/**
* Global Sensor Networks (GSN) Source Code
* Copyright (c) 2006-2016, Ecole Polytechnique Federale de Lausanne (EPFL)
* 
* This file is part of GSN.
* 
* GSN is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
* 
* GSN is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
* 
* You should have received a copy of the GNU General Public License
* along with GSN.  If not, see <http://www.gnu.org/licenses/>.
* 
* File: src/ch/epfl/gsn/wrappers/CoAPWrapper.java
*
* @author iseitani
* @author Julien Eberle
*
*/
package ch.epfl.gsn.wrappers;

import ch.epfl.gsn.beans.AddressBean;
import ch.epfl.gsn.beans.DataField;
import ch.epfl.gsn.networking.mqtt.MQTTWrapper;
import ch.epfl.gsn.wrappers.AbstractWrapper;
import java.io.Serializable;
import org.eclipse.californium.core.CoapClient;
import org.eclipse.californium.core.CoapResponse;
import org.eclipse.californium.core.coap.OptionSet;
import org.eclipse.californium.core.CoapHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


public class CoAPWrapper extends AbstractWrapper implements CoapHandler{
	
	private final transient Logger logger = LoggerFactory.getLogger(MQTTWrapper.class);

	private String serverURI; //="coap://[you_ipv6]:5683/.temp";
	private AddressBean addressBean;
	private CoapClient client;
	private long nextExpectedMessage;
   
	@Override
	public DataField[] getOutputFormat() {
		return new DataField[] {new DataField( "raw_packet" , "BINARY" , "The packet contains raw data received in the CoAP payload." ) };
	}

    @Override
    public boolean initialize() {
    	try {
			addressBean = getActiveAddressBean( );
			serverURI = addressBean.getPredicateValue("uri");
			if ( serverURI == null || serverURI.trim().length() == 0 ) {
				logger.error( "The uri parameter is missing from the CoAP wrapper, initialization failed." );
				return false;
			}
    	}catch (Exception e){
			logger.error("Error in instanciating CoAP Client @ "+serverURI,e);
			return false;
		}
       return true;
    }

    @Override
    public void dispose() {

    }

    @Override
    public String getWrapperName() {
       return "CoAP Wrapper";
    }
    
    public void run(){
          
    	client = new CoapClient(serverURI);
        
        while(isActive()){
        	if (System.currentTimeMillis() / 1000 > nextExpectedMessage){
        	    client.observe(this);
        	}
		    try{
		      Thread.sleep(60000);
		    }catch(Exception ex){}
		 }           
    }


	@Override
	public void onError() {
		logger.error( "CoAP observation error..." );
	}
	
	@Override
	public void onLoad(CoapResponse response) {
		OptionSet os = response.getOptions();
		nextExpectedMessage = os.getMaxAge() * 2 + (System.currentTimeMillis() / 1000);
		postStreamElement(new Serializable[]{response.getPayload()});
	}

}