/*

* Copyright (c) 2006 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "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:  This class represents the Widget Preferences object

*

*/

// INCLUDE FILES

#include <e32std.h>

#include <f32file.h>

#include <uri16.h>

#include <e32hashtab.h>

#include "Preferences.h"

// EXTERNAL DATA STRUCTURES

// EXTERNAL FUNCTION PROTOTYPES

// CONSTANTS

const TInt KMaxIntLength = 10;

const TInt KMaxKeyValueSize = 4096; //4 k

_LIT( KKeyFormat, "%d.%S" );

_LIT( KPrefsFile,"prefs.dat" );

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

// WidgetPreferences::WidgetPreferences

// C++ Constructor

//

//

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

WidgetPreferences::WidgetPreferences() :m_widgetid(0),

                                        m_widgetbundleid(0),

                                        m_basepath(0),

                                        m_filepath(0)

{

}

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

// WidgetPreferences::~WidgetPreferences

// Destructor

//

//

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

WidgetPreferences::~WidgetPreferences()

    if (m_preferences) {

        m_preferences->ResetAndDestroy();

        m_preferences->Close();

        delete m_preferences;        

    }

    delete m_basepath;

    delete m_widgetbundleid;        

    delete m_filepath; 

}

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

// WidgetPreferences::setBasePathL

//

//

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

void WidgetPreferences::setBasePathL(const TDesC& aValue)

{

    m_basepath = aValue.AllocL();    

}

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

// WidgetPreferences::setWidgetId

//

//

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

void WidgetPreferences::setWidgetId(TInt aValue)

{

    m_widgetid = aValue;

}

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

// WidgetPreferences::setBundleIdL

//

//

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

void WidgetPreferences::setWidgetBundleId(const TDesC& aValue)

{

    m_widgetbundleid = aValue.AllocL();

}

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

// WidgetPreferences::setBundleIdL

//

//

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

TDesC& WidgetPreferences::getWidgetBundleId()

{

   return *m_widgetbundleid;

}

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

// WidgetPreferences::PreferenceL

// Get preference for a key

//

//

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

TInt WidgetPreferences::preferenceL( const TDesC& akey, HBufC*& avalue)

{

    TInt rSuccess = KErrNotFound;

    TInt size = 0;

    if ( !m_basepath || (m_basepath->Length() <= 0) )

        return rSuccess;

    if ( akey.Length() <= KMaxKeyValueSize ) {

        HBufC* k = HBufC::NewLC( akey.Length() + KMaxIntLength + 1 );

        k->Des().Format( KKeyFormat, m_widgetid, &akey );

        PrefElement* pref = m_preferences->Find( *k );

        if ( !pref ) {

            CleanupStack::PopAndDestroy( k );

            return rSuccess;

        }

        size = pref->valueSize();            

        if ( size > KMaxKeyValueSize ) {

            // return contents from temp file whose name is stored 

            // in the m_value member of m_preferences

            RFs fs;

            if ( fs.Connect() == KErrNone ) {

                CleanupClosePushL( fs );

                HBufC* filePath = HBufC::NewLC( pref->value().Length() );

                TPtr fName( filePath->Des() );

                fName.Append( pref->value() );

                RFileReadStream readStream;

                if ( readStream.Open( fs, *filePath, EFileRead ) == KErrNone ) {

                    CleanupClosePushL( readStream );

                    TInt len( readStream.ReadInt32L() );

                    if ( len > 0 ) {                                       

                        HBufC* v = HBufC::NewLC( len );

                        TPtr ptrvalue = v->Des();

                        readStream.ReadL( ptrvalue, len );    

                        avalue = v; // ownership xfered

                        CleanupStack::Pop( v );

                        rSuccess = KErrNone;

                    }     

                    CleanupStack::PopAndDestroy();//readStream

                }   

                CleanupStack::PopAndDestroy( 2 ); //filePath,fs

            }

        }        

        else if ( size >= 0 ) {

            avalue = pref->value().AllocL();

            rSuccess = KErrNone;

        }

        CleanupStack::PopAndDestroy( k );

    }

    return rSuccess;

}

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

// WidgetPreferences::SetPreferenceL

// set Preference for a key

//

//

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

void WidgetPreferences::setPreferenceL( const TDesC& akey, const TDesC& avalue)

{

    if ( !m_basepath || (m_basepath->Length() <= 0) )

        return;

    if ( akey.Length() <= KMaxKeyValueSize ) {

        HBufC* k = HBufC::NewLC( akey.Length() + KMaxIntLength + 1 );

        k->Des().Format( KKeyFormat, m_widgetid, &akey );

        // if hash has the key and its value

        // delete the old value later when the new value was successfully updated

        PrefElement* prefExisting = NULL;

        prefExisting = m_preferences->Find( *k );                            

        if ( avalue.Length() <= KMaxKeyValueSize ) {

            PrefElement* pref = new (ELeave) PrefElement;   

            CleanupStack::PushL( pref );   

            pref->setValueL( avalue );

            pref->setValueSize( avalue.Length() );

            m_preferences->InsertL( k, pref );

            CleanupStack::Pop(); //pref   

        }

        else {

            // create a temp file and save the value in temp file. 

