Added YachtEvent message with encoder and decoder

- Updated Encoder and Decoder factories for the new message type
- Added an enum for handling yacht event types

#story[1100]

racevisionGame/src/main/java/network/MessageDecoders/DecoderFactory.java

@@ -39,7 +39,7 @@ public class DecoderFactory {
 
             case RACESTARTSTATUS: return new RaceStartStatusDecoder();
 
-            //case YACHTEVENTCODE: return new YachtEventCodeDecoder();//TODO
+            case YACHTEVENTCODE: return new YachtEventCodeDecoder();
 
             //case YACHTACTIONCODE: return new YachtActionCodeDecoder();//TODO
 

racevisionGame/src/main/java/network/MessageDecoders/YachtEventCodeDecoder.java

@@ -0,0 +1,47 @@
+package network.MessageDecoders;
+
+import network.Exceptions.InvalidMessageException;
+import network.Messages.AC35Data;
+import network.Messages.Enums.YachtEventEnum;
+import network.Messages.YachtEvent;
+
+import java.util.Arrays;
+
+import static network.Utils.ByteConverter.bytesToInt;
+import static network.Utils.ByteConverter.bytesToLong;
+import static network.Utils.ByteConverter.bytesToShort;
+
+/**
+ * Decodes {@link YachtEvent} messages.
+ */
+public class YachtEventCodeDecoder implements MessageDecoder {
+    private YachtEvent message;
+
+    @Override
+    public AC35Data decode(byte[] encodedMessage) throws InvalidMessageException {
+        // Deserialise message
+        byte[] timestamp = Arrays.copyOfRange(encodedMessage, 1, 7);
+        byte[] ackNum = Arrays.copyOfRange(encodedMessage, 7, 9);
+        byte[] raceID = Arrays.copyOfRange(encodedMessage, 9, 13);
+        byte[] sourceID = Arrays.copyOfRange(encodedMessage, 13, 17);
+        byte[] incidentID = Arrays.copyOfRange(encodedMessage, 17, 21);
+        byte eventID = encodedMessage[21];
+
+        // Unpack bytes into YachtEvent
+        this.message = new YachtEvent(
+                bytesToLong(timestamp),
+                bytesToShort(ackNum),
+                bytesToInt(raceID),
+                bytesToInt(sourceID),
+                bytesToInt(incidentID),
+                YachtEventEnum.fromByte(eventID)
+        );
+
+        // Return YachtEvent
+        return message;
+    }
+
+    public YachtEvent getMessage() {
+        return message;
+    }
+}

racevisionGame/src/main/java/network/MessageEncoders/EncoderFactory.java

@@ -39,7 +39,7 @@ public class EncoderFactory {
 
             case RACESTARTSTATUS: return new RaceStartStatusEncoder();
 
-            //case YACHTEVENTCODE: return new YachtEventCodeEncoder();//TODO
+            case YACHTEVENTCODE: return new YachtEventCodeEncoder();
 
             //case YACHTACTIONCODE: return new YachtActionCodeEncoder();//TODO
 

racevisionGame/src/main/java/network/MessageEncoders/YachtEventCodeEncoder.java

@@ -0,0 +1,43 @@
+package network.MessageEncoders;
+
+import network.Exceptions.InvalidMessageException;
+import network.Messages.AC35Data;
+import network.Messages.YachtEvent;
+
+import java.nio.ByteBuffer;
+
+import static network.Utils.ByteConverter.intToBytes;
+import static network.Utils.ByteConverter.longToBytes;
+
+/**
+ * Encodes a {@link YachtEvent} message.
+ */
+public class YachtEventCodeEncoder implements MessageEncoder {
+    @Override
+    public byte[] encode(AC35Data message) throws InvalidMessageException {
+        // Downcast message
+        YachtEvent yachtEvent = (YachtEvent)message;
+
+        // Serialise message
+        byte messageVersion = 0b10;
+        byte[] timestamp = longToBytes(yachtEvent.getCurrentTime(), 6);
+        byte[] ackNum = intToBytes(yachtEvent.getAckNum(), 2);
+        byte[] raceID = intToBytes(yachtEvent.getRaceID());
+        byte[] sourceID = intToBytes(yachtEvent.getSourceID());
+        byte[] incidentID = intToBytes(yachtEvent.getIncidentID());
+        byte eventID = yachtEvent.getYachtEvent().getValue();
+
+        // Pack bytes into string
+        ByteBuffer yachtEventMessage = ByteBuffer.allocate(22);
+        yachtEventMessage.put(messageVersion);
+        yachtEventMessage.put(timestamp);
+        yachtEventMessage.put(ackNum);
+        yachtEventMessage.put(raceID);
+        yachtEventMessage.put(sourceID);
+        yachtEventMessage.put(incidentID);
+        yachtEventMessage.put(eventID);
+
+        // Return byte string
+        return yachtEventMessage.array();
+    }
+}

