module Pairtree
  class Obj < ::Dir
    FILE_METHODS = [:atime, :open, :read, :file?, :directory?, :exist?, :exists?, :file?, :ftype, :lstat,
      :mtime, :readable?, :size, :stat, :truncate, :writable?, :zero?]
    FILE_METHODS.each do |file_method|
      define_method file_method do |fname, *args, &block|
        File.send(file_method, File.join(path, fname), *args, &block)
      end
    end

    def delete *args
      File.delete(*prepend_filenames(args))
    end
    alias_method :unlink, :delete

    def link *args
      File.link(*prepend_filenames(args))
    end

    def rename *args
      File.rename(*prepend_filenames(args))
    end

    def utime atime, mtime, *args
      File.utime(atime, mtime, *prepend_filenames(args))
    end

    def entries
      super - [".", ".."]
    end

    def each &block
      super { |entry| yield(entry) unless /^\.{1,2}$/.match?(entry) }
    end

    def glob(string, flags = 0)
      result = Dir.glob(File.join(path, string), flags) - [".", ".."]
      result.collect { |f| f.sub(%r{^#{path}/}, "") }
    end

    def [](string)
      glob(string, 0)
    end

    private

    def prepend_filenames(files)
      files.collect { |fname| File.join(path, fname) }
    end
  end
end