class IdpSingleSignOnServiceHelper {

    public URI getSingleSignOn(String entityId) {
        EntityDescriptor idpEntityDescriptor;
        try {
            CriteriaSet criteria = new CriteriaSet(new EntityIdCriterion(entityId));
            idpEntityDescriptor = metadataProvider.resolveSingle(criteria);
        } catch (ResolverException e) {
            LOG.error(format("Exception when accessing metadata: {0}", e));
            throw new RuntimeException(e);
        }

        if(idpEntityDescriptor!=null) {
            final IDPSSODescriptor idpssoDescriptor = idpEntityDescriptor.getIDPSSODescriptor(SAMLConstants.SAML20P_NS);
            final List<SingleSignOnService> singleSignOnServices = idpssoDescriptor.getSingleSignOnServices();
            if (singleSignOnServices.isEmpty()) {
                LOG.error(format("No singleSignOnServices present for IDP entityId: {0}", entityId));
            } else {
                if (singleSignOnServices.size() > 1) {
                    LOG.warn(format("More than one singleSignOnService present: {0} for {1}", singleSignOnServices.size(), entityId));
                }
                return URI.create(singleSignOnServices.get(0).getLocation());
            }
        }

        throw ApplicationException.createUnauditedException(ExceptionType.NOT_FOUND, UUID.randomUUID(), new RuntimeException(format("no entity descriptor for IDP: {0}", entityId)));

    }

    @Inject public  IdpSingleSignOnServiceHelper(@Named("VerifyMetadataResolver") MetadataResolver metadataProvider);

}