/* ====================================================================
 * The Vovida Software License, Version 1.0 
 * 
 * Copyright (c) 2000 Vovida Networks, Inc.  All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 
 * 2. 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.
 * 
 * 3. The names "VOCAL", "Vovida Open Communication Application Library",
 *    and "Vovida Open Communication Application Library (VOCAL)" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact vocal@vovida.org.
 *
 * 4. Products derived from this software may not be called "VOCAL", nor
 *    may "VOCAL" appear in their name, without prior written
 *    permission of Vovida Networks, Inc.
 * 
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND
 * NON-INFRINGEMENT ARE DISCLAIMED.  IN NO EVENT SHALL VOVIDA
 * NETWORKS, INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT DAMAGES
 * IN EXCESS OF $1,000, NOR FOR ANY 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.
 * 
 * ====================================================================
 * 
 * This software consists of voluntary contributions made by Vovida
 * Networks, Inc. and many individuals on behalf of Vovida Networks,
 * Inc.  For more information on Vovida Networks, Inc., please see
 * <http://www.vovida.org/>.
 *
 */

static const char* const Server_cxx_Version =
    "$Id: Server.cxx,v 1.20 2002/02/25 05:46:18 sprajpat Exp $";

#include "cpLog.h"
#include "Server.hxx"
#include "HeartbeatParms.hxx"
#include "HeartbeatUtil.h"


/**
 * Constructor
 * @param  serverType  Type of server to be created
 */
Server::Server( const ServerType serverType)
        : itsType(serverType), itsStatus(Inactive), heartbeatCount(0),
        numOfHeartbeatMissed(0)
{
    itsMaxMissedHB = HeartbeatParms::instance().getMaxMissedHeartbeats();
}

/**
 * Constructor provided for applications that don't talk to provisioning.  
 * @param serverType Type of server to be created
 * @param maxMissedHB the maximum number of heartbeat could be missed
 */
Server::Server( const ServerType serverType, const int maxMissedHB)
        : itsType(serverType), itsStatus(Inactive), heartbeatCount(0),
        numOfHeartbeatMissed(0), itsMaxMissedHB(maxMissedHB)
{}

/**
 * Copy Constructor
 * @param  rhs  Object from which to copy
 */
Server::Server( const Server& rhs )
{
    if (this != &rhs)
    {
        copyRhsToThis( rhs );
    }
}

/**
 * Operator overload for "="
 * @param  rhs  Object from which to copy
 * @return  Reference to this object with new data
 */
Server&
Server::operator=( const Server& rhs )
{
    if ( this != &rhs )
    {
        copyRhsToThis( rhs );
    }
    return *this;
}


/**
 * Copy member data from given object into this one
 * @param  rhs  Object from which to copy
 */
void
Server::copyRhsToThis( const Server& rhs )
{
    itsType = rhs.itsType;
    itsStatus = rhs.itsStatus;
    heartbeatCount = rhs.heartbeatCount;
    numOfHeartbeatMissed = rhs.numOfHeartbeatMissed;
    itsMaxMissedHB = rhs.itsMaxMissedHB;
}


/**
 * Destructor
 */
Server::~Server()
{ }


/**
 * Obtain the server's type 
 * @return  The server's type
 */
ServerType
Server::getType() const
{
    return itsType;
}

/**
 * Obtain the status of this server
 * @return  This server's status
 */
ServerStatus
Server::getStatus() const
{
    return itsStatus;
}

/**
 * Obtain the current heartbeat count
 * @return  The number of heartbeats counted for this server
 */
int
Server::getHeartbeatCount() const
{
    return heartbeatCount;
}

/**
 * Obtain the number of heartbeats missed for this server
 * @return  Number of heartbeats missed
 */
int
Server::getNumOfHeartbeatMissed() const
{
    return numOfHeartbeatMissed;
}

/**
 * Obtain the maximum number of heartbeats allowed before the server
 * is considered to be down.
 * @return  Max number of missed heartbeats
 */
int
Server::getMaxMissedHB() const
{
    return itsMaxMissedHB;
}

