module ActiveSupport
  module Cache
    class FileStore < Store
      attr_reader :cache_path

      def initialize(cache_path)
        @cache_path = cache_path
      end

      def read(name, options = nil)
        super
        File.open(real_file_path(name), 'rb') { |f| f.read } rescue nil
      end

      def write(name, value, options = nil)
        super
        ensure_cache_path(File.dirname(real_file_path(name)))
        File.open(real_file_path(name), "wb+") { |f| f.write(value) }
      rescue => e
        RAILS_DEFAULT_LOGGER.error "Couldn't create cache directory: #{name} (#{e.message})" if RAILS_DEFAULT_LOGGER
      end

      def delete(name, options = nil)
        super
        File.delete(real_file_path(name))
      rescue SystemCallError => e
        # If there's no cache, then there's nothing to complain about
      end

      def delete_matched(matcher, options = nil)
        super
        search_dir(@cache_path) do |f|
          if f =~ matcher
            begin
              File.delete(f)
            rescue SystemCallError => e
              # If there's no cache, then there's nothing to complain about
            end
          end
        end
      end

      private
        def real_file_path(name)
          '%s/%s.cache' % [@cache_path, name.gsub('?', '.').gsub(':', '.')]
        end

        def ensure_cache_path(path)
          FileUtils.makedirs(path) unless File.exists?(path)
        end

        def search_dir(dir, &callback)
          Dir.foreach(dir) do |d|
            next if d == "." || d == ".."
            name = File.join(dir, d)
            if File.directory?(name)
              search_dir(name, &callback)
            else
              callback.call name
            end
          end
        end
      end
  end
end