/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0 and the Server Side Public License, v 1; you may not use this file except
 * in compliance with, at your election, the Elastic License 2.0 or the Server
 * Side Public License, v 1.
 */

package org.elasticsearch.index.seqno;

import org.apache.logging.log4j.Level;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.lucene.store.AlreadyClosedException;
import org.elasticsearch.ExceptionsHelper;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.support.ActionFilters;
import org.elasticsearch.action.support.ActiveShardCount;
import org.elasticsearch.action.support.WriteResponse;
import org.elasticsearch.action.support.replication.ReplicatedWriteRequest;
import org.elasticsearch.action.support.replication.ReplicationOperation;
import org.elasticsearch.action.support.replication.ReplicationResponse;
import org.elasticsearch.action.support.replication.ReplicationTask;
import org.elasticsearch.action.support.replication.TransportWriteAction;
import org.elasticsearch.cluster.action.shard.ShardStateAction;
import org.elasticsearch.cluster.block.ClusterBlockLevel;
import org.elasticsearch.cluster.service.ClusterService;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.util.concurrent.ThreadContext;
import org.elasticsearch.index.IndexNotFoundException;
import org.elasticsearch.index.IndexingPressure;
import org.elasticsearch.index.shard.IndexShard;
import org.elasticsearch.index.shard.IndexShardClosedException;
import org.elasticsearch.index.shard.ShardId;
import org.elasticsearch.index.shard.ShardNotInPrimaryModeException;
import org.elasticsearch.indices.IndicesService;
import org.elasticsearch.indices.SystemIndices;
import org.elasticsearch.node.NodeClosedException;
import org.elasticsearch.tasks.Task;
import org.elasticsearch.tasks.TaskId;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.transport.TransportException;
import org.elasticsearch.transport.TransportResponseHandler;
import org.elasticsearch.transport.TransportService;

import java.io.IOException;
import java.util.Map;
import java.util.Objects;

import static org.elasticsearch.core.Strings.format;

/**
 * Write action responsible for syncing retention leases to replicas. This action is deliberately a write action so that if a replica misses
 * a retention lease sync then that shard will be marked as stale.
 */
public class RetentionLeaseSyncAction extends TransportWriteAction<
    RetentionLeaseSyncAction.Request,
    RetentionLeaseSyncAction.Request,
    RetentionLeaseSyncAction.Response> {

    public static final String ACTION_NAME = "indices:admin/seq_no/retention_lease_sync";
    private static final Logger LOGGER = LogManager.getLogger(RetentionLeaseSyncAction.class);

    @Inject
    public RetentionLeaseSyncAction(
        final Settings settings,
        final TransportService transportService,
        final ClusterService clusterService,
        final IndicesService indicesService,
        final ThreadPool threadPool,
        final ShardStateAction shardStateAction,
        final ActionFilters actionFilters,
        final IndexingPressure indexingPressure,
        final SystemIndices systemIndices
    ) {
        super(
            settings,
            ACTION_NAME,
            transportService,
            clusterService,
            indicesService,
            threadPool,
            shardStateAction,
            actionFilters,
            RetentionLeaseSyncAction.Request::new,
            RetentionLeaseSyncAction.Request::new,
            (service, ignore) -> ThreadPool.Names.MANAGEMENT,
            false,
            indexingPressure,
            systemIndices
        );
    }

    @Override
    protected void doExecute(Task parentTask, Request request, ActionListener<Response> listener) {
        assert false : "use RetentionLeaseSyncAction#sync";
    }

    final void sync(
        ShardId shardId,
        String primaryAllocationId,
        long primaryTerm,
        RetentionLeases retentionLeases,
        ActionListener<ReplicationResponse> listener
    ) {
        final ThreadContext threadContext = threadPool.getThreadContext();
        try (ThreadContext.StoredContext ignore = threadContext.stashContext()) {
            // we have to execute under the system context so that if security is enabled the sync is authorized
            threadContext.markAsSystemContext();
            final Request request = new Request(shardId, retentionLeases);
            try (var ignored = threadContext.newTraceContext()) {
                final ReplicationTask task = (ReplicationTask) taskManager.register("transport", "retention_lease_sync", request);
                transportService.sendChildRequest(
                    clusterService.localNode(),
                    transportPrimaryAction,
                    new ConcreteShardRequest<>(request, primaryAllocationId, primaryTerm),
                    task,
                    transportOptions,
                    new TransportResponseHandler<ReplicationResponse>() {
                        @Override
                        public ReplicationResponse read(StreamInput in) throws IOException {
                            return newResponseInstance(in);
                        }

