCommonHttpExchangeRatesDataSource(&BankOfRussiaDataSource{})
+		Container.current = newCommonHttpExchangeRatesDataSource(&BankOfRussiaDataSource{})
 		return nil
 	} else if config.ExchangeRatesDataSource == settings.SwissNationalBankDataSource {
-		Container.Current = newCommonHttpExchangeRatesDataSource(&SwissNationalBankDataSource{})
+		Container.current = newCommonHttpExchangeRatesDataSource(&SwissNationalBankDataSource{})
 		return nil
 	} else if config.ExchangeRatesDataSource == settings.NationalBankOfUkraineDataSource {
-		Container.Current = newCommonHttpExchangeRatesDataSource(&NationalBankOfUkraineDataSource{})
+		Container.current = newCommonHttpExchangeRatesDataSource(&NationalBankOfUkraineDataSource{})
 		return nil
 	} else if config.ExchangeRatesDataSource == settings.CentralBankOfUzbekistanDataSource {
-		Container.Current = newCommonHttpExchangeRatesDataSource(&CentralBankOfUzbekistanDataSource{})
+		Container.current = newCommonHttpExchangeRatesDataSource(&CentralBankOfUzbekistanDataSource{})
 		return nil
 	} else if config.ExchangeRatesDataSource == settings.InternationalMonetaryFundDataSource {
-		Container.Current = newCommonHttpExchangeRatesDataSource(&InternationalMonetaryFundDataSource{})
+		Container.current = newCommonHttpExchangeRatesDataSource(&InternationalMonetaryFundDataSource{})
 		return nil
 	} else if config.ExchangeRatesDataSource == settings.UserCustomExchangeRatesDataSource {
-		Container.Current = newUserCustomExchangeRatesDataSource()
+		Container.current = newUserCustomExchangeRatesDataSource()
 		return nil
 	}
 
 	return errs.ErrInvalidExchangeRatesDataSource
 }
+
+// GetLatestExchangeRates returns the latest exchange rates data from the current exchange rates data source
+func (e *ExchangeRatesDataSourceContainer) GetLatestExchangeRates(c core.Context, uid int64, currentConfig *settings.Config) (*models.LatestExchangeRateResponse, error) {
+	if Container.current == nil {
+		return nil, errs.ErrInvalidExchangeRatesDataSource
+	}
+
+	return e.current.GetLatestExchangeRates(c, uid, currentConfig)
+}

pkg/exchangerates/http_exchange_rates_datasource_test.go

@@ -326,15 +326,12 @@ func executeLatestExchangeRateHandler(t *testing.T, dataSourceType string) *mode
 	err := InitializeExchangeRatesDataSource(config)
 	assert.Nil(t, err)
 
-	dataSource := Container.Current
-	assert.NotNil(t, dataSource)
-
 	ginContext, _ := gin.CreateTestContext(httptest.NewRecorder())
 	context := &core.WebContext{
 		Context: ginContext,
 	}
 
-	exchangeRateResponse, err := dataSource.GetLatestExchangeRates(context, context.GetCurrentUid(), config)
+	exchangeRateResponse, err := Container.GetLatestExchangeRates(context, context.GetCurrentUid(), config)
 	assert.Nil(t, err)
 	assert.NotNil(t, exchangeRateResponse)
 

pkg/mail/mailer_container.go

@@ -1,12 +1,13 @@
 package mail
 
 import (
+	"github.com/mayswind/ezbookkeeping/pkg/errs"
 	"github.com/mayswind/ezbookkeeping/pkg/settings"
 )
 
 // MailerContainer contains the current mailer
 type MailerContainer struct {
-	Current Mailer
+	current Mailer
 }
 
 // Initialize a mailer container singleton instance
@@ -17,7 +18,7 @@ var (
 // InitializeMailer initializes the current mailer according to the config
 func InitializeMailer(config *settings.Config) error {
 	if !config.EnableSMTP {
-		Container.Current = nil
+		Container.current = nil
 		return nil
 	}
 
@@ -27,11 +28,15 @@ func InitializeMailer(config *settings.Config) error {
 		return err
 	}
 
-	Container.Current = mailer
+	Container.current = mailer
 	return nil
 }
 
 // SendMail sends an email according to argument
-func (u *MailerContainer) SendMail(message *MailMessage) error {
-	return u.Current.SendMail(message)
+func (m *MailerContainer) SendMail(message *MailMessage) error {
+	if m.current == nil {
+		return errs.ErrSMTPServerNotEnabled
+	}
+
+	return m.current.SendMail(message)
 }

pkg/mcp/query_latest_exchange_rates_tool_handler.go

@@ -68,13 +68,7 @@ func (h *mcpQueryLatestExchangeRatesToolHandler) Handle(c *core.WebContext, call
 		return nil, nil, errs.ErrIncompleteOrIncorrectSubmission
 	}
 
