/****************************************************************************

**

** Copyright (C) 2008-2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (developer.feedback@nokia.com)

**

** This file is part of the HbCore module of the UI Extensions for Mobile.

**

** GNU Lesser General Public License Usage

** This file may be used under the terms of the GNU Lesser General Public

** License version 2.1 as published by the Free Software Foundation and

** appearing in the file LICENSE.LGPL included in the packaging of this file.

** Please review the following information to ensure the GNU Lesser General

** Public License version 2.1 requirements will be met:

** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at developer.feedback@nokia.com.

**

****************************************************************************/

#include <QDebug>

#include "hbthemeindex_p.h"

#ifndef HB_BOOTSTRAPPED

#include "hbthemeclient_p.h"

#endif // HB_BOOTSTRAPPED

// Class HbThemeIndex has the logic of handling different versions of

// the theme index file formats.

HbThemeIndex::HbThemeIndex(const char *baseAddress) :

    mBaseAddress(baseAddress),

    mCount(0),

    mItemArray(0),

    mStringAreaStart(0)

{

}

HbThemeIndex::~HbThemeIndex()

{

}

int HbThemeIndex::itemCount()

{

    if (!mCount) {

        //int version = *(reinterpret_cast<const int *>(mBaseAddress));

        // Assumes version 1 for now

        const HbThemeIndexHeaderV1 *header = reinterpret_cast<const HbThemeIndexHeaderV1 *>(mBaseAddress);

        mCount = header->count;

    }

    return mCount;

}

const HbThemeIndexItem *HbThemeIndex::itemArray()

{

    if (!mItemArray) {

        // Assumes version 1 for now

        mItemArray = reinterpret_cast<const HbThemeIndexItem *>(mBaseAddress + sizeof(HbThemeIndexHeaderV1));

    }

    return mItemArray;

}

const char *HbThemeIndex::stringAreaStart()

{

    if (!mStringAreaStart) {

        // Assumes version 1 for now

        mStringAreaStart = mBaseAddress + sizeof(HbThemeIndexHeaderV1) + itemCount() * sizeof(HbThemeIndexItem);

    }

    return mStringAreaStart;

}

const HbThemeIndexItem *binaryFind(const QString &itemName, const char* themeIndexBase, const HbThemeIndexItem *itemArray, int count)

{

    int begin = 0;

    int end = count - 1;

    // binary search

    while (begin <= end) {

        int mid = begin + (end-begin)/2;

        // Fast string comparison, no unnecessary mem copy

        int comparison = itemName.compare(QLatin1String(themeIndexBase + itemArray[mid].iconnameOffset));

        // If the item was found, we're done.

        if (!comparison) {

            return &itemArray[mid];

        }

        // Is the target in lower or upper half?

        else if (comparison < 0) {

            end = mid - 1;

        } else {

            begin = mid + 1;

        }

    }   

    // Did not find the target, return 0.

    return 0;

}

/**

* Returns true if the current theme has a valid theme index included in it.

*/

bool ThemeIndexTables::isValid()

{

#ifndef HB_BOOTSTRAPPED

    // Retrieve tables from server if not done yet

    if (!tablesRetrieved) {

        HbThemeClient::global()->getThemeIndexTables(*this);

        tablesRetrieved = true;

#ifdef THEME_INDEX_TRACES

        qDebug() << "ThemeIndex: retrieved index tables, table[0] =" << tables[0] << "table[1] =" << tables[1];

#endif // THEME_INDEX_TRACES

    }

#endif // HB_BOOTSTRAPPED

    return tables[0] >= 0;

}

const HbThemeIndexItem *ThemeIndexTables::getItem(const QString &itemName, int &tableIndex)

{

    if (isValid()) {

        // Check the current theme index and its parents 

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

            int usedTable = tables[i];

            if (usedTable < 0) {

                break;

            }

            const char *baseAddress = reinterpret_cast<const char *>(usedTable);

            HbThemeIndex index(baseAddress);

            // Check the table

            int count = index.itemCount();

            const HbThemeIndexItem *itemArray = index.itemArray();

            // Get the correct item from the table using binary find

            const HbThemeIndexItem *item = binaryFind(itemName, baseAddress, itemArray, count);

            if (item) {

                tableIndex = i;

#ifdef THEME_INDEX_TRACES

                qDebug() << "ThemeIndex: Returned item for" << itemName.toUtf8() << "from table" << tableIndex;

#endif

                return item;

            }

        }

    }

    return 0;

}