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 *
 * The contents of this file are subject to the terms of the NASA Open
 * Source Agreement (NOSA), Version 1.3 only (the "Agreement").  You may
 * not use this file except in compliance with the Agreement.
 *
 * You can obtain a copy of the agreement at
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 *
 * See the Agreement for the specific language governing permissions
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 * When distributing Covered Code, include this NOSA HEADER in each
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package gov.nasa.gsfc.spdf.helm.test;

import java.io.InputStream;
import java.io.OutputStream;
import java.net.Authenticator;
import java.net.URL;
import java.net.HttpURLConnection;
import java.util.List;
import java.util.Map;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;

import javax.ws.rs.core.HttpHeaders;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;

import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.UniformInterfaceException;
import com.sun.jersey.api.client.WebResource;

import org.w3._1999.xhtml.Html;

import gov.nasa.gsfc.helm.data.schema.Eventlist;


/**
 * This class represents an example client of Heliophysics Event List
 * Manager (HELM) Web services.  It utilizes the client API of the
 * <a href="https://jersey.dev.java.net/">Jersey</a> JAX-RS (JSR 311)
 * reference implementation.  A similar example could be implemented
 * using any of the other competing APIs.
 *
 * @version $Revision: $
 * @author B. Harris
 */
public class JaxRsExample {

    /**
     * Client of HELM RESTful Web services.
     */
    private Client client = Client.create();


    /**
     * JAXB context for HELM XML data.
     */
    private JAXBContext helmJaxbContext =
        JAXBContext.newInstance("gov.nasa.gsfc.helm.data.schema");

    /**
     * JAXB context for XHTML data.
     */
    private JAXBContext xhtmlJaxbContext =
        JAXBContext.newInstance("org.w3._1999.xhtml");


    /**
     * This example's user-agent value.
     */
    private static final String EXAMPLE_USER_AGENT = "JaxRsExample";


    public JaxRsExample()
        throws JAXBException {

    }


    /**
     * Executes this example.
     *
     * @param endpoint base URL of HELM Web services
     * @param listname name of an eventlist
     */
    public void execute(String endpoint, String listname) 
        throws Exception {


/*
execute OPTIONS, HEAD?
System.out.println("Invoking HTTP OPTIONS " + url);
Wadl wadl = helm.options(Wadl.class);
*/

        Html eventlists = getEventlists(endpoint);

        System.out.println("eventlists:");
        marshal(System.out, eventlists);

        Eventlist eventlist = getEventlist(endpoint, listname);

        System.out.println("eventlist:");
        marshal(System.out, eventlist);

        String jsonEventlist = getJsonEventlist(endpoint, listname);

        System.out.println("JSON eventlist:");
        System.out.println("  " + jsonEventlist);

    }


    private Html getEventlists(String endpoint) {

        String url = endpoint + "/eventlists/";

        WebResource helm = client.resource(url);

        WebResource.Builder request = 
            helm.accept(MediaType.APPLICATION_XHTML_XML);
        request.header(HttpHeaders.USER_AGENT, EXAMPLE_USER_AGENT);

        System.out.println("Invoking HTTP GET " + url);

        return request.get(Html.class);
    }


    private Eventlist getEventlist(String endpoint, String listname) {

        String url = endpoint + "/eventlists/" + listname;

        WebResource helm = client.resource(url);

        WebResource.Builder request = 
            helm.accept(MediaType.APPLICATION_XML);
        request.header(HttpHeaders.USER_AGENT, EXAMPLE_USER_AGENT);

        System.out.println("Invoking HTTP GET " + url);

        return request.get(Eventlist.class);
    }


    private String getJsonEventlist(String endpoint, String listname) {

        String url = endpoint + "/eventlists/" + listname;

        WebResource helm = client.resource(url);

        WebResource.Builder request = 
            helm.accept(MediaType.APPLICATION_JSON);
        request.header(HttpHeaders.USER_AGENT, EXAMPLE_USER_AGENT);

        System.out.println("Invoking JSON HTTP GET " + url);

        return request.get(String.class);
    }



    private void marshal(OutputStream out, Object value) 
        throws JAXBException {

        Marshaller marshaller = null;

        if (value instanceof gov.nasa.gsfc.helm.data.schema.Eventlist) {

            marshaller = helmJaxbContext.createMarshaller();
        }
        else if (value instanceof org.w3._1999.xhtml.Html) {

            marshaller = xhtmlJaxbContext.createMarshaller();
        }
        else {

            System.err.println("Don't know how to marshall " +
                value.getClass().getName());
        }
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT,
                               Boolean.TRUE);

        marshaller.marshal(value, out);
    }


    /**
     * Instantiates an instance of this class and then invokes the
     * {@link #execute(String)} method.
     *
     * @param args command line arguments.  
     *            args[0] is the base URL of HELM Web services
     *            args[1] is the name of the eventlist to get
     * @throws Exception if an Exception occurs
     */
    public static void main(String[] args) 
        throws Exception {

        if (args.length < 2) {

            System.out.println("ERROR: missing argument(s)");
            System.out.println("USAGE: JaxRsExample endpoint eventlist-name");
            return;
        }

        JaxRsExample example = new JaxRsExample();

        example.execute(args[0], args[1]);
    }
}