/*
 * 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.rest.action.admin.cluster.state;

import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.admin.cluster.state.ClusterStateRequest;
import org.elasticsearch.action.admin.cluster.state.ClusterStateResponse;
import org.elasticsearch.client.Client;
import org.elasticsearch.client.Requests;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.settings.SettingsFilter;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentBuilderString;
import org.elasticsearch.rest.*;
import org.elasticsearch.rest.action.support.RestXContentBuilder;

import java.io.IOException;
import java.util.Set;


/**
 *
 */
public class RestClusterStateAction extends BaseRestHandler {

    private final SettingsFilter settingsFilter;

    @Inject
    public RestClusterStateAction(Settings settings, Client client, RestController controller,
                                  SettingsFilter settingsFilter) {
        super(settings, client);
        controller.registerHandler(RestRequest.Method.GET, "/_cluster/state", this);
        controller.registerHandler(RestRequest.Method.GET, "/_cluster/state/{metric}", this);
        controller.registerHandler(RestRequest.Method.GET, "/_cluster/state/{metric}/{indices}", this);

        this.settingsFilter = settingsFilter;
    }

    @Override
    public void handleRequest(final RestRequest request, final RestChannel channel) {
        final ClusterStateRequest clusterStateRequest = Requests.clusterStateRequest();
        clusterStateRequest.listenerThreaded(false);
        clusterStateRequest.local(request.paramAsBoolean("local", clusterStateRequest.local()));
        clusterStateRequest.masterNodeTimeout(request.paramAsTime("master_timeout", clusterStateRequest.masterNodeTimeout()));

        final String[] indices = Strings.splitStringByCommaToArray(request.param("indices", "_all"));
        boolean isAllIndicesOnly = indices.length == 1 && "_all".equals(indices[0]);
        if (!isAllIndicesOnly) {
            clusterStateRequest.indices(indices);
        }

        Set<String> metrics = Strings.splitStringByCommaToSet(request.param("metric", "_all"));
        boolean isAllMetricsOnly = metrics.size() == 1 && metrics.contains("_all");
        if (!isAllMetricsOnly) {
            clusterStateRequest.nodes(metrics.contains("nodes") || metrics.contains("master_node"));
            clusterStateRequest.routingTable(metrics.contains("routing_table"));
            clusterStateRequest.metaData(metrics.contains("metadata"));
            clusterStateRequest.blocks(metrics.contains("blocks"));
            clusterStateRequest.indexTemplates(request.paramAsStringArray("index_templates", Strings.EMPTY_ARRAY));
        }

        client.admin().cluster().state(clusterStateRequest, new ActionListener<ClusterStateResponse>() {
            @Override
            public void onResponse(ClusterStateResponse response) {
                try {
                    XContentBuilder builder = RestXContentBuilder.restContentBuilder(request);
                    builder.startObject();
                    builder.field(Fields.CLUSTER_NAME, response.getClusterName().value());
                    response.getState().settingsFilter(settingsFilter).toXContent(builder, request);
                    builder.endObject();
                    channel.sendResponse(new XContentRestResponse(request, RestStatus.OK, builder));
                } catch (Throwable e) {
                    onFailure(e);
                }
            }

            @Override
            public void onFailure(Throwable e) {
                if (logger.isDebugEnabled()) {
                    logger.debug("failed to handle cluster state", e);
                }
                try {
                    channel.sendResponse(new XContentThrowableRestResponse(request, e));
                } catch (IOException e1) {
                    logger.error("Failed to send failure response", e1);
                }
            }
        });
    }

    static final class Fields {
        static final XContentBuilderString CLUSTER_NAME = new XContentBuilderString("cluster_name");
    }
}
