From 76eac1c9dcb8a02e01ed45ed543c716d136ebb98 Mon Sep 17 00:00:00 2001
From: MaysWind <i@mayswind.net>
Date: Sat, 26 Dec 2020 21:47:51 +0800
Subject: [PATCH] add comments

---
 pkg/services/accounts.go                 | 11 +++++++++++
 pkg/services/base.go                     |  8 ++++++++
 pkg/services/tokens.go                   | 13 +++++++++++++
 pkg/services/transaction_categories.go   | 12 ++++++++++++
 pkg/services/transaction_tags.go         | 12 ++++++++++++
 pkg/services/transactions.go             | 10 ++++++++++
 pkg/services/twofactor_authorizations.go | 11 +++++++++++
 pkg/services/users.go                    | 12 ++++++++++++
 8 files changed, 89 insertions(+)

diff --git a/pkg/services/accounts.go b/pkg/services/accounts.go
index 6b9ca560..c862ed6e 100644
--- a/pkg/services/accounts.go
+++ b/pkg/services/accounts.go
@@ -12,11 +12,13 @@ import (
 	"github.com/mayswind/lab/pkg/uuid"
 )
 
+// AccountService represents account service
 type AccountService struct {
 	ServiceUsingDB
 	ServiceUsingUuid
 }
 
+// Initialize a account service singleton instance
 var (
 	Accounts = &AccountService{
 		ServiceUsingDB: ServiceUsingDB{
@@ -28,6 +30,7 @@ var (
 	}
 )
 
+// GetAllAccountsByUid returns all account models of user
 func (s *AccountService) GetAllAccountsByUid(uid int64) ([]*models.Account, error) {
 	if uid <= 0 {
 		return nil, errs.ErrUserIdInvalid
@@ -39,6 +42,7 @@ func (s *AccountService) GetAllAccountsByUid(uid int64) ([]*models.Account, erro
 	return accounts, err
 }
 
+// GetAccountAndSubAccountsByAccountId returns account model and sub account models according to account id
 func (s *AccountService) GetAccountAndSubAccountsByAccountId(uid int64, accountId int64) ([]*models.Account, error) {
 	if uid <= 0 {
 		return nil, errs.ErrUserIdInvalid
@@ -54,6 +58,7 @@ func (s *AccountService) GetAccountAndSubAccountsByAccountId(uid int64, accountI
 	return accounts, err
 }
 
+// GetMaxDisplayOrder returns the max display order according to account category
 func (s *AccountService) GetMaxDisplayOrder(uid int64, category models.AccountCategory) (int, error) {
 	if uid <= 0 {
 		return 0, errs.ErrUserIdInvalid
@@ -73,6 +78,7 @@ func (s *AccountService) GetMaxDisplayOrder(uid int64, category models.AccountCa
 	}
 }
 
+// GetMaxSubAccountDisplayOrder returns the max display order of sub account according to account category and parent account id
 func (s *AccountService) GetMaxSubAccountDisplayOrder(uid int64, category models.AccountCategory, parentAccountId int64) (int, error) {
 	if uid <= 0 {
 		return 0, errs.ErrUserIdInvalid
@@ -96,6 +102,7 @@ func (s *AccountService) GetMaxSubAccountDisplayOrder(uid int64, category models
 	}
 }
 
+// CreateAccounts saves a new account model to database
 func (s *AccountService) CreateAccounts(mainAccount *models.Account, childrenAccounts []*models.Account) error {
 	if mainAccount.Uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -171,6 +178,7 @@ func (s *AccountService) CreateAccounts(mainAccount *models.Account, childrenAcc
 	})
 }
 
+// ModifyAccounts saves an existed account model to database
 func (s *AccountService) ModifyAccounts(uid int64, accounts []*models.Account) error {
 	if uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -198,6 +206,7 @@ func (s *AccountService) ModifyAccounts(uid int64, accounts []*models.Account) e
 	})
 }
 
+// HideAccount updates hidden field of given accounts
 func (s *AccountService) HideAccount(uid int64, ids []int64, hidden bool) error {
 	if uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -223,6 +232,7 @@ func (s *AccountService) HideAccount(uid int64, ids []int64, hidden bool) error
 	})
 }
 
