refactor(account): generalize RemoveEmailIdentity to RemoveIdentity(kind)

Generalize the email-erase store op to any identity kind (with the same
last-identity guard and, for email, the pending-confirmation cleanup) so the
profile Unlink control can reuse it for Telegram/VK. RemoveEmailIdentity stays as a
thin wrapper for the admin console.

backend/internal/account/link.go

@@ -21,25 +21,25 @@ var ErrIdentityTaken = errors.New("account: identity already linked to another a
 // none, making it unreachable after logout. The admin email-erase refuses it.
 var ErrLastIdentity = errors.New("account: cannot remove the last identity")
 
-// RemoveEmailIdentity deletes the account's email identity and any pending confirmations
+// RemoveIdentity deletes the account's identity of the given kind (and, for an email,
-// for it, freeing the address for reuse. It refuses when the email is the account's only
+// any pending confirmations for it), freeing it for reuse. It refuses when that is the
-// identity (ErrLastIdentity) — that would leave the account unreachable — and returns
+// account's only identity (ErrLastIdentity) — which would leave the account
-// ErrNotFound when the account has no email identity. It backs the admin console's
+// unreachable — and returns ErrNotFound when the account has no identity of that kind.
-// "erase email" action.
+// It backs the profile Unlink control and the admin "erase email" action.
-func (s *Store) RemoveEmailIdentity(ctx context.Context, accountID uuid.UUID) error {
+func (s *Store) RemoveIdentity(ctx context.Context, accountID uuid.UUID, kind string) error {
 	ids, err := s.Identities(ctx, accountID)
 	if err != nil {
 		return err
 	}
-	hasEmail, others := false, 0
+	hasKind, others := false, 0
 	for _, id := range ids {
-		if id.Kind == KindEmail {
+		if id.Kind == kind {
-			hasEmail = true
+			hasKind = true
 		} else {
 			others++
 		}
 	}
-	if !hasEmail {
+	if !hasKind {
 		return ErrNotFound
 	}
 	if others == 0 {
@@ -48,21 +48,29 @@ func (s *Store) RemoveEmailIdentity(ctx context.Context, accountID uuid.UUID) er
 	return withTx(ctx, s.db, func(tx *sql.Tx) error {
 		delID := table.Identities.DELETE().WHERE(
 			table.Identities.AccountID.EQ(postgres.UUID(accountID)).
-				AND(table.Identities.Kind.EQ(postgres.String(KindEmail))),
+				AND(table.Identities.Kind.EQ(postgres.String(kind))),
 		)
 		if _, err := delID.ExecContext(ctx, tx); err != nil {
-			return fmt.Errorf("account: delete email identity %s: %w", accountID, err)
+			return fmt.Errorf("account: delete %s identity %s: %w", kind, accountID, err)
 		}
-		delConf := table.EmailConfirmations.DELETE().WHERE(
+		if kind == KindEmail {
-			table.EmailConfirmations.AccountID.EQ(postgres.UUID(accountID)),
+			delConf := table.EmailConfirmations.DELETE().WHERE(
-		)
+				table.EmailConfirmations.AccountID.EQ(postgres.UUID(accountID)),
-		if _, err := delConf.ExecContext(ctx, tx); err != nil {
+			)
-			return fmt.Errorf("account: delete email confirmations %s: %w", accountID, err)
+			if _, err := delConf.ExecContext(ctx, tx); err != nil {
+				return fmt.Errorf("account: delete email confirmations %s: %w", accountID, err)
+			}
 		}
 		return nil
 	})
 }
 
+// RemoveEmailIdentity erases the account's email identity. It backs the admin console's
+// "erase email" action; the user-facing profile never unlinks email (it is changed).
+func (s *Store) RemoveEmailIdentity(ctx context.Context, accountID uuid.UUID) error {
+	return s.RemoveIdentity(ctx, accountID, KindEmail)
+}
+
 // RequestLinkCode issues and mails a confirm-code for email to accountID,
 // replacing any prior pending code. Unlike RequestCode it never refuses up front
 // (taken or already-confirmed): possession of the address is the authorization for