/*
 * Copyright 2016 Red Hat, Inc. and/or its affiliates
 * and other contributors as indicated by the @author tags.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.keycloak.events.jpa;

import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.jboss.logging.Logger;
import org.keycloak.common.util.Time;
import org.keycloak.events.Event;
import org.keycloak.events.EventQuery;
import org.keycloak.events.EventStoreProvider;
import org.keycloak.events.EventType;
import org.keycloak.events.admin.AdminEvent;
import org.keycloak.events.admin.AdminEventQuery;
import org.keycloak.events.admin.AuthDetails;
import org.keycloak.events.admin.OperationType;
import org.keycloak.models.KeycloakSession;
import org.keycloak.models.utils.KeycloakModelUtils;

import javax.persistence.EntityManager;
import java.io.IOException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.UUID;

/**
 * @author <a href="mailto:sthorger@redhat.com">Stian Thorgersen</a>
 */
public class JpaEventStoreProvider implements EventStoreProvider {

    private static final ObjectMapper mapper = new ObjectMapper();
    private static final TypeReference<Map<String, String>> mapType = new TypeReference<Map<String, String>>() {
    };
    private static final Logger logger = Logger.getLogger(JpaEventStoreProvider.class);

    private final KeycloakSession session;
    private final EntityManager em;
    private final int maxDetailLength;
    private final int maxFieldLength;

    public JpaEventStoreProvider(KeycloakSession session, EntityManager em, int maxDetailLength, int maxFieldLength) {
        this.session = session;
        this.em = em;
        this.maxDetailLength = maxDetailLength;
        this.maxFieldLength = maxFieldLength;
    }

    @Override
    public EventQuery createQuery() {
        return new JpaEventQuery(em);
    }

    @Override
    public void clear() {
        em.createQuery("delete from EventEntity").executeUpdate();
    }

    @Override
    public void clear(String realmId) {
        em.createQuery("delete from EventEntity where realmId = :realmId").setParameter("realmId", realmId).executeUpdate();
    }

    @Override
    public void clear(String realmId, long olderThan) {
        em.createQuery("delete from EventEntity where realmId = :realmId and time < :time").setParameter("realmId", realmId).setParameter("time", olderThan).executeUpdate();
    }

    @Override
    public void clearExpiredEvents() {
        // By default, realm provider is always "jpa", so we can optimize and delete all events in single SQL, assuming that realms are saved in the DB as well.
        // Fallback to model API just with different realm provider than "jpa" (This is never the case in standard Keycloak installations)
        int numDeleted = 0;
        long currentTimeMillis = Time.currentTimeMillis();
        if (KeycloakModelUtils.isRealmProviderJpa(session)) {

            // Group realms by expiration times. This will be effective if different realms have same/similar event expiration times, which will probably be the case in most environments
            List<Long> eventExpirations = em.createQuery("select distinct realm.eventsExpiration from RealmEntity realm where realm.eventsExpiration > 0").getResultList();
            for (Long expiration : eventExpirations) {
                List<String> realmIds = em.createQuery("select realm.id from RealmEntity realm where realm.eventsExpiration = :expiration")
                        .setParameter("expiration", expiration)
                        .getResultList();
                int currentNumDeleted = em.createQuery("delete from EventEntity where realmId in :realmIds and time < :eventTime")
                        .setParameter("realmIds", realmIds)
                        .setParameter("eventTime", currentTimeMillis - (expiration * 1000))
                        .executeUpdate();
                logger.tracef("Deleted %d events for the expiration %d", currentNumDeleted, expiration);
                numDeleted += currentNumDeleted;
            }
            logger.debugf("Cleared %d expired events in all realms", numDeleted);
        } else {
            session.realms().getRealmsStream().forEach(realm -> {
                if (realm.isEventsEnabled() && realm.getEventsExpiration() > 0) {
                    long olderThan = Time.currentTimeMillis() - realm.getEventsExpiration() * 1000;
                    clear(realm.getId(), olderThan);
                }
            });
        }
    }

    @Override
    public void onEvent(Event event) {
        em.persist(convertEvent(event));
    }

    @Override
    public AdminEventQuery createAdminQuery() {
        return new JpaAdminEventQuery(em);
    }

    @Override
    public void clearAdmin() {
        em.createQuery("delete from AdminEventEntity").executeUpdate();
    }

    @Override
    public void clearAdmin(String realmId) {
        em.createQuery("delete from AdminEventEntity where realmId = :realmId").setParameter("realmId", realmId).executeUpdate();
    }

    @Override
    public void clearAdmin(String realmId, long olderThan) {
        em.createQuery("delete from AdminEventEntity where realmId = :realmId and time < :time").setParameter("realmId", realmId).setParameter("time", olderThan).executeUpdate();
    }

    @Override
    public void onEvent(AdminEvent event, boolean includeRepresentation) {
        em.persist(convertAdminEvent(event, includeRepresentation));
    }

