/*************************************************************************
 *  Copyright (C) 2010 by Volker Lanz <vl@fidra.de>                      *
 *                                                                       *
 *  This program is free software; you can redistribute it and/or        *
 *  modify it under the terms of the GNU General Public License as       *
 *  published by the Free Software Foundation; either version 3 of       *
 *  the License, or (at your option) any later version.                  *
 *                                                                       *
 *  This program is distributed in the hope that it will be useful,      *
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of       *
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        *
 *  GNU General Public License for more details.                         *
 *                                                                       *
 *  You should have received a copy of the GNU General Public License    *
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.*
 *************************************************************************/

#if !defined(COREBACKEND__H)

#define COREBACKEND__H

#include "../util/libpartitionmanagerexport.h"

#include <QObject>
#include <QList>

class CoreBackendManager;
class CoreBackendDevice;
class Device;
class PartitionTable;

class QString;

/**
  * Interface class for backend plugins.
  * @author Volker Lanz <vl@fidra.de>
  */

class LIBKPMCORE_EXPORT CoreBackend : public QObject
{
	Q_OBJECT
	Q_DISABLE_COPY(CoreBackend)

	friend class CoreBackendManager;

	protected:
		CoreBackend();
		virtual ~CoreBackend();

	Q_SIGNALS:
		/**
		 * Emitted to inform about progress of any kind.
		  * @param i the progress in percent (from 0 to 100)
		 */
		void progress(int i);

		/**
		  * Emitted to inform about scan progress.
		  * @param device_node the device being scanned just now (e.g. "/dev/sda")
		  * @param i the progress in percent (from 0 to 100)
		  */
		void scanProgress(const QString& device_node, int i);

	public:
        /**
          * Return the plugin's unique Id from JSON metadata
          * @return the plugin's unique Id from JSON metadata
          */
        QString id() { return m_id; }

        /**
          * Return the plugin's version from JSON metadata
          * @return the plugin's version from JSON metadata
          */
        QString version() { return m_version; }

		/**
		  * Initialize the plugin's FileSystem support
		  */
		virtual void initFSSupport() = 0;

		/**
		  * Scan for devices in the system.
		  * @return a QList of pointers to Device instances. The caller is responsible
		  *         for deleting these objects.
		  */
		virtual QList<Device*> scanDevices() = 0;

		/**
		  * Scan a single device in the system.
		  * @param device_node The path to the device that is to be scanned (e.g. /dev/sda)
		  * @return a pointer to a Device instance. The caller is responsible for deleting
		  *         this object.
		  */
		virtual Device* scanDevice(const QString& device_node) = 0;

		/**
		  * Open a device for reading.
		  * @param device_node The path of the device that is to be opened (e.g. /dev/sda)
		  * @return a pointer to a CoreBackendDevice or NULL if the open failed. If a pointer to
		  *         an instance is returned, it's the caller's responsibility to delete the
		  *         object.
		  */
		virtual CoreBackendDevice* openDevice(const QString& device_node) = 0;

		/**
		  * Open a device in exclusive mode for writing.
		  * @param device_node The path of the device that is to be opened (e.g. /dev/sda)
		  * @return a pointer to a CoreBackendDevice or NULL if the open failed. If a pointer to
		  *         an instance is returned, it's the caller's responsibility to delete the
		  *         object.
		  */
		virtual CoreBackendDevice* openDeviceExclusive(const QString& device_node) = 0;

		/**
		  * Close a CoreBackendDevice that has previously been opened.
		  * @param core_device Pointer to the CoreBackendDevice to be closed. Must not be NULL.
		  * @return true if closing the CoreBackendDevice succeeded, otherwise false.
		  *
		  * This method does not delete the object.
		  */
		virtual bool closeDevice(CoreBackendDevice* core_device) = 0;

		/**
		  * Emit progress.
		  * @param i the progress in percent (from 0 to 100)
		  * This is used to emit a progress() signal from somewhere deep inside the plugin
		  * backend code if that is ever necessary.
		  */
		virtual void emitProgress(int i);

		/**
		  * Emit scan progress.
		  * @param device_node the path to the device just being scanned (e.g. /dev/sda)
		  * @param i the progress in percent (from 0 to 100)
		  * This is used to emit a scanProgress() signal from the backend device scanning
		  * code.
		  */
		virtual void emitScanProgress(const QString& device_node, int i);

	protected:
		static void setPartitionTableForDevice(Device& d, PartitionTable* p);
		static void setPartitionTableMaxPrimaries(PartitionTable& p, qint32 max_primaries);

    private:
        void setId(const QString& id) { m_id = id; }
        void setVersion(const QString& version) { m_version = version; }

	private:
        QString m_id, m_version;

		class CoreBackendPrivate;
		CoreBackendPrivate* d;
};

#endif