/*
 * Copyright (c) 2008-2011 EMC Corporation
 * All Rights Reserved
 */

package com.emc.storageos.model.adapters;

import com.emc.storageos.model.StringHashMapEntry;

import javax.xml.bind.annotation.adapters.XmlAdapter;
import java.util.HashMap;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

/**
 * An JAXB XML adapter from Map (String,String) into List (StringHashMapEntry)
 * 
 * JAXB automatically converts a Map into a list to marshal it into an XML file.
 * The elements of a HashMap are "entry" pairs of key/value. If we want to replace the
 * HashMap elements with names "entry", "key", "value" into elements consistent with our
 * definition of REST guidelines, we need to translate Maps into Lists ourselves.
 * This class provide an adapter from Map (String,String) into List (StringHashMapEntry)
 * This class should be used in conjuction with XML annotation "XmlJavaTypeAdapter"
 */
public class StringMapAdapter extends XmlAdapter<List<StringHashMapEntry>, Map<String, String>>
{
    @Override
    public Map<String, String> unmarshal(List<StringHashMapEntry> list) {
        if (list == null) {
            return (HashMap<String, String>) null;
        }
        Map<String, String> map = new HashMap<String, String>(2 * list.size());
        for (StringHashMapEntry entry : list) {
            map.put(entry.getName(), entry.getValue());
        }
        return map;
    }

    @Override
    public List<StringHashMapEntry> marshal(Map<String, String> map) {
        if (map == null) {
            return (ArrayList<StringHashMapEntry>) null;
        }
        List<StringHashMapEntry> list = new ArrayList<StringHashMapEntry>();
        if (map != null) {
            for (Entry<String, String> entry : map.entrySet()) {
                StringHashMapEntry listEnt = new StringHashMapEntry(entry.getKey(), entry.getValue());
                list.add(listEnt);
            }
        }
        return list;
    }

}