/*

* Copyright (c) 2009 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:

*

*/

#ifndef  CXESETTINGSCENREPSTORE_H_

#define  CXESETTINGSCENREPSTORE_H_

//  Include Files

#include <QHash>

#include <QVariant>

#include <QMetaType>

#include "cxeerror.h"

#include "cxenamespace.h"

#include "xqsettingsmanager.h"

// forward declarations

class XQSettingsManager;

class XQSettingsKey;

/*

* Settings store intrerface.

*/

class CxeSettingsStore

{

public:

    /**

    * This needs to be here to be able to delete an object

    * of inherited class through mixin pointer.

    * If this is not defined, deleting through the mixin pointer

    * results in User-42 panic!

    */

    virtual ~CxeSettingsStore() {};

    /*

    * resets the cenrep store

    */

    virtual void reset() = 0;

    /*

    * Reads a value from cenrep

    * @param "key"   - setting key

    * @param "value" - setting value read from cenrep

    */

	virtual CxeError::Id get(const QString& key, QVariant &value) = 0;

    /*

    * Reads a value from cenrep

    * @param "uid"   - UID of the component that own setting key

    * @param "key"   - setting key id

    * @param "type"  - type of setting key

    * @param "value" - setting value read from cenrep

    */

	virtual void get(long int uid, unsigned long int key, Cxe::SettingKeyType type, QVariant &value) = 0;

	/*

    * Sets a new value to cenrep

    * @param "key"   - setting key

    * @param "newValue" - new value set to the key in cenrep

    */

	virtual CxeError::Id set(const QString& key,const QVariant newValue) = 0;

	/*

    * Reads/loads all run-time settings values from cenrep

    * @param QList<QString> contains list of all runtime key ids which we use to load values from cenrep.

    * returns: QHash container, "contains" values associated with each key that are read from cenrep

    * NOTE: loading runtime settings should be done only ONCE at start-up. Its an overhead to read runtime keys

    *       unnecessarily multiple times as the values of the runtime keys are not changed.

    *       Runtime keys are only used to configure camerax application.

    */

	virtual QHash<QString, QVariantList> loadRuntimeSettings(QList<QString>& settingKeys) = 0;

};

/*

* CxeSettingsCenRepStore class implements CxeSettingsStore.

* This class uses CenRep key mechanism for storing and retrieving settings information.

*/

class CxeSettingsCenRepStore : public QObject,

                               public CxeSettingsStore

{

    Q_OBJECT

public:

    CxeSettingsCenRepStore();

	~CxeSettingsCenRepStore();

public: // from base class

    /*

    * resets the cenrep store

    */

    void reset();

    /*

    * Reads a value from cenrep

    * @param "key"   - setting key

    * @param "value" - setting value read from cenrep

    */

	CxeError::Id get(const QString& key, QVariant &value);

    /*

    * Reads a value from cenrep

    * @param "uid"   - UID of the component that own setting key

    * @param "key"   - setting key id

    * @param "type"  - type of setting key

    * @param "value" - setting value read from cenrep

    */

    void get(long int uid, unsigned long int key, Cxe::SettingKeyType type, QVariant &value);

	/*

    * Sets a new value to cenrep

    * @param "key"   - setting key

    * @param "newValue" - new value set to the key in cenrep

    */

	CxeError::Id set(const QString& key,const QVariant newValue);

	/*

    * Reads/loads all run-time settings values from cenrep

    * @param QList<QString> contains list of all runtime key ids which we use to load values from cenrep.

    * returns: QHash container, "contains" values associated with each key that are read from cenrep

    * NOTE: loading runtime settings should be done only ONCE at start-up. Its an overhead to read runtime keys

    *       unnecessarily multiple times as the values of the runtime keys are not changed.

    *       Runtime keys are only used to configure camerax application.

    */

	QHash<QString, QVariantList> loadRuntimeSettings(QList<QString>& settingKeys);

signals:

    void settingValueChanged(long int uid, unsigned long int key, QVariant value);

private slots:

    void handleValueChanged(XQSettingsKey key, QVariant value);

private:

    class CxeCenRepDefinition

    {

    public:

        long int mRepositoryUid;            //! UID of the all the setting keys

        unsigned long int mKeyId;           //! key cenrep id

        bool mReadOnly;                     //! if the key holds data that is read-only

        XQSettingsManager::Type mDataType;  //! type of data that cenrep key holds

    };

private:

    /*

     *  add's key mapping to the hash container.

     */

    void addKeyMapping(QString key,

                       unsigned long int keyid,

                       XQSettingsManager::Type type,

                       bool readOnly = false);

    /*

    * Generates XQSettingsKey from given setting/runtime key

    */

    XQSettingsKey generateXQSettingsKey(const QString& key,CxeError::Id& error);

    /*

    * maps "string" type setting key ids to cenrep key ids that XQSettingsManager understands

    */

	void mapKeys();

protected:

    const QHash<QString, CxeCenRepDefinition>& keyMapping() const;

private: // data

    XQSettingsManager* mSettingsManager;

	QHash<QString, CxeCenRepDefinition> mKeyMapping;

};

/*

 * Settings store that reads key values from cenrep and keeps

 * cached copies of them in memory. Doesn't write anything back

 * to cenrep.

 */

class CxeSettingsLocalStore : public CxeSettingsCenRepStore

{

  Q_OBJECT

public:

     CxeSettingsLocalStore();

     ~CxeSettingsLocalStore();

     /*

     * Reads a value from local store.

     * @param "key"   - setting key

     * @param "value" - setting value read from cenrep

     */

     CxeError::Id get(const QString& key, QVariant &value);

     /*

     * Sets a new value to local store

     * @param "key"   - setting key

     * @param "newValue" - new value set to the key in cenrep

     */

     CxeError::Id set(const QString& key, const QVariant newValue);

private:

     bool useValueFromCenrep(const QString &key) const;

     QHash<QString, QVariant> mSettings;

};

#endif  // CXESETTINGSCENREPSTORE_H_