fix: unify email identity sync and retry first-bind defaults

backend/internal/repository/user_repo.go

@@ -209,14 +209,6 @@ func (r *userRepository) Update(ctx context.Context, userIn *service.User) error
 	return nil
 }
 
-func (r *userRepository) EnsureEmailAuthIdentity(ctx context.Context, userID int64, email string) error {
-	return ensureEmailAuthIdentityWithClient(ctx, r.client, userID, email, "service_dual_write")
-}
-
-func (r *userRepository) ReplaceEmailAuthIdentity(ctx context.Context, userID int64, oldEmail, newEmail string) error {
-	return replaceEmailAuthIdentityWithClient(ctx, r.client, userID, oldEmail, newEmail, "service_dual_write")
-}
-
 func ensureEmailAuthIdentityWithClient(ctx context.Context, client *dbent.Client, userID int64, email string, source string) error {
 	client = clientFromContext(ctx, client)
 	if client == nil || userID <= 0 {

backend/internal/service/admin_service.go

@@ -650,9 +650,6 @@ func (s *adminServiceImpl) CreateUser(ctx context.Context, input *CreateUserInpu
 	if err := s.userRepo.Create(ctx, user); err != nil {
 		return nil, err
 	}
-	if err := ensureEmailAuthIdentitySync(ctx, s.userRepo, user.ID, user.Email); err != nil {
-		return nil, fmt.Errorf("sync email auth identity: %w", err)
-	}
 	s.assignDefaultSubscriptions(ctx, user.ID)
 	return user, nil
 }
@@ -688,7 +685,6 @@ func (s *adminServiceImpl) UpdateUser(ctx context.Context, id int64, input *Upda
 	oldConcurrency := user.Concurrency
 	oldStatus := user.Status
 	oldRole := user.Role
-	oldEmail := user.Email
 
 	if input.Email != "" {
 		user.Email = input.Email
@@ -721,9 +717,6 @@ func (s *adminServiceImpl) UpdateUser(ctx context.Context, id int64, input *Upda
 	if err := s.userRepo.Update(ctx, user); err != nil {
 		return nil, err
 	}
-	if err := replaceEmailAuthIdentitySync(ctx, s.userRepo, user.ID, oldEmail, user.Email); err != nil {
-		return nil, fmt.Errorf("sync email auth identity: %w", err)
-	}
 
 	// 同步用户专属分组倍率
 	if input.GroupRates != nil && s.userGroupRateRepo != nil {

backend/internal/service/admin_service_email_identity_sync_test.go

@@ -31,6 +31,8 @@ type emailSyncRepoStub struct {
 	updated      []*User
 	ensureCalls  []ensureEmailCall
 	replaceCalls []replaceEmailCall
+	ensureErr    error
+	replaceErr   error
 }
 
 func (s *emailSyncRepoStub) Create(_ context.Context, user *User) error {
@@ -125,7 +127,7 @@ func (s *emailSyncRepoStub) DisableTotp(context.Context, int64) error { return n
 
 func (s *emailSyncRepoStub) EnsureEmailAuthIdentity(_ context.Context, userID int64, email string) error {
 	s.ensureCalls = append(s.ensureCalls, ensureEmailCall{userID: userID, email: email})
-	return nil
+	return s.ensureErr
 }
 
 func (s *emailSyncRepoStub) ReplaceEmailAuthIdentity(_ context.Context, userID int64, oldEmail, newEmail string) error {
@@ -134,11 +136,14 @@ func (s *emailSyncRepoStub) ReplaceEmailAuthIdentity(_ context.Context, userID i
 		oldEmail: oldEmail,
 		newEmail: newEmail,
 	})
-	return nil
+	return s.replaceErr
 }
 
