diff --git a/.gitignore b/.gitignore
index 0c6117d..c06a73d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
-pkg
\ No newline at end of file
+pkg
+.DS_Store
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..88d8f02
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+License: BSD 2-Clause License
+
+Copyright (c) Robin Laurén / Reaktor (c) 2017, All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification,  are permitted provided that the following conditions are met:
+
+Redistributions of source code must retain the above copyright notice, this list
+of conditions and the following disclaimer. Redistributions in binary form must
+reproducethe above copyright notice, this list of conditions and the following
+disclaimer in the documentation and/or other materials provided with the
+distribution. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/Modulefile b/Modulefile
deleted file mode 100644
index 9f666ce..0000000
--- a/Modulefile
+++ /dev/null
@@ -1,6 +0,0 @@
-name 'grahamgilbert-macdefaults'
-version '0.0.1'
-summary 'Manage defaults on an OS X system'
-author 'Graham Gilbert'
-source 'https://github.com/pebbleit/puppet-macdefaults.git'
-license 'Apache 2.0'
diff --git a/README.md b/README.md
index 164e750..44eb796 100644
--- a/README.md
+++ b/README.md
@@ -1,30 +1,118 @@
-OS X Defaults module for Puppet
-==================
-
-This module manages defaults on OS X. I didn't write 90% of this, but I can't for the life of me remember where I found it. I'm putting it on here for posterity.
-
-#Usage
-
-Possible valuse for ``type`` are:
-
-* string
-* data
-* int
-* float
-* bool
-* data
-* array
-* array-add
-* dict
-* dict-add
-
-Example Puppet Code:
-
-	include macdefaults
-	
-	mac-defaults { "set-a4":
-          domain => '/Library/Preferences/com.apple.print.PrintingPrefs',
-          key => 'DefaultPaperID',
-          type => 'string',
-          value => "iso-a4",
-	}
\ No newline at end of file
+# macOS Defaults module for Puppet
+
+## Note of potential disaster
+
+This module has not been tested. It was rolled straight into production and
+let to its own devices. It will probably blow up your whole server park unless
+you are careful. If it does, i'd appreciate a patch, so that it won't blow up
+any other server park.
+
+#### Table of Contents
+
+1. [Description](#description)
+1. [Setup - The basics of getting started with macdefaults](#setup)
+    * [What macdefaults affects](#what-macdefaults-affects)
+    * [Setup requirements](#setup-requirements)
+1. [Usage - Configuration options and additional functionality](#usage)
+1. [Reference - An under-the-hood peek at what the module is doing and how](#reference)
+1. [Limitations - OS compatibility, etc.](#limitations)
+1. [Development - Guide for contributing to the module](#development)
+
+## Description
+
+Set or remove your macOS `defaults` with macdefaults.
+
+This module is a re-write of the two modules i found floating around the
+interwebs for just this, namely:
+
+* https://github.com/wfarr/puppet-osx_defaults by Will Farrington, and
+* https://github.com/pebbleit/puppet-macdefaults by Graham Gilbert
+
+Neither of these have been updated for years, and one of the files contained
+some kind of incompatibility with Puppet 4. So here's my mash-up of these two
+modules.
+
+The module includes some rudimentary error checking for missing and ill-formed
+values.
+
+## Setup
+
+Clone or download this module to live nicely among your other puppet modules.
+Cross your fingers. Breathe normally.
+
+### What macdefaults affects
+
+You can set or remove any macOS `defaults` with this module, but you need to
+know the correct domain. For many fun and useful things to muck around with,
+have a look at https://github.com/boxen/puppet-osx.
+
+### Setup Requirements
+
+Requires `puppetlabs-stdlib` version 4.0.0 or higher, and a Mac to run the
+module on.
+
+## Usage
+
+In a manifest dealing with a macOS node (you know, a Mac), include something
+along the lines of
+
+```
+macdefaults { "AppleUpdatesThroughMunki":
+   ensure  => present,
+   domain  => "/Library/Preferences/ManagedInstalls",
+   key     => "InstallAppleSoftwareUpdates",
+   type    => 'bool',
+   value   => True,
+}
+```
+The example code above would ensure that Macs use Munki for Apple system udates.
+
+Possible values for `type` are those of OS X Defaults; ie. `string`, `data`,
+`int` (or `integer`), `float`, `bool` (or `boolean`), `array`, `array-add`,
+`dict` and `dict-add`. That said, i've never tested any other values than `int`;
+i just copied this from Graham's macdefaults README.md, so don't take my word
+for it. Read the source. Understand what you do. And send me a patch if you find
+a bug.
+
+The code includes some checking for idempotency. It used to be wicked clever,
+but rather opaque, so i expanded the code for readability. You can still find
+the original and quote ingenious checking code for boolean values in Gilbert's
+and Farrington's code.
+
+I removed the quotes inside some of the code, which might break stuff up.
+Please use quotes around any strange string values.
+
+Yet untested, but according to the puppet [language reference on case matching
+](https://docs.puppet.com/puppet/latest/reference/lang_conditional.html#case-matching-1),
+the values for the `bool` type _should_ be case-insensitive.
+
+## Reference
+
+* `man defaults` on your Mac
+* https://github.com/wfarr/puppet-osx_defaults by Will Farrington, and
+* https://github.com/pebbleit/puppet-macdefaults by Graham Gilbert
+* https://github.com/boxen/puppet-osx by Boxen
+
+## Limitations
+
+Me, mostly.
+
+## Development
+
+Merge/pull requests welcome.
+
+## Release Notes/Contributors/Etc.
+
+Second major rewrite. Works on my machine. Only tested with the `Int` type. Your
+mileage will most certainly vary. Handle with care and have mercy.
+
+If you think there are a lot of comments in the manifest file, it's just because
+that's how Puppet does it when you create a new module with `puppet module
+generate macdefaults`.
+
+## Bug warning
+
+This module was originally called osx_defaults (from Will Farrington's code) but
+i chose to go with the name macdefaults, as OS X is now known as macOS rather
+than OS X. I hope i managed to find-replace all relevant instances of the old
+name in the code!
diff --git a/examples/init.pp b/examples/init.pp
new file mode 100644
index 0000000..fbd0e73
--- /dev/null
+++ b/examples/init.pp
@@ -0,0 +1,12 @@
+# The baseline for module testing used by Puppet Labs is that each manifest
+# should have a corresponding test manifest that declares that class or defined
+# type.
+#
+# Tests are then run by using puppet apply --noop (to check for compilation
+# errors and view a log of events) or by fully applying the test in a virtual
+# environment (to compare the resulting system state to the desired state).
+#
+# Learn more about module testing here:
+# https://docs.puppet.com/guides/tests_smoke.html
+#
+include ::macdefaults
diff --git a/manifests/init.pp b/manifests/init.pp
index 9a8d946..f34dace 100644
--- a/manifests/init.pp
+++ b/manifests/init.pp
@@ -1,35 +1,92 @@
-# Note that type can be one of:
-# string, data, int, float, bool, data, array, array-add, dict, dict-add
-define mac-defaults($domain, $key, $value = false, $type = "string", $action = "write") {
-case $operatingsystem {
- Darwin:{
-  case $action {
-    "write": {
-      exec {"defaults write $domain $key -$type '$value'":
-        path => "/bin:/usr/bin",
-          unless => $type ? {
-            'bool' => $value ? {
-              'TRUE' => "defaults read $domain $key | grep -qx 1",
-              'FALSE' => "defaults read $domain $key | grep -qx 0"
-              },
-          default => "defaults read $domain $key | grep -qx $value | sed -e 's/ (.*)/\1/'"
-        }
-      }
-    }
-    "delete": {
-      exec {"defaults delete $domain $key":
-        path => "/bin:/usr/bin",
-        logoutput => false,
-        onlyif => "defaults read $domain | grep -q '$key'"
-      }
-    }
+# Class: macdefaults
+# ===========================
+#
+# Handle macOS `defaults` from Puppet
+#
+# Parameters
+# ----------
+#
+# * `ensure` - present or absent
+# * `domain`
+# * `key`
+# * `type`
+# * `value`
+#
+# Examples
+# --------
+#
+# @example
+#   macdefaults { "AppleUpdatesThroughMunki":
+#     ensure  => present,
+#     domain  => "/Library/Preferences/ManagedInstalls",
+#     key     => "InstallAppleSoftwareUpdates",
+#     type    => 'bool',
+#     value   => True,
+#   }
+#
+# Authors
+# -------
+#
+# @author Robin Laurén <robin.lauren@reaktor.com>
+#
+# Based on the works of
+# * Will Farrington https://github.com/wfarr/puppet-osx_defaults
+# * Graham Gilbert https://github.com/pebbleit/puppet-macdefaults
+#
+# Copyright
+# ---------
+#
+# Copyright (c) Robin Laurén / Reaktor (c) 2017, All rights reserved.
+# License: BSD 2-Clause License (see LICENSE)
+
+class macdefaults (
+  String $ensure = 'present',
+  String $domain = undef,
+  String $key    = undef,
+  $value         = undef,
+  String $type   = 'string',
+) {
+
+  assert_type(Enum['present', 'absent'], $ensure)
+  assert_type(Enum['string', 'data', 'int', 'integer', 'float', 'bool', 'boolean', 'date', 'array', 'array-add', 'dict', 'dict-add'], $type)
+  assert_type(String, $domain)
+  assert_type(String, $key)
+
+  if ($facts['operatingsystem'] != 'Darwin') {
+    fail('macdefaults only works on macOS')
   }
- }
-}
 
