/**
 * Copyright (c) 2012, University of Konstanz, Distributed Systems Group
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * * Neither the name of the University of Konstanz nor the
 * names of its contributors may be used to endorse or promote products
 * derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.jscsi.initiator.connection.state;

import org.jscsi.exception.InternetSCSIException;
import org.jscsi.initiator.connection.Connection;
import org.jscsi.parser.ProtocolDataUnit;
import org.jscsi.parser.ProtocolDataUnitFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * <h1>IState</h1>
 * <p/>
 * Each inherited state must implement this interface.
 * 
 * @author Volker Wildi
 */
public interface IState {

    // --------------------------------------------------------------------------
    // --------------------------------------------------------------------------

    /**
     * This method is always invoked, when a request message must be send or
     * response message must be received and then parsed.
     * 
     * @throws InternetSCSIException
     *             if any violation of the iSCSI Standard (RfC3720) has emerged.
     */
    public void execute() throws InternetSCSIException;

    /**
     * This method shows if another state is following this one.
     * 
     * @return <code>true</code>, if another state must follow this state. Else
     *         an final state is reached.
     */
    public boolean nextStateFollowing();

    /**
     * This method checks the correctness of the given <code>ProtocolDataUnit</code> instance within the
     * current state of a
     * connection.
     * 
     * @param protocolDataUnit
     *            The <code>ProtocolDataUnit</code> instance to check.
     * @return <code>Exception</code> if any problem occured with the PDU, <code>null</code> otherwise.
     */
    public Exception isCorrect(final ProtocolDataUnit protocolDataUnit);

    // --------------------------------------------------------------------------
    // --------------------------------------------------------------------------
    // --------------------------------------------------------------------------
    // --------------------------------------------------------------------------

}

/**
 * <h1>AbstractState</h1>
 * <p/>
 * Each connection state must extend this abstract class to support some basic features.
 * 
 * @author Volker Wildi
 */
abstract class AbstractState implements IState {

    // --------------------------------------------------------------------------
    // --------------------------------------------------------------------------

    /** The Logger interface. */
    protected static final Logger LOGGER = LoggerFactory.getLogger(AbstractState.class);

    // --------------------------------------------------------------------------
    // --------------------------------------------------------------------------

    /** The context connection used by all message kinds. */
    protected final Connection connection;

    /** Factory to create the <code>ProtocolDataUnit</code> instances. */
    protected final ProtocolDataUnitFactory protocolDataUnitFactory = new ProtocolDataUnitFactory();

    /** boolean to mark following states. */
    protected boolean stateFollowing;
    
    //OODRIVE
    /** initiator task tag value. */
    protected int initiatorTaskTag;

    // --------------------------------------------------------------------------
    // --------------------------------------------------------------------------

    /** {@inheritDoc} */
    public Exception isCorrect(final ProtocolDataUnit protocolDataUnit) {

        return null;
    }

    // --------------------------------------------------------------------------
    // --------------------------------------------------------------------------

    /**
     * Constructor, which each subclass must implement to set the context
     * connection correctly.
     * 
     * @param initConnection
     *            The connection, which is used for the message transmission.
     */
    protected AbstractState(final Connection initConnection, final int initInitiatorTaskTag) {

        connection = initConnection;
        // OODRIVE
        initiatorTaskTag = initInitiatorTaskTag ;
    }

    /**
     * {@inheritDoc}
     */
    public boolean nextStateFollowing() {
        return this.stateFollowing;
    }

    // --------------------------------------------------------------------------
    // --------------------------------------------------------------------------
    // --------------------------------------------------------------------------
    // --------------------------------------------------------------------------

}