/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.syncope.core.provisioning.java.pushpull.stream;

import java.util.HashSet;
import java.util.List;
import java.util.Optional;
import java.util.Set;
import org.apache.syncope.common.lib.to.Item;
import org.apache.syncope.common.lib.to.Mapping;
import org.apache.syncope.common.lib.to.Provision;
import org.apache.syncope.common.lib.to.ProvisioningReport;
import org.apache.syncope.common.lib.to.PullTaskTO;
import org.apache.syncope.common.lib.types.ConflictResolutionAction;
import org.apache.syncope.common.lib.types.IdMImplementationType;
import org.apache.syncope.common.lib.types.MappingPurpose;
import org.apache.syncope.common.lib.types.PullMode;
import org.apache.syncope.common.lib.types.TaskType;
import org.apache.syncope.core.persistence.api.dao.ImplementationDAO;
import org.apache.syncope.core.persistence.api.dao.NotFoundException;
import org.apache.syncope.core.persistence.api.dao.RealmSearchDAO;
import org.apache.syncope.core.persistence.api.entity.AnyType;
import org.apache.syncope.core.persistence.api.entity.AnyUtils;
import org.apache.syncope.core.persistence.api.entity.ExternalResource;
import org.apache.syncope.core.persistence.api.entity.Implementation;
import org.apache.syncope.core.persistence.api.entity.policy.InboundCorrelationRuleEntity;
import org.apache.syncope.core.persistence.api.entity.policy.InboundPolicy;
import org.apache.syncope.core.persistence.api.entity.task.PullTask;
import org.apache.syncope.core.provisioning.api.Connector;
import org.apache.syncope.core.provisioning.api.job.JobExecutionException;
import org.apache.syncope.core.provisioning.api.pushpull.AnyPullResultHandler;
import org.apache.syncope.core.provisioning.api.pushpull.InboundActions;
import org.apache.syncope.core.provisioning.api.pushpull.ProvisioningProfile;
import org.apache.syncope.core.provisioning.api.pushpull.SyncopePullResultHandler;
import org.apache.syncope.core.provisioning.api.pushpull.stream.SyncopeStreamPullExecutor;
import org.apache.syncope.core.provisioning.java.pushpull.PullJobDelegate;
import org.apache.syncope.core.provisioning.java.utils.MappingUtils;
import org.apache.syncope.core.spring.security.SecureRandomUtils;
import org.identityconnectors.framework.common.objects.ObjectClass;
import org.springframework.beans.factory.annotation.Autowired;

public class StreamPullJobDelegate extends PullJobDelegate implements SyncopeStreamPullExecutor {

    @Autowired
    private ImplementationDAO implementationDAO;

    @Autowired
    private RealmSearchDAO realmSearchDAO;

    private InboundPolicy inboundPolicy(
            final AnyType anyType,
            final ConflictResolutionAction conflictResolutionAction,
            final String inboundCorrelationRule) {

        InboundCorrelationRuleEntity inboundCorrelationRuleEntity = null;
        if (inboundCorrelationRule != null) {
            Implementation impl = implementationDAO.findById(inboundCorrelationRule).orElse(null);
            if (impl == null || !IdMImplementationType.INBOUND_CORRELATION_RULE.equals(impl.getType())) {
                LOG.debug("Invalid  {} {}, ignoring...", Implementation.class.getSimpleName(), inboundCorrelationRule);
            } else {
                inboundCorrelationRuleEntity = entityFactory.newEntity(InboundCorrelationRuleEntity.class);
                inboundCorrelationRuleEntity.setAnyType(anyType);
                inboundCorrelationRuleEntity.setImplementation(impl);
            }
        }

        InboundPolicy inboundPolicy = entityFactory.newEntity(InboundPolicy.class);
        inboundPolicy.setConflictResolutionAction(conflictResolutionAction);

        if (inboundCorrelationRuleEntity != null) {
            inboundPolicy.add(inboundCorrelationRuleEntity);
            inboundCorrelationRuleEntity.setInboundPolicy(inboundPolicy);
        }

        return inboundPolicy;
    }

    private Provision provision(
            final AnyType anyType,
            final String keyColumn,
            final List<String> columns) throws JobExecutionException {

        Provision provision = new Provision();
        provision.setAnyType(anyType.getKey());
        provision.setObjectClass(anyType.getKey());

        Mapping mapping = new Mapping();
        provision.setMapping(mapping);

        AnyUtils anyUtils = anyUtilsFactory.getInstance(anyType.getKind());
        if (anyUtils.getField(keyColumn).isEmpty()) {
            plainSchemaDAO.findById(keyColumn).
                    orElseThrow(() -> new JobExecutionException("Plain Schema for key column not found: " + keyColumn));
        }

