add service

internal/repository/interfaces.go

@@ -37,6 +37,7 @@ type InviteRepository interface {
 	CreateTx(ctx context.Context, tx pgx.Tx, invite *model.InviteCode) error
 	FindByCode(ctx context.Context, code int64) (*model.InviteCode, error)
 	FindActiveByCode(ctx context.Context, code int64) (*model.InviteCode, error)
+	FindActiveByUserID(ctx context.Context, userID int) (*model.InviteCode, error)
 	DecrementCanBeUsedCountTx(ctx context.Context, tx pgx.Tx, code int64) error
 	DeactivateExpired(ctx context.Context) (int, error)
 	GetUserInvites(ctx context.Context, userID int) ([]*model.InviteCode, error)

internal/repository/invite.go

@@ -110,6 +110,38 @@ func (r *inviteRepository) FindActiveByCode(ctx context.Context, code int64) (*m
 	return invite, nil
 }
 
+func (r *inviteRepository) FindActiveByUserID(ctx context.Context, userID int) (*model.InviteCode, error) {
+	query := r.qb.Select(
+		"id", "user_id", "code", "can_be_used_count",
+		"is_active", "created_at", "expires_at",
+	).From("invite_codes").Where(sq.And{
+		sq.Eq{"user_id": userID},
+		sq.Eq{"is_active": true},
+		sq.Expr("expires_at > now()"),
+		sq.Expr("can_be_used_count > 0"),
+	}).OrderBy("created_at DESC").Limit(1)
+
+	sqlQuery, args, err := query.ToSql()
+	if err != nil {
+		return nil, errs.NewInternalError(errs.DatabaseError, "failed to build query", err)
+	}
+
+	invite := &model.InviteCode{}
+	err = r.pool.QueryRow(ctx, sqlQuery, args...).Scan(
+		&invite.ID, &invite.UserID, &invite.Code, &invite.CanBeUsedCount,
+		&invite.IsActive, &invite.CreatedAt, &invite.ExpiresAt,
+	)
+
+	if errors.Is(err, pgx.ErrNoRows) {
+		return nil, errs.NewBusinessError(errs.InviteInvalidOrExpired, "no active invite code found")
+	}
+	if err != nil {
+		return nil, errs.NewInternalError(errs.DatabaseError, "failed to find active invite code by user", err)
+	}
+
+	return invite, nil
+}
+
 func (r *inviteRepository) DecrementCanBeUsedCountTx(ctx context.Context, tx pgx.Tx, code int64) error {
 	query := r.qb.Update("invite_codes").
 		Set("can_be_used_count", sq.Expr("can_be_used_count - 1")).