-func TestAdminService_CreateUser_EnsuresEmailAuthIdentity(t *testing.T) {
+func TestAdminService_CreateUser_DoesNotReturnPartialSuccessFromEmailIdentityResync(t *testing.T) {
-	repo := &emailSyncRepoStub{nextID: 55}
+	repo := &emailSyncRepoStub{
+		nextID:    55,
+		ensureErr: fmt.Errorf("unexpected email resync"),
+	}
 	svc := &adminServiceImpl{userRepo: repo}
 
 	user, err := svc.CreateUser(context.Background(), &CreateUserInput{
@@ -147,14 +152,12 @@ func TestAdminService_CreateUser_EnsuresEmailAuthIdentity(t *testing.T) {
 	})
 	require.NoError(t, err)
 	require.NotNil(t, user)
-	require.Equal(t, []ensureEmailCall{{
+	require.Equal(t, int64(55), user.ID)
-		userID: 55,
+	require.Empty(t, repo.ensureCalls)
-		email:  "admin-created@example.com",
-	}}, repo.ensureCalls)
 	require.Empty(t, repo.replaceCalls)
 }
 
-func TestAdminService_UpdateUser_ReplacesEmailAuthIdentity(t *testing.T) {
+func TestAdminService_UpdateUser_DoesNotReturnPartialSuccessFromEmailIdentityResync(t *testing.T) {
 	repo := &emailSyncRepoStub{
 		user: &User{
 			ID:          91,
@@ -163,6 +166,7 @@ func TestAdminService_UpdateUser_ReplacesEmailAuthIdentity(t *testing.T) {
 			Status:      StatusActive,
 			Concurrency: 3,
 		},
+		replaceErr: fmt.Errorf("unexpected email resync"),
 	}
 	svc := &adminServiceImpl{userRepo: repo}
 
@@ -172,10 +176,6 @@ func TestAdminService_UpdateUser_ReplacesEmailAuthIdentity(t *testing.T) {
 	require.NoError(t, err)
 	require.NotNil(t, updated)
 	require.Equal(t, "after@example.com", updated.Email)
-	require.Equal(t, []replaceEmailCall{{
+	require.Empty(t, repo.replaceCalls)
-		userID:   91,
-		oldEmail: "before@example.com",
-		newEmail: "after@example.com",
-	}}, repo.replaceCalls)
 	require.Empty(t, repo.ensureCalls)
 }

backend/internal/service/auth_service.go

@@ -768,9 +768,6 @@ func (s *AuthService) postAuthUserBootstrap(ctx context.Context, user *User, sig
 	}
 	s.updateUserSignupSource(ctx, user.ID, signupSource)
 
-	if signupSource == "email" {
-		s.ensureEmailAuthIdentity(ctx, user)
-	}
 	if touchLogin {
 		s.touchUserLogin(ctx, user.ID)
 	}
@@ -807,21 +804,81 @@ func (s *AuthService) backfillEmailIdentityOnSuccessfulLogin(ctx context.Context
 	if s == nil || user == nil || user.ID <= 0 {
 		return
 	}
-	if s.ensureEmailAuthIdentity(ctx, user) {
+	identity, created := s.ensureEmailAuthIdentity(ctx, user)
+	if s.shouldApplyEmailFirstBindDefaults(ctx, user.ID, identity, created) {
 		if err := s.ApplyProviderDefaultSettingsOnFirstBind(ctx, user.ID, "email"); err != nil {
 			logger.LegacyPrintf("service.auth", "[Auth] Failed to apply email first bind defaults: user_id=%d err=%v", user.ID, err)
 		}
 	}
 }
 
