/**

* Copyright (c) 2010 Sasken Communication Technologies Ltd.

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the "{License}"

* which accompanies  this distribution, and is available

* at the URL "{LicenseUrl}".

*

* Initial Contributors:

* Narasimhulu Kavadapu, Sasken Communication Technologies Ltd - Initial contribution

*

* Contributors:

*

* Description:

* class to maintian session & all credential keys.

*/

#include "sessionSP.h"

#include "requestSP.h"

#include <qfile.h>

#include <QTimer>

#include <qdebug.h>

///////////////////////////////////////////////////////////////////////////////////////////////////

// global

static const QString kAPIRestURL = "http://api.facebook.com/restserver.php";

static const QString kAPIRestSecureURL = "https://api.facebook.com/restserver.php";

static const int kMaxBurstRequests = 3;

static const int kBurstDuration = 2;

static FBSession* sharedSession = NULL;

///////////////////////////////////////////////////////////////////////////////////////////////////

// Static class functions

FBSession* FBSession::session()

{

    return sharedSession;

}

void FBSession::setSession(FBSession* aSession)

{

    sharedSession = aSession;

}

FBSession* FBSession::sessionForApplication ( const QString& aAppKey, const QString& aAppSecret, const QString& aSessionProxy)

{

    FBSession* session = new FBSession ( aAppKey, aAppSecret, aSessionProxy );

    return session;

}

///////////////////////////////////////////////////////////////////////////////////////////////////

// instance public functions

FBSession::FBSession( const QString& aAppKey, const QString& aAppSecret, const QString& aGetSessionProxy ) :

        iApiKey (aAppKey),

        iApiSecret ( aAppSecret ),

        iGetSessionProxy ( aGetSessionProxy ),

        iRequestBurstCount(0),

        m_Client(new SmfCredMgrClient(this))	

{

    if (!sharedSession)

    {

        sharedSession = this;

    }

}

FBSession::~FBSession()

{

	if(m_Client){

		delete m_Client;

		m_Client = NULL;

	}

}

const QString& FBSession::apiURL() const

{

    return kAPIRestURL;

}

const QString& FBSession::apiSecureURL() const

{

    return kAPIRestSecureURL;

}

bool FBSession::isConnected() const

{

    return iSessionKey.length() > 0 ;

}

void FBSession::beginSession (const QString& aSessionKey, const QString& aSessionSecret, const QDateTime& aExpires )

{

    iSessionKey = aSessionKey;

    iSessionSecret = aSessionSecret;

    iExpirationDate = aExpires;

    save();

}

bool FBSession::resume()

{

	QString CMRegToken = iSettings.value("CMRegToken").toString();

	QDateTime ExpiryTime = iSettings.value("ExpiryTime").toDateTime();

	SmfAuthParams Params;

	if(m_Client->AuthDataSet(CMRegToken,ExpiryTime,Params))

	{

		QByteArray accessToken = Params.value("accessToken");

		emit sessionDidLogin( accessToken );

        return true;

    }

    return false;

}

void FBSession::cancelLogin() {

    if (!isConnected()) {

        emit sessionDidNotLogin();

    }

}

void FBSession::logout() {

	iExpirationDate = QDateTime();

	iSessionKey.clear();

	iSessionSecret.clear();

	unsave();

	emit sessionDidLogout();

}

void FBSession::send (FBRequest* aRequest) {

    performRequest (aRequest, true);

}

///////////////////////////////////////////////////////////////////////////////////////////////////

// instance private functions

void FBSession::save()

{

    SmfAuthParams Params;

    Params.insert("accessToken",iSessionKey.toAscii());

    QList<QUrl> UrlList;

    UrlList.append(QUrl("http://www.facebook.com"));

    QStringList PluginList;

    PluginList.append(QString("facebook"));

    QString UID("0xEFE2FD23");

    //Currently Hardcoded with current time bcoz CM is not handling expiry time as '0' value

    iExpirationDate = QDateTime::currentDateTime();

    iExpirationDate.addYears(1);

    QString CMRegToken = m_Client->StoreAuthData(Params,iExpirationDate,UrlList,PluginList,UID,true);

    if(CMRegToken.size()){

    	iSettings.setValue("CMRegToken", CMRegToken);

    	iSettings.setValue("ExpiryTime", iExpirationDate);

    }

}

void FBSession::unsave()

{

	//Delete saved keys from Credential Manager.

}

void FBSession::startFlushTimer()

{

	int t = kBurstDuration;

    QTimer::singleShot( t, this, SLOT(requestTimerReady()));

}

void FBSession::enqueueRequest(FBRequest* aRequest)

{

    iRequestQueue.append(aRequest);

    startFlushTimer();

}

bool FBSession::performRequest(FBRequest* aRequest, bool aEnqueue) {

    // Stagger requests that happen in short bursts to prevent the server from rejecting

    // them for making too many requests in a short time

    int seconds = iLastRequestTime.secsTo( QDateTime::currentDateTime() );

	bool burst = seconds && (seconds < kBurstDuration);

	if (burst && (iRequestBurstCount > kMaxBurstRequests))

    {

        if (aEnqueue)

        {

            enqueueRequest(aRequest);

        }

        return false;

    }

    else

    {

        aRequest->connect();

		if (burst) {

			iRequestBurstCount++;

		} else {

            iRequestBurstCount = 1;

            iLastRequestTime = aRequest->timeStamp();

        }

    }

    return true;

}

void FBSession::flushRequestQueue()

{

    while ( iRequestQueue.count() ) {

      FBRequest* request = iRequestQueue.at(0);

      if (performRequest(request, false)) {

          iRequestQueue.removeAt(0);

      } else {

        startFlushTimer();

        break;

      }

    }

}

///////////////////////////////////////////////////////////////////////////////////////////////////

// instance provate slots

void FBSession::requestTimerReady()

{

    flushRequestQueue();

}