define drush::install::composer(

  $autoupdate,

  $version,

  $install_path,

  $install_type,

) {

  #private()

  if $caller_module_name != $module_name {

    warning("${name} is not part of the public API of the ${module_name} \

module and should not be directly included in the manifest.")

  }

  # If version is 'master' or a single major release number,

  # transform into something composer understands.

  $real_version = $version ? {

    /\./     => $version,

    'master' => 'dev-master',

    default  => "${version}.*",

  }

  file { $install_path:

    ensure => directory,

  }

  $base_path = dirname($install_path)

  $composer_home = "${base_path}/.composer"

  $prefer = "--prefer-${install_type}"

  $cmd = "${drush::composer_path} require drush/drush:${real_version} ${prefer}"

  exec { $cmd:

    cwd         => $install_path,

    environment => ["COMPOSER_HOME=${composer_home}"],

    require     => File[$install_path],

  }

  if ! $autoupdate {

    Exec[$cmd] { creates => "${install_path}/composer.json"}

  }

}