/*
 * 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.admin.cluster.node.tasks.list;

import com.carrotsearch.hppc.cursors.ObjectObjectCursor;

import org.elasticsearch.action.FailedNodeException;
import org.elasticsearch.action.TaskOperationFailure;
import org.elasticsearch.action.support.tasks.BaseTasksResponse;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamInputReader;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.xcontent.ToXContent;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentFactory;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * Returns the list of tasks currently running on the nodes
 */
public class ListTasksResponse extends BaseTasksResponse implements ToXContent {

    private List<TaskInfo> tasks;

    private Map<DiscoveryNode, List<TaskInfo>> nodes;

    public ListTasksResponse() {
    }

    public ListTasksResponse(List<TaskInfo> tasks, List<TaskOperationFailure> taskFailures, List<? extends FailedNodeException> nodeFailures) {
        super(taskFailures, nodeFailures);
        if (tasks == null) {
            this.tasks = Collections.emptyList();
        } else {
            this.tasks = Collections.unmodifiableList(new ArrayList<>(tasks));
        }
    }

    @Override
    public void readFrom(StreamInput in) throws IOException {
        super.readFrom(in);
        tasks = Collections.unmodifiableList(in.readList(new StreamInputReader<TaskInfo>() {
            @Override
            public TaskInfo read(StreamInput t) throws IOException {
                return new TaskInfo(t);
            }
        }));
    }

    @Override
    public void writeTo(StreamOutput out) throws IOException {
        super.writeTo(out);
        out.writeList(tasks);
    }

    /**
     * Returns the list of tasks by node
     */
    public Map<DiscoveryNode, List<TaskInfo>> getPerNodeTasks() {
        if (nodes != null) {
            return nodes;
        }
        Map<DiscoveryNode, List<TaskInfo>> nodeTasks = new HashMap<>();

        Set<DiscoveryNode> nodes = new HashSet<>();
        for (TaskInfo shard : tasks) {
            nodes.add(shard.getNode());
        }

        for (DiscoveryNode node : nodes) {
            List<TaskInfo> tasks = new ArrayList<>();
            for (TaskInfo taskInfo : this.tasks) {
                if (taskInfo.getNode().equals(node)) {
                    tasks.add(taskInfo);
                }
            }
            nodeTasks.put(node, tasks);
        }
        this.nodes = nodeTasks;
        return nodeTasks;
    }

    public List<TaskInfo> getTasks() {
        return tasks;
    }

    @Override
    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
        if (getTaskFailures() != null && getTaskFailures().size() > 0) {
            builder.startArray("task_failures");
            for (TaskOperationFailure ex : getTaskFailures()){
                builder.startObject();
                builder.value(ex);
                builder.endObject();
            }
            builder.endArray();
        }

        if (getNodeFailures() != null && getNodeFailures().size() > 0) {
            builder.startArray("node_failures");
            for (FailedNodeException ex : getNodeFailures()) {
                builder.startObject();
                ex.toXContent(builder, params);
                builder.endObject();
            }
            builder.endArray();
        }

        builder.startObject("nodes");
        for (Map.Entry<DiscoveryNode, List<TaskInfo>> entry : getPerNodeTasks().entrySet()) {
            DiscoveryNode node = entry.getKey();
            builder.startObject(node.getId(), XContentBuilder.FieldCaseConversion.NONE);
            builder.field("name", node.name());
            builder.field("transport_address", node.address().toString());
            builder.field("host", node.getHostName());
            builder.field("ip", node.getAddress());

            if (!node.attributes().isEmpty()) {
                builder.startObject("attributes");
                for (Map.Entry<String, String> attr : node.attributes().entrySet()) {
                    builder.field(attr.getKey(), attr.getValue(), XContentBuilder.FieldCaseConversion.NONE);
                }
                builder.endObject();
            }
            builder.startObject("tasks");
            for(TaskInfo task : entry.getValue()) {
                builder.startObject(task.getTaskId().toString(), XContentBuilder.FieldCaseConversion.NONE);
                task.toXContent(builder, params);
                builder.endObject();
            }
            builder.endObject();
            builder.endObject();
        }
        builder.endObject();
        return builder;
    }

    @Override
    public String toString() {
        try {
            XContentBuilder builder = XContentFactory.jsonBuilder().prettyPrint();
            builder.startObject();
            toXContent(builder, EMPTY_PARAMS);
            builder.endObject();
            return builder.string();
        } catch (IOException e) {
            return "{ \"error\" : \"" + e.getMessage() + "\"}";
        }
    }
}