/*
* 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 <S32FILE.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)
{
    m_preferences = new RPtrHashMap<TDesC,PrefElement>();    
}

// ----------------------------------------------------------------------------
// WidgetPreferences::~WidgetPreferences
// Destructor
//
//
// ----------------------------------------------------------------------------
WidgetPreferences::~WidgetPreferences()
{
    TRAP_IGNORE( saveL() );
    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
    }
}

// ----------------------------------------------------------------------------
// WidgetPreferences::SaveL
// SAve preferences to persistent storage
//
//
// ----------------------------------------------------------------------------
void WidgetPreferences::saveL()
{
    if ( !m_basepath || (m_basepath->Length() <= 0) )
        return;

    RFs fs;

    if ( fs.Connect() == KErrNone ) {
        
        CleanupClosePushL( fs );
        HBufC* filePath = HBufC::NewLC( m_basepath->Length() + KPrefsFile().Length() );

        TPtr fName( filePath->Des() );
        fName.Append( *m_basepath );
        fName.Append( KPrefsFile );

        RFileWriteStream writeStream;
        TInt fileerror = writeStream.Replace( fs, *filePath, EFileWrite );

        if ( fileerror != KErrNone ) {
            fs.CreatePrivatePath( EDriveC );
            fileerror = writeStream.Create( fs, *filePath, EFileWrite|EFileShareExclusive );
        }

        if ( fileerror == KErrNone ) {
            CleanupClosePushL( writeStream );
            writeStream.WriteInt32L( m_preferences->Count() );
            
            TPtrHashMapIter<TDesC,PrefElement> it( *m_preferences );
            const TDesC* key;
            const PrefElement* pref;

            while ( ( key = it.NextKey() ) != 0 ) {
                pref = it.CurrentValue();
                writeStream.WriteInt32L( key->Length() );
                writeStream.WriteL( *key );
                writeStream.WriteInt32L( pref->value().Length() );
                writeStream.WriteL( pref->value() );
                writeStream.WriteInt32L( pref->valueSize() );
            }

            writeStream.CommitL();
            CleanupStack::PopAndDestroy(); //writeStream
        }

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

}

// ----------------------------------------------------------------------------
// WidgetPreferences::LoadL
// Load preferences from persistent storage
//
//
// ----------------------------------------------------------------------------
void WidgetPreferences::loadL()
{
    RFs fs;
    if ( !m_basepath || (m_basepath->Length() <= 0) )
        return;

    if ( fs.Connect() == KErrNone ) {
        CleanupClosePushL( fs );
        HBufC* filePath = HBufC::NewLC( m_basepath->Length() + KPrefsFile().Length() );

        TPtr fName( filePath->Des() );
        fName.Append( *m_basepath );
        fName.Append( KPrefsFile );

        RFileReadStream readStream;

        if ( readStream.Open( fs, *filePath, EFileRead ) == KErrNone ) {
            CleanupClosePushL( readStream );
            TInt count( readStream.ReadInt32L() );

            for( TInt i = 0; i < count; i++ ) {
                TInt len = readStream.ReadInt32L();

                if ( len > 0 ) {
                    HBufC* key = HBufC::NewLC( len );
                    TPtr ptrkey = key->Des();
                    readStream.ReadL( ptrkey, len );
                    len = readStream.ReadInt32L();

                    if ( len <= KMaxKeyValueSize ) {
                        HBufC* value = HBufC::NewLC( len );
                        TPtr ptrvalue = value->Des();
                        readStream.ReadL( ptrvalue, len );
                        PrefElement* pref = new ( ELeave ) PrefElement;
                        CleanupStack::PushL( pref );
                        pref->setValueL( ptrvalue );
                        TInt size = readStream.ReadInt32L();
                        pref->setValueSize( size );
                        m_preferences->InsertL( key, pref );
                        CleanupStack::Pop(); //pref 
                        CleanupStack::PopAndDestroy(); //value
                        CleanupStack::Pop(); //key
                    }
                    else {
                        CleanupStack::PopAndDestroy( key );
                    }
                }
                else {
                    break;
                }
            }

            CleanupStack::PopAndDestroy(); //readStream
        }

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