+// ModifyAccountDisplayOrders updates display order of given accounts
 func (s *AccountService) ModifyAccountDisplayOrders(uid int64, accounts []*models.Account) error {
 	if uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -248,6 +258,7 @@ func (s *AccountService) ModifyAccountDisplayOrders(uid int64, accounts []*model
 	})
 }
 
+// DeleteAccount deletes an existed account from database
 func (s *AccountService) DeleteAccount(uid int64, accountId int64) error {
 	if uid <= 0 {
 		return errs.ErrUserIdInvalid
diff --git a/pkg/services/base.go b/pkg/services/base.go
index 79ce892d..f754d3de 100644
--- a/pkg/services/base.go
+++ b/pkg/services/base.go
@@ -6,34 +6,42 @@ import (
 	"github.com/mayswind/lab/pkg/uuid"
 )
 
+// ServiceUsingDB represents a service that need to use db
 type ServiceUsingDB struct {
 	container *datastore.DataStoreContainer
 }
 
+// UserDB returns the datastore which contains user
 func (s *ServiceUsingDB) UserDB() *datastore.Database {
 	return s.container.UserStore.Choose(0)
 }
 
+// TokenDB returns the datastore which contains user token
 func (s *ServiceUsingDB) TokenDB(uid int64) *datastore.Database {
 	return s.container.TokenStore.Choose(uid)
 }
 
+// UserDataDB returns the datastore which contains user data
 func (s *ServiceUsingDB) UserDataDB(uid int64) *datastore.Database {
 	return s.container.UserDataStore.Choose(uid)
 }
 
+// ServiceUsingConfig represents a service that need to use config
 type ServiceUsingConfig struct {
 	container *settings.ConfigContainer
 }
 
+// CurrentConfig returns the current config
 func (s *ServiceUsingConfig) CurrentConfig() *settings.Config {
 	return s.container.Current
 }
 
+// ServiceUsingUuid represents a service that need to use uuid
 type ServiceUsingUuid struct {
 	container *uuid.UuidContainer
 }
 
+// GenerateUuid generates a new uuid according to given uuid type
 func (s *ServiceUsingUuid) GenerateUuid(uuidType uuid.UuidType) int64 {
 	return s.container.GenerateUuid(uuidType)
 }
diff --git a/pkg/services/tokens.go b/pkg/services/tokens.go
index 60ee8649..dfea2195 100644
--- a/pkg/services/tokens.go
+++ b/pkg/services/tokens.go
@@ -19,11 +19,13 @@ import (
 	"github.com/mayswind/lab/pkg/utils"
 )
 
+// TokenService represents user token service
 type TokenService struct {
 	ServiceUsingDB
 	ServiceUsingConfig
 }
 
+// Initialize a user token service singleton instance
 var (
 	Tokens = &TokenService{
 		ServiceUsingDB: ServiceUsingDB{
@@ -35,6 +37,7 @@ var (
 	}
 )
 
+// GetAllTokensByUid returns all token models of given user
 func (s *TokenService) GetAllTokensByUid(uid int64) ([]*models.TokenRecord, error) {
 	if uid <= 0 {
 		return nil, errs.ErrUserIdInvalid
@@ -46,6 +49,7 @@ func (s *TokenService) GetAllTokensByUid(uid int64) ([]*models.TokenRecord, erro
 	return tokenRecords, err
 }
 
+// GetAllUnexpiredNormalTokensByUid returns all available token models of given user
 func (s *TokenService) GetAllUnexpiredNormalTokensByUid(uid int64) ([]*models.TokenRecord, error) {
 	if uid <= 0 {
 		return nil, errs.ErrUserIdInvalid
@@ -59,6 +63,7 @@ func (s *TokenService) GetAllUnexpiredNormalTokensByUid(uid int64) ([]*models.To
 	return tokenRecords, err
 }
 
+// ParseToken returns the token model according to request data
 func (s *TokenService) ParseToken(c *core.Context) (*jwt.Token, *core.UserTokenClaims, error) {
 	claims := &core.UserTokenClaims{}
 
@@ -101,14 +106,17 @@ func (s *TokenService) ParseToken(c *core.Context) (*jwt.Token, *core.UserTokenC
 	return token, claims, err
 }
 
