/*
 * Copyright 2013 Rackspace
 *
 *    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.
 */

package com.rackspacecloud.blueflood.io;

import com.codahale.metrics.Timer;
import com.rackspacecloud.blueflood.service.ElasticClientManager;
import com.rackspacecloud.blueflood.service.RemoteElasticSearchServer;
import com.rackspacecloud.blueflood.types.Event;
import com.rackspacecloud.blueflood.utils.Metrics;
import org.elasticsearch.action.bulk.BulkRequestBuilder;
import org.elasticsearch.action.index.IndexRequestBuilder;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.Client;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.search.SearchHit;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import static org.elasticsearch.index.query.QueryBuilders.boolQuery;
import static org.elasticsearch.index.query.QueryBuilders.rangeQuery;
import static org.elasticsearch.index.query.QueryBuilders.termQuery;

public class EventElasticSearchIO implements EventsIO {
    private final Timer eventSearchTimer = Metrics.timer(EventElasticSearchIO.class,
            "Search time for events");
    private final Timer eventInsertTimer = Metrics.timer(EventElasticSearchIO.class,
            "Insertion time for events");
    public static final String EVENT_INDEX = "events";
    public static final String ES_TYPE = "graphite_event";
    private final Client client;

    public EventElasticSearchIO() {
        this(RemoteElasticSearchServer.getInstance());
    }
    public EventElasticSearchIO(Client client) {
        this.client = client;
    }
    public EventElasticSearchIO(ElasticClientManager manager) {
        this(manager.getClient());
    }

    @Override
    public void insert(String tenant, List<Map<String, Object>> events) throws Exception {
        final Timer.Context eventInsertTimerContext = eventInsertTimer.time();
        BulkRequestBuilder bulk = client.prepareBulk();

        for (Map<String, Object> event : events) {
            event.put(Event.FieldLabels.tenantId.toString(), tenant);
            IndexRequestBuilder requestBuilder = client.prepareIndex(EVENT_INDEX, ES_TYPE)
                    .setSource(event)
                    .setRouting(tenant);
            bulk.add(requestBuilder);
        }
        bulk.execute().actionGet();
        eventInsertTimerContext.stop();
    }

    @Override
    public List<Map<String, Object>> search(String tenant, Map<String, List<String>> query) throws Exception {
        final Timer.Context eventSearchTimerContext = eventSearchTimer.time();
        BoolQueryBuilder qb = boolQuery()
                .must(termQuery(Event.FieldLabels.tenantId.toString(), tenant));

        if (query != null) {
            qb = extractQueryParameters(query, qb);
        }

        SearchResponse response = client.prepareSearch(EVENT_INDEX)
                .setRouting(tenant)
                .setSize(100000)
                .setVersion(true)
                .setQuery(qb)
                .execute()
                .actionGet();

        eventSearchTimerContext.stop();

        List<Map<String, Object>> events = new ArrayList<Map<String, Object>>();
        for (SearchHit hit : response.getHits().getHits()) {
            events.add(hit.getSource());
        }

        return events;
    }

    private BoolQueryBuilder extractQueryParameters(Map<String, List<String>> query, BoolQueryBuilder qb) {
        String tagsQuery = extractFieldFromQuery(Event.FieldLabels.tags.toString(), query);
        String untilQuery = extractFieldFromQuery(Event.untilParameterName, query);
        String fromQuery = extractFieldFromQuery(Event.fromParameterName, query);

        if (!tagsQuery.equals(""))
            qb = qb.must(termQuery(Event.FieldLabels.tags.toString(), tagsQuery));

        if (!untilQuery.equals("") && !fromQuery.equals("")) {
            qb = qb.must(rangeQuery(Event.FieldLabels.when.toString())
                    .to(Long.parseLong(untilQuery))
                    .from(Long.parseLong(fromQuery)));
        } else if (!untilQuery.equals("")) {
            qb = qb.must(rangeQuery(Event.FieldLabels.when.toString()).to(Long.parseLong(untilQuery)));
        } else if (!fromQuery.equals("")) {
            qb = qb.must(rangeQuery(Event.FieldLabels.when.toString()).from(Long.parseLong(fromQuery)));
        }

        return qb;
    }

    private String extractFieldFromQuery(String name, Map<String, List<String>> query) {
        String result = "";
        if (query.containsKey(name)) {
            try {
                result = query.get(name).get(0);
            }
            catch (IndexOutOfBoundsException e) {
                result = "";
            }
        }
        return result;
    }
}