/**
 * Store the maximum number of missed heartbeats
 * @param  Maximum number of missed heartbeats
 */
void
Server::setMaxMissedHB( const int maxMissedHB )
{
    itsMaxMissedHB = maxMissedHB;
}

/**
 * Handle an incoming heartbeat by updating the server's counts
 * @param  key  Server's address
 */
void
Server::processHeartbeat( const Data& key )
{
    incrHeartbeatCountByOne();

    if (itsStatus == Inactive)
    {
        gotFirstHeartbeat(key);
    }
    else if (itsStatus == ActivePending )
    {
            gotHiccup();
    }

}

/**
 * Handle the first heartbeat for the given server by changing its state to active. 
 * @param  key  Server's address
 */
void
Server::gotFirstHeartbeat( const Data& key )
{
    setStatus(Active);
    displayStatus(key);
}

void
Server::displayStatus(const Data& key)
{
    cpLog( LOG_ALERT, "\n");
    cpLog( LOG_ALERT, "** %s Up: %s **", convertToString(itsType),
           key.logData() );
}

/**
 * Handle receiving a heartbeat after one or more was missed by making
 * the server active.
 */
void
Server::gotHiccup()
{
    /// first heartbeat received after losing
    /// 1..(maxHBloss-1) beats.

    /// Assume for now that hiccups are ignored
    setStatus(Active);

    /// reset hb missed counter
    clearNumOfHeartbeatMissed();
}

/**
 * Increment the count of heartbeats received.
 */
void
Server::incrHeartbeatCountByOne()
{
    heartbeatCount++;
}

/**
 * Increment the count of heartbeats missed.
 */
void
Server::incrNumOfHeartbeatMissed()
{
    numOfHeartbeatMissed++;
}

/**
 * Check to see if a server is no longer heartbeating. 
 * @return  True if the max number of heartbeats missed has exceeded the 
 *          allowed limit, false if not.
 */
bool
Server::serverIsDead() const
{
    /// dead if missed max number of HB's allowed
    if ( numOfHeartbeatMissed >= itsMaxMissedHB )
    {
        return true;
    }
    return false;
}

/**
 * Check if given server is no longer heartbeating and
 * change its state accordingly. Clear the counts if necessary
 * @param  serverId  Address of server
 */
void
Server::doHouseKeeping( const Data& serverId )
{
    if ( itsStatus != Inactive )
    {
        if ( heartbeatCount == 0 )
        {
            incrNumOfHeartbeatMissed();

            /// *** keep this code around in case we decide
            /// *** to reinstate the ActivePending state.
            ///if ( itsStatus == Active)
            ///   setStatus(ActivePending);

            cpLog( LOG_DEBUG_HB,"missed %d HBs", numOfHeartbeatMissed);
            if ( serverIsDead() )
            {
                setStatus(Inactive);

                cpLog( LOG_ALERT, "\n");
                cpLog( LOG_ALERT, "** %s Down: %s **", 
		       convertToString(itsType),
                       serverId.logData() );

                /// clear HB counters
                clearHeartbeatCount();
                clearNumOfHeartbeatMissed();
            }
        }
        else
        {
            /// clear HB counters
            clearHeartbeatCount();
            clearNumOfHeartbeatMissed();
        }
    }
}

/**
 * Store the server type
 * @param  type  Type of server
 */
void
Server::setType( const ServerType type )
{
    itsType = type;
}

/**
 * Store the server's current status
 * @param  status  Status of server 
 */
void
Server::setStatus( const ServerStatus status )
{
    itsStatus = status;
}

/**
 * Reset the heartbeat count to zero 
 */
void
Server::clearHeartbeatCount ()
{
    heartbeatCount = 0;
}

/**
 * Reset the number of missed heartbeats to zero 
 */
void
Server::clearNumOfHeartbeatMissed ()
{
    numOfHeartbeatMissed = 0;
}