module Metafiles
  # https://github.com/github/markup#markups
  EXTENSIONS = Set.new %w[
    .adoc .asc .asciidoc .creole .html .markdown .md .mdown .mediawiki .mkdn
    .org .pod .rdoc .rst .rtf .textile .txt .wiki
  ].freeze
  BASENAMES = Set.new %w[
    about authors changelog changes copying copyright history license licence
    news notes notice readme todo
  ].freeze

  module_function

  def list?(file)
    return false if %w[.DS_Store INSTALL_RECEIPT.json].include?(file)
    !copy?(file)
  end

  def copy?(file)
    file = file.downcase
    ext  = File.extname(file)
    file = File.basename(file, ext) if EXTENSIONS.include?(ext)
    BASENAMES.include?(file)
  end
end