/*
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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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 * or
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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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 * following below this NOSA HEADER, with the fields enclosed by
 * brackets "[]" replaced with your own identifying information:
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 *
 * Copyright (c) 2008-2010 United States Government as represented by
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 * claimed in the United States under Title 17, U.S.Code. All Other
 * Rights Reserved.
 *
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package gov.nasa.gsfc.spdf.helm.test;

import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintStream;
import java.net.Authenticator;
import java.net.URL;
import java.net.URLEncoder;
import java.net.HttpURLConnection;
import java.net.PasswordAuthentication;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.List;
import java.util.Map;
import java.util.SimpleTimeZone;


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

import javax.xml.datatype.DatatypeConfigurationException;
import javax.xml.datatype.DatatypeConstants;
import javax.xml.datatype.DatatypeFactory;
import javax.xml.datatype.Duration;
import javax.xml.datatype.XMLGregorianCalendar;

import org.w3._1999.xhtml.*;

import org.spase_group.data.schema.Contact;
import org.spase_group.data.schema.EnumPhenomenonType;
import org.spase_group.data.schema.EnumRole;
import org.spase_group.data.schema.ResourceHeader;
import org.spase_group.data.schema.TimeSpan;

import gov.nasa.gsfc.helm.data.schema.Event;
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 basic
 * <code>java.net.HttpURLConnection</code> class.  A similar example 
 * could be implemented using any of the other competing APIs.
 *
 * @version $Revision: $
 * @author B. Harris
 */
public class WsExample {

    /**
     * Address of web services.
     */
    private String endpoint = "http://helm.gsfc.nasa.gov/WS/cdasr/1";


    /**
     * 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(Html.class);

    /**
     * Eventlist Object Factory.
     */
    private gov.nasa.gsfc.helm.data.schema.ObjectFactory
        eventlistFactory =
            new gov.nasa.gsfc.helm.data.schema.ObjectFactory();

    /**
     * Spase Object Factory.
     */
    private org.spase_group.data.schema.ObjectFactory spaseFactory =
        new org.spase_group.data.schema.ObjectFactory();

    /**
     * XML Datatype Factory.
     */
    private DatatypeFactory datatypeFactory = null;


    /**
     * HTTP User-Agent value to use.
     */
    private static final String USER_AGENT = "WsExample";

    /**
     * A UTC TimeZone.
     */
    private static final SimpleTimeZone UTC_TIME_ZONE =
        new SimpleTimeZone(0, "UTC");


    /**
     * Creates a WsExample.
     *
     * @throws JAXBException if unable to instantiate the required
     *     JAXB contexts
     */
    public WsExample(String endpoint)
        throws JAXBException, DatatypeConfigurationException {

        this.endpoint = endpoint;

        try {

            datatypeFactory = DatatypeFactory.newInstance();
        }
        catch (DatatypeConfigurationException e) {

            System.err.println(
                "DatatypeConfigurationException: " + e.getMessage());

            throw e;
        }

    }


    /**
     * Executes this example.
     *
     * @param listname name of eventlist to get
     */
    public void execute(String listname) 
        throws Exception {

        System.out.println("Java SE Example");

        InputStream responseStream = getOptions();
        print(System.out, responseStream);
        System.out.println();

        Eventlist eventlist = getXmlEventlist(listname);

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

        Eventlist exampleEventlist = createExampleEventlist();

        System.out.println("Example Eventlist:");
        marshal(System.out, exampleEventlist);
        System.out.println();

        Eventlist shiftedEventlist = 
            shiftTimes(exampleEventlist, "PT1H");

        System.out.println("shiftedEventlist (response entity):");
        marshal(System.out, shiftedEventlist);
        System.out.println();


        Html lists = 
            getEventlistsByXPath(
                "//spase:StartDate[" +
                "node()>xs:dateTime('2005-01-01T00:00:00') and " +
                "node()<xs:dateTime('2005-01-31T00:00:00')]");

        System.out.println("Lists (response entity):");

        marshal(System.out, lists);
        System.out.println();


        responseStream = getJsonEventlist(listname);
        print(System.out, responseStream);
        System.out.println();

