package MV3500Cohort2018JanuaryMarch.homework3;

// package edu.nps.moves.examples; // copy example from OpenDIS distribution, modify to serve as template

import java.io.*;
import java.net.*;
import java.util.*;

import edu.nps.moves.dis.*; // OpenDIS version 4
import edu.nps.moves.disutil.CoordinateConversions;
import edu.nps.moves.disutil.DisTime;

/**
 * Creates and sends ESPDUs in IEEE binary format. 
 *
 * @author DMcG
 */
public class Landas_OpenDisEspduSender
{
    /**
     * Default constructor to silence javadoc warning
     * @see <a href="https://stackoverflow.com/questions/4488716/java-default-constructor" target="_blank">StackOverflow: Java default constructor</a>
     */
    public Landas_OpenDisEspduSender ()
    {
        // default initializations occur here
    }
    static final int NUMBER_TO_SEND = 5000;

    /** Type of network connection */
	public enum NetworkMode {
        /** accessor
         * @see <a href="https://en.wikipedia.org/wiki/Unicast" target="_blank">https://en.wikipedia.org/wiki/Unicast</a> */
		UNICAST,
        /** accessor
         * @see <a href="https://en.wikipedia.org/wiki/Multicast" target="_blank">https://en.wikipedia.org/wiki/Multicast</a> */
        MULTICAST,
        /** accessor
         * @see <a href="https://en.wikipedia.org/wiki/Broadcasting_(networking)" target="_blank">https://en.wikipedia.org/wiki/Broadcasting_(networking)</a> */
        BROADCAST
	};

    /** Default multicast group address we send on */
    public static final String DEFAULT_MULTICAST_GROUP="239.1.2.3";
   
    /** Default port we send on */
    public static final int    DIS_DESTINATION_PORT = 3000;
    
    /**
     * positions for entity track
     */
    public static final ArrayList <Float[]> track_coordinates = new ArrayList<>();
    
/** Possible system properties, passed in via -Dattr=val
     * networkMode: unicast, broadcast, multicast
     * destinationIp: where to send the packet. If in multicast mode, this can be multicast.
     *                To determine broadcast destination IP, use an online broadcast address
     *                calculator, for example http://www.remotemonitoringsystems.ca/broadcast.php
     *                If in multicast mode, a join() will be done on the multicast address.
     * port: port used for both source and destination.
     * @param args command-line arguments 
     */
    @SuppressWarnings("deprecation")
    public static void main(String args[])
{
    /** an entity state pdu */
    EntityStatePdu espdu = new EntityStatePdu();
    MulticastSocket socket = null; // must be initialized, even if null
    DisTime disTime = DisTime.getInstance(); // TODO explain
    int alternator = -1;
    
    // ICBM coordinates for my office
//    double lat = 36.595517; 
//    double lon = -121.877000;
    
    // Default settings. These are used if no system properties are set. 
    // If system properties are passed in, these are over ridden.
    int port = DIS_DESTINATION_PORT;
    NetworkMode mode = NetworkMode.BROADCAST;
    InetAddress destinationIp = null; // must be initialized, even if null
    
    try
    {
        destinationIp = InetAddress.getByName(DEFAULT_MULTICAST_GROUP);
    }
    catch(UnknownHostException e)
    {
        System.out.println(e + " Cannot create multicast address");
        System.exit(0);
    }
    
    // All system properties, passed in on the command line via -Dattribute=value
    Properties systemProperties = System.getProperties();
    
    // IP address we send to
    String destinationIpString = systemProperties.getProperty("destinationIp");
    
    // Port we send to, and local port we open the socket on
    String portString = systemProperties.getProperty("port");
    
    // Network mode: unicast, multicast, broadcast
    String networkModeString = systemProperties.getProperty("networkMode"); // unicast or multicast or broadcast
        
    // Set up a socket to send information
    try
    {
        // Port we send to
        if(portString != null)
            port = Integer.parseInt(portString);
        
        socket = new MulticastSocket(port);
        
        // Where we send packets to, the destination IP address
        if(destinationIpString != null)
        {
            destinationIp = InetAddress.getByName(destinationIpString);
        }