    @Override
    public void close() {
    }

    private EventEntity convertEvent(Event event) {
        EventEntity eventEntity = new EventEntity();
        eventEntity.setId(event.getId() == null ? UUID.randomUUID().toString() : event.getId());
        eventEntity.setTime(event.getTime());
        eventEntity.setType(event.getType().toString());
        eventEntity.setRealmId(event.getRealmId());
        eventEntity.setClientId(event.getClientId());
        eventEntity.setUserId(event.getUserId());
        eventEntity.setSessionId(event.getSessionId());
        eventEntity.setIpAddress(event.getIpAddress());
        eventEntity.setError(event.getError());
        try {
            if (maxDetailLength > 0 && event.getDetails() != null) {
                Map<String, String> result = new HashMap<>(event.getDetails());
                result.entrySet().forEach(t -> t.setValue(trimToMaxDetailLength(t.getValue())));

                eventEntity.setDetailsJson(trimToMaxFieldLength(mapper.writeValueAsString(result)));
            } else {
                eventEntity.setDetailsJson(mapper.writeValueAsString(event.getDetails()));
            }
        } catch (IOException ex) {
            logger.error("Failed to write log details", ex);
        }
        return eventEntity;
    }

    private String trimToMaxDetailLength(String detail) {
        if (detail != null && detail.length() > maxDetailLength) {
            logger.warnf("Detail '%s' will be truncated.", detail);
            // (maxDetailLength - 3) takes "..." into account
            return detail.substring(0, maxDetailLength - 3).concat("...");
        } else {
            return detail;
        }
    }

    private String trimToMaxFieldLength(String field) {
        if (maxFieldLength > 0 && field != null && field.length() > maxFieldLength) {
            logger.warnf("Field '%s' will be truncated.", field);
            // (maxFieldLength - 3) takes "..." into account
            return field.substring(0, maxFieldLength - 3).concat("...");
        } else {
            return field;
        }
    }

    static Event convertEvent(EventEntity eventEntity) {
        Event event = new Event();
        event.setId(eventEntity.getId() == null ? UUID.randomUUID().toString() : eventEntity.getId());
        event.setTime(eventEntity.getTime());
        event.setType(EventType.valueOf(eventEntity.getType()));
        event.setRealmId(eventEntity.getRealmId());
        event.setClientId(eventEntity.getClientId());
        event.setUserId(eventEntity.getUserId());
        event.setSessionId(eventEntity.getSessionId());
        event.setIpAddress(eventEntity.getIpAddress());
        event.setError(eventEntity.getError());
        try {
            Map<String, String> details = mapper.readValue(eventEntity.getDetailsJson(), mapType);
            event.setDetails(details);
        } catch (IOException ex) {
            logger.error("Failed to read log details", ex);
        }
        return event;
    }
    
    private AdminEventEntity convertAdminEvent(AdminEvent adminEvent, boolean includeRepresentation) {
        AdminEventEntity adminEventEntity = new AdminEventEntity();
        adminEventEntity.setId(adminEvent.getId() == null ? UUID.randomUUID().toString() : adminEvent.getId());
        adminEventEntity.setTime(adminEvent.getTime());
        adminEventEntity.setRealmId(adminEvent.getRealmId());
        setAuthDetails(adminEventEntity, adminEvent.getAuthDetails());
        adminEventEntity.setOperationType(adminEvent.getOperationType().toString());

        if (adminEvent.getResourceTypeAsString() != null) {
            adminEventEntity.setResourceType(adminEvent.getResourceTypeAsString());
        }

        adminEventEntity.setResourcePath(adminEvent.getResourcePath());
        adminEventEntity.setError(adminEvent.getError());
        
        if(includeRepresentation) {
            adminEventEntity.setRepresentation(trimToMaxFieldLength(adminEvent.getRepresentation()));
        }
        return adminEventEntity;
    }

    static AdminEvent convertAdminEvent(AdminEventEntity adminEventEntity) {
        AdminEvent adminEvent = new AdminEvent();
        adminEvent.setId(adminEventEntity.getId() == null ? UUID.randomUUID().toString() : adminEventEntity.getId());
        adminEvent.setTime(adminEventEntity.getTime());
        adminEvent.setRealmId(adminEventEntity.getRealmId());
        setAuthDetails(adminEvent, adminEventEntity);
        adminEvent.setOperationType(OperationType.valueOf(adminEventEntity.getOperationType()));

        if (adminEventEntity.getResourceType() != null) {
            adminEvent.setResourceTypeAsString(adminEventEntity.getResourceType());
        }

        adminEvent.setResourcePath(adminEventEntity.getResourcePath());
        adminEvent.setError(adminEventEntity.getError());
        
        if(adminEventEntity.getRepresentation() != null) {
            adminEvent.setRepresentation(adminEventEntity.getRepresentation());
        }
        return adminEvent;
    }
    
    private static void setAuthDetails(AdminEventEntity adminEventEntity, AuthDetails authDetails) {
        adminEventEntity.setAuthRealmId(authDetails.getRealmId());
        adminEventEntity.setAuthClientId(authDetails.getClientId());
        adminEventEntity.setAuthUserId(authDetails.getUserId());
        adminEventEntity.setAuthIpAddress(authDetails.getIpAddress());
    }
    
    private static void setAuthDetails(AdminEvent adminEvent, AdminEventEntity adminEventEntity) {
        AuthDetails authDetails = new AuthDetails();
        authDetails.setRealmId(adminEventEntity.getAuthRealmId());
        authDetails.setClientId(adminEventEntity.getAuthClientId());
        authDetails.setUserId(adminEventEntity.getAuthUserId());
        authDetails.setIpAddress(adminEventEntity.getAuthIpAddress());
        adminEvent.setAuthDetails(authDetails);
    }

}
