/*
 * Copyright (c) 2013 EMC Corporation
 * All Rights Reserved
 */
package com.emc.storageos.volumecontroller.impl.utils.attrmatchers;

import java.net.URI;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.CollectionUtils;

import com.emc.storageos.db.client.constraint.AlternateIdConstraint;
import com.emc.storageos.db.client.constraint.URIQueryResultList;
import com.emc.storageos.db.client.model.StoragePool;
import com.emc.storageos.volumecontroller.AttributeMatcher;
import com.google.common.base.Joiner;

/**
 * NeighborhoodsMatcher is responsible to filter out storage pools which do not belong to the specified vArrays.
 * 
 */
public class NeighborhoodsMatcher extends AttributeMatcher {

    private static final Logger _logger = LoggerFactory.getLogger(NeighborhoodsMatcher.class);

    /**
     * Filters out storage pools which do not belong to the specified vArrays.
     * 
     * @param pools : storage pools
     * @param attributeMap : map of attributes which includes set of vArrays
     * 
     * @return list of pools in the specified vArrays
     */
    @Override
    public List<StoragePool> matchStoragePoolsWithAttributeOn(List<StoragePool> pools, Map<String, Object> attributeMap,
            StringBuffer errorMessage) {
        List<StoragePool> matchedPools = new ArrayList<StoragePool>();

        Set<String> vArrays = (Set<String>) attributeMap.get(Attributes.varrays.toString());
        if (vArrays != null && !vArrays.isEmpty()) {
            _logger.info("Pools Matching vArrays Started {}, {} :", vArrays, Joiner.on("\t").join(getNativeGuidFromPools(pools)));
            List<URI> vArrayPools = getVarrayPools(vArrays);
            Iterator<StoragePool> poolIterator = pools.iterator();
            while (poolIterator.hasNext()) {
                StoragePool pool = poolIterator.next();
                // check if the storage pool is part varray pool list.
                // if it is not in the list then remove it
                if (vArrayPools.contains(pool.getId())) {
                    matchedPools.add(pool);
                }
            }
        }
        if (CollectionUtils.isEmpty(matchedPools)) {
            errorMessage.append(String.format("Virtual Arrays %s does not have Storage Pools. ", vArrays));
            _logger.error(errorMessage.toString());
        }
        _logger.info("Pools Matching vArrays Ended: {}", Joiner.on("\t").join(getNativeGuidFromPools(matchedPools)));
        return matchedPools;
    }

    /**
     * Get storage pools which belong to given vArrays.
     * 
     * @param vArrays
     * @return
     */

    private List<URI> getVarrayPools(Set<String> vArrays) {
        List<URI> poolURIs = new ArrayList<URI>();
        Iterator<String> vArrayItr = vArrays.iterator();
        while (vArrayItr.hasNext()) {
            URIQueryResultList vArrayPoolsQueryResult = new URIQueryResultList();
            _objectCache.getDbClient().queryByConstraint(AlternateIdConstraint.Factory
                    .getVirtualArrayStoragePoolsConstraint(vArrayItr.next()),
                    vArrayPoolsQueryResult);
            Iterator<URI> poolIterator = vArrayPoolsQueryResult.iterator();
            while (poolIterator.hasNext()) {
                poolURIs.add(poolIterator.next());
            }
        }
        return poolURIs;
    }

    @Override
    protected boolean isAttributeOn(Map<String, Object> attributeMap) {
        // this should run always.
        return true;
    }
}