/**
 * @file llpluginprocesschild.h
 * @brief LLPluginProcessChild handles the child side of the external-process plugin API.
 *
 * @cond
 * $LicenseInfo:firstyear=2008&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 * @endcond
 */

#ifndef LL_LLPLUGINPROCESSCHILD_H
#define LL_LLPLUGINPROCESSCHILD_H

#include <queue>
#include "llpluginmessage.h"
#include "llpluginmessagepipe.h"
#include "llplugininstance.h"
#include "llhost.h"
#include "llpluginsharedmemory.h"

class LLPluginInstance;

class LLPluginProcessChild: public LLPluginMessagePipeOwner, public LLPluginInstanceMessageListener
{
    LOG_CLASS(LLPluginProcessChild);
public:
    LLPluginProcessChild();
    ~LLPluginProcessChild();

    void init(U32 launcher_port);
    void idle(void);
    void sleep(F64 seconds);
    void pump();

    // returns true if the plugin is in the steady state (processing messages)
    bool isRunning(void);

    // returns true if the plugin is unloaded or we're in an unrecoverable error state.
    bool isDone(void);

    void killSockets(void);

    F64 getSleepTime(void) const { return mSleepTime; };

    void sendMessageToPlugin(const LLPluginMessage &message);
    void sendMessageToParent(const LLPluginMessage &message);

    // Inherited from LLPluginMessagePipeOwner
    /* virtual */ void receiveMessageRaw(const std::string &message);

    // Inherited from LLPluginInstanceMessageListener
    /* virtual */ void receivePluginMessage(const std::string &message);

private:

    enum EState
    {
        STATE_UNINITIALIZED,
        STATE_INITIALIZED,          // init() has been called
        STATE_CONNECTED,            // connected back to launcher
        STATE_PLUGIN_LOADING,       // plugin library needs to be loaded
        STATE_PLUGIN_LOADED,        // plugin library has been loaded
        STATE_PLUGIN_INITIALIZING,  // plugin is processing init message
        STATE_RUNNING,              // steady state (processing messages)
        STATE_SHUTDOWNREQ,          // Parent has requested a shutdown.
        STATE_UNLOADING,            // plugin has sent shutdown_response and needs to be unloaded
        STATE_UNLOADED,             // plugin has been unloaded
        STATE_ERROR,                // generic bailout state
        STATE_DONE                  // state machine will sit in this state after either error or normal termination.
    };
    void setState(EState state);

    EState mState;

    LLHost mLauncherHost;
    LLSocket::ptr_t mSocket;

    std::string mPluginFile;
    std::string mPluginDir;

    LLPluginInstance *mInstance;

    typedef std::map<std::string, LLPluginSharedMemory*> sharedMemoryRegionsType;
    sharedMemoryRegionsType mSharedMemoryRegions;

    LLTimer mHeartbeat;
    F64     mSleepTime;
    F64     mCPUElapsed;
    bool    mBlockingRequest;
    bool    mBlockingResponseReceived;
    std::queue<std::string> mMessageQueue;
    LLTimer mWaitGoodbye;
    void deliverQueuedMessages();

};

#endif // LL_LLPLUGINPROCESSCHILD_H