        // Type of transport: unicast, broadcast, or multicast
		// TODO convert to String constants
        if(networkModeString != null)
        {
            if(networkModeString.equalsIgnoreCase("unicast"))
                mode = NetworkMode.UNICAST;
            else if(networkModeString.equalsIgnoreCase("broadcast"))
                mode = NetworkMode.BROADCAST;
            else if(networkModeString.equalsIgnoreCase("multicast"))
            {
                mode = NetworkMode.MULTICAST;
                if(!destinationIp.isMulticastAddress())
                {
                    throw new RuntimeException("Sending to multicast address, but destination address " + destinationIp.toString() + "is not multicast");
                }
                
                socket.joinGroup(destinationIp);
            }
        } // end networkModeString
    }
    catch(IOException | RuntimeException e)
    {
        System.out.println("Unable to initialize networking. Exiting.");
        System.out.println(e);
        System.exit(-1);
    }
    
    // Initialize values in the Entity State PDU object. The exercise ID is 
    // a way to differentiate between different virtual worlds on one network.
    // Note that some values (such as the PDU type and PDU family) are set
    // automatically when you create the ESPDU.
    espdu.setExerciseID((short)1);
    
    // The EID is the unique identifier for objects in the world. This 
    // EID should match up with the ID for the object specified in the 
    // VMRL/x3d/virtual world.
    EntityID entityID = espdu.getEntityID();
    entityID.setSite(1);  // 0 is apparently not a valid site number, per the spec
    entityID.setApplication(1); 
    entityID.setEntity(2); 
    
    // Set the entity type. SISO has a big list of enumerations, so that by
    // specifying various numbers we can say this is an M1A2 American tank,
    // the USS Enterprise, and so on. We'll make this a tank. There is a 
    // separate project elsehwhere in this project that implements DIS 
    // enumerations in C++ and Java, but to keep things simple we just use
    // numbers here.
    EntityType entityType = espdu.getEntityType();
    entityType.setEntityKind((short)1);      // Platform (vs lifeform, munition, sensor, etc.)
    entityType.setCountry(225);              // USA
    entityType.setDomain((short)1);          // Land (vs air, surface, subsurface, space)
    entityType.setCategory((short)1);        // Tank
    entityType.setSubcategory((short)20);     // Maintenance equipment trailer(20)
    entityType.setSpec((short)3);            // M1A2 Abrams
    

    Set<InetAddress> broadcastAddresses;
    // Loop through sending N ESPDUs
    try
    {
        
//         Point point = new Point();
//            point.setX(1.5f);
//            point.setY(1.9f);
//        
//         List<Point> track_coordinates = new ArrayList<Point>();
//         track_coordinates.add(point);
//         System.out.println("********" + track_coordinates);
        
//        ArrayList <Float[]> track_coordinates = new ArrayList<>();
        
        Float[] TrackCoor1 = new Float [2];
        TrackCoor1[0] = 36.585657f;
        TrackCoor1[1] = -121.879920f;
        track_coordinates.add(TrackCoor1);
        Float[] TrackCoor2 = new Float [2];
        TrackCoor2[0] = 36.584853f;
        TrackCoor2[1] = -121.880024f;
        track_coordinates.add(TrackCoor2);
        Float[] TrackCoor3 = new Float [2];
        TrackCoor3[0] = 36.583500f;
        TrackCoor3[1] = -121.879615f;
        track_coordinates.add(TrackCoor3);
        Float[] TrackCoor4 = new Float [2];
        TrackCoor4[0] = 36.586307f;
        TrackCoor4[1] = -121.874582f;
        track_coordinates.add(TrackCoor4);
        Float[] TrackCoor5 = new Float [2];
        TrackCoor5[0] = 36.588670f;
        TrackCoor5[1] = -121.877928f;
        track_coordinates.add(TrackCoor5);
        Float[] TrackCoor6 = new Float [2];
        TrackCoor6[0] = 36.591124f;
        TrackCoor6[1] = -121.880074f;
        track_coordinates.add(TrackCoor6);
        Float[] TrackCoor7 = new Float [2];
        TrackCoor7[0] = 36.592827f;
        TrackCoor7[1] = -121.877149f;
        track_coordinates.add(TrackCoor7);
        Float[] TrackCoor8 = new Float [2];
        TrackCoor8[0] = 36.594051f;
        TrackCoor8[1] = -121.877452f;
        track_coordinates.add(TrackCoor8);
        Float[] TrackCoor9 = new Float [2];
        TrackCoor9[0] = 36.594245f;
        TrackCoor9[1] = -121.876477f;
        track_coordinates.add(TrackCoor9);
        Float[] TrackCoor10 = new Float [2];
        TrackCoor10[0] = 36.595230f;
        TrackCoor10[1] = -121.877537f;
        track_coordinates.add(TrackCoor10);
//        System.out.println("********" + String.valueOf(track_coordinates[0]) );
//        System.out.println("********" + track_coordinates.get(5)[1]);
        