-	dataSource := exchangerates.Container.Current
-
-	if dataSource == nil {
-		return nil, nil, errs.ErrInvalidExchangeRatesDataSource
-	}
-
-	exchangeRateResponse, err := dataSource.GetLatestExchangeRates(c, user.Uid, currentConfig)
+	exchangeRateResponse, err := exchangerates.Container.GetLatestExchangeRates(c, user.Uid, currentConfig)
 
 	if err != nil {
 		return nil, nil, err

pkg/middlewares/request_id.go

@@ -11,12 +11,7 @@ const requestIdHeader = "X-Request-ID"
 // RequestId generates a new request id and add it to context and response header
 func RequestId(config *settings.Config) core.MiddlewareHandlerFunc {
 	return func(c *core.WebContext) {
-		if requestid.Container.Current == nil {
-			c.Next()
-			return
-		}
-
-		requestId := requestid.Container.Current.GenerateRequestId(c.ClientIP(), c.ClientPort())
+		requestId := requestid.Container.GenerateRequestId(c.ClientIP(), c.ClientPort())
 		c.SetContextId(requestId)
 
 		if config.EnableRequestIdHeader {

pkg/requestid/request_id_container.go

@@ -7,7 +7,7 @@ import (
 
 // RequestIdContainer contains the current request id generator
 type RequestIdContainer struct {
-	Current RequestIdGenerator
+	current RequestIdGenerator
 }
 
 // Initialize a request id container singleton instance
@@ -23,11 +23,33 @@ func InitializeRequestIdGenerator(c core.Context, config *settings.Config) error
 		return err
 	}
 
-	Container.Current = generator
+	Container.current = generator
 	return nil
 }
 
 // GenerateRequestId returns a new request id by the current request id generator
-func (u *RequestIdContainer) GenerateRequestId(clientIpAddr string, clientPort uint16) string {
-	return u.Current.GenerateRequestId(clientIpAddr, clientPort)
+func (r *RequestIdContainer) GenerateRequestId(clientIpAddr string, clientPort uint16) string {
+	if r.current == nil {
+		return ""
+	}
+
+	return r.current.GenerateRequestId(clientIpAddr, clientPort)
+}
+
+// GetCurrentServerUniqId returns current server unique id
+func (r *RequestIdContainer) GetCurrentServerUniqId() uint16 {
+	if r.current == nil {
+		return 0
+	}
+
+	return r.current.GetCurrentServerUniqId()
+}
+
+// GetCurrentInstanceUniqId returns current application instance unique id
+func (r *RequestIdContainer) GetCurrentInstanceUniqId() uint16 {
+	if r.current == nil {
+		return 0
+	}
+
+	return r.current.GetCurrentInstanceUniqId()
 }

pkg/services/base.go

@@ -6,7 +6,6 @@ import (
 
 	"github.com/mayswind/ezbookkeeping/pkg/core"
 	"github.com/mayswind/ezbookkeeping/pkg/datastore"
-	"github.com/mayswind/ezbookkeeping/pkg/errs"
 	"github.com/mayswind/ezbookkeeping/pkg/mail"
 	"github.com/mayswind/ezbookkeeping/pkg/settings"
 	"github.com/mayswind/ezbookkeeping/pkg/storage"
@@ -61,7 +60,7 @@ type ServiceUsingConfig struct {
 
 // CurrentConfig returns the current config
 func (s *ServiceUsingConfig) CurrentConfig() *settings.Config {
-	return s.container.Current
+	return s.container.GetCurrentConfig()
 }
 
 // ServiceUsingMailer represents a service that need to use mailer
@@ -71,11 +70,7 @@ type ServiceUsingMailer struct {
 
 // SendMail sends an email according to argument
 func (s *ServiceUsingMailer) SendMail(message *mail.MailMessage) error {
-	if s.container.Current == nil {
-		return errs.ErrSMTPServerNotEnabled
-	}
-
-	return s.container.Current.SendMail(message)
+	return s.container.SendMail(message)
 }
 
 // ServiceUsingUuid represents a service that need to use uuid

pkg/settings/setting_container.go

@@ -2,7 +2,7 @@ package settings
 
 // ConfigContainer contains the current setting config
 type ConfigContainer struct {
-	Current *Config
+	current *Config
 }
 
 // Initialize a config container singleton instance
@@ -15,5 +15,10 @@ var (
 
 // SetCurrentConfig sets the current config by a given config
 func SetCurrentConfig(config *Config) {
-	Container.Current = config
+	Container.current = config
+}
+
+// GetCurrentConfig returns the current config
+func (c *ConfigContainer) GetCurrentConfig() *Config {
+	return c.current
 }

pkg/uuid/uuid_container.go

@@ -7,7 +7,7 @@ import (
 
 // UuidContainer contains the current uuid generator
 type UuidContainer struct {
-	Current UuidGenerator
+	current UuidGenerator
 }
 
 // Initialize a uuid container singleton instance
@@ -19,7 +19,7 @@ var (
 func InitializeUuidGenerator(config *settings.Config) error {
 	if config.UuidGeneratorType == settings.InternalUuidGeneratorType {
 		generator, err := NewInternalUuidGenerator(config)
-		Container.Current = generator
+		Container.current = generator
 
 		return err
 	}
@@ -29,10 +29,18 @@ func InitializeUuidGenerator(config *settings.Config) error {
 
 // GenerateUuid returns a new uuid by the current uuid generator
 func (u *UuidContainer) GenerateUuid(uuidType UuidType) int64 {
-	return u.Current.GenerateUuid(uuidType)
+	if u.current == nil {
+		return 0
+	}
+
+	return u.current.GenerateUuid(uuidType)
 }
 
 // GenerateUuids returns new uuids by the current uuid generator
 func (u *UuidContainer) GenerateUuids(uuidType UuidType, count uint16) []int64 {
-	return u.Current.GenerateUuids(uuidType, count)
+	if u.current == nil {
+		return nil
+	}
+
+	return u.current.GenerateUuids(uuidType, count)
 }