/**
 Copyright 2006 OCLC, Online Computer Library Center
 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.
 */

package ORG.oclc.oai.harvester2.verb;

import java.io.IOException;
import java.net.URLEncoder;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.TransformerException;
import org.xml.sax.SAXException;

/**
 * This class represents an ListIdentifiers response on either the server or
 * on the client
 *
 * @author Jeffrey A. Young, OCLC Online Computer Library Center
 */
public class ListIdentifiers extends HarvesterVerb {
    /**
     * Mock object constructor (for unit testing purposes)
     */
    public ListIdentifiers() {
        super();
    }
    
    /**
     * Client-side ListIdentifiers verb constructor
     *
     * @param baseURL the baseURL of the server to be queried
     * @exception MalformedURLException the baseURL is bad
     * @exception SAXException the xml response is bad
     * @exception IOException an I/O error occurred
     */
    public ListIdentifiers(String baseURL, String from, String until,
            String set, String metadataPrefix)
    throws IOException, ParserConfigurationException, SAXException,
    TransformerException {
        super(getRequestURL(baseURL, from, until, set, metadataPrefix));
    }
    
    /**
     * Client-side ListIdentifiers verb constructor (resumptionToken version)
     * @param baseURL
     * @param resumptionToken
     * @throws IOException
     * @throws ParserConfigurationException
     * @throws SAXException
     * @throws TransformerException
     */
    public ListIdentifiers(String baseURL, String resumptionToken)
    throws IOException, ParserConfigurationException, SAXException,
    TransformerException {
        super(getRequestURL(baseURL, resumptionToken));
    }
    
    /**
     * Get the oai:resumptionToken from the response
     * 
     * @return the oai:resumptionToken value
     * @throws TransformerException
     * @throws NoSuchFieldException
     */
    public String getResumptionToken()
    throws TransformerException, NoSuchFieldException {
        if (SCHEMA_LOCATION_V2_0.equals(getSchemaLocation())) {
            return getSingleString("/oai20:OAI-PMH/oai20:ListIdentifiers/oai20:resumptionToken");
        } else if (SCHEMA_LOCATION_V1_1_LIST_IDENTIFIERS.equals(getSchemaLocation())) {
            return getSingleString("/oai11_ListIdentifiers:ListIdentifiers/oai11_ListIdentifiers:resumptionToken");
        } else {
            throw new NoSuchFieldException(getSchemaLocation());
        }
    }
    
    /**
     * Construct the query portion of the http request
     *
     * @return a String containing the query portion of the http request
     */
    private static String getRequestURL(String baseURL, String from,
            String until, String set,
            String metadataPrefix) {
        StringBuffer requestURL =  new StringBuffer(baseURL);
        requestURL.append("?verb=ListIdentifiers");
        if (from != null) requestURL.append("&from=").append(from);
        if (until != null) requestURL.append("&until=").append(until);
        if (set != null) requestURL.append("&set=").append(set);
        requestURL.append("&metadataPrefix=").append(metadataPrefix);
        return requestURL.toString();
    }
    
    /**
     * Construct the query portion of the http request (resumptionToken version)
     * @param baseURL
     * @param resumptionToken
     * @return
     */
    private static String getRequestURL(String baseURL,
            String resumptionToken) {
        StringBuffer requestURL =  new StringBuffer(baseURL);
        requestURL.append("?verb=ListIdentifiers");
        requestURL.append("&resumptionToken=").append(URLEncoder.encode(resumptionToken));
        return requestURL.toString();
    }
}