+// CreateToken generates a new normal token and saves to database
 func (s *TokenService) CreateToken(user *models.User, ctx *core.Context) (string, *core.UserTokenClaims, error) {
 	return s.createToken(user, core.USER_TOKEN_TYPE_NORMAL, s.getUserAgent(ctx), s.CurrentConfig().TokenExpiredTimeDuration)
 }
 
+// CreateRequire2FAToken generates a new token requiring user to verify 2fa passcode and saves to database
 func (s *TokenService) CreateRequire2FAToken(user *models.User, ctx *core.Context) (string, *core.UserTokenClaims, error) {
 	return s.createToken(user, core.USER_TOKEN_TYPE_REQUIRE_2FA, s.getUserAgent(ctx), s.CurrentConfig().TemporaryTokenExpiredTimeDuration)
 }
 
+// DeleteToken deletes given token from database
 func (s *TokenService) DeleteToken(tokenRecord *models.TokenRecord) error {
 	if tokenRecord.Uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -131,6 +139,7 @@ func (s *TokenService) DeleteToken(tokenRecord *models.TokenRecord) error {
 	})
 }
 
+// DeleteTokens deletes given tokens from database
 func (s *TokenService) DeleteTokens(uid int64, tokenRecords []*models.TokenRecord) error {
 	if uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -152,6 +161,7 @@ func (s *TokenService) DeleteTokens(uid int64, tokenRecords []*models.TokenRecor
 	})
 }
 
+// DeleteTokenByClaims deletes given token from database
 func (s *TokenService) DeleteTokenByClaims(claims *core.UserTokenClaims) error {
 	uid, err := utils.StringToInt64(claims.Id)
 
@@ -168,6 +178,7 @@ func (s *TokenService) DeleteTokenByClaims(claims *core.UserTokenClaims) error {
 	return s.DeleteToken(&models.TokenRecord{Uid: uid, UserTokenId: userTokenId, CreatedUnixTime: claims.IssuedAt})
 }
 
+// DeleteTokensBeforeTime deletes tokens that is created before specific tim
 func (s *TokenService) DeleteTokensBeforeTime(uid int64, expireTime int64) error {
 	if uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -179,6 +190,7 @@ func (s *TokenService) DeleteTokensBeforeTime(uid int64, expireTime int64) error
 	})
 }
 
+// ParseFromTokenId returns token model according to token id
 func (s *TokenService) ParseFromTokenId(tokenId string) (*models.TokenRecord, error) {
 	pairs := strings.Split(tokenId, ":")
 
@@ -213,6 +225,7 @@ func (s *TokenService) ParseFromTokenId(tokenId string) (*models.TokenRecord, er
 	return tokenRecord, nil
 }
 
+// GenerateTokenId generates token id according to token model
 func (s *TokenService) GenerateTokenId(tokenRecord *models.TokenRecord) string {
 	return fmt.Sprintf("%d:%d:%d", tokenRecord.Uid, tokenRecord.CreatedUnixTime, tokenRecord.UserTokenId)
 }
diff --git a/pkg/services/transaction_categories.go b/pkg/services/transaction_categories.go
index fa8b74be..f450594e 100644
--- a/pkg/services/transaction_categories.go
+++ b/pkg/services/transaction_categories.go
@@ -11,11 +11,13 @@ import (
 	"github.com/mayswind/lab/pkg/uuid"
 )
 
+// TransactionCategoryService represents transaction category service
 type TransactionCategoryService struct {
 	ServiceUsingDB
 	ServiceUsingUuid
 }
 
+// Initialize a transaction category service singleton instance
 var (
 	TransactionCategories = &TransactionCategoryService{
 		ServiceUsingDB: ServiceUsingDB{
@@ -27,6 +29,7 @@ var (
 	}
 )
 
+// GetAllCategoriesByUid returns all transaction category models of user
 func (s *TransactionCategoryService) GetAllCategoriesByUid(uid int64, categoryType models.TransactionCategoryType, parentCategoryId int64) ([]*models.TransactionCategory, error) {
 	if uid <= 0 {
 		return nil, errs.ErrUserIdInvalid
@@ -53,6 +56,7 @@ func (s *TransactionCategoryService) GetAllCategoriesByUid(uid int64, categoryTy
 	return categories, err
 }
 
