class Jeweler::Commands::BuildGem

def self.build_for(jeweler)
  command = new
  command.base_dir = jeweler.base_dir
  command.gemspec_helper = jeweler.gemspec_helper
  command.version_helper = jeweler.version_helper
  command
end

def initialize
  self.file_utils = FileUtils
end

def run
  gemspec_helper.update_version(version_helper) unless gemspec_helper.has_version?
  gemspec = gemspec_helper.parse
  if Gem::Version.new(`gem -v`) >= Gem::Version.new('2.0.0.a')
    gem_file_name = Gem::Package.build(gemspec)
  else
    require 'rubygems/builder'
    gem_file_name = Gem::Builder.new(gemspec).build
  end
  pkg_dir = File.join(base_dir, 'pkg')
  file_utils.mkdir_p pkg_dir
  gem_file_name = File.join(base_dir, gem_file_name)
  file_utils.mv gem_file_name, pkg_dir
end