# @summary Manages the GPG keys that Apt uses to authenticate packages. 
#
# @note 
#   The apt::key defined type makes use of the apt_key type, but includes extra functionality to help prevent duplicate keys.
#
# @example Declare Apt key for apt.puppetlabs.com source
#   apt::key { 'puppetlabs':
#     id      => '6F6B15509CF8E59E6E469F327F438280EF8D349F',
#     server  => 'keyserver.ubuntu.com',
#     options => 'http-proxy="http://proxyuser:proxypass@example.org:3128"',
#   }
#
# @param id
#   Specifies a GPG key to authenticate Apt package signatures. Valid options: a string containing a key ID (8 or 16 hexadecimal 
#   characters, optionally prefixed with "0x") or a full key fingerprint (40 hexadecimal characters).
#
# @param ensure
#   Specifies whether the key should exist. Valid options: 'present', 'absent' or 'refreshed'. Using 'refreshed' will make keys auto
#   update when they have expired (assuming a new key exists on the key server).
#
# @param content
#   Supplies the entire GPG key. Useful in case the key can't be fetched from a remote location and using a file resource is inconvenient.
#
# @param source
#   Specifies the location of an existing GPG key file to copy. Valid options: a string containing a URL (ftp://, http://, or https://) or 
#   an absolute path.
#
# @param server
#   Specifies a keyserver to provide the GPG key. Valid options: a string containing a domain name or a full URL (http://, https://,
#   hkp:// or hkps://). The hkps:// protocol is currently only supported on Ubuntu 18.04.
#
# @param weak_ssl
#    Specifies whether strict SSL verification on a https URL should be disabled. Valid options: true or false.
#
# @param options
#   Passes additional options to `apt-key adv --keyserver-options`.
#
define apt::key (
  Pattern[/\A(0x)?[0-9a-fA-F]{8}\Z/, /\A(0x)?[0-9a-fA-F]{16}\Z/, /\A(0x)?[0-9a-fA-F]{40}\Z/] $id                        = $title,
  Enum['present', 'absent', 'refreshed'] $ensure                                                                        = present,
  Optional[String] $content                                                                                             = undef,
  Optional[Pattern[/\Ahttps?:\/\//, /\Aftp:\/\//, /\A\/\w+/]] $source                                                   = undef,
  Pattern[/\A((hkp|hkps|http|https):\/\/)?([a-z\d])([a-z\d-]{0,61}\.)+[a-z\d]+(:\d{2,5})?(\/[a-zA-Z\d\-_.]+)*\/?$/] $server = $::apt::keyserver,
  Boolean $weak_ssl                                                                                                     = false,
  Optional[String] $options                                                                                             = $::apt::key_options,
  ) {

  case $ensure {
    /^(refreshed|present)$/: {
      if defined(Anchor["apt_key ${id} absent"]){
        fail("key with id ${id} already ensured as absent")
      }

      if !defined(Anchor["apt_key ${id} present"]) {
        apt_key { $title:
          ensure   => present,
          refresh  => $ensure == 'refreshed',
          id       => $id,
          source   => $source,
          content  => $content,
          server   => $server,
          weak_ssl => $weak_ssl,
          options  => $options,
        } -> anchor { "apt_key ${id} present": }

        case $facts['os']['name'] {
          'Debian': {
            if versioncmp($facts['os']['release']['major'], '9') >= 0 {
              ensure_packages(['gnupg'])
              Apt::Key<| title == $title |>
            }
          }
          'Ubuntu': {
            if versioncmp($facts['os']['release']['full'], '17.04') >= 0 {
              ensure_packages(['gnupg'])
              Apt::Key<| title == $title |>
            }
          }
          default: { }
        }
      }
    }

    absent: {
      if defined(Anchor["apt_key ${id} present"]){
        fail("key with id ${id} already ensured as present")
      }

      if !defined(Anchor["apt_key ${id} absent"]){
        apt_key { $title:
          ensure   => $ensure,
          id       => $id,
          source   => $source,
          content  => $content,
          server   => $server,
          weak_ssl => $weak_ssl,
          options  => $options,
        } -> anchor { "apt_key ${id} absent": }
      }
    }

    default: {
      fail("Invalid \'ensure\' value \'${ensure}\' for apt::key")
    }
  }
}