+// GetCategoryByCategoryId returns a transaction category model according to transaction category id
 func (s *TransactionCategoryService) GetCategoryByCategoryId(uid int64, categoryId int64) (*models.TransactionCategory, error) {
 	if uid <= 0 {
 		return nil, errs.ErrUserIdInvalid
@@ -74,6 +78,7 @@ func (s *TransactionCategoryService) GetCategoryByCategoryId(uid int64, category
 	return category, nil
 }
 
+// GetMaxDisplayOrder returns the max display order according to transaction category type
 func (s *TransactionCategoryService) GetMaxDisplayOrder(uid int64, categoryType models.TransactionCategoryType) (int, error) {
 	if uid <= 0 {
 		return 0, errs.ErrUserIdInvalid
@@ -93,6 +98,7 @@ func (s *TransactionCategoryService) GetMaxDisplayOrder(uid int64, categoryType
 	}
 }
 
+// GetMaxSubCategoryDisplayOrder returns the max display order of sub transaction category according to transaction category type and parent transaction category id
 func (s *TransactionCategoryService) GetMaxSubCategoryDisplayOrder(uid int64, categoryType models.TransactionCategoryType, parentCategoryId int64) (int, error) {
 	if uid <= 0 {
 		return 0, errs.ErrUserIdInvalid
@@ -116,6 +122,7 @@ func (s *TransactionCategoryService) GetMaxSubCategoryDisplayOrder(uid int64, ca
 	}
 }
 
+// CreateCategory saves a new transaction category model to database
 func (s *TransactionCategoryService) CreateCategory(category *models.TransactionCategory) error {
 	if category.Uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -133,6 +140,7 @@ func (s *TransactionCategoryService) CreateCategory(category *models.Transaction
 	})
 }
 
+// CreateCategories saves a few transaction category models to database
 func (s *TransactionCategoryService) CreateCategories(uid int64, categories map[*models.TransactionCategory][]*models.TransactionCategory) ([]*models.TransactionCategory, error) {
 	if uid <= 0 {
 		return nil, errs.ErrUserIdInvalid
@@ -186,6 +194,7 @@ func (s *TransactionCategoryService) CreateCategories(uid int64, categories map[
 	return allCategories, nil
 }
 
+// ModifyCategory saves an existed transaction category model to database
 func (s *TransactionCategoryService) ModifyCategory(category *models.TransactionCategory) error {
 	if category.Uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -206,6 +215,7 @@ func (s *TransactionCategoryService) ModifyCategory(category *models.Transaction
 	})
 }
 
+// HideCategory updates hidden field of given transaction categories
 func (s *TransactionCategoryService) HideCategory(uid int64, ids []int64, hidden bool) error {
 	if uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -231,6 +241,7 @@ func (s *TransactionCategoryService) HideCategory(uid int64, ids []int64, hidden
 	})
 }
 
+// ModifyCategoryDisplayOrders updates display order of given transaction categories
 func (s *TransactionCategoryService) ModifyCategoryDisplayOrders(uid int64, categories []*models.TransactionCategory) error {
 	if uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -256,6 +267,7 @@ func (s *TransactionCategoryService) ModifyCategoryDisplayOrders(uid int64, cate
 	})
 }
 
+// DeleteCategory deletes an existed transaction category from database
 func (s *TransactionCategoryService) DeleteCategory(uid int64, categoryId int64) error {
 	if uid <= 0 {
 		return errs.ErrUserIdInvalid
diff --git a/pkg/services/transaction_tags.go b/pkg/services/transaction_tags.go
index c8514256..da66f684 100644
--- a/pkg/services/transaction_tags.go
+++ b/pkg/services/transaction_tags.go
@@ -11,11 +11,13 @@ import (
 	"github.com/mayswind/lab/pkg/uuid"
 )
 
+// TransactionTagService represents transaction tag service
 type TransactionTagService struct {
 	ServiceUsingDB
 	ServiceUsingUuid
 }
 
