/*-
 * ============LICENSE_START=======================================================
 * OSAM
 * ================================================================================
 * Copyright (C) 2018 AT&T
 * ================================================================================
 * 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.
 * ============LICENSE_END=========================================================
 */
package org.onap.osam.job.impl;

import com.google.common.collect.Lists;
import lombok.extern.slf4j.Slf4j;
import org.onap.osam.common.exception.GenericUncheckedException;
import org.onap.osam.common.exception.InvalidOperationException;
import org.onap.osam.job.dao.job.JobStatus;
import org.onap.osam.job.dao.job.OsamJob;
import org.onap.osam.job.IJobsDataAccessService;
import org.onap.osam.job.repository.job.OsamJobRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.springframework.util.StringUtils;

import javax.annotation.PostConstruct;
import java.nio.ByteBuffer;
import java.sql.Timestamp;
import java.time.LocalDateTime;
import java.util.Collection;
import java.util.Date;
import java.util.Optional;
import java.util.UUID;

@Slf4j
@Service
public class JobsDataAccessService implements IJobsDataAccessService {

    private OsamJobRepository osamJobRepository;
    private Long maxOpenedRequestsToAbstractOlt;
    private int pollingIntervalSeconds;

    @Autowired
    public JobsDataAccessService(OsamJobRepository osamJobRepository,
                                 @Value("0") Long maxOpenedRequestsToAbstractOlt,
                                 @Value("10") int pollingIntervalSeconds) {
        // tha @Value will inject conservative defaults; overridden in @PostConstruct from configuration
        this.osamJobRepository = osamJobRepository;
        this.maxOpenedRequestsToAbstractOlt = maxOpenedRequestsToAbstractOlt;
        this.pollingIntervalSeconds = pollingIntervalSeconds;
    }

    @PostConstruct
    public void configure() {
        //TODO define defaults
        /*maxOpenedRequestsToAbstractOlt = Integer.parseInt(System.getProperty(VidProperties.MSO_MAX_OPENED_INSTANTIATION_REQUESTS));
        pollingIntervalSeconds = Integer.parseInt(System.getProperty(VidProperties.MSO_ASYNC_POLLING_INTERVAL_SECONDS));*/
    }

    public void deleteAll() {
        osamJobRepository.deleteAll();
    }

    @Override
    public UUID add(OsamJob job) {
        osamJobRepository.save(job);
        return job.getUuid();
    }

    @Override
    public Optional<OsamJob> pull(JobStatus topic, String ownerId) {
        OsamJob osamJob;
        int updatedEntities;
        do {

            Optional<OsamJob> optionalOsamJob = selectQueryByJobStatus(topic);
            if (!optionalOsamJob.isPresent()) {
                return optionalOsamJob;
            }

            osamJob = optionalOsamJob.get();
            final UUID uuid = osamJob.getUuid();
            final Integer age = osamJob.getAge();

            osamJob.setTakenBy(ownerId);

            // It might become that a job was taken and pushed-back already, before we
            // arrived here, so we're verifying the age was not pushed forward.
            // Age is actually forwarded upon pushBack().
            updatedEntities = osamJobRepository.updateOsamCoreJobsAge(ownerId, uuid, age);

        } while (updatedEntities == 0);

        return Optional.ofNullable(osamJob);
    }

    private java.sql.Timestamp nowMinusInterval() {
        return Timestamp.valueOf(LocalDateTime.now().minusSeconds(pollingIntervalSeconds));
    }

    private Optional<OsamJob> selectQueryByJobStatus(JobStatus topic){
        //TODO Pavel understand this interval
        //String intervalCondition = (topic==JobStatus.CREATING) ? "" : (" and MODIFIED_DATE <= '" + nowMinusInterval()+"'");
        return osamJobRepository.queryFirst1ByStatusAndTakenByIsNullAndDeletedAtIsNullOrderByModifiedDateAsc(topic).stream().findFirst();

    }

    private Optional<OsamJob> sqlQueryForTopic(JobStatus topic) {
        switch (topic) {
            case IN_PROGRESS:
            case RESOURCE_IN_PROGRESS:
            case CREATING:
            case PENDING:
                return selectQueryByJobStatus(topic);
            //TODO Pavel - at first stage, using the naive query for pending topic
            /*case PENDING:
                return osamJobRepository.findOsamJobsPending(maxOpenedRequestsToAbstractOlt);*/
            default:
                throw new GenericUncheckedException("Unsupported topic to pull from: " + topic);
        }
    }


    private byte[] getUuidAsByteArray(UUID owner) {
        ByteBuffer bb = ByteBuffer.wrap(new byte[16]);
        bb.putLong(owner.getMostSignificantBits());
        bb.putLong(owner.getLeastSignificantBits());
        return bb.array();
    }

    @Override
    public void pushBack(OsamJob job) {
        final Optional<OsamJob> remoteDaoJob = osamJobRepository.findByUuid(job.getUuid());

        if (!remoteDaoJob.isPresent()) {
            throw new IllegalStateException("Can push back only pulled jobs. Add new jobs using add()");
        }

        if (remoteDaoJob.get().getTakenBy() == null) {
            throw new IllegalStateException("Can push back only pulled jobs. This one already pushed back.");
        }

        job.setTakenBy(null);

        Integer age = job.getAge();
        job.setAge(age + 1);

        log.debug("{}/{}", job.getStatus(), job.getType());

        osamJobRepository.save(job);
    }

    /*private OsamJob castToOsamJob(OsamJob job) {
        if (!(job instanceof OsamJob)) {
            throw new UnsupportedOperationException("Can't add " + job.getClass() + " to " + this.getClass());
        }
        return (OsamJob) job;
    }*/

    @Override
    public Collection<OsamJob> peek() {
        return Lists.newArrayList(osamJobRepository.findAll());
    }

    @Override
    public OsamJob peek(UUID jobId) {
        return osamJobRepository.findByUuid(jobId).orElse(null);
    }

    @Override
    public void delete(UUID jobId) {
        Date now = new Date();
        Integer updatedEntities = osamJobRepository.updateOsamCoreJobToBeDeleted(now, jobId, JobStatus.PENDING.toString(), JobStatus.STOPPED.toString());

        if (updatedEntities == 0) {
            final Optional<OsamJob> remoteDaoJob = osamJobRepository.findByUuid(jobId);

            if (!remoteDaoJob.isPresent() || remoteDaoJob.get().getUuid() == null) {
                log.debug("jobId {}: Service does not exist", jobId);
                throw new InvalidOperationException("Service does not exist");
            }

            if (!remoteDaoJob.get().equals(JobStatus.PENDING) && !remoteDaoJob.get().getStatus().equals(JobStatus.STOPPED) || !StringUtils.isEmpty(remoteDaoJob.get().getTakenBy())) {
                log.debug("jobId {}: Service status does not allow deletion from the queue, status = {}", jobId, remoteDaoJob.get().getStatus() +
                ", takenBy " + remoteDaoJob.get().getTakenBy());
                throw new InvalidOperationException("Service status does not allow deletion from the queue");
            }

            throw new InvalidOperationException("Service deletion failed");
        }
    }

    @Override
    public boolean mute(UUID jobId) {
        if (jobId == null) {
            return false;
        }
        final String prefix = "DUMP";
        Integer updatedEntities = osamJobRepository.muteOsamCoreJob(jobId, prefix);
        return updatedEntities != 0;
    }
}