/*
 * 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.action.delete;

import org.elasticsearch.ExceptionsHelper;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
import org.elasticsearch.action.admin.indices.create.TransportCreateIndexAction;
import org.elasticsearch.action.delete.index.IndexDeleteRequest;
import org.elasticsearch.action.delete.index.IndexDeleteResponse;
import org.elasticsearch.action.delete.index.ShardDeleteResponse;
import org.elasticsearch.action.delete.index.TransportIndexDeleteAction;
import org.elasticsearch.action.support.AutoCreateIndex;
import org.elasticsearch.action.support.replication.TransportShardReplicationOperationAction;
import org.elasticsearch.cluster.ClusterService;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.action.shard.ShardStateAction;
import org.elasticsearch.cluster.block.ClusterBlockException;
import org.elasticsearch.cluster.block.ClusterBlockLevel;
import org.elasticsearch.cluster.metadata.MappingMetaData;
import org.elasticsearch.cluster.routing.ShardIterator;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.lucene.uid.Versions;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.index.engine.Engine;
import org.elasticsearch.index.shard.service.IndexShard;
import org.elasticsearch.indices.IndexAlreadyExistsException;
import org.elasticsearch.indices.IndicesService;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.transport.TransportService;

/**
 * Performs the delete operation.
 */
public class TransportDeleteAction extends TransportShardReplicationOperationAction<DeleteRequest, DeleteRequest, DeleteResponse> {

    private final AutoCreateIndex autoCreateIndex;

    private final TransportCreateIndexAction createIndexAction;

    private final TransportIndexDeleteAction indexDeleteAction;

    @Inject
    public TransportDeleteAction(Settings settings, TransportService transportService, ClusterService clusterService,
                                 IndicesService indicesService, ThreadPool threadPool, ShardStateAction shardStateAction,
                                 TransportCreateIndexAction createIndexAction, TransportIndexDeleteAction indexDeleteAction) {
        super(settings, transportService, clusterService, indicesService, threadPool, shardStateAction);
        this.createIndexAction = createIndexAction;
        this.indexDeleteAction = indexDeleteAction;
        this.autoCreateIndex = new AutoCreateIndex(settings);
    }

    @Override
    protected String executor() {
        return ThreadPool.Names.INDEX;
    }

    @Override
    protected void doExecute(final DeleteRequest request, final ActionListener<DeleteResponse> listener) {
        if (autoCreateIndex.shouldAutoCreate(request.index(), clusterService.state())) {
            request.beforeLocalFork();
            createIndexAction.execute(new CreateIndexRequest(request.index()).cause("auto(delete api)").masterNodeTimeout(request.timeout()), new ActionListener<CreateIndexResponse>() {
                @Override
                public void onResponse(CreateIndexResponse result) {
                    innerExecute(request, listener);
                }

                @Override
                public void onFailure(Throwable e) {
                    if (ExceptionsHelper.unwrapCause(e) instanceof IndexAlreadyExistsException) {
                        // we have the index, do it
                        innerExecute(request, listener);
                    } else {
                        listener.onFailure(e);
                    }
                }
            });
        } else {
            innerExecute(request, listener);
        }
    }

    @Override
    protected boolean resolveRequest(final ClusterState state, final DeleteRequest request, final ActionListener<DeleteResponse> listener) {
        request.routing(state.metaData().resolveIndexRouting(request.routing(), request.index()));
        request.index(state.metaData().concreteIndex(request.index()));
        if (state.metaData().hasIndex(request.index())) {
            // check if routing is required, if so, do a broadcast delete
            MappingMetaData mappingMd = state.metaData().index(request.index()).mappingOrDefault(request.type());
            if (mappingMd != null && mappingMd.routing().required()) {
                if (request.routing() == null) {
                    indexDeleteAction.execute(new IndexDeleteRequest(request), new ActionListener<IndexDeleteResponse>() {
                        @Override
                        public void onResponse(IndexDeleteResponse indexDeleteResponse) {
                            // go over the response, see if we have found one, and the version if found
                            long version = Versions.MATCH_ANY;
                            boolean found = false;
                            for (ShardDeleteResponse deleteResponse : indexDeleteResponse.getResponses()) {
                                if (deleteResponse.isFound()) {
                                    version = deleteResponse.getVersion();
                                    found = true;
                                    break;
                                }
                            }
                            listener.onResponse(new DeleteResponse(request.index(), request.type(), request.id(), version, found));
                        }

                        @Override
                        public void onFailure(Throwable e) {
                            listener.onFailure(e);
                        }
                    });
                    return false;
                }
            }
        }
        return true;
    }

    private void innerExecute(final DeleteRequest request, final ActionListener<DeleteResponse> listener) {
        super.doExecute(request, listener);
    }

    @Override
    protected boolean checkWriteConsistency() {
        return true;
    }

    @Override
    protected DeleteRequest newRequestInstance() {
        return new DeleteRequest();
    }

    @Override
    protected DeleteRequest newReplicaRequestInstance() {
        return new DeleteRequest();
    }

    @Override
    protected DeleteResponse newResponseInstance() {
        return new DeleteResponse();
    }

    @Override
    protected String transportAction() {
        return DeleteAction.NAME;
    }

    @Override
    protected ClusterBlockException checkGlobalBlock(ClusterState state, DeleteRequest request) {
        return state.blocks().globalBlockedException(ClusterBlockLevel.WRITE);
    }

    @Override
    protected ClusterBlockException checkRequestBlock(ClusterState state, DeleteRequest request) {
        return state.blocks().indexBlockedException(ClusterBlockLevel.WRITE, request.index());
    }

    @Override
    protected PrimaryResponse<DeleteResponse, DeleteRequest> shardOperationOnPrimary(ClusterState clusterState, PrimaryOperationRequest shardRequest) {
        DeleteRequest request = shardRequest.request;
        IndexShard indexShard = indicesService.indexServiceSafe(shardRequest.request.index()).shardSafe(shardRequest.shardId);
        Engine.Delete delete = indexShard.prepareDelete(request.type(), request.id(), request.version())
                .versionType(request.versionType())
                .origin(Engine.Operation.Origin.PRIMARY);
        indexShard.delete(delete);
        // update the request with teh version so it will go to the replicas
        request.version(delete.version());

        if (request.refresh()) {
            try {
                indexShard.refresh(new Engine.Refresh("refresh_flag_delete").force(false));
            } catch (Exception e) {
                // ignore
            }
        }

        DeleteResponse response = new DeleteResponse(request.index(), request.type(), request.id(), delete.version(), delete.found());
        return new PrimaryResponse<DeleteResponse, DeleteRequest>(shardRequest.request, response, null);
    }

    @Override
    protected void shardOperationOnReplica(ReplicaOperationRequest shardRequest) {
        DeleteRequest request = shardRequest.request;
        IndexShard indexShard = indicesService.indexServiceSafe(shardRequest.request.index()).shardSafe(shardRequest.shardId);
        Engine.Delete delete = indexShard.prepareDelete(request.type(), request.id(), request.version())
                .origin(Engine.Operation.Origin.REPLICA);

        indexShard.delete(delete);

        if (request.refresh()) {
            try {
                indexShard.refresh(new Engine.Refresh("refresh_flag_delete").force(false));
            } catch (Exception e) {
                // ignore
            }
        }

    }

    @Override
    protected ShardIterator shards(ClusterState clusterState, DeleteRequest request) {
        return clusterService.operationRouting()
                .deleteShards(clusterService.state(), request.index(), request.type(), request.id(), request.routing());
    }
}