        
            
//        System.out.println("Sending " + NUMBER_TO_SEND + " ESPDU packets to " + destinationIp.toString());
//        for(int idx = 0; idx < NUMBER_TO_SEND; idx++)
        for(int idx = 0; idx < 10; idx++)
        {
        System.out.println("Sending ESPDU packet " + idx + " to " + destinationIp.toString());
            // DIS time is a pain in the ass. DIS time units are 2^31-1 units per
            // hour, and time is set to DIS time units from the top of the hour. 
            // This means that if you start sending just before the top of the hour
            // the time units can roll over to zero as you are sending. The receivers
            // (escpecially homegrown ones) are often not able to detect rollover
            // and may start discarding packets as dupes or out of order. We use
            // an NPS timestamp here, hundredths of a second since the start of the
            // year. The DIS standard for time is often ignored in the wild; I've seen
            // people use Unix time (seconds since 1970) and more. Or you can
            // just stuff idx into the timestamp field to get something that is monotonically
            // increasing.
            
            // Note that timestamp is used to detect duplicate and out of order packets. 
            // That means if you DON'T change the timestamp, many implementations will simply
            // discard subsequent packets that have an identical timestamp. Also, if they
            // receive a PDU with an timestamp lower than the last one they received, they
            // may discard it as an earlier, out-of-order PDU. So it is a good idea to
            // update the timestamp on ALL packets sent.
            

            // An alterative approach: actually follow the standard. It's a crazy concept,
            // but it might just work.
            int timestamp = disTime.getDisAbsoluteTimestamp();
            espdu.setTimestamp(timestamp);
            

            // Set the position of the entity in the world. DIS uses a cartesian
            // coordinate system with the origin at the center of the earth, the x
            // axis out at the equator and prime meridian, y out at the equator and
            // 90 deg east, and z up and out the north pole. To place an object on
            // the earth's surface you also need a model for the shape of the earth
            // (it's not a sphere.) All the fancy math necessary to do this is in
            // the SEDRIS SRM package. There are also some one-off formulas for 
            // doing conversions from, for example, lat/lon/altitude to DIS coordinates.
            // Here we use those one-off formulas.
            // Modify the position of the object. This will send the object a little
            // due east by adding some to the longitude every iteration. Since we
            // are on the Pacific coast, this sends the object east. Assume we are
            // at zero altitude. In other worlds you'd use DTED to determine the
            // local ground altitude at that lat/lon, or you'd just use ground clamping.
            // The x and y values will change, but the z value should not.
            //lon = lon + (double)((double)idx / 100000.0);
            //System.out.println("lla=" + lat + "," + lon + ", 0.0");
            Float lat = track_coordinates.get(idx)[0];
            Float lon = track_coordinates.get(idx)[1];
            
//            double direction = Math.pow((double)(-1.0), (double)(idx));
//            lon = lon + (direction * 0.00006);
            
            
//            System.out.println(lon);
            
            double disCoordinates[] = CoordinateConversions.getXYZfromLatLonDegrees(lat, lon, 1.0);
            Vector3Double location = espdu.getEntityLocation();
            location.setX(disCoordinates[0]);
            location.setY(disCoordinates[1]);
            location.setZ(disCoordinates[2]);
            System.out.println("lat, lon: " + lat + ", " + lon);
            System.out.println("DIS coord: " + disCoordinates[0] + ", " + disCoordinates[1] + ", " + disCoordinates[2]);

            // Optionally, we can do some rotation of the entity
            /*
            Orientation orientation = espdu.getEntityOrientation();
            float psi = orientation.getPsi();
            psi = psi + idx;
            orientation.setPsi(psi);
            orientation.setTheta((float)(orientation.getTheta() + idx /2.0));
             */
            
            // You can set other ESPDU values here, such as the velocity, acceleration,
            // and so on.

