/*
 * 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", the "GNU Affero General Public License v3.0 only", 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", the "GNU Affero General Public
 * License v3.0 only", or the "Server Side Public License, v 1".
 */

package org.elasticsearch.action.termvectors;

import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.support.ActionFilters;
import org.elasticsearch.action.support.single.shard.TransportSingleShardAction;
import org.elasticsearch.cluster.ProjectState;
import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
import org.elasticsearch.cluster.project.ProjectResolver;
import org.elasticsearch.cluster.routing.ShardIterator;
import org.elasticsearch.cluster.service.ClusterService;
import org.elasticsearch.common.io.stream.Writeable;
import org.elasticsearch.index.IndexService;
import org.elasticsearch.index.shard.IndexShard;
import org.elasticsearch.index.shard.ShardId;
import org.elasticsearch.index.termvectors.TermVectorsService;
import org.elasticsearch.indices.IndicesService;
import org.elasticsearch.injection.guice.Inject;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.transport.TransportService;

import java.io.IOException;

/**
 * Performs the get operation.
 */
public class TransportTermVectorsAction extends TransportSingleShardAction<TermVectorsRequest, TermVectorsResponse> {

    private final IndicesService indicesService;

    @Inject
    public TransportTermVectorsAction(
        ClusterService clusterService,
        TransportService transportService,
        IndicesService indicesService,
        ThreadPool threadPool,
        ActionFilters actionFilters,
        ProjectResolver projectResolver,
        IndexNameExpressionResolver indexNameExpressionResolver
    ) {
        super(
            TermVectorsAction.NAME,
            threadPool,
            clusterService,
            transportService,
            actionFilters,
            projectResolver,
            indexNameExpressionResolver,
            TermVectorsRequest::new,
            threadPool.executor(ThreadPool.Names.GET)
        );
        this.indicesService = indicesService;
    }

    @Override
    protected ShardIterator shards(ProjectState project, InternalRequest request) {
        final var operationRouting = clusterService.operationRouting();
        if (request.request().doc() != null && request.request().routing() == null) {
            // artificial document without routing specified, ignore its "id" and use either random shard or according to preference
            return operationRouting.searchShards(project, new String[] { request.concreteIndex() }, null, request.request().preference())
                .getFirst();
        }

        return operationRouting.useOnlyPromotableShardsForStateless(
            operationRouting.getShards(

                project,

                request.concreteIndex(),

                request.request().id(),

                request.request().routing(),

                request.request().preference()

            )
        );
    }

    @Override
    protected boolean resolveIndex(TermVectorsRequest request) {
        return true;
    }

    @Override
    protected void resolveRequest(ProjectState state, InternalRequest request) {
        // update the routing (request#index here is possibly an alias or a parent)
        request.request().routing(state.metadata().resolveIndexRouting(request.request().routing(), request.request().index()));
    }

    @Override
    protected void asyncShardOperation(TermVectorsRequest request, ShardId shardId, ActionListener<TermVectorsResponse> listener)
        throws IOException {
        IndexService indexService = indicesService.indexServiceSafe(shardId.getIndex());
        IndexShard indexShard = indexService.getShard(shardId.id());
        if (request.realtime()) { // it's a realtime request which is not subject to refresh cycles
            super.asyncShardOperation(request, shardId, listener);
        } else {
            indexShard.ensureShardSearchActive(b -> {
                try {
                    super.asyncShardOperation(request, shardId, listener);
                } catch (Exception ex) {
                    listener.onFailure(ex);
                }
            });
        }
    }

    @Override
    protected TermVectorsResponse shardOperation(TermVectorsRequest request, ShardId shardId) {
        IndexService indexService = indicesService.indexServiceSafe(shardId.getIndex());
        IndexShard indexShard = indexService.getShard(shardId.id());
        return TermVectorsService.getTermVectors(indexShard, request);
    }

    @Override
    protected Writeable.Reader<TermVectorsResponse> getResponseReader() {
        return TermVectorsResponse::new;
    }
}