/**
 * @file llpluginmessagepipe.h
 * @brief Classes that implement connections from the plugin system to pipes/pumps.
 *
 * @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_LLPLUGINMESSAGEPIPE_H
#define LL_LLPLUGINMESSAGEPIPE_H

#include "lliosocket.h"
#include "llthread.h"
#include "llmutex.h"

class LLPluginMessagePipe;

// Inherit from this to be able to receive messages from the LLPluginMessagePipe
class LLPluginMessagePipeOwner
{
    LOG_CLASS(LLPluginMessagePipeOwner);
public:
    LLPluginMessagePipeOwner();
    virtual ~LLPluginMessagePipeOwner();

    // called with incoming messages
    virtual void receiveMessageRaw(const std::string &message) = 0;
    // called when the socket has an error
    virtual apr_status_t socketError(apr_status_t error);

    // called from LLPluginMessagePipe to manage the connection with LLPluginMessagePipeOwner -- do not use!
    virtual void setMessagePipe(LLPluginMessagePipe *message_pipe);

protected:
    // returns false if writeMessageRaw() would drop the message
    bool canSendMessage(void);
    // call this to send a message over the pipe
    bool writeMessageRaw(const std::string &message);
    // call this to close the pipe
    void killMessagePipe(void);

    LLPluginMessagePipe *mMessagePipe;
    apr_status_t mSocketError;
};

class LLPluginMessagePipe
{
    LOG_CLASS(LLPluginMessagePipe);
public:
    LLPluginMessagePipe(LLPluginMessagePipeOwner *owner, LLSocket::ptr_t socket);
    virtual ~LLPluginMessagePipe();

    bool addMessage(const std::string &message);
    void clearOwner(void);

    bool pump(F64 timeout = 0.0f);
    bool pumpOutput();
    bool pumpInput(F64 timeout = 0.0f);

protected:
    void processInput(void);

    // used internally by pump()
    void setSocketTimeout(apr_interval_time_t timeout_usec);

    LLMutex mInputMutex;
    std::string mInput;
    LLMutex mOutputMutex;
    std::string mOutput;
    std::string::size_type mOutputStartIndex;

    LLPluginMessagePipeOwner *mOwner;
    LLSocket::ptr_t mSocket;
};

#endif // LL_LLPLUGINMESSAGE_H