module CarrierWave
  module Compatibility

    ##
    # Mix this module into an Uploader to make it mimic Paperclip's storage paths
    # This will make your Uploader use the same default storage path as paperclip
    # does. If you need to override it, you can override the +paperclip_path+ method
    # and provide a Paperclip style path:
    #
    #     class MyUploader < CarrierWave::Uploader::Base
    #       include CarrierWave::Compatibility::Paperclip
    #       
    #       def paperclip_path
    #         ":rails_root/public/uploads/:id/:attachment/:style_:basename.:extension"
    #       end
    #     end
    #
    # ---
    #
    # This file contains code taken from Paperclip
    # 
    # LICENSE
    # 
    # The MIT License
    # 
    # Copyright (c) 2008 Jon Yurek and thoughtbot, inc.
    # 
    # Permission is hereby granted, free of charge, to any person obtaining a copy
    # of this software and associated documentation files (the "Software"), to deal
    # in the Software without restriction, including without limitation the rights
    # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    # copies of the Software, and to permit persons to whom the Software is
    # furnished to do so, subject to the following conditions:
    # 
    # The above copyright notice and this permission notice shall be included in
    # all copies or substantial portions of the Software.
    # 
    # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    # THE SOFTWARE.
    #
    module Paperclip

      def store_path(for_file=filename)
        path = paperclip_path
        path ||= File.join(*[store_dir, paperclip_style.to_s, for_file].compact)
        interpolate_paperclip_path(path, for_file)
      end

      def store_dir
        ":rails_root/public/system/:attachment/:id"
      end

      def paperclip_default_style
        :original
      end

      def paperclip_path
      end

      def paperclip_style
        version_name || paperclip_default_style
      end

    private

      def interpolate_paperclip_path(path, filename)
        mappings.inject(path) do |agg, pair|
          agg.gsub(":#{pair[0]}", pair[1].call(self, filename).to_s)
        end
      end

      def mappings
        {
          :rails_root   => lambda{|u, f| CarrierWave.config[:root] },
          :rails_env    => lambda{|u, f| CarrierWave.config[:env] },
          :class        => lambda{|u, f| u.model.class.name.underscore.pluralize},
          :id           => lambda{|u, f| u.model.id },
          :id_partition => lambda{|u, f| ("%09d" % u.model.id).scan(/\d{3}/).join("/")},
          :attachment   => lambda{|u, f| u.mounted_as.to_s.downcase.pluralize },
          :style        => lambda{|u, f| u.paperclip_style },
          :basename     => lambda{|u, f| f.gsub(/#{File.extname(f)}$/, "") },
          :extension    => lambda{|u, f| File.extname(f).gsub(/^\.+/, "")}
        }
      end

    end # Paperclip
  end # Compatibility
end # CarrierWave