racevisionGame/src/main/java/network/Messages/Enums/YachtEventEnum.java

@@ -0,0 +1,24 @@
+package network.Messages.Enums;
+
+/**
+ * Yacht event codes
+ */
+public enum YachtEventEnum {
+    NOT_AN_EVENT(-1),
+    COLLISION(1);
+
+    private byte value;
+
+    YachtEventEnum(int value) { this.value = (byte)value; }
+
+    public byte getValue() {
+        return value;
+    }
+
+    public static YachtEventEnum fromByte(byte value) {
+        switch(value) {
+            case 1: return COLLISION;
+            default: return NOT_AN_EVENT;
+        }
+    }
+}

racevisionGame/src/main/java/network/Messages/YachtEvent.java

@@ -0,0 +1,51 @@
+package network.Messages;
+
+import network.Messages.Enums.MessageType;
+import network.Messages.Enums.YachtEventEnum;
+
+/**
+ * Represents a Yacht Event Code message defined in the AC35 spec, with Event IDs amended for the purposes of
+ * a game.
+ */
+public class YachtEvent extends AC35Data {
+    private long currentTime;
+    private int ackNum;
+    private int raceID;
+    private int sourceID;
+    private int incidentID;
+    private YachtEventEnum yachtEvent;
+
+    public YachtEvent(long currentTime, int ackNum, int raceID, int sourceID, int incidentID, YachtEventEnum yachtEvent) {
+        super(MessageType.YACHTEVENTCODE);
+        this.currentTime = currentTime;
+        this.ackNum = ackNum;
+        this.raceID = raceID;
+        this.sourceID = sourceID;
+        this.incidentID = incidentID;
+        this.yachtEvent = yachtEvent;
+    }
+
+    public YachtEventEnum getYachtEvent() {
+        return yachtEvent;
+    }
+
+    public int getSourceID() {
+        return sourceID;
+    }
+
+    public int getIncidentID() {
+        return incidentID;
+    }
+
+    public long getCurrentTime() {
+        return currentTime;
+    }
+
+    public int getAckNum() {
+        return ackNum;
+    }
+
+    public int getRaceID() {
+        return raceID;
+    }
+}

racevisionGame/src/test/java/network/MessageDecoders/YachtEventCodeDecoderTest.java

@@ -0,0 +1,47 @@
+package network.MessageDecoders;
+
+import network.MessageEncoders.RaceVisionByteEncoder;
+import network.Messages.Enums.YachtEventEnum;
+import network.Messages.YachtEvent;
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.testng.Assert.*;
+
+/**
+ * Tests for the YachtEvent decoder and encoder
+ */
+public class YachtEventCodeDecoderTest {
+    private YachtEvent decodedMessage;
+    private YachtEvent originalMessage;
+
+    @Before
+    public void setUp() throws Exception {
+        long timestamp = System.currentTimeMillis();
+
+        originalMessage = new YachtEvent(
+                timestamp,
+                55,
+                35,
+                0,
+                1,
+                YachtEventEnum.COLLISION
+        );
+
+        byte[] encodedMessage = RaceVisionByteEncoder.encode(originalMessage);
+
+        YachtEventCodeDecoder testDecoder = new YachtEventCodeDecoder();
+        testDecoder.decode(encodedMessage);
+        decodedMessage = testDecoder.getMessage();
+    }
+
+    @Test
+    public void decodingEqualsOriginal() {
+        assertEquals(originalMessage.getCurrentTime(), decodedMessage.getCurrentTime());
+        assertEquals(originalMessage.getAckNum(), decodedMessage.getAckNum());
+        assertEquals(originalMessage.getRaceID(), decodedMessage.getRaceID());
+        assertEquals(originalMessage.getSourceID(), decodedMessage.getSourceID());
+        assertEquals(originalMessage.getIncidentID(), decodedMessage.getIncidentID());
+        assertEquals(originalMessage.getYachtEvent(), decodedMessage.getYachtEvent());
+    }
+}