#
# Ronin Exploits - A Ruby library for Ronin that provides exploitation and
# payload crafting functionality.
#
# Copyright (c) 2007-2009 Hal Brodigan (postmodern.mod3 at gmail.com)
#
# 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 2 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, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#

module Ronin
  module Controls
    module FileSystem
      #
      # The current working directory, all file-system actions will
      # be performed relative to.
      #
      # @return [String]
      #   The current working directory.
      #
      # @since 0.3.0
      #
      def cwd
        @cwd ||= ''
      end

      #
      # Changes the current working directory.
      #
      # @param [String] path
      #   The new current working directory.
      #
      # @return [String]
      #   The new current working directory.
      #
      # @since 0.3.0
      #
      def chdir(path)
        @cwd = path
      end

      #
      # Goes up one directory.
      #
      # @return [String]
      #   The new current working directory.
      #
      # @since 0.3.0
      #
      def updir!
        chdir(join_paths(cwd,'..'))
      end

      protected

      #
      # @return [String]
      #   The File name separator to use.
      #
      # @since 0.3.0
      #
      def path_separator
        File::SEPARATOR
      end

      #
      # Joins multiple paths with the path_separator.
      #
      # @param [Array] paths
      #   The paths to be joined.
      #
      # @return [String]
      #   The joined paths.
      #
      # @since 0.3.0
      #
      def join_paths(*paths)
        paths.join(path_separator)
      end

      #
      # Expands a path into it's absolute form.
      #
      # @param [String] path
      #   The path to be expanded.
      #
      # @return [String]
      #   The expanded path.
      #
      # @since 0.3.0
      #
      def expand_path(path)
        File.expand_path(path)
      end

      #
      # Converts a sub-path to an absolute path, but only if it is a
      # realitive path.
      #
      # @param [String] sub_path
      #   The sub-path to expand.
      #
      # @return [String]
      #   An absolute path.
      #
      # @since 0.3.0
      #
      def absolute_path(sub_path)
        if sub_path[0..0] == path_separator
          return sub_path
        else
          return expand_path(join_paths(cwd,sub_path))
        end
      end

      #
      # Specifies that the path could not be found.
      #
      # @param [String] path
      #   The path which could not be found.
      #
      # @raise [Errno::ENOENT]
      #   The file could not be found.
      #
      # @since 0.3.0
      #
      def file_not_found!(path)
        path = path.to_s

        raise(Errno::ENOENT,"No such file or directory - #{path.dump}",caller)
      end
    end
  end
end