/*
 * Copyright 2017-present Open Networking Laboratory
 *
 * 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.onosproject.openstacknetworking.impl;

import org.apache.felix.scr.annotations.Activate;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Deactivate;
import org.apache.felix.scr.annotations.Reference;
import org.apache.felix.scr.annotations.ReferenceCardinality;
import org.apache.felix.scr.annotations.Service;
import org.onlab.util.KryoNamespace;
import org.onosproject.core.ApplicationId;
import org.onosproject.core.CoreService;
import org.onosproject.openstacknetworking.api.OpenstackSecurityGroupEvent;
import org.onosproject.openstacknetworking.api.OpenstackSecurityGroupStore;
import org.onosproject.openstacknetworking.api.OpenstackSecurityGroupStoreDelegate;
import org.onosproject.store.AbstractStore;
import org.onosproject.store.serializers.KryoNamespaces;
import org.onosproject.store.service.ConsistentMap;
import org.onosproject.store.service.MapEvent;
import org.onosproject.store.service.MapEventListener;
import org.onosproject.store.service.Serializer;
import org.onosproject.store.service.StorageService;
import org.onosproject.store.service.Versioned;
import org.openstack4j.model.network.SecurityGroup;
import org.openstack4j.model.network.SecurityGroupRule;
import org.openstack4j.openstack.networking.domain.NeutronSecurityGroup;
import org.openstack4j.openstack.networking.domain.NeutronSecurityGroupRule;
import org.slf4j.Logger;

import java.util.concurrent.ExecutorService;

import static com.google.common.base.Preconditions.checkArgument;
import static java.util.concurrent.Executors.newSingleThreadExecutor;
import static org.onlab.util.Tools.groupedThreads;
import static org.onosproject.openstacknetworking.api.Constants.OPENSTACK_NETWORKING_APP_ID;
import static org.slf4j.LoggerFactory.getLogger;

/**
 * Manages the inventory of OpenStack security group using a {@code ConsistentMap}.
 *
 */
@Service
@Component(immediate = true)
public class DistributedSecurityGroupStore
        extends AbstractStore<OpenstackSecurityGroupEvent, OpenstackSecurityGroupStoreDelegate>
        implements OpenstackSecurityGroupStore {

    protected final Logger log = getLogger(getClass());

    private static final String ERR_NOT_FOUND = " does not exist";
    private static final String ERR_DUPLICATE = " already exists";

    private static final KryoNamespace SERIALIZER_SECURITY_GROUP = KryoNamespace.newBuilder()
            .register(KryoNamespaces.API)
            .register(SecurityGroup.class)
            .register(SecurityGroupRule.class)
            .register(NeutronSecurityGroupRule.class)
            .register(NeutronSecurityGroup.class)
            .build();

    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
    protected CoreService coreService;

    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
    protected StorageService storageService;

    private final ExecutorService eventExecutor = newSingleThreadExecutor(
            groupedThreads(this.getClass().getSimpleName(), "event-handler", log));

    private final MapEventListener<String, SecurityGroup> securityGroupMapListener =
            new OpenstackSecurityGroupMapListener();
    private final MapEventListener<String, SecurityGroupRule> securityGroupRuleMapListener =
            new OpenstackSecurityGroupRuleMapListener();

    private ConsistentMap<String, SecurityGroup> osSecurityGroupStore;
    private ConsistentMap<String, SecurityGroupRule> osSecurityGroupRuleStore;

    @Activate
    protected void activate() {
        ApplicationId appId = coreService.registerApplication(OPENSTACK_NETWORKING_APP_ID);

        osSecurityGroupStore = storageService.<String, SecurityGroup>consistentMapBuilder()
                .withSerializer(Serializer.using(SERIALIZER_SECURITY_GROUP))
                .withName("openstack-securitygroupstore")
                .withApplicationId(appId)
                .build();
        osSecurityGroupStore.addListener(securityGroupMapListener);

        osSecurityGroupRuleStore = storageService.<String, SecurityGroupRule>consistentMapBuilder()
                .withSerializer(Serializer.using(SERIALIZER_SECURITY_GROUP))
                .withName("openstack-securitygrouprulestore")
                .withApplicationId(appId)
                .build();
        osSecurityGroupRuleStore.addListener(securityGroupRuleMapListener);

