class Gem::Specification

def dependencies_to_gemfile(dependencies, group = nil)
  gemfile = String.new
  if dependencies.any?
    gemfile << "group :#{group} do\n" if group
    dependencies.each do |dependency|
      gemfile << "  " if group
      gemfile << %(gem "#{dependency.name}")
      req = dependency.requirements_list.first
      gemfile << %(, "#{req}") if req
      gemfile << "\n"
    end
    gemfile << "end\n" if group
  end
  gemfile
end

def extension_dir
  @bundler_extension_dir ||= if source.respond_to?(:extension_dir_name)
    unique_extension_dir = [source.extension_dir_name, File.basename(full_gem_path)].uniq.join("-")
    File.expand_path(File.join(extensions_dir, unique_extension_dir))
  else
    rg_extension_dir
  end
end

def full_gem_path
  # this cannot check source.is_a?(Bundler::Plugin::API::Source)
  # because that _could_ trip the autoload, and if there are unresolved
  # gems at that time, this method could be called inside another require,
  # thus raising with that constant being undefined. Better to check a method
  if source.respond_to?(:path) || (source.respond_to?(:bundler_plugin_api_source?) && source.bundler_plugin_api_source?)
    Pathname.new(loaded_from).dirname.expand_path(source.root).to_s.tap{|x| x.untaint if RUBY_VERSION < "2.7" }
  else
    rg_full_gem_path
  end
end

def gem_dir
  full_gem_path
end

def git_version
  return unless loaded_from && source.is_a?(Bundler::Source::Git)
  " #{source.revision[0..6]}"
end

def groups
  @groups ||= []
end

def load_paths
  full_require_paths
end

def loaded_from
  if relative_loaded_from
    source.path.join(relative_loaded_from).to_s
  else
    rg_loaded_from
  end
end

def nondevelopment_dependencies
  dependencies - development_dependencies
end

def source
  (defined?(@source) && @source) || Gem::Source::Installed.new
end

def to_gemfile(path = nil)
  gemfile = String.new("source 'https://rubygems.org'\n")
  gemfile << dependencies_to_gemfile(nondevelopment_dependencies)
  unless development_dependencies.empty?
    gemfile << "\n"
    gemfile << dependencies_to_gemfile(development_dependencies, :development)
  end
  gemfile
end