/**
 * @file media_plugin_base.cpp
 * @brief Media plugin base class for LLMedia API plugin system
 *
 * All plugins should be a subclass of MediaPluginBase.
 *
 * @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
 */

#include "linden_common.h"
#include "media_plugin_base.h"


// TODO: Make sure that the only symbol exported from this library is LLPluginInitEntryPoint
////////////////////////////////////////////////////////////////////////////////
/// Media plugin constructor.
///
/// @param[in] host_send_func Function for sending messages from plugin to plugin loader shell
/// @param[in] host_user_data Message data for messages from plugin to plugin loader shell

MediaPluginBase::MediaPluginBase(
    LLPluginInstance::sendMessageFunction host_send_func,
    void *host_user_data )
{
    mHostSendFunction = host_send_func;
    mHostUserData = host_user_data;
    mDeleteMe = false;
    mPixels = 0;
    mWidth = 0;
    mHeight = 0;
    mTextureWidth = 0;
    mTextureHeight = 0;
    mDepth = 0;
    mStatus = STATUS_NONE;
}

/**
 * Converts current media status enum value into string (STATUS_LOADING into "loading", etc.)
 *
 * @return Media status string ("loading", "playing", "paused", etc)
 *
 */
std::string MediaPluginBase::statusString()
{
    std::string result;

    switch(mStatus)
    {
        case STATUS_LOADING:    result = "loading";     break;
        case STATUS_LOADED:     result = "loaded";      break;
        case STATUS_ERROR:      result = "error";       break;
        case STATUS_PLAYING:    result = "playing";     break;
        case STATUS_PAUSED:     result = "paused";      break;
        case STATUS_DONE:       result = "done";        break;
        default:
            // keep the empty string
        break;
    }

    return result;
}

/**
 * Set media status.
 *
 * @param[in] status Media status (STATUS_LOADING, STATUS_PLAYING, STATUS_PAUSED, etc)
 *
 */
void MediaPluginBase::setStatus(EStatus status)
{
    if(mStatus != status)
    {
        mStatus = status;
        sendStatus();
    }
}


/**
 * Receive message from plugin loader shell.
 *
 * @param[in] message_string Message string
 * @param[in] user_data Message data
 *
 */
void MediaPluginBase::staticReceiveMessage(const char *message_string, void **user_data)
{
    MediaPluginBase *self = (MediaPluginBase*)*user_data;

    if(self != NULL)
    {
        self->receiveMessage(message_string);

        // If the plugin has processed the delete message, delete it.
        if(self->mDeleteMe)
        {
            delete self;
            *user_data = NULL;
        }
    }
}

/**
 * Send message to plugin loader shell.
 *
 * @param[in] message Message data being sent to plugin loader shell
 *
 */
void MediaPluginBase::sendMessage(const LLPluginMessage &message)
{
    std::string output = message.generate();
    mHostSendFunction(output.c_str(), &mHostUserData);
}

/**
 * Notifies plugin loader shell that part of display area needs to be redrawn.
 *
 * @param[in] left Left X coordinate of area to redraw (0,0 is at top left corner)
 * @param[in] top Top Y coordinate of area to redraw (0,0 is at top left corner)
 * @param[in] right Right X-coordinate of area to redraw (0,0 is at top left corner)
 * @param[in] bottom Bottom Y-coordinate of area to redraw (0,0 is at top left corner)
 *
 */
void MediaPluginBase::setDirty(int left, int top, int right, int bottom)
{
    LLPluginMessage message(LLPLUGIN_MESSAGE_CLASS_MEDIA, "updated");

    message.setValueS32("left", left);
    message.setValueS32("top", top);
    message.setValueS32("right", right);
    message.setValueS32("bottom", bottom);

    sendMessage(message);
}

/**
 * Sends "media_status" message to plugin loader shell ("loading", "playing", "paused", etc.)
 *
 */
void MediaPluginBase::sendStatus()
{
    LLPluginMessage message(LLPLUGIN_MESSAGE_CLASS_MEDIA, "media_status");

