/**
 * @file Common/config.h
 * @brief eVaf configuration interface implementation
 * @author Enar Vaikene
 *
 * Copyright (c) 2011-2019 Enar Vaikene
 *
 * This file is part of the eVaf C++ cross-platform application development framework.
 *
 * This file can be used under the terms of the GNU General Public License
 * version 3.0 as published by the Free Software Foundation and appearing in
 * the file LICENSE included in the packaging of this file. Please review the
 * the following information to ensure the GNU General Public License version
 * 3.0 requirements will be met: http://www.gnu.org/copyleft/gpl.html.
 *
 * Alternatively, this file may be used in accordance with the Commercial License
 * Agreement provided with the Software.
 */

#ifndef __COMMON_CONFIG_H
#  define __COMMON_CONFIG_H

#include "iconfig.h"

#include <QObject>
#include <QString>
#include <QVariant>
#include <QHash>
#include <QQueue>

namespace eVaf {
namespace Common {
    class IniFile;
namespace Internal {

/**
 * Structure for queued write operations
 */
struct NameValuePair
{
    NameValuePair(QString const & n, QVariant const & v)
        : name(n)
        , value(v)
    {}

    QString name;
    QVariant value;
};

/**
 * Default implementation of the iConfig interface.
 *
 * This class implements the iConfig interface using INI files in the eVaf::Common::iApp::instance()->etcDir() directory.
 */
class Config : public iConfig
{
    Q_OBJECT

public:

    /**
     * Destroys the iConfig interface instance.
     */
    static void destroyInstance();

    Config();

    virtual ~Config();

    /**
     * Returns the current implementation of the iConfig interface
     */
    iConfig * _interface() const;

    /**
     * Initializes the iConfig interface implementation.
     * @return True if succeeded; false if not
     */
    bool init();

    /**
     * Finalizes the iConfig interface implementation.
     */
    void done();

    /*
        iConfig interface
    */

    virtual QVariant getValue(QString const & paramName, QVariant const & defaultValue) const;

    virtual bool setValue(QString const & paramName, QVariant const & value, bool commit);


private: // Members

    /// List of already opened INI files
    mutable QHash<QString, IniFile *> mIniFiles;

    /// Commit queue
    QQueue<NameValuePair> mCommitQueue;


private: // Methods

    /// Commits queued parameters
    bool commitValues();

    /// Writes a parameter value to the INI file
    bool writeValue(QString const & paramName, QVariant const & value);

    /// Writes a name/value pair to the INI file
    inline bool writeValue(NameValuePair const & param)
    {
        return writeValue(param.name, param.value);
    }

};

} // namespace eVaf::Common::Internal
} // namespace eVaf::Common
} // namespace eVaf

#endif // config.h