+// Initialize a transaction tag service singleton instance
 var (
 	TransactionTags = &TransactionTagService{
 		ServiceUsingDB: ServiceUsingDB{
@@ -27,6 +29,7 @@ var (
 	}
 )
 
+// GetAllTagsByUid returns all transaction tag models of user
 func (s *TransactionTagService) GetAllTagsByUid(uid int64) ([]*models.TransactionTag, error) {
 	if uid <= 0 {
 		return nil, errs.ErrUserIdInvalid
@@ -38,6 +41,7 @@ func (s *TransactionTagService) GetAllTagsByUid(uid int64) ([]*models.Transactio
 	return tags, err
 }
 
+// GetTagByTagId returns a transaction tag model according to transaction tag id
 func (s *TransactionTagService) GetTagByTagId(uid int64, tagId int64) (*models.TransactionTag, error) {
 	if uid <= 0 {
 		return nil, errs.ErrUserIdInvalid
@@ -59,6 +63,7 @@ func (s *TransactionTagService) GetTagByTagId(uid int64, tagId int64) (*models.T
 	return tag, nil
 }
 
+// GetMaxDisplayOrder returns the max display order
 func (s *TransactionTagService) GetMaxDisplayOrder(uid int64) (int, error) {
 	if uid <= 0 {
 		return 0, errs.ErrUserIdInvalid
@@ -78,6 +83,7 @@ func (s *TransactionTagService) GetMaxDisplayOrder(uid int64) (int, error) {
 	}
 }
 
+// GetAllTagIdsOfTransactions returns transaction tag ids for given transactions
 func (s *TransactionTagService) GetAllTagIdsOfTransactions(uid int64, transactionIds []int64) (map[int64][]int64, error) {
 	if uid <= 0 {
 		return nil, errs.ErrUserIdInvalid
@@ -104,6 +110,7 @@ func (s *TransactionTagService) GetAllTagIdsOfTransactions(uid int64, transactio
 	return allTransactionTagIds, err
 }
 
+// CreateTag saves a new transaction tag model to database
 func (s *TransactionTagService) CreateTag(tag *models.TransactionTag) error {
 	if tag.Uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -128,6 +135,7 @@ func (s *TransactionTagService) CreateTag(tag *models.TransactionTag) error {
 	})
 }
 
+// ModifyTag saves an existed transaction tag model to database
 func (s *TransactionTagService) ModifyTag(tag *models.TransactionTag) error {
 	if tag.Uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -156,6 +164,7 @@ func (s *TransactionTagService) ModifyTag(tag *models.TransactionTag) error {
 	})
 }
 
+// HideTag updates hidden field of given transaction tags
 func (s *TransactionTagService) HideTag(uid int64, ids []int64, hidden bool) error {
 	if uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -181,6 +190,7 @@ func (s *TransactionTagService) HideTag(uid int64, ids []int64, hidden bool) err
 	})
 }
 
+// ModifyTagDisplayOrders updates display order of given transaction tags
 func (s *TransactionTagService) ModifyTagDisplayOrders(uid int64, tags []*models.TransactionTag) error {
 	if uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -206,6 +216,7 @@ func (s *TransactionTagService) ModifyTagDisplayOrders(uid int64, tags []*models
 	})
 }
 
+// DeleteTag deletes an existed transaction tag from database
 func (s *TransactionTagService) DeleteTag(uid int64, tagId int64) error {
 	if uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -232,6 +243,7 @@ func (s *TransactionTagService) DeleteTag(uid int64, tagId int64) error {
 	})
 }
 
+// ExistsTagName returns whether the given tag name exists
 func (s *TransactionTagService) ExistsTagName(uid int64, name string) (bool, error) {
 	if name == "" {
 		return false, errs.ErrTransactionTagNameIsEmpty
diff --git a/pkg/services/transactions.go b/pkg/services/transactions.go
index 98f6e3ff..d9b67478 100644
--- a/pkg/services/transactions.go
+++ b/pkg/services/transactions.go
@@ -13,11 +13,13 @@ import (
 	"github.com/mayswind/lab/pkg/uuid"
 )
 
+// TransactionService represents transaction service
 type TransactionService struct {
 	ServiceUsingDB
 	ServiceUsingUuid
 }
 
