package org.gcube.keycloak.event;

import java.net.MalformedURLException;
import java.net.URL;

import org.jboss.logging.Logger;
import org.keycloak.Config.Scope;
import org.keycloak.events.EventListenerProviderFactory;
import org.keycloak.models.ClientModel;
import org.keycloak.models.KeycloakSession;
import org.keycloak.models.KeycloakSessionFactory;
import org.keycloak.models.RealmModel;

/**
 * @author <a href="mailto:marco.lettere@nubisware.com">Marco Lettere</a>
 * @author <a href="mailto:mauro.mugnaini@nubisware.com">Mauro Mugnaini</a>
 */
public class OrchestratorEventPublisherProviderFactory implements EventListenerProviderFactory {

    private static final Logger logger = Logger.getLogger(OrchestratorEventPublisherProviderFactory.class);

    public static final String MASTER_REALM_NAME = "master";
    public static final String ORCHESTRATOR_CLIENT_ID = "orchestrator";
    public static final String KEYCLOAK_CLIENT_ID = "keycloak-client";

    private static final int CHECK_DELAY = 60 * 1000; // One minute

    public static URL ORCHESTRATOR_ENDPOINT;
    public static URL KEYCLOAK_ENDPOINT;
    public static String KEYCLOAK_CLIENT_SECRET;

    protected Long lastEndpointCheck = new Long(0);
    protected OrchestratorEventPublisherProvider oepp;

    public OrchestratorEventPublisherProviderFactory() {
        logger.info("New OrchestratorEventPublisherProviderFactory has been created");
    }

    @Override
    public void close() {
    }

    @Override
    public synchronized OrchestratorEventPublisherProvider create(KeycloakSession keycloakSession) {
        Long now = System.currentTimeMillis();
        Long elapsed = now - lastEndpointCheck;
        if (oepp == null || elapsed > CHECK_DELAY) {
            lastEndpointCheck = now;
            ClientModel orchestratorClient = getClientInActualOrMasterRealm(keycloakSession, ORCHESTRATOR_CLIENT_ID);
            ClientModel keycloakClient = getClientInActualOrMasterRealm(keycloakSession, KEYCLOAK_CLIENT_ID);
            logger.debug("Getting configured orchestrator endpoint address from client's base URL");
            String orchestratorAddress = orchestratorClient.getBaseUrl();
            logger.debug("Getting configured keycloak endpoint address from client's base URL");
            String keycloakAddress = keycloakClient.getBaseUrl();
            logger.debug("Getting configured keycloak client client-secret from client");
            String keycloakClientSecret = keycloakClient.getSecret();
            URL newOrchestratorEndpoint;
            URL newKeycloakEndpoint;
            try {
                newOrchestratorEndpoint = new URL(orchestratorAddress);
            } catch (MalformedURLException e) {
                logger.errorf("Can't create new orchestrator endpoint address: %s",
                        orchestratorAddress, e);
                oepp = null;
                return null;
            }
            try {
                newKeycloakEndpoint = new URL(keycloakAddress);
            } catch (MalformedURLException e) {
                logger.errorf("Can't create new keycloak token address: %s", keycloakAddress, e);
                oepp = null;
                return null;
            }
            if (oepp == null || !newOrchestratorEndpoint.equals(ORCHESTRATOR_ENDPOINT)
                    || !newKeycloakEndpoint.equals(KEYCLOAK_ENDPOINT)
                    || !keycloakClientSecret.equals(KEYCLOAK_CLIENT_SECRET)) {

                logger.infof("Creating new orchestrator event publisher provider for endpoint: %s",
                        orchestratorAddress);
                // Address and other fileds will be then read from static fields in this class by 
                // the createEventSender() called by the superclass' constructor, overridden in the impl.
                ORCHESTRATOR_ENDPOINT = newOrchestratorEndpoint;
                KEYCLOAK_ENDPOINT = newKeycloakEndpoint;
                KEYCLOAK_CLIENT_SECRET = keycloakClientSecret;
                oepp = new OrchestratorEventPublisherProvider();
            }

        } else {
            logger.debugf("Next check is in %d millis", CHECK_DELAY - elapsed);
        }
        return oepp;
    }

    protected ClientModel getClientInActualOrMasterRealm(KeycloakSession keycloakSession, String clientId) {
        logger.debug("Getting actual realm from session's context");
        RealmModel realm = keycloakSession.getContext().getRealm();
        logger.debugf("Trying getting '%s' client in current realm '%s'", clientId, realm.getName());
        ClientModel client = realm.getClientByClientId(clientId);
        if (client == null) {
            logger.debugf("Not found. Now trying getting '%s' in '%s' realm", clientId, MASTER_REALM_NAME);
            realm = keycloakSession.realms().getRealmByName(MASTER_REALM_NAME);
            client = realm.getClientByClientId(clientId);
            if (client == null) {
                logger.warnf("Cannot find '%s' client not even in '%s' realm", clientId, realm.getName(),
                        MASTER_REALM_NAME);

                return null;
            }
        }
        return client;
    }

    @Override
    public String getId() {
        return "orchestrator-event-publisher";
    }

    @Override
    public void init(Scope scope) {
    }

    @Override
    public void postInit(KeycloakSessionFactory keycloakSessionFactory) {
    }

}