/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch 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.elasticsearch.index.seqno;

import org.apache.logging.log4j.message.ParameterizedMessage;
import org.apache.lucene.store.AlreadyClosedException;
import org.elasticsearch.ExceptionsHelper;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.support.replication.ReplicationOperation;
import org.elasticsearch.action.support.replication.ReplicationRequest;
import org.elasticsearch.action.support.replication.ReplicationResponse;
import org.elasticsearch.action.support.replication.TransportReplicationAction;
import org.elasticsearch.cluster.action.shard.ShardStateAction;
import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.cluster.service.ClusterService;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.index.shard.IndexShard;
import org.elasticsearch.index.shard.IndexShardClosedException;
import org.elasticsearch.index.shard.ShardId;
import org.elasticsearch.index.translog.Translog;
import org.elasticsearch.indices.IndicesService;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.transport.TransportService;

import java.io.IOException;

/**
 * Background global checkpoint sync action initiated when a shard goes inactive. This is needed because while we send the global checkpoint
 * on every replication operation, after the last operation completes the global checkpoint could advance but without a follow-up operation
 * the global checkpoint will never be synced to the replicas.
 */
public class GlobalCheckpointSyncAction extends TransportReplicationAction<
        GlobalCheckpointSyncAction.Request,
        GlobalCheckpointSyncAction.Request,
        ReplicationResponse> {

    public static final String ACTION_NAME = "indices:admin/seq_no/global_checkpoint_sync";

    @Inject
    public GlobalCheckpointSyncAction(
            final TransportService transportService,
            final ClusterService clusterService,
            final IndicesService indicesService,
            final ThreadPool threadPool,
            final ShardStateAction shardStateAction,
            final IndexNameExpressionResolver indexNameExpressionResolver) {
        super(
                ACTION_NAME,
                transportService,
                clusterService,
                indicesService,
                threadPool,
                shardStateAction,
                indexNameExpressionResolver,
                Request::new,
                Request::new,
                ThreadPool.Names.MANAGEMENT);
    }

    public void updateGlobalCheckpointForShard(final ShardId shardId) {
        execute(
            new Request(shardId),
            ActionListener.wrap(
                r -> {},
                e -> {
                    if (ExceptionsHelper.unwrap(e, AlreadyClosedException.class, IndexShardClosedException.class) == null) {
                        logger.info(new ParameterizedMessage("{} global checkpoint sync failed", shardId), e);
                    }
                }
            )
        );
    }

    @Override
    protected ReplicationResponse read(StreamInput in) throws IOException {
        return new ReplicationResponse(in);
    }

    @Override
    protected void sendReplicaRequest(
            final ConcreteReplicaRequest<Request> replicaRequest,
            final DiscoveryNode node,
            final ActionListener<ReplicationOperation.ReplicaResponse> listener) {
        super.sendReplicaRequest(replicaRequest, node, listener);
    }

    @Override
    protected PrimaryResult<Request, ReplicationResponse> shardOperationOnPrimary(
            final Request request, final IndexShard indexShard) throws Exception {
        maybeSyncTranslog(indexShard);
        return new PrimaryResult<>(request, new ReplicationResponse());
    }

    @Override
    protected ReplicaResult shardOperationOnReplica(final Request request, final IndexShard indexShard) throws Exception {
        maybeSyncTranslog(indexShard);
        return new ReplicaResult();
    }

    private void maybeSyncTranslog(final IndexShard indexShard) throws IOException {
        if (indexShard.getTranslogDurability() == Translog.Durability.REQUEST &&
            indexShard.getLastSyncedGlobalCheckpoint() < indexShard.getLastKnownGlobalCheckpoint()) {
            indexShard.sync();
        }
    }

    public static final class Request extends ReplicationRequest<Request> {

        public Request(final ShardId shardId) {
            super(shardId);
        }

        public Request(StreamInput in) throws IOException {
            super(in);
        }

        @Override
        public String toString() {
            return "GlobalCheckpointSyncAction.Request{" +
                    "shardId=" + shardId +
                    ", timeout=" + timeout +
                    ", index='" + index + '\'' +
                    ", waitForActiveShards=" + waitForActiveShards +
                    "}";
        }
    }

}