/*
 * #%L
 * Protempa Framework
 * %%
 * Copyright (C) 2012 - 2013 Emory University
 * %%
 * Licensed 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.
 * #L%
 */
package org.protempa.xml;

import com.thoughtworks.xstream.converters.MarshallingContext;
import com.thoughtworks.xstream.converters.UnmarshallingContext;
import com.thoughtworks.xstream.io.HierarchicalStreamReader;
import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
import org.protempa.query.And;

import java.util.ArrayList;
import org.protempa.KnowledgeSource;

/**
 * Convert String array object to/from XML <keyIDs></keyIDs>
 *
 * @author mgrand
 */
class TermIDsConverter extends AbstractConverter {

    TermIDsConverter(KnowledgeSource knowledgeSource) {
        super(knowledgeSource);
    }

    /**
     * This converter is intended to be explicitly called from other converters
     * as it corresponds to nothing more specific than an array of AND objects.
     */
    @Override
    public boolean canConvert(@SuppressWarnings("rawtypes") Class clazz) {
        return String[].class.equals(clazz);
    }

    /**
     * @see com.thoughtworks.xstream.converters.Converter#marshal(java.lang.Object,
     *      com.thoughtworks.xstream.io.HierarchicalStreamWriter,
     *      com.thoughtworks.xstream.converters.MarshallingContext)
     */
    @Override
    public void marshal(Object value, HierarchicalStreamWriter writer, MarshallingContext context) {
        @SuppressWarnings("unchecked")
        And<String>[] termIds = (And<String>[]) value;
        for (And<String> and : termIds) {
            context.convertAnother(and);
        }
    }

    /*
     * (non-Javadoc)
     *
     * @see
     * com.thoughtworks.xstream.converters.Converter#unmarshal(com.thoughtworks
     * .xstream.io.HierarchicalStreamReader,
     * com.thoughtworks.xstream.converters.UnmarshallingContext)
     */
    @Override
    public Object unmarshal(HierarchicalStreamReader reader, UnmarshallingContext context) {
        ArrayList<And<String>> keyIdList = new ArrayList<>();
        while (reader.hasMoreChildren()) {
            reader.moveDown();
            expect(reader, "and");
            keyIdList.add(unmarshallAnd(context));
            reader.moveUp();
        }
        return keyIdList.toArray(new String[keyIdList.size()]);
    }

    @SuppressWarnings("unchecked")
    private And<String> unmarshallAnd(UnmarshallingContext context) {
        return (And<String>) context.convertAnother(null, And.class);
    }

}
