/*
** Copyright (C) 2020 Dirk-Jan C. Binnema <djcb@djcbsoftware.nl>
**
** 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, 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, write to the Free Software Foundation,
** Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
**
*/

#ifndef MU_SCANNER_HH__
#define MU_SCANNER_HH__

#include <functional>
#include <memory>

#include <dirent.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

namespace Mu {

/// @brief Maildir scanner
///
/// Scans maildir (trees) recursively, and calls the Handler callback for
/// directories & files.
///
/// It filters out (i.e., does call the handler for):
///  - files starting with '.'
///  - files that do not live in a cur / new leaf maildir
///  - directories '.' and '..'
///
class Scanner {
public:
        enum struct HandleType {
                File,
                EnterNewCur, /* cur/ or new/ */
                EnterDir, /* some other directory */
                LeaveDir
        };

        /// Prototype for a handler function
        using Handler     = std::function<bool(const std::string& fullpath,
                                               struct stat* statbuf,
                                               HandleType htype)>;
        /**
         * Construct a scanner object for scanning a directory, recursively.
         *
         * If handler is a directory
         *
         *
         * @param root_dir root dir to start scanning
         * @param handler handler function for some direntry
         */
        Scanner (const std::string& root_dir, Handler handler);

        /**
         * DTOR
         */
        ~Scanner();

        /**
         * Start the scan; this is a blocking call than runs until
         * finished or (from another thread) stop() is called.
         *
         * @return true if starting worked; false otherwise
         */
        bool start();

        /**
         * Stop the scan
         *
         * @return true if stopping worked; false otherwi%sse
         */
        bool stop();

        /**
         * Is a scan currently running?
         *
         * @return true or false
         */
        bool is_running() const;

private:
        struct                          Private;
        std::unique_ptr<Private>        priv_;
};

} // namespace Mu

#endif /* MU_SCANNER_HH__ */
