/* This file is part of Clementine.

   Clementine 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.

   Clementine 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 Clementine.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef LIBRARYWATCHER_H
#define LIBRARYWATCHER_H

#include "directory.h"
#include "song.h"
#include "engine_fwd.h"

#include <QObject>
#include <QStringList>
#include <QMap>

#include <boost/shared_ptr.hpp>

class QFileSystemWatcher;
class QTimer;

class LibraryBackendInterface;

class LibraryWatcher : public QObject {
  Q_OBJECT

 public:
  LibraryWatcher(QObject* parent = 0);

  void SetBackend(boost::shared_ptr<LibraryBackendInterface> backend) { backend_ = backend; }
  void SetEngine(EngineBase* engine) { engine_ = engine; } // TODO: shared_ptr

 signals:
  void NewOrUpdatedSongs(const SongList& songs);
  void SongsMTimeUpdated(const SongList& songs);
  void SongsDeleted(const SongList& songs);

  void ScanStarted();
  void ScanFinished();

 public slots:
  void AddDirectories(const DirectoryList& directories);
  void RemoveDirectories(const DirectoryList& directories);

 private slots:
  void DirectoryChanged(const QString& path);
  void RescanPathsNow();
  void ScanDirectory(const QString& path);

 private:
  static bool FindSongByPath(const SongList& list, const QString& path, Song* out);
  inline static QString ExtensionPart( const QString &fileName );
  inline static QString DirectoryPart( const QString &fileName );
  static QString PickBestImage(const QStringList& images);
  static QString ImageForSong(const QString& path, QMap<QString, QStringList>& album_art);

 private:
  EngineBase* engine_;
  boost::shared_ptr<LibraryBackendInterface> backend_;

  QFileSystemWatcher* fs_watcher_;
  QTimer* rescan_timer_;

  QMap<QString, Directory> paths_watched_;
  QStringList paths_needing_rescan_;

  int total_watches_;

  #ifdef Q_OS_DARWIN
  static const int kMaxWatches = 100;
  #endif
};

// Thanks Amarok
inline QString LibraryWatcher::ExtensionPart( const QString &fileName ) {
  return fileName.contains( '.' ) ? fileName.mid( fileName.lastIndexOf('.') + 1 ).toLower() : "";
}
inline QString LibraryWatcher::DirectoryPart( const QString &fileName ) {
  return fileName.section( '/', 0, -2 );
}

#endif // LIBRARYWATCHER_H