/////////////////////////////////////////////////////////////////////////////////
//
//  Copyright (C) 2011-     Statoil ASA
//  Copyright (C) 2013-     Ceetron Solutions AS
//  Copyright (C) 2011-2012 Ceetron AS
//
//  ResInsight 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.
//
//  ResInsight 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 at <http://www.gnu.org/licenses/gpl.html>
//  for more details.
//
/////////////////////////////////////////////////////////////////////////////////

#include "RiaSocketServer.h"
#include "RiaSocketCommand.h"

#include "RiaApplication.h"
#include "RiaLogging.h"
#include "RiaPreferences.h"

#include "RimCase.h"
#include "RimEclipseCase.h"
#include "RimEclipseView.h"
#include "RimProject.h"

#include "RiuMainWindow.h"
#include "RiuViewer.h"

#include "cafFactory.h"

#include <QtNetwork>
#include <QtWidgets/QMdiSubWindow>

#include <cstdlib>

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
RiaSocketServer::RiaSocketServer( QObject* parent )
    : QObject( parent )
    , m_tcpServer( nullptr )
    , m_currentClient( nullptr )
    , m_currentCommandSize( 0 )
    , m_currentCommand( nullptr )
{
    m_tcpServer = new QTcpServer( this );

    m_nextPendingConnectionTimer = new QTimer( this );
    m_nextPendingConnectionTimer->setInterval( 100 );
    m_nextPendingConnectionTimer->setSingleShot( true );

    if ( !m_tcpServer->listen( QHostAddress::LocalHost, 40001 ) )
    {
        QString txt = "Disabled communication with Octave due to another ResInsight process running.";

        RiaLogging::warning( txt );

        return;
    }

    connect( m_nextPendingConnectionTimer, SIGNAL( timeout() ), this, SLOT( slotNewClientConnection() ) );
    connect( m_tcpServer, SIGNAL( newConnection() ), this, SLOT( slotNewClientConnection() ) );
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
RiaSocketServer::~RiaSocketServer()
{
    assert( m_currentCommand == nullptr );
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
unsigned short RiaSocketServer::serverPort()
{
    if ( m_tcpServer )
        return m_tcpServer->serverPort();
    else
        return 0;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void RiaSocketServer::slotNewClientConnection()
{
    // If we are currently handling a connection, just ignore the new one until the current one is disconnected.

    if ( m_currentClient && ( m_currentClient->state() != QAbstractSocket::UnconnectedState ) )
    {
        // PMonLog("Starting Timer");
        m_nextPendingConnectionTimer->start(); // Reset and start again
        return;
    }

    // Read pending data from socket

    if ( m_currentClient && m_currentCommand )
    {
        bool isFinshed = m_currentCommand->interpretMore( this, m_currentClient );

        if ( !isFinshed )
        {
            QString txt;
            txt = "ResInsight SocketServer : The command did not finish up correctly at the presence of a new one.";

            RiaLogging::error( txt );
        }
    }

    handleNextPendingConnection();
}

//--------------------------------------------------------------------------------------------------
/// Find the requested reservoir by caseId
//--------------------------------------------------------------------------------------------------
RimEclipseCase* RiaSocketServer::findReservoir( int caseId )
{
    int currCaseId = caseId;
    if ( caseId < 0 )
    {
        currCaseId = RiaApplication::instance()->currentScriptCaseId();
    }

    if ( currCaseId < 0 )
    {
        RimEclipseView* eclipseView = dynamic_cast<RimEclipseView*>( RiaApplication::instance()->activeReservoirView() );
        if ( eclipseView )
        {
            return eclipseView->eclipseCase();
        }

        // If the active mdi window is different from an Eclipse view, search through available mdi windows to find the
        // last activated Eclipse view. The sub windows are returned with the most recent activated window at the back.
        QList<QMdiSubWindow*> subWindows = RiuMainWindow::instance()->subWindowList( QMdiArea::ActivationHistoryOrder );
        for ( int i = subWindows.size() - 1; i > -1; i-- )
        {
            RiuViewer* viewer = subWindows[i]->widget()->findChild<RiuViewer*>();
            if ( viewer )
            {
                RimEclipseView* riv = dynamic_cast<RimEclipseView*>( viewer->ownerReservoirView() );
                if ( riv )
                {
                    return riv->eclipseCase();
                }
            }
        }
    }
    else
    {
        RimProject* project = RimProject::current();
        if ( !project ) return nullptr;

        std::vector<RimCase*> cases;
        project->allCases( cases );

        for ( size_t i = 0; i < cases.size(); i++ )
        {
            if ( cases[i]->caseId == currCaseId )
            {
                return dynamic_cast<RimEclipseCase*>( cases[i] );
            }
        }
    }

    return nullptr;
}

//--------------------------------------------------------------------------------------------------
/// Reads the command name size, the command string and creates a new command object based on the string read.
/// Tries to interpret the command as well.
/// Returns whether the command actually was completely finished in one go.
//--------------------------------------------------------------------------------------------------
bool RiaSocketServer::readCommandFromOctave()
{
    QDataStream socketStream( m_currentClient );
    socketStream.setVersion( riOctavePlugin::qtDataStreamVersion );