    message.setValue("status", statusString());

    sendMessage(message);
}

#if LL_LINUX

#include <dlfcn.h>

size_t SymbolGrabber::registerSymbol( SymbolToGrab aSymbol )
{
    gSymbolsToGrab.emplace_back(aSymbol);
    return gSymbolsToGrab.size();
}

bool SymbolGrabber::grabSymbols(std::vector< std::string > const &aDSONames)
{
    if (sSymsGrabbed)
        return true;

    for( std::vector< std::string >::const_iterator itr = aDSONames.begin(); itr != aDSONames.end(); ++itr )
    {
        auto pDSO = dlopen( itr->c_str(), RTLD_NOW );

        if( pDSO )
        {
            sLoadedLibraries.push_back(pDSO);

            for (auto i = 0; i < gSymbolsToGrab.size(); ++i)
            {
                if (!*gSymbolsToGrab[i].mPPFunc)
                    *gSymbolsToGrab[i].mPPFunc = dlsym(pDSO, gSymbolsToGrab[i].mName);
            }
        }
    }

    bool sym_error = false;

    for( auto i = 0; i < gSymbolsToGrab.size(); ++i )
    {
        if( gSymbolsToGrab[ i ].mRequired && ! *gSymbolsToGrab[ i ].mPPFunc )
            sym_error = true;
    }

    sSymsGrabbed = !sym_error;
    return sSymsGrabbed;
}

void SymbolGrabber::ungrabSymbols()
{

}
#endif


#if LL_WINDOWS
# define LLSYMEXPORT __declspec(dllexport)
#elif LL_LINUX
# define LLSYMEXPORT __attribute__ ((visibility("default")))
#else
# define LLSYMEXPORT /**/
#endif

extern "C"
{
    LLSYMEXPORT int LLPluginInitEntryPoint(LLPluginInstance::sendMessageFunction host_send_func, void *host_user_data, LLPluginInstance::sendMessageFunction *plugin_send_func, void **plugin_user_data);
}

/**
 * Plugin initialization and entry point. Establishes communication channel for messages between plugin and plugin loader shell.  TODO:DOC - Please check!
 *
 * @param[in] host_send_func Function for sending messages from plugin to plugin loader shell
 * @param[in] host_user_data Message data for messages from plugin to plugin loader shell
 * @param[out] plugin_send_func Function for plugin to receive messages from plugin loader shell
 * @param[out] plugin_user_data Pointer to plugin instance
 *
 * @return int, where 0=success
 *
 */
LLSYMEXPORT int
LLPluginInitEntryPoint(LLPluginInstance::sendMessageFunction host_send_func, void *host_user_data, LLPluginInstance::sendMessageFunction *plugin_send_func, void **plugin_user_data)
{
    return init_media_plugin(host_send_func, host_user_data, plugin_send_func, plugin_user_data);
}

#ifdef WIN32
int WINAPI DllEntryPoint( HINSTANCE hInstance, unsigned long reason, void* params )
{
    return 1;
}
#endif

#if LL_LINUX
pid_t getParentPid( pid_t aPid )
{
    std::stringstream strm;
    strm << "/proc/" << aPid << "/status";
    std::ifstream in{ strm.str() };

    if( !in.is_open() )
        return 0;

    pid_t res {0};
    while( !in.eof() && res == 0 )
    {
        std::string line;
        line.resize( 1024, 0 );
        in.getline( &line[0], line.length() );

        auto i = line.find( "PPid:"  );

        if( i == std::string::npos )
            continue;

        char const *pIn = line.c_str() + 5; // Skip over pid;
        while( *pIn != 0 && isspace( *pIn ) )
               ++pIn;

        if( *pIn )
            res = atoll( pIn );
    }
     return res;
}

bool isPluginPid( pid_t aPid )
{
    auto myPid = getpid();

    do
    {
        if( aPid == myPid )
            return true;
        aPid = getParentPid( aPid );
    } while( aPid > 1 );

    return false;
}
#endif