/*

* Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: Utility class for fetching email.

*

*/

#include "qtemailfetcher.h"

#include <csearchdocument.h>

#include <nmapiemailaddress.h>

#include <nmapimessagebody.h>

#include <nmapimailbox.h>

#include <QTimer>

#include <QDebug>

//Symbian specific details; picked up from cemailplugin.cpp. 

//Refactor it to cpixmaindefs.h

_LIT(KMsgBaseAppClassGeneric, "root msg email");

_LIT(KMsgSubject, "Subject");

_LIT(KMsgRecipients, "Recipients");

_LIT(KMsgBody, "Body");

_LIT(KMailBoxId, "MailBoxId");

_LIT(KFolderId, "FolderId");

_LIT(KMailBoxName, "MailBoxName");

_LIT(KMimeTypeField, CPIX_MIMETYPE_FIELD);

_LIT(KMimeTypeMsg, "Messages");

//------------------------------------------------------------------------------

QEmailFetcher::QEmailFetcher( MEmailItemObserver& aObserver )

    :iEmailObserver( aObserver ), 

     iEmailEventNotifier( NULL ),

     iEmailService( NULL ),

     iMailBoxListings( NULL ), 

     iMailFolderList( NULL ),

     iEnvelopeListing( NULL ),

     iCurrentMailboxIndex( 0 ), 

     iCurrentFolderIndex( 0 )

    {

    qDebug() << "QEmailFetcher::QEmailFetcher";

    }

//------------------------------------------------------------------------------

QEmailFetcher::~QEmailFetcher()

    {

    delete iEmailEventNotifier;

    delete iEmailService;

    delete iMailFolderList;

    }

//------------------------------------------------------------------------------

QEmailFetcher* QEmailFetcher::newInstance( MEmailItemObserver& aObserver ){

    QEmailFetcher* emailFetcher = NULL;

    qDebug() << "QEmailFetcher::newInstance :START";

    //Leak free init.

    try{

        emailFetcher = new QEmailFetcher( aObserver );

        emailFetcher->iEmailService = new NmApiEmailService( emailFetcher );

        emailFetcher->iEmailEventNotifier =  new NmApiEventNotifier( emailFetcher );

        emailFetcher->iMailBoxListings = new NmApiMailboxListing( emailFetcher );

    }catch(...){ //cleanup.

    qDebug() << "QEmailFetcher::newInstance ( Catch Block)";

        delete emailFetcher; 

        delete emailFetcher->iEmailService;

        delete emailFetcher->iEmailEventNotifier;

        delete emailFetcher->iMailBoxListings;

        emailFetcher->iEmailService = NULL;

        emailFetcher->iEmailEventNotifier = NULL;

        emailFetcher->iMailBoxListings = NULL;

        throw; //rethrow the exception to caller.

    }    

    qDebug() << "QEmailFetcher::newInstance :END";

    return emailFetcher; //returns only if not null.

}

//------------------------------------------------------------------------------

    qDebug() << "QEmailFetcher::initialize :START";

    //Monitor for Message changes

    //Start the monitoring

    qDebug() << "QEmailFetcher::initialize :END";

}

//------------------------------------------------------------------------------

void QEmailFetcher::emailServiceIntialized(bool aAllOk){

    qDebug() << "QEmailFetcher::emailServiceIntialized :START  aAllOk = " << aAllOk;

    if( aAllOk ){

        connect( iMailBoxListings, SIGNAL(mailboxesListed(qint32)), this, SLOT(handleMailboxesListed(qint32)) );

    }

    qDebug() << "QEmailFetcher::emailServiceIntialized :END";

}

//------------------------------------------------------------------------------

void QEmailFetcher::StartHarvesting(){

    qDebug() << "QEmailFetcher::StartHarvesting :START";

    bool ret = iMailBoxListings->start();

    qDebug() << "QEmailFetcher::StartHarvesting :END return = " << ret;

}

//------------------------------------------------------------------------------

namespace {

// Taken from qt/src/corelib/kernel/qcore_symbian_p.cpp, as recomended in

// http://qt.nokia.com/files/pdf/whitepaper-using-qt-and-symbian-c-together, page 34.

// URL last accessed on April 6th, 2010.

