public class Packet {  
	
	public enum ServiceLevel {NORMAL, HIGH};
	public final int MaxDestPort = 1;    //MAX port number on router
	public final int MinDestPort = 0;    //MIN port number on router
	public final int MaxPayload = 60;  //MAX size of payload
	
	private int pkPacketID;		//Packet number
	private int pkDestPort;		//Destination port
	private ServiceLevel pkServiceLevel;  // Pack service level
	private String pkPayload;  //  Packet message
	
	/*
	 * Getters and setters
	 */
	// post - pkPacketID returned
	public int getPkPacketID() {
		return pkPacketID;
	}
	
	//pre - pkPacketID integer
	//post - pkPacketID set if packetID => 1
	public boolean setPkPacketID(int pkPacketID) {
		if (pkPacketID < 1)
			return false;
		this.pkPacketID = pkPacketID;
		return true;
	}
	
	// post - current pkDestPort returned
	public int getPkDestPort() {
		return pkDestPort;
	}
	
	// pre - pkDestPort integer
	// post - pkDestPort set if a valid port number
	public boolean setPkDestPort(int pkDestPort) {
		if (pkDestPort < MinDestPort || pkDestPort > MaxDestPort)
			return false;
		this.pkDestPort = pkDestPort;
		return true;
	}
	
	// post - return the service level of the packet
	public ServiceLevel getPkServiceLevel() {
		return pkServiceLevel;
	}
	
	//pkServiceLevel set to valid level
	//post - pkServiceLevel set to new level
	public void setPkServiceLevel(ServiceLevel pkServiceLevel) {
		this.pkServiceLevel = pkServiceLevel;
		return;
	}
	
	// post - payload returned
	public String getPkPayload() {
		return pkPayload;
	}
	
	//pre - pkPayload string
	//post - pkPayload string set if length > MaxPayload
	public boolean setPkPayload(String pkPayload) {
		if (pkPayload.length() > MaxPayload)
			return false;
		this.pkPayload = pkPayload;
		return true;
	}
	
	//post - image of packet returned
	public String toString () {
		return ("(" + pkPacketID + ", " + pkDestPort + " , " + pkServiceLevel + ")\n" + "    " + 
				pkPayload + "\n");
	}
}