    }


    /**
     * Makes an HTTP OPTIONS request.
     *
     * @return InputStream containing response (OPTIONS)
     */
    private InputStream getOptions()
        throws Exception {

        URL endpointUrl = new URL(endpoint + "/");

        HttpURLConnection optionsCon = (HttpURLConnection)
            endpointUrl.openConnection();
        optionsCon.setRequestProperty("User-Agent", USER_AGENT);
        optionsCon.setRequestMethod("OPTIONS");

        System.out.println("Invoking HTTP OPTIONS " + endpointUrl);
        
        return optionsCon.getInputStream();
    }


    /**
     * Gets (HTTP GET) the XML representation of the specified user's
     * specified eventlist.
     *
     * @param listname name of eventlist to get
     * @return requested eventlist
     */
    private Eventlist getXmlEventlist(String listname)
        throws Exception {

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

        URL eventlistUrl = new URL(url);
        HttpURLConnection eventlistCon = (HttpURLConnection)
            eventlistUrl.openConnection();
        eventlistCon.setRequestProperty("Accept", "application/xml");
        eventlistCon.setRequestProperty("User-Agent", USER_AGENT);

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

        InputStream responseStream = eventlistCon.getInputStream();
        Unmarshaller unmarshaller = 
            helmJaxbContext.createUnmarshaller();
        Eventlist el = (Eventlist)
            unmarshaller.unmarshal(responseStream);

        return el;
    }


    /**
     * Gets (HTTP GET) the specified user's eventlists that match the
     * given XPath expression.
     *
     * @param xpathp XPath predicate to select eventlists
     * @return XHTML describing specified eventlists
     */
    private Html getEventlistsByXPath(String xpathp)
        throws Exception {

        String encodedXPathP = "xpathp=" + URLEncoder.encode(xpathp);

        String url = endpoint + "/eventlists?" + encodedXPathP;

        URL eventlistUrl = new URL(url);
        HttpURLConnection eventlistCon = (HttpURLConnection)
            eventlistUrl.openConnection();
        eventlistCon.setRequestProperty("Accept", 
                                        "application/xhtml+xml");
        eventlistCon.setRequestProperty("User-Agent", USER_AGENT);

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

        InputStream responseStream = eventlistCon.getInputStream();
        Unmarshaller unmarshaller = 
            xhtmlJaxbContext.createUnmarshaller();
        Html lists = (Html)
            unmarshaller.unmarshal(responseStream);

        return lists;
    }


    /**
     * Gets (HTTP GET) the JSON representation of the specified
     * user's specified eventlist.
     *
     * @param listname name of eventlist to get
     * @return InputStream containing JSON representation of eventlist
     * @throws Exception if any Exception occurs
     */
    private InputStream getJsonEventlist(String listname)
        throws Exception {

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

        URL eventlistUrl = new URL(url);
        HttpURLConnection eventlistCon = (HttpURLConnection)
            eventlistUrl.openConnection();
        eventlistCon.setRequestProperty("Accept", "application/json");
        eventlistCon.setRequestProperty("User-Agent", USER_AGENT);

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

        return eventlistCon.getInputStream();
    }


    /**
     * Shifts the times of all events in the given eventlist by the
     * given duration.
     *
     * @param eventlist eventlist whose times are to be shifted
     * @param duration the quantity by which the times are to be shifted
     * @return resulting eventlist
     * @throws Exception if any Exception occurs
     */
    private Eventlist shiftTimes(Eventlist eventlist, String duration) 
        throws Exception {

        String url = endpoint + "/shiftTimes?quantity=" + duration;

        URL eventlistUrl = new URL(url);
        HttpURLConnection eventlistCon = (HttpURLConnection)
            eventlistUrl.openConnection();
        eventlistCon.setDoOutput(true);
        eventlistCon.setRequestMethod("POST");
        eventlistCon.setRequestProperty("Accept",
                                        "application/xml");
        eventlistCon.setRequestProperty("Content-Type",
                                        "application/xml");
        eventlistCon.setRequestProperty("User-Agent", USER_AGENT);

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

        OutputStream requestStream = eventlistCon.getOutputStream();

