/*

* 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 <cpixmaindefs.h>

//#include <QThread> //If we happen to use QThread::yieldCurrentThread()

//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(KMimeTypeField, CPIX_MIMETYPE_FIELD);

_LIT(KMimeTypeMsg, "Messages");

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

QEmailFetcher::QEmailFetcher( MEmailItemObserver& aObserver )

    :iEmailObserver( aObserver ), 

     iEmailEventNotifier( NULL ),

     iEmailService( NULL ),

     iMailBoxListings( NULL ), 

     iMailFolderList( NULL ),

     iEnvelopeListing( NULL )

    {

    }

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

QEmailFetcher::~QEmailFetcher()

    {

    delete iEmailEventNotifier;

    delete iEmailService;

    delete iMailBoxListings;

    delete iMailFolderList;

    }

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

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

    QEmailFetcher* emailFetcher = NULL;

    //Leak free init.

    try{

        QEmailFetcher* emailFetcher = new QEmailFetcher( aObserver );

        //Uncomment 'this' once the actual APIs are ready.

        emailFetcher->iEmailService = new NmEmailService( emailFetcher );

        emailFetcher->iEmailEventNotifier =  new NmEventNotifier( emailFetcher );

        emailFetcher->iMailBoxListings = new NmMailboxListing( emailFetcher );

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

        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.

    }

    initialize( emailFetcher ); //Do the rest of the init.

    return emailFetcher; //returns only if not null.

}

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

void QEmailFetcher::initialize( QEmailFetcher* aThis ){

    //The use of 'aThis' is because the current function is static.

    connect( aThis->iEmailService, SIGNAL(initialized(bool)), 

             aThis, SLOT(emailServiceIntialized(bool)) );

    aThis->iEmailService->initialise();

    aThis->connect( aThis->iEmailEventNotifier, 

                    SIGNAL(messageEvent(MessageEvent, quint64, quint64, QList<quint64>)),

                    aThis, 

                    SLOT(handleMessageEvent(MessageEvent, quint64, quint64, QList<quint64>)) );

}

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

void QEmailFetcher::emailServiceIntialized(bool aAllOk){

    if( aAllOk ){

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

    }

}

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

void QEmailFetcher::StartHarvesting(){

    iMailBoxListings->start();

}

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

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());

}

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

// TODO Remove this code if qt_QString2TPtrC works.

// TODO If this function is used, remember to release memory.

// Ownership with caller.

//HBufC* qt_QString2HBufC(const QString& aString)

//{

//    HBufC *buffer;

//#ifdef QT_NO_UNICODE

//    TPtrC8 ptr(reinterpret_cast<const TUint8*>(aString.toLocal8Bit().constData()));

//#else

//    TPtrC16 ptr(qt_QString2TPtrC(aString));

//#endif

//    buffer = q_check_ptr(HBufC::New(ptr.Length()));

//    buffer->Des().Copy(ptr);

//    return buffer;

//}

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

//Private free function creates CSearchDocument from EMailMessageEnvelope.

CSearchDocument* getSearchDocument( const NmMessageEnvelope& aEnvelope ){

    QList<NmEmailAddress> toList;

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

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

    //We need ALL the recipients in a SINGLE field.

    QString recipients = "";

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

        recipients += toList.at( i ).displayName() + " "; //or should we get address?

    NmMessageBody body;

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

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

    const_cast<NmMessageEnvelope&>(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 );

    doc->AddFieldL( KMimeTypeField, KMimeTypeMsg, CDocumentField::EStoreYes | CDocumentField::EIndexUnTokenized);

    doc->AddFieldL( KMsgSubject, qt_QString2TPtrC( aEnvelope.subject() ), CDocumentField::EStoreYes | CDocumentField::EIndexTokenized );

    doc->AddFieldL( KMsgRecipients, qt_QString2TPtrC( recipients ), CDocumentField::EStoreYes | CDocumentField::EIndexTokenized );

    doc->AddFieldL( KMsgBody, qt_QString2TPtrC( msgBody ), CDocumentField::EStoreYes | CDocumentField::EIndexTokenized );

    //TODO: What should go in here?

    doc->AddExcerptL( KNullDesC );

    );

    return doc;

}

} //anonymous namespace

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

//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::handleMailboxesListed(int aCount){

    QList<NmMailbox> mailBoxes;

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

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

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

            delete iMailFolderList; iMailFolderList = NULL;

            iMailFolderList = new NmFolderListing( this, mailBoxes.at( i ).id() );

            connect( iMailFolderList, SIGNAL(foldersListed()), this, SLOT(mailFoldersListed()) );

            const int waitForSeconds = 30; //TODO Move this constant out of here if needed elsewhere

            QTimer::singleShot( waitForSeconds, iMailFolderList, SLOT( start()) );

        }

    }

}

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

void QEmailFetcher::mailFoldersListed(int aCount){

    if( aCount == NmFolderListing::FolderListingFailed ) return; //silently.

    QList<NmFolder> folders;

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

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

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

            delete iEnvelopeListing; iEnvelopeListing = NULL; 

            iEnvelopeListing = new NmEnvelopeListing( this, folders.at( i ).id(), 0 );

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

            iEnvelopeListing->start();

        }

    }

}

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

void QEmailFetcher::processMessages(int aCount){

    if( aCount == NmMailboxListing::MailboxListingFailed ) return; //silently.

    QList<NmMessageEnvelope> envelopes;

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

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

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

        //Create document and call back observer.

        QT_TRAP_THROWING( iEmailObserver.HandleDocumentL( getSearchDocument( envelope ), ECPixAddAction ) );

        }

    }

}

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

void QEmailFetcher::handleMessageEvent( const MessageEvent aEvent, quint64 aMailboxId, quint64 aFolderId, QList<quint64> aMessageList){

    NmMessageEnvelope envelope;

    const int messageCount = aMessageList.count();

    if( messageCount>0 ){

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

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

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

                QT_TRAP_THROWING( 

                   iEmailObserver.HandleDocumentL( getSearchDocument( envelope ), 

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

                           aEvent == MessageCreated ? ECPixAddAction : ECPixUpdateAction ) );

            }

        }

    }

    else if( aEvent == MessageDeleted ) {

        //TODO We can do better. For delete, we dont have to create full document. Just the ID should be enough.

        //We can have another function called getPartialSearchDocument so deletes will be faster.

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

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

                QT_TRAP_THROWING( 

                iEmailObserver.HandleDocumentL( getSearchDocument( envelope ), ECPixRemoveAction ) );

            }

        }

    }

    }

}