/*
 * Copyright (c) 2008-2012 EMC Corporation
 * All Rights Reserved
 */
package com.emc.storageos.volumecontroller.impl.plugins.metering.vnxfile.processor;

import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.apache.commons.httpclient.methods.PostMethod;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.emc.storageos.db.client.model.Stat;
import com.emc.storageos.plugins.BaseCollectionException;
import com.emc.storageos.plugins.common.domainmodel.Operation;
import com.emc.storageos.plugins.metering.vnxfile.VNXFileConstants;
import com.emc.storageos.volumecontroller.impl.plugins.metering.vnxfile.VNXFileProcessor;
import com.emc.nas.vnxfile.xmlapi.ResponsePacket;
import com.emc.nas.vnxfile.xmlapi.VolumeSetStats;
import com.emc.nas.vnxfile.xmlapi.VolumeSetStats.Sample;
import com.emc.nas.vnxfile.xmlapi.VolumeSetStats.Sample.Item;

/**
 * VNXVolumeStatsProcessor is responsible to process the result received from
 * XML API Server after getting the Volume Statistics Information.
 */
public class VNXVolumeStatsProcessor extends VNXFileProcessor {

    /**
     * Logger instance.
     */
    private final Logger _logger = LoggerFactory
            .getLogger(VNXVolumeStatsProcessor.class);

    @SuppressWarnings("unchecked")
    @Override
    public void processResult(Operation operation, Object resultObj,
            Map<String, Object> keyMap) throws BaseCollectionException {
        final PostMethod result = (PostMethod) resultObj;
        _logger.info("processing volumeStats response" + resultObj);
        try {
            ResponsePacket responsePacket = (ResponsePacket) _unmarshaller
                    .unmarshal(result.getResponseBodyAsStream());
            List<Object> volumeStats = getQueryStatsResponse(responsePacket);
            Iterator<Object> iterator = volumeStats.iterator();
            Map<String, String> volFileMap = (Map<String, String>) keyMap
                    .get(VNXFileConstants.VOLFILESHAREMAP);
            List<Stat> statsList = (List<Stat>) keyMap.get(VNXFileConstants.STATS);
            // There are cases where we will get error for movers, we should ignore the error
            // and proceed with rest of the Mover stats.
            while (iterator.hasNext()) {
                VolumeSetStats volStats = (VolumeSetStats) iterator.next();
                List<Sample> sampleList = volStats.getSample();
                processVolumeSampleList(sampleList, keyMap, volFileMap, statsList);
            }
        } catch (final Exception ex) {
            _logger.error(
                    "Exception occurred while processing the volume stats response due to {}",
                    ex.getMessage());
        } finally {
            result.releaseConnection();
        }

    }

    /**
     * Process the each Volume sample list and inject
     * bwIn, bwOut for each fileshare. We also have a one-to-one
     * mapping between volume to Fileshare.
     * 
     * @param sampleList : List of Sample objects of a volume
     * @param keyMap : keyMap
     * @param volFileMap : Volume-to-Fileshare Mapping
     * @param statsList : StatsList to update.
     */
    private void processVolumeSampleList(List<Sample> sampleList,
            Map<String, Object> keyMap, Map<String, String> volFileMap,
            List<Stat> statsList) {

        Iterator<Sample> itemItr = sampleList.iterator();
        while (itemItr.hasNext()) {
            Sample volSample = itemItr.next();
            List<Item> volItems = volSample.getItem();
            Iterator<Item> volItemsItr = volItems.iterator();
            while (volItemsItr.hasNext()) {
                Item volItem = volItemsItr.next();
                if (volFileMap.containsKey(volItem.getVolume())) {
                    String fileSystem = volFileMap.get(volItem.getVolume());
                    // No filesystem found for volume then skip
                    if (null != fileSystem) {
                        injectBWInOut(fileSystem, keyMap, volItem, statsList);
                    }
                }
            }

        }

    }

    /**
     * Inject bwIn & bwOut in stat object.
     * 
     * @param fileShareId : FileshareId to update.
     * @param keyMap : KeyMap
     * @param volItem : VolItem contains the bytesRead/bytesWrite values.
     * @param statsList : Stat List to update.
     */
    private void injectBWInOut(String fileShareId, Map<String, Object> keyMap,
            Item volItem, List<Stat> statsList) {
        Iterator<Stat> statsItr = statsList.iterator();
        while (statsItr.hasNext()) {
            Stat stat = statsItr.next();
            if (null != fileShareId && fetchNativeId(stat.getNativeGuid()).equals(fileShareId)) {
                stat.setBandwidthOut(volItem.getBytesRead().longValue());
                stat.setBandwidthIn(volItem.getBytesWritten().longValue());
                break;
            }
        }
    }

    @Override
    protected void setPrerequisiteObjects(List<Object> inputArgs)
            throws BaseCollectionException {

    }

}