+// Initialize a transaction service singleton instance
 var (
 	Transactions = &TransactionService{
 		ServiceUsingDB: ServiceUsingDB{
@@ -29,6 +31,7 @@ var (
 	}
 )
 
+// GetTransactionsByMaxTime returns transactions before given time
 func (s *TransactionService) GetTransactionsByMaxTime(uid int64, maxTime int64, count int) ([]*models.Transaction, error) {
 	if uid <= 0 {
 		return nil, errs.ErrUserIdInvalid
@@ -44,6 +47,7 @@ func (s *TransactionService) GetTransactionsByMaxTime(uid int64, maxTime int64,
 	return transactions, err
 }
 
+// GetTransactionsInMonthByPage returns transactions in given year and month
 func (s *TransactionService) GetTransactionsInMonthByPage(uid int64, year int, month int, page int, count int) ([]*models.Transaction, error) {
 	if uid <= 0 {
 		return nil, errs.ErrUserIdInvalid
@@ -74,6 +78,7 @@ func (s *TransactionService) GetTransactionsInMonthByPage(uid int64, year int, m
 	return transactions, err
 }
 
+// GetTransactionByTransactionId returns a transaction model according to transaction id
 func (s *TransactionService) GetTransactionByTransactionId(uid int64, transactionId int64) (*models.Transaction, error) {
 	if uid <= 0 {
 		return nil, errs.ErrUserIdInvalid
@@ -95,6 +100,7 @@ func (s *TransactionService) GetTransactionByTransactionId(uid int64, transactio
 	return transaction, nil
 }
 
+// GetAllTransactionCount returns total count of transactions
 func (s *TransactionService) GetAllTransactionCount(uid int64) (int64, error) {
 	if uid <= 0 {
 		return 0, errs.ErrUserIdInvalid
@@ -103,6 +109,7 @@ func (s *TransactionService) GetAllTransactionCount(uid int64) (int64, error) {
 	return s.UserDataDB(uid).Where("uid=? AND deleted=?", uid, false).Count(&models.Transaction{})
 }
 
+// GetMonthTransactionCount returns total count of transactions in given year and month
 func (s *TransactionService) GetMonthTransactionCount(uid int64, year int64, month int64) (int64, error) {
 	if uid <= 0 {
 		return 0, errs.ErrUserIdInvalid
@@ -122,6 +129,7 @@ func (s *TransactionService) GetMonthTransactionCount(uid int64, year int64, mon
 	return s.UserDataDB(uid).Where("uid=? AND deleted=? AND transaction_time>=? AND transaction_time<?", uid, false, startUnixTime, endUnixTime).Count(&models.Transaction{})
 }
 
+// CreateTransaction saves a new transaction to database
 func (s *TransactionService) CreateTransaction(transaction *models.Transaction, tagIds []int64) error {
 	if transaction.Uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -346,6 +354,7 @@ func (s *TransactionService) CreateTransaction(transaction *models.Transaction,
 	})
 }
 
+// ModifyTransaction saves an existed transaction to database
 func (s *TransactionService) ModifyTransaction(transaction *models.Transaction, addTagIds []int64, removeTagIds []int64) error {
 	if transaction.Uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -630,6 +639,7 @@ func (s *TransactionService) ModifyTransaction(transaction *models.Transaction,
 	return nil
 }
 
+// DeleteTransaction deletes an existed transaction from database
 func (s *TransactionService) DeleteTransaction(uid int64, transactionId int64) error {
 	if uid <= 0 {
 		return errs.ErrUserIdInvalid
diff --git a/pkg/services/twofactor_authorizations.go b/pkg/services/twofactor_authorizations.go
index 1a6f6757..d623d00c 100644
--- a/pkg/services/twofactor_authorizations.go
+++ b/pkg/services/twofactor_authorizations.go
@@ -22,12 +22,14 @@ const (
 	twoFactorRecoveryCodeLength int  = 10 // bytes
 )
 
+// TwoFactorAuthorizationService represents 2fa service
 type TwoFactorAuthorizationService struct {
 	ServiceUsingDB
 	ServiceUsingConfig
 	ServiceUsingUuid
 }
 
