/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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.apache.cassandra.streaming.management;

import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import javax.management.openmbean.ArrayType;
import javax.management.openmbean.CompositeData;
import javax.management.openmbean.CompositeDataSupport;
import javax.management.openmbean.CompositeType;
import javax.management.openmbean.OpenDataException;
import javax.management.openmbean.OpenType;
import javax.management.openmbean.SimpleType;

import com.google.common.base.Function;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;

import org.apache.cassandra.streaming.SessionInfo;
import org.apache.cassandra.streaming.StreamOperation;
import org.apache.cassandra.streaming.StreamState;
import org.apache.cassandra.utils.TimeUUID;

/**
 */
public class StreamStateCompositeData
{
    private static final String[] ITEM_NAMES = new String[]{"planId", "description", "sessions",
                                                            "currentRxBytes", "totalRxBytes", "rxPercentage",
                                                            "currentTxBytes", "totalTxBytes", "txPercentage"};
    private static final String[] ITEM_DESCS = new String[]{"Plan ID of this stream",
                                                            "Stream plan description",
                                                            "Active stream sessions",
                                                            "Number of bytes received across all streams",
                                                            "Total bytes available to receive across all streams",
                                                            "Percentage received across all streams",
                                                            "Number of bytes sent across all streams",
                                                            "Total bytes available to send across all streams",
                                                            "Percentage sent across all streams"};
    private static final OpenType<?>[] ITEM_TYPES;

    public static final CompositeType COMPOSITE_TYPE;
    static
    {
        try
        {
            ITEM_TYPES = new OpenType[]{SimpleType.STRING,
                                         SimpleType.STRING,
                                         ArrayType.getArrayType(SessionInfoCompositeData.COMPOSITE_TYPE),
                                         SimpleType.LONG, SimpleType.LONG, SimpleType.DOUBLE,
                                         SimpleType.LONG, SimpleType.LONG, SimpleType.DOUBLE};
            COMPOSITE_TYPE = new CompositeType(StreamState.class.getName(),
                                            "StreamState",
                                            ITEM_NAMES,
                                            ITEM_DESCS,
                                            ITEM_TYPES);
        }
        catch (OpenDataException e)
        {
            throw new RuntimeException(e);
        }
    }

    public static CompositeData toCompositeData(final StreamState streamState)
    {
        Map<String, Object> valueMap = new HashMap<>();
        valueMap.put(ITEM_NAMES[0], streamState.planId.toString());
        valueMap.put(ITEM_NAMES[1], streamState.streamOperation.getDescription());

        CompositeData[] sessions = new CompositeData[streamState.sessions.size()];
        Lists.newArrayList(Iterables.transform(streamState.sessions, new Function<SessionInfo, CompositeData>()
        {
            public CompositeData apply(SessionInfo input)
            {
                return SessionInfoCompositeData.toCompositeData(streamState.planId, input);
            }
        })).toArray(sessions);
        valueMap.put(ITEM_NAMES[2], sessions);

        long currentRxBytes = 0;
        long totalRxBytes = 0;
        long currentTxBytes = 0;
        long totalTxBytes = 0;
        for (SessionInfo sessInfo : streamState.sessions)
        {
            currentRxBytes += sessInfo.getTotalSizeReceived();
            totalRxBytes += sessInfo.getTotalSizeToReceive();
            currentTxBytes += sessInfo.getTotalSizeSent();
            totalTxBytes += sessInfo.getTotalSizeToSend();
        }
        double rxPercentage = (totalRxBytes == 0 ? 100L : currentRxBytes * 100L / totalRxBytes);
        double txPercentage = (totalTxBytes == 0 ? 100L : currentTxBytes * 100L / totalTxBytes);

        valueMap.put(ITEM_NAMES[3], currentRxBytes);
        valueMap.put(ITEM_NAMES[4], totalRxBytes);
        valueMap.put(ITEM_NAMES[5], rxPercentage);
        valueMap.put(ITEM_NAMES[6], currentTxBytes);
        valueMap.put(ITEM_NAMES[7], totalTxBytes);
        valueMap.put(ITEM_NAMES[8], txPercentage);

        try
        {
            return new CompositeDataSupport(COMPOSITE_TYPE, valueMap);
        }
        catch (OpenDataException e)
        {
            throw new RuntimeException(e);
        }
    }

    public static StreamState fromCompositeData(CompositeData cd)
    {
        assert cd.getCompositeType().equals(COMPOSITE_TYPE);
        Object[] values = cd.getAll(ITEM_NAMES);
        TimeUUID planId = TimeUUID.fromString((String) values[0]);
        String typeString = (String) values[1];
        Set<SessionInfo> sessions = Sets.newHashSet(Iterables.transform(Arrays.asList((CompositeData[]) values[2]),
                                                                        new Function<CompositeData, SessionInfo>()
                                                                        {
                                                                            public SessionInfo apply(CompositeData input)
                                                                            {
                                                                                return SessionInfoCompositeData.fromCompositeData(input);
                                                                            }
                                                                        }));
        return new StreamState(planId, StreamOperation.fromString(typeString), sessions);
    }
}