-func (s *AuthService) ensureEmailAuthIdentity(ctx context.Context, user *User) bool {
+func (s *AuthService) shouldApplyEmailFirstBindDefaults(
-	if s == nil || s.entClient == nil || user == nil || user.ID <= 0 {
+	ctx context.Context,
+	userID int64,
+	identity *dbent.AuthIdentity,
+	created bool,
+) bool {
+	if created {
+		return true
+	}
+	if s == nil || s.entClient == nil || userID <= 0 || identity == nil || identity.UserID != userID {
 		return false
 	}
+	if emailAuthIdentitySource(identity.Metadata) != "auth_service_dual_write" {
+		return false
+	}
+
+	hasGrant, err := s.hasProviderGrantRecord(ctx, userID, "email", "first_bind")
+	if err != nil {
+		logger.LegacyPrintf("service.auth", "[Auth] Failed to inspect email first bind grant state: user_id=%d err=%v", userID, err)
+		return false
+	}
+	return !hasGrant
+}
+
+func emailAuthIdentitySource(metadata map[string]any) string {
+	if len(metadata) == 0 {
+		return ""
+	}
+	raw, ok := metadata["source"]
+	if !ok {
+		return ""
+	}
+	return strings.TrimSpace(fmt.Sprint(raw))
+}
+
+func (s *AuthService) hasProviderGrantRecord(
+	ctx context.Context,
+	userID int64,
+	providerType string,
+	grantReason string,
+) (bool, error) {
+	if s == nil || s.entClient == nil || userID <= 0 {
+		return false, nil
+	}
+
+	rows, err := s.entClient.QueryContext(
+		ctx,
+		`SELECT 1 FROM user_provider_default_grants WHERE user_id = ? AND provider_type = ? AND grant_reason = ? LIMIT 1`,
+		userID,
+		strings.TrimSpace(providerType),
+		strings.TrimSpace(grantReason),
+	)
+	if err != nil {
+		return false, err
+	}
+	defer rows.Close()
+	return rows.Next(), rows.Err()
+}
+
+func (s *AuthService) ensureEmailAuthIdentity(ctx context.Context, user *User) (*dbent.AuthIdentity, bool) {
+	if s == nil || s.entClient == nil || user == nil || user.ID <= 0 {
+		return nil, false
+	}
 
 	email := strings.ToLower(strings.TrimSpace(user.Email))
 	if email == "" || isReservedEmail(email) {
-		return false
+		return nil, false
 	}
 
 	client := s.entClient
@@ -840,7 +897,7 @@ func (s *AuthService) ensureEmailAuthIdentity(ctx context.Context, user *User) b
 	existed, err := buildQuery().Exist(ctx)
 	if err != nil {
 		logger.LegacyPrintf("service.auth", "[Auth] Failed to inspect email auth identity: user_id=%d email=%s err=%v", user.ID, email, err)
-		return false
+		return nil, false
 	}
 
 	if !existed {
@@ -861,21 +918,21 @@ func (s *AuthService) ensureEmailAuthIdentity(ctx context.Context, user *User) b
 			DoNothing().
 			Exec(ctx); err != nil {
 			logger.LegacyPrintf("service.auth", "[Auth] Failed to ensure email auth identity: user_id=%d email=%s err=%v", user.ID, email, err)
-			return false
+			return nil, false
 		}
 	}
 
 	identity, err := buildQuery().Only(ctx)
 	if err != nil {
 		logger.LegacyPrintf("service.auth", "[Auth] Failed to reload email auth identity: user_id=%d email=%s err=%v", user.ID, email, err)
-		return false
+		return nil, false
 	}
 	if identity.UserID != user.ID {
 		logger.LegacyPrintf("service.auth", "[Auth] Email auth identity ownership mismatch: user_id=%d email=%s owner_id=%d", user.ID, email, identity.UserID)
-		return false
+		return nil, false
 	}
 
-	return !existed
+	return identity, !existed
 }
 
 func inferLegacySignupSource(email string) string {

backend/internal/service/auth_service_identity_sync_test.go

@@ -5,6 +5,7 @@ package service_test
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"testing"
 	"time"
 
@@ -34,6 +35,24 @@ func (s *authIdentityDefaultSubAssignerStub) AssignOrExtendSubscription(
 	return &service.UserSubscription{UserID: input.UserID, GroupID: input.GroupID}, true, nil
 }
 