    // If we have not read the currentCommandSize
    // read the size of the command if all the data is available

    if ( m_currentCommandSize == 0 )
    {
        if ( m_currentClient->bytesAvailable() < (int)sizeof( qint64 ) ) return false;

        socketStream >> m_currentCommandSize;
    }

    // Check if the complete command is available, return and whait for readyRead() if not
    if ( m_currentClient->bytesAvailable() < m_currentCommandSize ) return false;

    // Now we can read the command name

    QByteArray  command = m_currentClient->read( m_currentCommandSize );
    QTextStream commandStream( command );

    QList<QByteArray> args;
    while ( !commandStream.atEnd() )
    {
        QByteArray arg;
        commandStream >> arg;
        args.push_back( arg );
    }

    CVF_ASSERT( args.size() > 0 );

    // Create the actual RiaSocketCommand object that will interpret the socket data

    m_currentCommand = RiaSocketCommandFactory::instance()->create( args[0] );

    if ( m_currentCommand )
    {
        bool finished = m_currentCommand->interpretCommand( this, args, socketStream );
        return finished;
    }
    else
    {
        QString txt;
        txt = QString( "ResInsight SocketServer: Unknown command: %1" ).arg( args[0].data() );

        RiaLogging::error( txt );
        return true;
    }
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void RiaSocketServer::slotCurrentClientDisconnected()
{
    if ( m_currentCommand )
    {
        // Make sure we read what can be read.
        bool isFinished = m_currentCommand->interpretMore( this, m_currentClient );

        if ( !isFinished )
        {
            QString txt;
            txt = QString( "ResInsight SocketServer: The command was interrupted and did not finish because the "
                           "connection to octave disconnected." );

            RiaLogging::error( txt );
        }
    }

    handleNextPendingConnection();
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void RiaSocketServer::slotReadyRead()
{
    if ( m_currentCommand )
    {
        bool isFinished = m_currentCommand->interpretMore( this, m_currentClient );

        if ( isFinished )
        {
            handleNextPendingConnection();
        }
    }
    else
    {
        bool isFinished = readCommandFromOctave();
        if ( isFinished )
        {
            handleNextPendingConnection();
        }
    }
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void RiaSocketServer::showErrorMessage( const QString& message ) const
{
    RiaLogging::error( message );
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void RiaSocketServer::terminateCurrentConnection()
{
    if ( m_currentClient )
    {
        m_currentClient->disconnect( SIGNAL( disconnected() ) );
        m_currentClient->disconnect( SIGNAL( readyRead() ) );
        m_currentClient->deleteLater();
        m_currentClient = nullptr;
    }

    // Clean up more state:

    if ( m_currentCommand )
    {
        delete m_currentCommand;
        m_currentCommand = nullptr;
    }

    m_currentCommandSize = 0;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void RiaSocketServer::handleNextPendingConnection()
{
    if ( m_currentClient && ( m_currentClient->state() != QAbstractSocket::UnconnectedState ) )
    {
        // PMonLog("Starting Timer");
        m_nextPendingConnectionTimer->start(); // Reset and start again
        return;
    }

    // Stop timer
    if ( m_nextPendingConnectionTimer->isActive() )
    {
        // PMonLog("Stopping Timer");
        m_nextPendingConnectionTimer->stop();
    }

    terminateCurrentConnection();

    QTcpSocket* clientToHandle = m_tcpServer->nextPendingConnection();
    if ( clientToHandle )
    {
        CVF_ASSERT( m_currentClient == nullptr );
        CVF_ASSERT( m_currentCommand == nullptr );

        m_currentClient      = clientToHandle;
        m_currentCommandSize = 0;

        connect( m_currentClient, SIGNAL( disconnected() ), this, SLOT( slotCurrentClientDisconnected() ) );
        connect( m_currentClient, SIGNAL( readyRead() ), this, SLOT( slotReadyRead() ) );

        if ( m_currentClient->bytesAvailable() )
        {
            bool isFinished = this->readCommandFromOctave();
            if ( isFinished )
            {
                // Call ourselves recursively until there are none left, or until it can not be processed in one go.
                this->handleNextPendingConnection();
            }
        }
    }
}