        Marshaller marshaller = helmJaxbContext.createMarshaller();

        marshaller.marshal(eventlist, requestStream);

        InputStream responseStream = eventlistCon.getInputStream();

        Unmarshaller unmarshaller = helmJaxbContext.createUnmarshaller();

        return (Eventlist)unmarshaller.unmarshal(responseStream);
    }


    /**
     * Creates a minimal example Eventlist.
     *
     * @return an example Eventlist
     */
    private Eventlist createExampleEventlist()
        throws Exception {

        Eventlist el = eventlistFactory.createEventlist();
                                       // an example Eventlist
        ResourceHeader rh = spaseFactory.createResourceHeader();
                                       // a ResourceHeader
        rh.setResourceName("Example Eventlist");
        rh.setReleaseDate(getCurrentXMLGregorianCalendar());
        rh.setDescription("Example Eventlist");
        rh.getContact().add(createExampleContact());

        el.setResourceHeader(rh);

        el.setName("Example Eventlist");

        el.getPhenomenonType().add(EnumPhenomenonType.GEOMAGNETIC_STORM);

        el.getKeyword().add("example");

        el.getEvent().add(createExampleEvent());

        return el;
    }


    /**
     * Get the current UTC time as an XMLGregorianCalendar object.
     *
     * @return the current UTC time.
     */
    private XMLGregorianCalendar getCurrentXMLGregorianCalendar() {

        GregorianCalendar now = new GregorianCalendar(UTC_TIME_ZONE);
                                       // current time

        return datatypeFactory.newXMLGregorianCalendar(
                   now.get(Calendar.YEAR),
                   now.get(Calendar.MONTH) + 1,
                   now.get(Calendar.DAY_OF_MONTH),
                   now.get(Calendar.HOUR_OF_DAY),
                   now.get(Calendar.MINUTE),
                   now.get(Calendar.SECOND),
                   now.get(Calendar.MILLISECOND),
                   0);
    }


    /**
     * Creates an example Contact.
     *
     * @return an example Contact.
     */
    private Contact createExampleContact() {

        Contact c = spaseFactory.createContact();

        c.setPersonID("spase://example/Person/Johh.Doe");
        c.getRole().add(EnumRole.PUBLISHER);

        return c;
    }


    /**
     * Creates an example Event.
     *
     * @return an example Event.
     */
    private Event createExampleEvent() {

        Event e = eventlistFactory.createEvent();

        TimeSpan ts = spaseFactory.createTimeSpan();

        ts.setStartDate(
            datatypeFactory.newXMLGregorianCalendar(
                "2010-01-01T00:00:00.000Z"));
        ts.setStopDateEntity(
            spaseFactory.createStopDate(
                datatypeFactory.newXMLGregorianCalendar(
                    "2010-01-02T00:00:00.000Z")));

        e.setTimeSpan(ts);

        e.setDescription("Example Event");
        
        return e;
    }


    /**
     * Write information from the given InputStream to the given
     * PrintStream.
     *
     * @param out output PrintStream
     * @param in InputStream
     */
    private void print(PrintStream out, InputStream in) 
        throws IOException {

        int b = 0;
        while ((b = in.read()) != -1) {

            out.write(b);
        }
        out.println();
    }


    /**
     * Marshals the given Eventlist to the given OutputStream.
     *
     * @param out OutputStream
     * @param value Eventlist to be marshalled to out
     */
    private void marshal(OutputStream out, Eventlist value) 
        throws JAXBException {

        Marshaller marshaller = helmJaxbContext.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT,
                               Boolean.TRUE);

        marshaller.marshal(value, out);
    }


    /**
     * Marshals the given XHTML to the given OutputStream.
     *
     * @param out OutputStream
     * @param value XHTML to be marshalled to out
     */
    private void marshal(OutputStream out, Html value) 
        throws JAXBException {

        Marshaller marshaller = xhtmlJaxbContext.createMarshaller();
        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, String, 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 {

        String pass = "";

        if (args.length < 2) {

            System.out.println("ERROR: missing argument(s)");
            System.out.println(
                "USAGE: WsExample endpoint eventlist-name");
            return;
        }
        WsExample example = new WsExample(args[0]);

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