+type flakyAuthIdentityDefaultSubAssignerStub struct {
+	failuresRemaining int
+	calls             []*service.AssignSubscriptionInput
+}
+
+func (s *flakyAuthIdentityDefaultSubAssignerStub) AssignOrExtendSubscription(
+	_ context.Context,
+	input *service.AssignSubscriptionInput,
+) (*service.UserSubscription, bool, error) {
+	cloned := *input
+	s.calls = append(s.calls, &cloned)
+	if s.failuresRemaining > 0 {
+		s.failuresRemaining--
+		return nil, false, errors.New("temporary assign failure")
+	}
+	return &service.UserSubscription{UserID: input.UserID, GroupID: input.GroupID}, true, nil
+}
+
 type authIdentitySettingRepoStub struct {
 	values map[string]string
 }
@@ -333,6 +352,55 @@ func TestAuthServiceLogin_DoesNotApplyEmailFirstBindDefaultsWhenIdentityAlreadyE
 	require.Equal(t, 0, countProviderGrantRecords(t, client, user.ID, "email", "first_bind"))
 }
 
+func TestAuthServiceLogin_RetriesEmailFirstBindDefaultsAfterPreviousFailure(t *testing.T) {
+	assigner := &flakyAuthIdentityDefaultSubAssignerStub{failuresRemaining: 1}
+	svc, _, client := newAuthServiceWithEnt(t, map[string]string{
+		service.SettingKeyRegistrationEnabled:                    "true",
+		service.SettingKeyAuthSourceDefaultEmailBalance:          "8.5",
+		service.SettingKeyAuthSourceDefaultEmailConcurrency:      "4",
+		service.SettingKeyAuthSourceDefaultEmailSubscriptions:    `[{"group_id":11,"validity_days":30}]`,
+		service.SettingKeyAuthSourceDefaultEmailGrantOnFirstBind: "true",
+	}, assigner)
+	ctx := context.Background()
+
+	passwordHash, err := svc.HashPassword("password")
+	require.NoError(t, err)
+	user, err := client.User.Create().
+		SetEmail("retry-first-bind@example.com").
+		SetUsername("retry-user").
+		SetPasswordHash(passwordHash).
+		SetBalance(1.5).
+		SetConcurrency(2).
+		SetRole(service.RoleUser).
+		SetStatus(service.StatusActive).
+		Save(ctx)
+	require.NoError(t, err)
+
+	token, gotUser, err := svc.Login(ctx, user.Email, "password")
+	require.NoError(t, err)
+	require.NotEmpty(t, token)
+	require.NotNil(t, gotUser)
+
+	storedUser, err := client.User.Get(ctx, user.ID)
+	require.NoError(t, err)
+	require.Equal(t, 1.5, storedUser.Balance)
+	require.Equal(t, 2, storedUser.Concurrency)
+	require.Len(t, assigner.calls, 1)
+	require.Equal(t, 0, countProviderGrantRecords(t, client, user.ID, "email", "first_bind"))
+
+	token, gotUser, err = svc.Login(ctx, user.Email, "password")
+	require.NoError(t, err)
+	require.NotEmpty(t, token)
+	require.NotNil(t, gotUser)
+
+	storedUser, err = client.User.Get(ctx, user.ID)
+	require.NoError(t, err)
+	require.Equal(t, 10.0, storedUser.Balance)
+	require.Equal(t, 6, storedUser.Concurrency)
+	require.Len(t, assigner.calls, 2)
+	require.Equal(t, 1, countProviderGrantRecords(t, client, user.ID, "email", "first_bind"))
+}
+
 func countProviderGrantRecords(
 	t *testing.T,
 	client *dbent.Client,

backend/internal/service/user_service.go

@@ -161,33 +161,6 @@ type userAuthIdentityReader interface {
 	ListUserAuthIdentities(ctx context.Context, userID int64) ([]UserAuthIdentityRecord, error)
 }
 
