module.exports = function(hljs) {

  var PUPPET_KEYWORDS = {
    keyword:
    /* language keywords */
      'and case default else elsif false if in import enherits node or true undef unless main settings $string ',
    literal:
    /* metaparameters */
      'alias audit before loglevel noop require subscribe tag ' +
    /* normal attributes */
      'owner ensure group mode name|0 changes context force incl lens load_path onlyif provider returns root show_diff type_check ' +
      'en_address ip_address realname command environment hour monute month monthday special target weekday '+
      'creates cwd ogoutput refresh refreshonly tries try_sleep umask backup checksum content ctime force ignore ' +
      'links mtime purge recurse recurselimit replace selinux_ignore_defaults selrange selrole seltype seluser source ' +
      'souirce_permissions sourceselect validate_cmd validate_replacement allowdupe attribute_membership auth_membership forcelocal gid '+
      'ia_load_module members system host_aliases ip allowed_trunk_vlans description device_url duplex encapsulation etherchannel ' +
      'native_vlan speed principals allow_root auth_class auth_type authenticate_user k_of_n mechanisms rule session_owner shared options ' +
      'device fstype enable hasrestart directory present absent link atboot blockdevice device dump pass remounts poller_tag use ' +
      'message withpath adminfile allow_virtual allowcdrom category configfiles flavor install_options instance package_settings platform ' +
      'responsefile status uninstall_options vendor unless_system_user unless_uid binary control flags hasstatus manifest pattern restart running ' +
      'start stop allowdupe auths expiry gid groups home iterations key_membership keys managehome membership password password_max_age ' +
      'password_min_age profile_membership profiles project purge_ssh_keys role_membership roles salt shell uid baseurl cost descr enabled ' +
      'enablegroups exclude failovermethod gpgcheck gpgkey http_caching include includepkgs keepalive metadata_expire metalink mirrorlist ' +
      'priority protect proxy proxy_password proxy_username repo_gpgcheck s3_enabled skip_if_unavailable sslcacert sslclientcert sslclientkey ' +
      'sslverify mounted',
    built_in:
    /* core facts */
      'architecture augeasversion blockdevices boardmanufacturer boardproductname boardserialnumber cfkey dhcp_servers ' +
      'domain ec2_ ec2_userdata facterversion filesystems ldom fqdn gid hardwareisa hardwaremodel hostname id|0 interfaces '+
      'ipaddress ipaddress_ ipaddress6 ipaddress6_ iphostnumber is_virtual kernel kernelmajversion kernelrelease kernelversion ' +
      'kernelrelease kernelversion lsbdistcodename lsbdistdescription lsbdistid lsbdistrelease lsbmajdistrelease lsbminordistrelease ' +
      'lsbrelease macaddress macaddress_ macosx_buildversion macosx_productname macosx_productversion macosx_productverson_major ' +
      'macosx_productversion_minor manufacturer memoryfree memorysize netmask metmask_ network_ operatingsystem operatingsystemmajrelease '+
      'operatingsystemrelease osfamily partitions path physicalprocessorcount processor processorcount productname ps puppetversion '+
      'rubysitedir rubyversion selinux selinux_config_mode selinux_config_policy selinux_current_mode selinux_current_mode selinux_enforced '+
      'selinux_policyversion serialnumber sp_ sshdsakey sshecdsakey sshrsakey swapencrypted swapfree swapsize timezone type uniqueid uptime '+
      'uptime_days uptime_hours uptime_seconds uuid virtual vlans xendomains zfs_version zonenae zones zpool_version'
  };

  var COMMENT = hljs.COMMENT('#', '$');

  var IDENT_RE = '([A-Za-z_]|::)(\\w|::)*';

  var TITLE = hljs.inherit(hljs.TITLE_MODE, {begin: IDENT_RE});

  var VARIABLE = {className: 'variable', begin: '\\$' + IDENT_RE};

  var STRING = {
    className: 'string',
    contains: [hljs.BACKSLASH_ESCAPE, VARIABLE],
    variants: [
      {begin: /'/, end: /'/},
      {begin: /"/, end: /"/}
    ]
  };

  return {
    aliases: ['pp'],
    contains: [
      COMMENT,
      VARIABLE,
      STRING,
      {
        beginKeywords: 'class', end: '\\{|;',
        illegal: /=/,
        contains: [TITLE, COMMENT]
      },
      {
        beginKeywords: 'define', end: /\{/,
        contains: [
          {
            className: 'title', begin: hljs.IDENT_RE, endsParent: true
          }
        ]
      },
      {
        begin: hljs.IDENT_RE + '\\s+\\{', returnBegin: true,
        end: /\S/,
        contains: [
          {
            className: 'name',
            begin: hljs.IDENT_RE
          },
          {
            begin: /\{/, end: /\}/,
            keywords: PUPPET_KEYWORDS,
            relevance: 0,
            contains: [
              STRING,
              COMMENT,
              {
                begin:'[a-zA-Z_]+\\s*=>'
              },
              {
                className: 'number',
                begin: '(\\b0[0-7_]+)|(\\b0x[0-9a-fA-F_]+)|(\\b[1-9][0-9_]*(\\.[0-9_]+)?)|[0_]\\b',
                relevance: 0
              },
              VARIABLE
            ]
          }
        ],
        relevance: 0
      }
    ]
  }
};