+// Initialize a 2fa service singleton instance
 var (
 	TwoFactorAuthorizations = &TwoFactorAuthorizationService{
 		ServiceUsingDB: ServiceUsingDB{
@@ -42,6 +44,7 @@ var (
 	}
 )
 
+// GetUserTwoFactorSettingByUid returns the 2fa setting model according to user uid
 func (s *TwoFactorAuthorizationService) GetUserTwoFactorSettingByUid(uid int64) (*models.TwoFactor, error) {
 	if uid <= 0 {
 		return nil, errs.ErrUserIdInvalid
@@ -65,6 +68,7 @@ func (s *TwoFactorAuthorizationService) GetUserTwoFactorSettingByUid(uid int64)
 	return twoFactor, nil
 }
 
+// GenerateTwoFactorSecret generates a new 2fa secret
 func (s *TwoFactorAuthorizationService) GenerateTwoFactorSecret(user *models.User) (*otp.Key, error) {
 	if user == nil {
 		return nil, errs.ErrUserNotFound
@@ -80,6 +84,7 @@ func (s *TwoFactorAuthorizationService) GenerateTwoFactorSecret(user *models.Use
 	return key, err
 }
 
+// CreateTwoFactorSetting saves a new 2fa setting to database
 func (s *TwoFactorAuthorizationService) CreateTwoFactorSetting(twoFactor *models.TwoFactor) error {
 	if twoFactor.Uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -100,6 +105,7 @@ func (s *TwoFactorAuthorizationService) CreateTwoFactorSetting(twoFactor *models
 	})
 }
 
+// DeleteTwoFactorSetting deletes an existed 2fa setting from database
 func (s *TwoFactorAuthorizationService) DeleteTwoFactorSetting(uid int64) error {
 	if uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -118,6 +124,7 @@ func (s *TwoFactorAuthorizationService) DeleteTwoFactorSetting(uid int64) error
 	})
 }
 
+// ExistsTwoFactorSetting returns whether the given user has existed 2fa setting
 func (s *TwoFactorAuthorizationService) ExistsTwoFactorSetting(uid int64) (bool, error) {
 	if uid <= 0 {
 		return false, errs.ErrUserIdInvalid
@@ -126,6 +133,7 @@ func (s *TwoFactorAuthorizationService) ExistsTwoFactorSetting(uid int64) (bool,
 	return s.UserDB().Cols("uid").Where("uid=?", uid).Exist(&models.TwoFactor{})
 }
 
+// GetAndUseUserTwoFactorRecoveryCode checks whether the given 2fa recovery code exists and marks it used
 func (s *TwoFactorAuthorizationService) GetAndUseUserTwoFactorRecoveryCode(uid int64, recoveryCode string, salt string) error {
 	if uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -146,6 +154,7 @@ func (s *TwoFactorAuthorizationService) GetAndUseUserTwoFactorRecoveryCode(uid i
 	})
 }
 
+// GenerateTwoFactorRecoveryCodes generates new 2fa recovery codes
 func (s *TwoFactorAuthorizationService) GenerateTwoFactorRecoveryCodes() ([]string, error) {
 	recoveryCodes := make([]string, twoFactorRecoveryCodeCount)
 
@@ -162,6 +171,7 @@ func (s *TwoFactorAuthorizationService) GenerateTwoFactorRecoveryCodes() ([]stri
 	return recoveryCodes, nil
 }
 
+// CreateTwoFactorRecoveryCodes saves new 2fa recovery codes to database
 func (s *TwoFactorAuthorizationService) CreateTwoFactorRecoveryCodes(uid int64, recoveryCodes []string, salt string) error {
 	twoFactorRecoveryCodes := make([]*models.TwoFactorRecoveryCode, len(recoveryCodes))
 
@@ -194,6 +204,7 @@ func (s *TwoFactorAuthorizationService) CreateTwoFactorRecoveryCodes(uid int64,
 	})
 }
 
+// DeleteTwoFactorRecoveryCodes deletes existed 2fa recovery codes from database
 func (s *TwoFactorAuthorizationService) DeleteTwoFactorRecoveryCodes(uid int64) error {
 	if uid <= 0 {
 		return errs.ErrUserIdInvalid
diff --git a/pkg/services/users.go b/pkg/services/users.go
index 8e0ea5fe..f7bab034 100644
--- a/pkg/services/users.go
+++ b/pkg/services/users.go
@@ -12,11 +12,13 @@ import (
 	"github.com/mayswind/lab/pkg/uuid"
 )
 