-type emailAuthIdentitySynchronizer interface {
-	EnsureEmailAuthIdentity(ctx context.Context, userID int64, email string) error
-	ReplaceEmailAuthIdentity(ctx context.Context, userID int64, oldEmail, newEmail string) error
-}
-
-func ensureEmailAuthIdentitySync(ctx context.Context, repo UserRepository, userID int64, email string) error {
-	syncer, ok := repo.(emailAuthIdentitySynchronizer)
-	if !ok {
-		return nil
-	}
-	return syncer.EnsureEmailAuthIdentity(ctx, userID, email)
-}
-
-func replaceEmailAuthIdentitySync(ctx context.Context, repo UserRepository, userID int64, oldEmail, newEmail string) error {
-	oldNormalized := strings.ToLower(strings.TrimSpace(oldEmail))
-	newNormalized := strings.ToLower(strings.TrimSpace(newEmail))
-	if oldNormalized == newNormalized {
-		return nil
-	}
-
-	syncer, ok := repo.(emailAuthIdentitySynchronizer)
-	if !ok {
-		return nil
-	}
-	return syncer.ReplaceEmailAuthIdentity(ctx, userID, oldEmail, newEmail)
-}
-
 // ChangePasswordRequest 修改密码请求
 type ChangePasswordRequest struct {
 	CurrentPassword string `json:"current_password"`
@@ -281,7 +254,6 @@ func (s *UserService) UpdateProfile(ctx context.Context, userID int64, req Updat
 		return nil, fmt.Errorf("get user: %w", err)
 	}
 	oldConcurrency := user.Concurrency
-	oldEmail := user.Email
 
 	// 更新字段
 	if req.Email != nil {
@@ -326,9 +298,6 @@ func (s *UserService) UpdateProfile(ctx context.Context, userID int64, req Updat
 	if err := s.userRepo.Update(ctx, user); err != nil {
 		return nil, fmt.Errorf("update user: %w", err)
 	}
-	if err := replaceEmailAuthIdentitySync(ctx, s.userRepo, user.ID, oldEmail, user.Email); err != nil {
-		return nil, fmt.Errorf("sync email auth identity: %w", err)
-	}
 	if s.authCacheInvalidator != nil && user.Concurrency != oldConcurrency {
 		s.authCacheInvalidator.InvalidateAuthCacheByUserID(ctx, userID)
 	}

backend/internal/service/user_service_email_identity_sync_test.go

@@ -9,7 +9,7 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func TestUpdateProfile_ReplacesEmailAuthIdentityWhenEmailChanges(t *testing.T) {
+func TestUpdateProfile_DoesNotReturnPartialSuccessFromEmailIdentityResync(t *testing.T) {
 	repo := &emailSyncRepoStub{
 		user: &User{
 			ID:          19,
@@ -17,6 +17,7 @@ func TestUpdateProfile_ReplacesEmailAuthIdentityWhenEmailChanges(t *testing.T) {
 			Username:    "tester",
 			Concurrency: 2,
 		},
+		replaceErr: context.DeadlineExceeded,
 	}
 	svc := NewUserService(repo, nil, nil, nil)
 
@@ -28,10 +29,6 @@ func TestUpdateProfile_ReplacesEmailAuthIdentityWhenEmailChanges(t *testing.T) {
 	require.NotNil(t, updated)
 	require.Equal(t, newEmail, updated.Email)
 	require.Equal(t, 1, repo.updateCalls)
-	require.Equal(t, []replaceEmailCall{{
+	require.Empty(t, repo.replaceCalls)
-		userID:   19,
-		oldEmail: "profile-before@example.com",
-		newEmail: "profile-after@example.com",
-	}}, repo.replaceCalls)
 	require.Empty(t, repo.ensureCalls)
 }