        log.info("Started");
    }

    @Deactivate
    protected void deactivate() {
        osSecurityGroupStore.removeListener(securityGroupMapListener);
        osSecurityGroupRuleStore.removeListener(securityGroupRuleMapListener);
        eventExecutor.shutdown();

        log.info("Stopped");
    }

    @Override
    public void createSecurityGroup(SecurityGroup sg) {
        osSecurityGroupStore.compute(sg.getId(), (id, existing) -> {
            final String error = sg.getName() + ERR_DUPLICATE;
            checkArgument(existing == null, error);
            return sg;
        });
    }

    @Override
    public SecurityGroup updateSecurityGroup(String sgId, SecurityGroup newSg) {
        Versioned<SecurityGroup> sg = osSecurityGroupStore.replace(sgId, newSg);
        return sg == null ? null : sg.value();
    }

    @Override
    public SecurityGroup removeSecurityGroup(String sgId) {
        Versioned<SecurityGroup> sg = osSecurityGroupStore.remove(sgId);
        return sg == null ? null : sg.value();
    }

    @Override
    public void createSecurityGroupRule(SecurityGroupRule sgRule) {
        osSecurityGroupRuleStore.compute(sgRule.getId(), (id, existing) -> {
            final String error = sgRule.getId() + ERR_DUPLICATE;
            checkArgument(existing == null, error);
            return sgRule;
        });
    }

    @Override
    public SecurityGroupRule removeSecurityGroupRule(String sgRuleId) {
        Versioned<SecurityGroupRule> sgRule = osSecurityGroupRuleStore.remove(sgRuleId);
        return sgRule == null ? null : sgRule.value();
    }

    @Override
    public SecurityGroup securityGroup(String sgId) {
        Versioned<SecurityGroup> osSg = osSecurityGroupStore.get(sgId);
        return osSg == null ? null : osSg.value();
    }

    @Override
    public SecurityGroupRule securityGroupRule(String sgRuleId) {
        Versioned<SecurityGroupRule> osSgRule = osSecurityGroupRuleStore.get(sgRuleId);
        return osSgRule == null ? null : osSgRule.value();
    }

    private class OpenstackSecurityGroupMapListener implements MapEventListener<String, SecurityGroup> {

        @Override
        public void event(MapEvent<String, SecurityGroup> event) {
            switch (event.type()) {
                case INSERT:
                    log.debug("Openstack Security Group created {}", event.newValue());
                    eventExecutor.execute(() ->
                            notifyDelegate(new OpenstackSecurityGroupEvent(
                                    OpenstackSecurityGroupEvent.Type.OPENSTACK_SECURITY_GROUP_CREATED,
                                    securityGroup(event.newValue().value().getId()))));
                    break;

                case REMOVE:
                    log.debug("Openstack Security Group removed {}", event.newValue());
                    eventExecutor.execute(() ->
                            notifyDelegate(new OpenstackSecurityGroupEvent(
                                    OpenstackSecurityGroupEvent.Type.OPENSTACK_SECURITY_GROUP_REMOVED,
                                    event.oldValue().value())));
                    break;
                default:
            }
        }
    }

    private class OpenstackSecurityGroupRuleMapListener implements MapEventListener<String, SecurityGroupRule> {

        @Override
        public void event(MapEvent<String, SecurityGroupRule> event) {
            switch (event.type()) {
                case INSERT:
                    log.debug("Openstack Security Group Rule created {}", event.newValue());
                    eventExecutor.execute(() ->
                            notifyDelegate(new OpenstackSecurityGroupEvent(
                                    OpenstackSecurityGroupEvent.Type.OPENSTACK_SECURITY_GROUP_RULE_CREATED,
                                    securityGroupRule(event.newValue().value().getId()))));
                    break;

                case REMOVE:
                    log.debug("Openstack Security Group Rule removed {}", event.oldValue());
                    eventExecutor.execute(() ->
                            notifyDelegate(new OpenstackSecurityGroupEvent(
                                    OpenstackSecurityGroupEvent.Type.OPENSTACK_SECURITY_GROUP_RULE_REMOVED,
                                    event.oldValue().value())));
                    break;
                default:
            }
        }
    }
}