+  $defaults_cmd = '/usr/bin/defaults'
 
-}
+  case $ensure {
+
+    'present': {
+      if ($value == undef) {
+        fail ('`value` is missing')
+      }
+
+      if ($type =~ /^bool(ean)?$/) {
+        $bvalue = assert_type(Boolean, $value)
+        $nvalue = bool2num($bvalue)
+        $value  = bool2str($bvalue)
+        $check  = "${defaults_cmd} read ${domain} ${key} -${type} ${value} | grep -qx ${nvalue}"
+      } else {
+        $check = "${defaults_cmd} read ${domain} ${key} -${type} | grep -qx ${value}"
+      }
+
+      exec { "${defaults_cmd} write ${domain} ${key} -${type} ${value}":
+        unless  => $check,
+      }
+    }
 
-class macdefaults{
+    'absent': {
+      exec { "${defaults_cmd} delete ${domain} ${key}":
+        onlyif => "${defaults_cmd} read ${domain} | egrep '^${key}$''",
+      }
+    }
 
+    default: {
+      fail ('macdefaults ensure => [present | absent] domain key type value')
+    }
+  }
 }
diff --git a/metadata.json b/metadata.json
new file mode 100644
index 0000000..fc34319
--- /dev/null
+++ b/metadata.json
@@ -0,0 +1,14 @@
+{
+  "name": "llauren-macdefaults",
+  "version": "0.2.0",
+  "author": "llauren",
+  "summary": "Handle MacOS Defaults",
+  "license": "FreeBSD",
+  "source": "https://github.com/llauren/puppet-macdefaults",
+  "project_page": "https://github.com/llauren/puppet-macdefaults",
+  "issues_url": "https://github.com/llauren/puppet-macdefaults/issues",
+  "dependencies": [
+    {"name":"puppetlabs-stdlib","version_requirement":">= 4.0.0"}
+  ],
+  "data_provider": null
+}