// Returned TPtrC is valid as long as the given parameter is valid and unmodified

static inline TPtrC qt_QString2TPtrC( const QString& string )

{

    return TPtrC16(static_cast<const TUint16*>(string.utf16()), string.length());

}

//------------------------------------------------------------------------------

    qDebug() << "getPartialSearchDocument :START";

    CSearchDocument* doc = 0;

    QT_TRAP_THROWING(

        //Use qt_Qstring2TPtrC since we are working with <b>const</b> EmailMessageEnvelope.

                                     KMsgBaseAppClassGeneric );        

        );

    qDebug() << "getPartialSearchDocument :END";

    return doc;

    }

} //anonymous namespace

//------------------------------------------------------------------------------

    QList<NmApiEmailAddress> toList;

    //Need to cast away const-ness since the get method is unfortunately not const.

    const_cast<NmApiMessageEnvelope&>(aEnvelope).getToRecipients( toList );

    QString recipients = "";

    for( int i=0; i<toList.length(); i++ )

    NmApiMessageBody body;

    //Cast away const-ness since the get method is unfortunately not const.

    //Returns void. Cannot check for success/failure.

    const_cast<NmApiMessageEnvelope&>(aEnvelope).getPlainTextBody( body ); 

    QString msgBody = body.content();

    CSearchDocument* doc = 0;

    QT_TRAP_THROWING(

    //Use qt_Qstring2TPtrC since we are working with <b>const</b> EmailMessageEnvelope.

    doc = CSearchDocument::NewL( qt_QString2TPtrC( QString().setNum( aEnvelope.id() ) ), 

                                 KMsgBaseAppClassGeneric );

    //Adding subject and body to the excerpt. 

    QString excerpt ;

    excerpt = aEnvelope.subject();

    excerpt += msgBody ;

    doc->AddExcerptL( qt_QString2TPtrC(excerpt) );

    );

    return doc;

}

//------------------------------------------------------------------------------

void QEmailFetcher::NotifyHarvestingComplete(){

    qDebug() << "QEmailFetcher::NotifyHarvestingComplete :START";

    iCurrentMailboxIndex = iCurrentFolderIndex = 0;

    QT_TRAP_THROWING( iEmailObserver.HarvestingCompleted() );

    qDebug() << "QEmailFetcher::NotifyHarvestingComplete :END";

    return;

}

//------------------------------------------------------------------------------

void QEmailFetcher::handleMailboxesListed(qint32 aCount){

    qDebug() << "QEmailFetcher::handleMailboxesListed :START";

    iCurrentMailboxIndex = 0;

    if( aCount == NmApiMailboxListing::MailboxListingFailed ) {

        NotifyHarvestingComplete();

        qDebug() << "QEmailFetcher::handleMailboxesListed :MailboxListingFailed";

        return;

    }

    if( aCount>0 && iMailBoxListings->getMailboxes( iMailBoxes ) ){

        //Already set to NULL in constructor, so safe to call delete first time.

        qDebug() << "QEmailFetcher::handleMailboxesListed :processNextMailbox";

        processNextMailbox();

    }else{

        qDebug() << "QEmailFetcher::handleMailboxesListed :Harvesting Completed";

        NotifyHarvestingComplete();

        return;

    }

}

//------------------------------------------------------------------------------

//Options to make async (like other plugins' Asynchronizer):

//1. Use http://doc.trolltech.com/4.6/qtimer.html and connect timeout() signal to something?

//Downside: 

//Have to save the state of the function and resume. Achievable via static members. 

//Remeber to reset counters.

//2. Use timer; unlike above, have handleMailboxesListed() simply trigger a  

//Timer controlled function.

//3. Use QThread::currentThread()->yieldCurrentThread();

//Downside: Not tested.

//4. As recommended by the email API documentation, use SingleShotTimer:

//QTimer::singleShot(nsecs,nmFolderListing,SLOT(start());

//

//Recommendation: Use option 4.

void QEmailFetcher::processNextMailbox(){

    qDebug() << "QEmailFetcher::processNextMailbox :START";

    //No more mailboxes, notify completion.

    if( iCurrentMailboxIndex >= iMailBoxes.count() ) {

        NotifyHarvestingComplete();

        qDebug() << "QEmailFetcher::processNextMailbox :END (harvesting completed)";

        return;

    }

    //More mailboxes available.