            // m_value member of PrefElement contains the temp file name.

            RFs fs;

            RFile file;

            if ( fs.Connect() == KErrNone ) {

                CleanupClosePushL( fs );

                // create and write to file

                TFileName tempFileName;

                file.Temp( fs, *m_basepath, tempFileName, EFileWrite|EFileShareExclusive );

                CleanupClosePushL( file );

                HBufC* filePath = HBufC::NewLC( tempFileName.Length() );

                TPtr fName( filePath->Des() );

                fName.Append( tempFileName );

                RFileWriteStream writeStream( file );

                CleanupClosePushL( writeStream );        

                TRAPD( err, 

                    writeStream.WriteInt32L( avalue.Length() );

                    writeStream.WriteL( avalue );             

                    writeStream.CommitL(); );

                // If an error occured while writing to the file, delete the temp file

                // This should be the case when disk is full

                if ( err != KErrNone )

                    {

                    CleanupStack::PopAndDestroy( ); //writeStream

                    file.Close();

                    fs.Delete( *filePath );

                    User::Leave( err );

                    }

                // create new preference element

                PrefElement* pref = new ( ELeave ) PrefElement;

                CleanupStack::PushL( pref );  

                pref->setValueSize( avalue.Length() );

                pref->setValueL( *filePath );               

                // update new preference element

                m_preferences->InsertL( k, pref );

                CleanupStack::Pop( pref );

                CleanupStack::PopAndDestroy( ); //writeStream

                CleanupStack::PopAndDestroy( 3 ); //filePath,file,fs

            }           

        }        

        // now the new value is updated, it's safe to delete the old value

        if ( prefExisting ) {

            prefExisting->setCleanFileFlag( ETrue );

            delete prefExisting;

        }

        CleanupStack::Pop();   // k

    }

}

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

// WidgetPreferences::removePreferenceL

// remove Preference for a key

//

//

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

void WidgetPreferences::removePreferenceL( const TDesC& akey, const TDesC& avalue)

{

    if ( !m_basepath || (m_basepath->Length() <= 0) )

        return;

    // double check value is NULL

    if ( avalue != KNullDesC ) {

        return;

        }

    if ( akey.Length() <= KMaxKeyValueSize ) {

        HBufC* k = HBufC::NewLC( akey.Length() + KMaxIntLength + 1 );

        k->Des().Format( KKeyFormat, m_widgetid, &akey );

        // if hash has the key and its value

        // delete the old value later when the new value was successfully updated

        PrefElement* prefExisting = NULL;

        prefExisting = m_preferences->Find( *k );                            

        m_preferences->Remove(k);

        // now the new value is updated, it's safe to delete the old value

        if ( prefExisting ) {

            prefExisting->setCleanFileFlag( ETrue );

            delete prefExisting;

        }

        CleanupStack::PopAndDestroy();   // k

        // Save update to persistent storage

    }

}

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

// WidgetPreferences::SaveL

// SAve preferences to persistent storage

//

//

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

void WidgetPreferences::saveL()

{

    if ( !m_basepath || (m_basepath->Length() <= 0) )

        return;

    RFs fs;

            }

}

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

// WidgetPreferences::LoadL

// Load preferences from persistent storage

//

//

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

void WidgetPreferences::loadL()

{

    RFs fs;

    }

}

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

// PrefElement::PrefElement

// C++ constructor

//

//

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

PrefElement::PrefElement() : m_value (0), m_valuesize (0), m_cleanFileFlag (EFalse)

{

}

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

// PrefElement::~PrefElement

// Destructor

//

//

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

PrefElement::~PrefElement()

{

    // When we update the existing key with newer value:

    // if the value > 4k, which means a file was created to store the value;

    // we need to delete the old file.

    // If called from ~Preferences(), we shouldn't do this -- cleanFileFlag is false

    if ( m_cleanFileFlag && m_valuesize > KMaxKeyValueSize ) {

        HBufC* filePathExisting = HBufC::NewLC( value().Length() );

        TPtr fName( filePathExisting->Des() );

        fName.Append( value() );

        RFs fs;

        if ( fs.Connect() == KErrNone ) {

            fs.Delete(*filePathExisting);

            fs.Close();

        }              

        CleanupStack::PopAndDestroy(); //filePathExisting

    }

    delete m_value;

}

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

// PrefElement::setValueL

// set value for a preference

//

//

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

void PrefElement::setValueL( const TDesC& value )

{

    if ( m_value ) {

        delete m_value;

    }

    m_value  = value.AllocL();

}