        Item connObjectKeyItem = new Item();
        connObjectKeyItem.setExtAttrName(keyColumn);
        connObjectKeyItem.setIntAttrName(keyColumn);
        connObjectKeyItem.setPurpose(MappingPurpose.PULL);
        mapping.setConnObjectKeyItem(connObjectKeyItem);

        columns.stream().
                filter(column -> anyUtils.getField(column).isPresent() || plainSchemaDAO.existsById(column)).
                map(column -> {
                    Item item = new Item();
                    item.setExtAttrName(column);
                    item.setIntAttrName(column);
                    item.setPurpose(MappingPurpose.PULL);
                    mapping.add(item);
                    return item;
                }).forEach(mapping::add);

        return provision;
    }

    private ExternalResource externalResource(
            final AnyType anyType,
            final String keyColumn,
            final List<String> columns,
            final ConflictResolutionAction conflictResolutionAction,
            final String inboundCorrelationRule) throws JobExecutionException {

        Provision provision = provision(anyType, keyColumn, columns);

        ExternalResource resource = entityFactory.newEntity(ExternalResource.class);
        resource.setKey("StreamPull_" + SecureRandomUtils.generateRandomUUID().toString());
        resource.getProvisions().add(provision);

        resource.setInboundPolicy(inboundPolicy(anyType, conflictResolutionAction, inboundCorrelationRule));

        return resource;
    }

    @Override
    public List<ProvisioningReport> pull(
            final AnyType anyType,
            final String keyColumn,
            final List<String> columns,
            final ConflictResolutionAction conflictResolutionAction,
            final String inboundCorrelationRule,
            final Connector connector,
            final PullTaskTO pullTaskTO,
            final String executor) throws JobExecutionException {

        LOG.debug("Executing stream pull");

        taskType = TaskType.PULL;
        try {
            ExternalResource resource =
                    externalResource(anyType, keyColumn, columns, conflictResolutionAction, inboundCorrelationRule);
            Provision provision = resource.getProvisions().getFirst();

            task = entityFactory.newEntity(PullTask.class);
            task.setName(pullTaskTO.getName());
            task.setResource(resource);
            task.setMatchingRule(pullTaskTO.getMatchingRule());
            task.setUnmatchingRule(pullTaskTO.getUnmatchingRule());
            task.setPullMode(PullMode.FULL_RECONCILIATION);
            task.setPerformCreate(true);
            task.setPerformUpdate(true);
            task.setPerformDelete(false);
            task.setSyncStatus(false);
            task.setDestinationRealm(realmSearchDAO.findByFullPath(pullTaskTO.getDestinationRealm()).
                    orElseThrow(() -> new NotFoundException("Realm " + pullTaskTO.getDestinationRealm())));
            task.setRemediation(pullTaskTO.isRemediation());

            profile = new ProvisioningProfile<>(
                    connector,
                    taskType,
                    task,
                    conflictResolutionAction,
                    getInboundActions(pullTaskTO.getActions().stream().
                            map(implementationDAO::findById).flatMap(Optional::stream).
                            toList()),
                    executor,
                    false);

            dispatcher = buildDispatcher();

            for (InboundActions action : profile.getActions()) {
                action.beforeAll(profile);
            }

            dispatcher.addHandlerSupplier(provision.getObjectClass(), () -> {
                SyncopePullResultHandler handler;
                switch (anyType.getKind()) {
                    case USER:
                        handler = buildUserHandler();
                        break;

                    case GROUP:
                        handler = buildGroupHandler();
                        break;

                    case ANY_OBJECT:
                    default:
                        handler = buildAnyObjectHandler();
                }
                handler.setProfile(profile);
                return handler;
            });

            // execute filtered pull
            Set<String> moreAttrsToGet = new HashSet<>();
            profile.getActions().forEach(a -> moreAttrsToGet.addAll(a.moreAttrsToGet(profile, provision)));

            connector.fullReconciliation(
                    new ObjectClass(provision.getObjectClass()),
                    dispatcher,
                    MappingUtils.buildOperationOptions(
                            MappingUtils.getInboundItems(provision.getMapping().getItems().stream()),
                            moreAttrsToGet.toArray(String[]::new)));

            AnyPullResultHandler handler =
                    (AnyPullResultHandler) dispatcher.nonConcurrentHandler(provision.getObjectClass());
            try {
                handler.setManagers();
            } catch (Exception e) {
                LOG.error("While setting managers", e);
            }

            for (InboundActions action : profile.getActions()) {
                action.afterAll(profile);
            }

            return profile.getResults();
        } catch (Exception e) {
            throw e instanceof final JobExecutionException jobExecutionException
                    ? jobExecutionException
                    : new JobExecutionException("While stream pulling", e);
        }
    }
}
