/*==LICENSE==*

CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011  Cyan Worlds, Inc.

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

You can contact Cyan Worlds, Inc. by email legal@cyan.com
 or by snail mail at:
      Cyan Worlds, Inc.
      14617 N Newport Hwy
      Mead, WA   99021

*==LICENSE==*/
/*****************************************************************************
*
*   $/Plasma20/Sources/Plasma/PubUtilLib/plNetGameLib/Private/plNglTrans.cpp
*   
***/

#include "../Pch.h"
#pragma hdrstop


namespace Ngl {
/*****************************************************************************
*
*   Private
*
***/

enum {
    kPerfCurrTransactions,
    kNumPerf
};

static const unsigned kDefaultTimeoutMs = 5 * 60 * 1000;

static bool                         s_running;
static CCritSect                    s_critsect;
static LISTDECL(NetTrans, m_link)   s_transactions;
static long                         s_perf[kNumPerf];
static unsigned                     s_timeoutMs = kDefaultTimeoutMs;


/*****************************************************************************
*
*   Internal functions
*
***/

//============================================================================
static NetTrans * FindTransIncRef_CS (unsigned transId, const char tag[]) {
    // There shouldn't be more than a few transactions; just do a linear scan
    for (NetTrans * trans = s_transactions.Head(); trans; trans = s_transactions.Next(trans))
        if (trans->m_transId == transId) {
            trans->IncRef(tag);
            return trans;
        }

    return nil;
}

//============================================================================
static NetTrans * FindTransIncRef (unsigned transId, const char tag[]) {
    NetTrans * trans;
    s_critsect.Enter();
    {
        trans = FindTransIncRef_CS(transId, tag);
    }
    s_critsect.Leave();
    return trans;
}

//============================================================================
static void CancelTrans_CS (NetTrans * trans, ENetError error) {
    ASSERT(IS_NET_ERROR(error));
    if (trans->m_state != kTransStateComplete) {
        trans->m_result = error;
        trans->m_state  = kTransStateComplete;
    }
}


/*****************************************************************************
*
*   NetTrans implementation
*
***/

//============================================================================
NetTrans::NetTrans (ENetProtocol protocol, ETransType transType)
:   m_state(kTransStateWaitServerConnect)
,   m_result(kNetPending)
,   m_transId(0)
,   m_connId(0)
,   m_protocol(protocol)
,   m_hasSubTrans(false)
,   m_transType(transType)
{
    AtomicAdd(&s_perf[kPerfCurrTransactions], 1);
    AtomicAdd(&s_perfTransCount[m_transType], 1);
//  DebugMsg("%s@%p created", s_transTypes[m_transType], this);
}

//============================================================================
NetTrans::~NetTrans () {
    ASSERT(!m_link.IsLinked());
    AtomicAdd(&s_perfTransCount[m_transType], -1);
    AtomicAdd(&s_perf[kPerfCurrTransactions], -1);
//  DebugMsg("%s@%p destroyed", s_transTypes[m_transType], this);
}

//============================================================================
bool NetTrans::CanStart () const {
    switch (m_protocol) {
        case kNetProtocolCli2Auth: return AuthQueryConnected();
        case kNetProtocolCli2Game: return GameQueryConnected();
        case kNetProtocolCli2File: return FileQueryConnected();
        case kNetProtocolCli2Csr:  return CsrQueryConnected();
        case kNetProtocolCli2GateKeeper: return GateKeeperQueryConnected();
        DEFAULT_FATAL(m_protocol);
    }
}


/*****************************************************************************
*
*   Module functions
*
***/

//============================================================================
void NetTransInitialize () {
    s_critsect.Enter();
    {
        s_running = true;
    }
    s_critsect.Leave();
}

//============================================================================
void NetTransDestroy (bool wait) {
    s_critsect.Enter();
    {
        s_running = false;
    }
    s_critsect.Leave();

    NetTransCancelAll(kNetErrRemoteShutdown);
    
    if (!wait)
        return;
        
    while (s_perf[kPerfCurrTransactions]) {
        NetTransUpdate();
        AsyncSleep(10);
    }
}

//============================================================================
void NetTransSetTimeoutMs (unsigned ms) {
    s_timeoutMs = ms ? ms : kDefaultTimeoutMs;
}

//============================================================================
unsigned NetTransGetTimeoutMs () {
    return s_timeoutMs;
}

//============================================================================
void NetTransSend (NetTrans * trans) {
    trans->IncRef("Lifetime");
    s_critsect.Enter();
    {
        static unsigned s_transId;
        while (!trans->m_transId)
            trans->m_transId = ++s_transId;
        s_transactions.Link(trans, kListTail);
        if (!s_running)
            CancelTrans_CS(trans, kNetErrRemoteShutdown);
    }
    s_critsect.Leave();
}

//============================================================================
bool NetTransRecv (unsigned transId, const byte msg[], unsigned bytes) {
    NetTrans * trans = FindTransIncRef(transId, "Recv");

    if (!trans)
        return true;    // transaction was canceled.

