/**
 * The contents of this file are subject to the license and copyright
 * detailed in the LICENSE and NOTICE files at the root of the source
 * tree and available online at
 *
 * http://www.dspace.org/license/
 */
package org.dspace.app.xmlui.cocoon;

import java.io.IOException;

import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.generation.AbstractGenerator;
import org.dspace.content.authority.Choices;
import org.dspace.content.authority.ChoiceAuthorityManager;
import org.dspace.content.authority.ChoicesXMLGenerator;

import org.xml.sax.SAXException;

import org.apache.log4j.Logger;

/**
 * Generate XML description of Choice values to be used by
 * AJAX UI client.
 *
 * @author Larry Stone
 */
public class AJAXMenuGenerator extends AbstractGenerator
{
    private static Logger log = Logger.getLogger(AJAXMenuGenerator.class);

    /**
     * Generate the AJAX response Document.
     *
     * Looks for request paraemters:
     *  field - MD field key, i.e. form key, REQUIRED.
     *  start - index to start from, default 0.
     *  limit - max number of lines, default 1000.
     *  format - opt. result XML/XHTML format: "select", "ul", "xml"(default)
     *  locale - explicit locale, pass to choice plugin
     */
    public void generate()
        throws IOException, SAXException, ProcessingException
    {
        int start = 0;
        int limit = 1000;
        int collection = -1;
        String format = parameters.getParameter("format",null);
        String field = parameters.getParameter("field",null);
        String sstart = parameters.getParameter("start",null);
        if (sstart != null && sstart.length() > 0)
        {
            start = Integer.parseInt(sstart);
        }
        String slimit = parameters.getParameter("limit",null);
        if (slimit != null && slimit.length() > 0)
        {
            limit = Integer.parseInt(slimit);
        }
        String scoll = parameters.getParameter("collection",null);
        if (scoll != null && scoll.length() > 0)
        {
            collection = Integer.parseInt(scoll);
        }
        String query = parameters.getParameter("query",null);

        // localization
        String locale = parameters.getParameter("locale",null);
        log.debug("AJAX menu generator: field="+field+", query="+query+", start="+sstart+", limit="+slimit+", format="+format+", field="+field+", query="+query+", start="+sstart+", limit="+slimit+", format="+format+", locale = "+locale);

        Choices result =
            ChoiceAuthorityManager.getManager().getMatches(field, query, collection, start, limit, locale);

        log.debug("Result count = "+result.values.length+", default="+result.defaultSelected);

        ChoicesXMLGenerator.generate(result, format, contentHandler);
    }
}