    delete iMailFolderList; iMailFolderList = NULL;

    iMailFolderList = new NmApiFolderListing( this, iMailBoxes.at( iCurrentMailboxIndex++ ).id() );

    connect( iMailFolderList, SIGNAL(foldersListed( qint32 )), this, SLOT(handleMailFoldersListed( qint32)) );

    qDebug() << "QEmailFetcher::processNextMailbox :END (goto next mailbox)";

}

//------------------------------------------------------------------------------

void QEmailFetcher::handleMailFoldersListed(int aCount){

    qDebug() << "QEmailFetcher::handleMailFoldersListed :START";

    iCurrentFolderIndex = 0;    

    if( aCount == NmApiFolderListing::FolderListingFailed ){

        qDebug() << "QEmailFetcher::handleMailFoldersListed :FolderListingFailed";

        processNextMailbox();

        return;//Don't proceed futher.

    }

    if( aCount && iMailFolderList->getFolders( iFolders ) ){ 

       qDebug() << "QEmailFetcher::handleMailFoldersListed :processNextFolder";

        processNextFolder();

    }else{

        qDebug() << "QEmailFetcher::handleMailFoldersListed :processNextMailbox";

        processNextMailbox();

        return;

    }

}

//------------------------------------------------------------------------------

void QEmailFetcher::processNextFolder(){

    qDebug() << "QEmailFetcher::processNextFolder :START";

    //No more folders in current mailbox.

    if( iCurrentFolderIndex >= iFolders.count() ) {

        qDebug() << "QEmailFetcher::processNextFolder :processNextMailbox";

        processNextMailbox();

        return;//Don't proceed futher.

    }

    //More folders to process.

    //Already set to NULL in constructor, so safe to call delete first time.

    delete iEnvelopeListing; iEnvelopeListing = NULL; 

    iEnvelopeListing= new NmApiEnvelopeListing( 

            this, 

            iFolders.at( iCurrentFolderIndex++ ).id(),

            iMailBoxes.at( iCurrentMailboxIndex-1 ).id() ); //we have already incremented iMailboxIndex.

    connect(iEnvelopeListing, SIGNAL(envelopesListed(qint32)),this,SLOT(processMessages(qint32)));

    iEnvelopeListing->start();

    qDebug() << "QEmailFetcher::processNextFolder :processNextFolder";

}

//------------------------------------------------------------------------------

void QEmailFetcher::processMessages(qint32 aCount){

    qDebug() << "QEmailFetcher::processMessages :START";

    if( aCount == NmApiEnvelopeListing::EnvelopeListingFailed ) {

        qDebug() << "QEmailFetcher::processMessages :EnvelopeListingFailed";

        processNextFolder();

        return;//Don't proceed futher.

    }

    QList<NmApiMessageEnvelope> envelopes;

    if ( aCount > 0 && iEnvelopeListing->getEnvelopes(envelopes) ) {

        for( int i=0; i<envelopes.count(); i++ ) {

            const NmApiMessageEnvelope &envelope = envelopes.at( i );

            //Create document and call back observer.

        }

    }

    qDebug() << "QEmailFetcher::processMessages :END";

}

//------------------------------------------------------------------------------

    NmApiMessageEnvelope envelope;

    qDebug() << "QEmailFetcher::handleMessageEvent :START";

    const int messageCount = aMessageList.count();

    if( messageCount>0 ){

    if( aEvent == MessageCreated || aEvent == MessageChanged ){

        qDebug() << "QEmailFetcher::handleMessageEvent :MessageCreated || MessageChanged";

        for( int i=0; i<messageCount; i++ ){

            if( iEmailService->getEnvelope( aMailboxId, aFolderId, aMessageList.at( i ), envelope ) ){

               qDebug() << "QEmailFetcher::handleMessageEvent :HandleDocumentL";

                QT_TRAP_THROWING( 

                           //Doing this simply avoids *duplicate* code for update action.

                           aEvent == MessageCreated ? ECPixAddAction : ECPixUpdateAction ) );

            }

        }

    }

    else if( aEvent == MessageDeleted ) {

        qDebug() << "QEmailFetcher::handleMessageEvent :MessageDeleted";

        for( int i=0; i<messageCount; i++ ){

                qDebug() << "QEmailFetcher::handleMessageEvent :MessageDeleted : HandleDocumentL";

                QT_TRAP_THROWING( 

            }

        }

    }

}