Refactoring of config wrapper

lib/mobilizon/config.ex

@@ -0,0 +1,77 @@
+defmodule Mobilizon.Config do
+  @moduledoc """
+  Configuration wrapper.
+  """
+
+  @spec instance_config :: keyword
+  def instance_config, do: Application.get_env(:mobilizon, :instance)
+
+  @spec instance_url :: String.t()
+  def instance_url, do: instance_config()[:instance]
+
+  @spec instance_name :: String.t()
+  def instance_name, do: instance_config()[:name]
+
+  @spec instance_description :: String.t()
+  def instance_description, do: instance_config()[:description]
+
+  @spec instance_version :: String.t()
+  def instance_version, do: instance_config()[:version]
+
+  @spec instance_hostname :: String.t()
+  def instance_hostname, do: instance_config()[:hostname]
+
+  @spec instance_registrations_open? :: boolean
+  def instance_registrations_open?, do: to_boolean(instance_config()[:registrations_open])
+
+  @spec instance_repository :: String.t()
+  def instance_repository, do: instance_config()[:repository]
+
+  @spec instance_email_from :: String.t()
+  def instance_email_from, do: instance_config()[:email_from]
+
+  @spec instance_email_reply_to :: String.t()
+  def instance_email_reply_to, do: instance_config()[:email_reply_to]
+
+  @spec get(module | atom) :: any
+  def get(key), do: get(key, nil)
+
+  @spec get([module | atom]) :: any
+  def get([key], default), do: get(key, default)
+
+  def get([parent_key | keys], default) do
+    case get_in(Application.get_env(:mobilizon, parent_key), keys) do
+      nil -> default
+      any -> any
+    end
+  end
+
+  @spec get(module | atom, any) :: any
+  def get(key, default), do: Application.get_env(:mobilizon, key, default)
+
+  @spec get!(module | atom) :: any
+  def get!(key) do
+    value = get(key, nil)
+
+    if value == nil do
+      raise("Missing configuration value: #{inspect(key)}")
+    else
+      value
+    end
+  end
+
+  @spec put([module | atom], any) :: any
+  def put([key], value), do: put(key, value)
+
+  def put([parent_key | keys], value) do
+    parent = put_in(Application.get_env(:mobilizon, parent_key), keys, value)
+
+    Application.put_env(:mobilizon, parent_key, parent)
+  end
+
+  @spec put(module | atom, any) :: any
+  def put(key, value), do: Application.put_env(:mobilizon, key, value)
+
+  @spec to_boolean(boolean | String.t()) :: boolean
+  defp to_boolean(boolean), do: "true" == String.downcase("#{boolean}")
+end