CommandFrame.java

/**
 * Copyright (c) 2010-2016 by the respective copyright holders.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.openhab.binding.plcbus.internal.protocol;

import java.util.ArrayList;
import java.util.List;

/**
 * CommandFrame in PLCBus Protocols
 *
 * @author Robin Lenz
 * @since 1.1.0
 */
public class CommandFrame {

    private boolean extendAddress;
    private boolean threePhase;
    private boolean demandAck;
    private Command command;

    public CommandFrame() {
    }

    public CommandFrame(Command command) {
        this.command = command;
    }

    /**
     * Flag if the address should be extended
     * 
     * @return True if the Address should be extended
     */
    private boolean shouldExtendAddress() {
        return extendAddress;
    }

    /**
     * Sets the flag if the address should be extended
     * 
     * @param value
     *            Value for the address
     */
    public void setExtendAddressTo(boolean value) {
        this.extendAddress = value;
    }

    /**
     * Flag for three phase mode
     * 
     * @return true if PLCBus is in three phase mode
     */
    public boolean isThreePhase() {
        return threePhase;
    }

    /**
     * Sets the flag for three phase mode
     * 
     * @param value
     *            for three phase mode
     */
    public void setThreePhaseTo(boolean value) {
        threePhase = value;
    }

    /**
     * Flag for demand with Acknowlagement
     * 
     * @return true if PLCBus should demand
     */
    private boolean shouldDemandAck() {
        return demandAck;
    }

    /**
     * Sets demand mode
     * 
     * @param value
     *            for demand mode
     */
    public void setDemandAckTo(boolean value) {
        demandAck = value;
    }

    /**
     * Returns bytes of command frame
     * 
     * @return bytes of command frame
     */
    public List<Byte> getBytes() {
        List<Byte> result = new ArrayList<Byte>();

        result.add(getCommandByte());
        result.addAll(getDataBytes());

        return result;
    }

    /**
     * Return the first parameter
     * 
     * @return first parameter
     */
    public int getFirstParameter() {
        return command.getData1();
    }

    /**
     * Returns the second parameter
     * 
     * @return second parameter
     */
    public int getSecondParameter() {
        return command.getData2();
    }

    /**
     * Initializes command frame from byte array
     * 
     * @param data
     *            bytes of command frame
     */
    public void parse(byte[] data) {
        extendAddress = ((data[0] & 0x80) == 0x80);
        threePhase = ((data[0] & 0x40) == 0x40);
        demandAck = ((data[0] & 0x20) == 0x20);

        command = CommandFactory.createBy((byte) (data[0] & 0x1F));

        if (command != null) {
            command.parse(new byte[] { data[1], data[2] });
        }
    }

    private byte getCommandByte() {
        byte result = 0x00;

        if (shouldExtendAddress()) {
            result |= 0x80;
        }

        if (isThreePhase()) {
            result |= 0x40;
        }

        if (shouldDemandAck()) {
            result |= 0x20;
        }

        if (command != null) {
            result |= command.getId();
        }

        return result;
    }

    private List<Byte> getDataBytes() {
        if (command == null) {
            return null;
        }

        return command.getDataBytes();
    }

    /**
     * Returns the command of frame
     * 
     * @return command of frame
     */
    public Command getCommand() {
        return command;
    }

}