            // Marshal out the espdu object to a byte array, then send a datagram
            // packet with that data in it.
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            DataOutputStream dos = new DataOutputStream(baos);
            espdu.marshal(dos);

            FirePdu fire = new FirePdu();
            byte[] fireArray = fire.marshal();
            
            // The byte array here is the packet in DIS format. We put that into a 
            // datagram and send it.
            byte[] data = baos.toByteArray();

            broadcastAddresses = getBroadcastAddresses();
            Iterator it = broadcastAddresses.iterator();
            while(it.hasNext())
            {
               InetAddress broadcast = (InetAddress)it.next();
               System.out.println("Sending broadcast datagram packet to " + broadcast);
               DatagramPacket packet = new DatagramPacket(data, data.length, broadcast, 3000);
               socket.send(packet);
			   // TODO experiment with these!  8)
//               packet = new DatagramPacket(fireArray, fireArray.length, broadcast, 3000); // alternate
//               socket.send(packet);
            }
            
            // Send every 1 sec. Otherwise this will be all over in a fraction of a second.
            Thread.sleep(3000);

            location = espdu.getEntityLocation();
            
            System.out.println("Espdu #" + idx + " EID=[" + entityID.getSite() + "," + entityID.getApplication() + "," + entityID.getEntity() + "]");
            System.out.println(" DIS coordinates location=[" + location.getX() + "," + location.getY() + "," + location.getZ() + "]");
            double c[] = {location.getX(), location.getY(), location.getZ()};
            double lla[] = CoordinateConversions.xyzToLatLonDegrees(c);
//            System.out.println(" Location (lat/lon/alt): [" + lla[0] + ", " + lla[1] + ", " + lla[2] + "]");

        }
    }
    catch(IOException | InterruptedException e)
    {
        System.out.println(e);
    }
        
}

 /**
    * A number of sites get all snippy about using 255.255.255.255 for a broadcast
    * address; it trips their security software and they kick you off their 
    * network. (Comcast, NPS.) This determines the broadcast address for all
    * connected interfaces, based on the IP and subnet mask. If you have
    * a dual-homed host it will return a broadcast address for both. If you have
    * some VMs running on your host this will pick up the addresses for those
    * as well--eg running VMWare on your laptop with a local IP this will
    * also pick up a 192.168 address assigned to the VM by the host OS.
    * 
    * @return set of all broadcast addresses
    */
   public static Set<InetAddress> getBroadcastAddresses()
   {
       Set<InetAddress> broadcastAddresses = new HashSet<>();
       Enumeration interfaces;
       
       try
       {
           interfaces = NetworkInterface.getNetworkInterfaces();
           
           while(interfaces.hasMoreElements())
           {
               NetworkInterface anInterface = (NetworkInterface)interfaces.nextElement();
               
               if(anInterface.isUp())
               {
                   Iterator it = anInterface.getInterfaceAddresses().iterator();
                   while(it.hasNext())
                   {
                       InterfaceAddress anAddress = (InterfaceAddress)it.next();
                       if((anAddress == null || anAddress.getAddress().isLinkLocalAddress()))
                           continue;
                       
                       //System.out.println("Getting broadcast address for " + anAddress);
                       InetAddress broadcastAddress = anAddress.getBroadcast();
                       if(broadcastAddress != null)
                          broadcastAddresses.add(broadcastAddress);
                   }
               }
           }
           
       }
       catch(SocketException e)
       {
           e.printStackTrace();
           System.out.println(e);
       }
       
       return broadcastAddresses;   
   }

}