                        @Override
                        public void handleResponse(ReplicationResponse response) {
                            task.setPhase("finished");
                            taskManager.unregister(task);
                            listener.onResponse(response);
                        }

                        @Override
                        public void handleException(TransportException e) {
                            LOGGER.log(getExceptionLogLevel(e), () -> format("%s retention lease sync failed", shardId), e);
                            task.setPhase("finished");
                            taskManager.unregister(task);
                            listener.onFailure(e);
                        }
                    }
                );
            }
        }
    }

    static Level getExceptionLogLevel(Exception e) {
        return ExceptionsHelper.unwrap(
            e,
            NodeClosedException.class,
            IndexNotFoundException.class,
            AlreadyClosedException.class,
            IndexShardClosedException.class,
            ShardNotInPrimaryModeException.class,
            ReplicationOperation.RetryOnPrimaryException.class
        ) == null ? Level.WARN : Level.DEBUG;
    }

    @Override
    protected void dispatchedShardOperationOnPrimary(
        Request request,
        IndexShard primary,
        ActionListener<PrimaryResult<Request, Response>> listener
    ) {
        ActionListener.completeWith(listener, () -> {
            assert request.waitForActiveShards().equals(ActiveShardCount.NONE) : request.waitForActiveShards();
            Objects.requireNonNull(request);
            Objects.requireNonNull(primary);
            primary.persistRetentionLeases();
            return new WritePrimaryResult<>(request, new Response(), null, primary, LOGGER, postWriteRefresh);
        });
    }

    @Override
    protected void dispatchedShardOperationOnReplica(Request request, IndexShard replica, ActionListener<ReplicaResult> listener) {
        ActionListener.completeWith(listener, () -> {
            Objects.requireNonNull(request);
            Objects.requireNonNull(replica);
            replica.updateRetentionLeasesOnReplica(request.getRetentionLeases());
            replica.persistRetentionLeases();
            return new WriteReplicaResult<>(request, null, null, replica, LOGGER);
        });
    }

    @Override
    public ClusterBlockLevel indexBlockLevel() {
        return null;
    }

    public static final class Request extends ReplicatedWriteRequest<Request> {

        private RetentionLeases retentionLeases;

        public RetentionLeases getRetentionLeases() {
            return retentionLeases;
        }

        public Request(StreamInput in) throws IOException {
            super(in);
            retentionLeases = new RetentionLeases(in);
        }

        public Request(final ShardId shardId, final RetentionLeases retentionLeases) {
            super(Objects.requireNonNull(shardId));
            this.retentionLeases = Objects.requireNonNull(retentionLeases);
            waitForActiveShards(ActiveShardCount.NONE);
        }

        @Override
        public void writeTo(final StreamOutput out) throws IOException {
            super.writeTo(Objects.requireNonNull(out));
            retentionLeases.writeTo(out);
        }

        @Override
        public Task createTask(long id, String type, String action, TaskId parentTaskId, Map<String, String> headers) {
            return new ReplicationTask(id, type, action, "retention_lease_sync shardId=" + shardId, parentTaskId, headers);
        }

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

    }

    public static final class Response extends ReplicationResponse implements WriteResponse {

        public Response() {}

        Response(StreamInput in) throws IOException {
            super(in);
        }

        @Override
        public void setForcedRefresh(final boolean forcedRefresh) {
            // ignore
        }

    }

    @Override
    protected Response newResponseInstance(StreamInput in) throws IOException {
        return new Response(in);
    }

}