+// UserService represents user service
 type UserService struct {
 	ServiceUsingDB
 	ServiceUsingUuid
 }
 
+// Initialize a user service singleton instance
 var (
 	Users = &UserService{
 		ServiceUsingDB: ServiceUsingDB{
@@ -28,6 +30,7 @@ var (
 	}
 )
 
+// GetUserByUsernameOrEmailAndPassword returns the user model according to login name and password
 func (s *UserService) GetUserByUsernameOrEmailAndPassword(loginname string, password string) (*models.User, error) {
 	var user *models.User
 	var err error
@@ -51,6 +54,7 @@ func (s *UserService) GetUserByUsernameOrEmailAndPassword(loginname string, pass
 	return user, nil
 }
 
+// GetUserById returns the user model according to user uid
 func (s *UserService) GetUserById(uid int64) (*models.User, error) {
 	if uid <= 0 {
 		return nil, errs.ErrUserIdInvalid
@@ -68,6 +72,7 @@ func (s *UserService) GetUserById(uid int64) (*models.User, error) {
 	return user, nil
 }
 
+// GetUserByUsername returns the user model according to user name
 func (s *UserService) GetUserByUsername(username string) (*models.User, error) {
 	if username == "" {
 		return nil, errs.ErrUsernameIsEmpty
@@ -85,6 +90,7 @@ func (s *UserService) GetUserByUsername(username string) (*models.User, error) {
 	return user, nil
 }
 
+// GetUserByEmail returns the user model according to user email
 func (s *UserService) GetUserByEmail(email string) (*models.User, error) {
 	if email == "" {
 		return nil, errs.ErrEmailIsEmpty
@@ -102,6 +108,7 @@ func (s *UserService) GetUserByEmail(email string) (*models.User, error) {
 	return user, nil
 }
 
+// CreateUser saves a new user model to database
 func (s *UserService) CreateUser(user *models.User) error {
 	exists, err := s.ExistsUsername(user.Username)
 
@@ -146,6 +153,7 @@ func (s *UserService) CreateUser(user *models.User) error {
 	})
 }
 
+// UpdateUser saves an existed user model to database
 func (s *UserService) UpdateUser(user *models.User) (keyProfileUpdated bool, err error) {
 	if user.Uid <= 0 {
 		return false, errs.ErrUserIdInvalid
@@ -208,6 +216,7 @@ func (s *UserService) UpdateUser(user *models.User) (keyProfileUpdated bool, err
 	return keyProfileUpdated, nil
 }
 
+// UpdateUserLastLoginTime updates the last login time field
 func (s *UserService) UpdateUserLastLoginTime(uid int64) error {
 	if uid <= 0 {
 		return errs.ErrUserIdInvalid
@@ -219,6 +228,7 @@ func (s *UserService) UpdateUserLastLoginTime(uid int64) error {
 	})
 }
 
+// ExistsUsername returns whether the given user name exists
 func (s *UserService) ExistsUsername(username string) (bool, error) {
 	if username == "" {
 		return false, errs.ErrUsernameIsEmpty
@@ -227,6 +237,7 @@ func (s *UserService) ExistsUsername(username string) (bool, error) {
 	return s.UserDB().Cols("username").Where("username=? AND deleted=?", username, false).Exist(&models.User{})
 }
 
+// ExistsEmail returns whether the given user email exists
 func (s *UserService) ExistsEmail(email string) (bool, error) {
 	if email == "" {
 		return false, errs.ErrEmailIsEmpty
@@ -235,6 +246,7 @@ func (s *UserService) ExistsEmail(email string) (bool, error) {
 	return s.UserDB().Cols("email").Where("email=? AND deleted=?", email, false).Exist(&models.User{})
 }
 
+// IsPasswordEqualsUserPassword returns whether the given password is correct
 func (s *UserService) IsPasswordEqualsUserPassword(password string, user *models.User) bool {
 	return user.Password == utils.EncodePassword(password, user.Salt)
 }