cleaned up data structure, cleaned up some code

lib/labelmaker_web/tools.ex

@@ -0,0 +1,22 @@
+defmodule LabelmakerWeb.Tools do
+  alias LabelmakerWeb.Constants
+
+  def process_parameters(parameters) do
+    parameters =
+      parameters
+      |> Map.take(Constants.permitted_keys())
+      |> Map.new(fn {k, v} -> {String.to_atom(k), v} end)
+      |> Enum.filter(fn {k, v} ->
+        case k do
+          :color -> v in Constants.colors()
+          :font -> v in Constants.fonts()
+          :label -> String.length(v) <= Constants.max_label_length()
+          :size -> v in Constants.sizes()
+          _ -> true
+        end
+      end)
+      |> Map.new()
+
+    Map.merge(Constants.defaults(), parameters)
+  end
+end