    // Update the timeout time
    trans->m_timeoutAtMs = TimeGetMs() + s_timeoutMs;

    bool result = trans->Recv(msg, bytes);

    if (!result)
        NetTransCancel(transId, kNetErrInternalError);

    trans->DecRef("Recv");
    return result;
}

//============================================================================
void NetTransCancel (unsigned transId, ENetError error) {
    s_critsect.Enter();
    {
        NetTrans * trans = s_transactions.Head();
        for (; trans; trans = trans->m_link.Next()) {
            if (trans->m_transId == transId) {
                CancelTrans_CS(trans, error);
                break;
            }
        }
    }
    s_critsect.Leave();
}

//============================================================================
void NetTransCancelByProtocol (ENetProtocol protocol, ENetError error) {
    s_critsect.Enter();
    {
        NetTrans * trans = s_transactions.Head();
        for (; trans; trans = trans->m_link.Next()) {
            if (trans->m_protocol == protocol)
                CancelTrans_CS(trans, error);
        }
    }
    s_critsect.Leave();
}

//============================================================================
void NetTransCancelByConnId (unsigned connId, ENetError error) {
    s_critsect.Enter();
    {
        NetTrans * trans = s_transactions.Head();
        for (; trans; trans = trans->m_link.Next()) {
            if (trans->m_connId == connId)
                CancelTrans_CS(trans, error);
        }
    }
    s_critsect.Leave();
}

//============================================================================
void NetTransCancelAll (ENetError error) {
    s_critsect.Enter();
    {
        NetTrans * trans = s_transactions.Head();
        for (; trans; trans = trans->m_link.Next())
            CancelTrans_CS(trans, error);
    }
    s_critsect.Leave();
}

//============================================================================
void NetTransUpdate () {
    LISTDECL(NetTrans, m_link) completed;
    LISTDECL(NetTrans, m_link) parentCompleted;

    s_critsect.Enter();
    NetTrans * next, * trans = s_transactions.Head();
    for (; trans; trans = next) {
        next = s_transactions.Next(trans);

        bool done = false;
        while (!done) {
            switch (trans->m_state) {
                case kTransStateComplete:
                    if (trans->m_hasSubTrans)
                        parentCompleted.Link(trans);
                    else
                        completed.Link(trans);
                    done = true;
                break;

                case kTransStateWaitServerConnect:
                    if (!trans->CanStart()) {
                        done = true;
                        break;
                    }
                    if (trans->m_protocol && 0 == (trans->m_connId = ConnGetId(trans->m_protocol))) {
                        done = true;
                        break;
                    }
                    // This is the default "next state", trans->Send() can override this
                    trans->m_state = kTransStateWaitServerResponse;
                    // Set timeout time before calling Send(), allowing Send() to change it if it wants to.
                    trans->m_timeoutAtMs = TimeGetMs() + s_timeoutMs;
                    if (!trans->Send()) {
                        // Revert back to current state so that we'll attempt to send again
                        trans->m_state = kTransStateWaitServerConnect;
                        done = true;
                        break;
                    }
                break;
                
                case kTransStateWaitServerResponse:
                    // Check for timeout
                    if ((int)(TimeGetMs() - trans->m_timeoutAtMs) > 0) {
                        // Check to see if the transaction wants to "abort" the timeout
                        if (trans->TimedOut())
                            CancelTrans_CS(trans, kNetErrTimeout);
                        else
                            trans->m_timeoutAtMs = TimeGetMs() + s_timeoutMs; // Reset the timeout counter
                    }
                    done = true;
                break;

                DEFAULT_FATAL(trans->m_state);
            }
        }
    }
    s_critsect.Leave();

    // Post completed transactions    
    while (NetTrans * trans = completed.Head()) {
        completed.Unlink(trans);
        trans->Post();
        trans->DecRef("Lifetime");
    }
    // Post completed parent transactions
    while (NetTrans * trans = parentCompleted.Head()) {
        parentCompleted.Unlink(trans);
        trans->Post();
        trans->DecRef("Lifetime");
    }
}


} // namespace Ngl