/*
    open source routing machine
    Copyright (C) Dennis Luxen, others 2010

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU AFFERO General Public License as published by
the Free Software Foundation; either version 3 of the License, or
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 Affero General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
or see http://www.gnu.org/licenses/agpl.txt.


Custom validators for use with boost::program_options.
*/

#include <boost/program_options.hpp>

namespace boost {
    namespace program_options {
        // Class for reporting missing files
        class missing_file_error : public boost::program_options::invalid_option_value {
        public:
            missing_file_error(const std::string& path) : invalid_option_value(path), path(path) {};
            ~missing_file_error() throw() {};
            const char* what() const throw() {
                std::string err = get_option_name() + " file not found: " + path;
                return err.c_str();
            };
        protected:
            std::string path;
        };
    }

    namespace filesystem {
        // Validator for boost::filesystem::path, that verifies that the file exists.
        // The validate() function must be defined in the same namespace as the target type,
        // (boost::filesystem::path in this case), otherwise it will not be called
        void validate(boost::any& v, const std::vector<std::string>& values, boost::filesystem::path*, int) {
            boost::program_options::validators::check_first_occurrence(v);  // avoid previous assignments
            const std::string& input_string = boost::program_options::validators::get_single_string(values); // avoid multiple assignments
            if(boost::filesystem::is_regular_file(input_string)) {
                v = boost::any(boost::filesystem::path(input_string));
            } else {
                throw boost::program_options::missing_file_error(input_string);
            }
        }
    }
}