Name Generation and Registry for Rhea

name_registry.ex

defmodule DB.NameRegistry do
  @moduledoc """
  Creates and verifies usage of names
  """

  import Ecto.Query
  alias DB.Repo

  @adjectives ~w(
    aged ancient autumn billowing bitter black blue bold
    broken cold cool crimson damp dark dawn delicate divine
    dry empty falling floral fragrant frosty green hidden
    holy icy late lingering little lively long misty morning
    muddy nameless old patient polished proud purple quiet
    red restless rough shy silent small snowy solitary
    sparkling spring still summer throbbing twilight
    wandering weathered white wild winter wispy withered young
  )

  @nouns ~w(
    bird breeze brook bush butterfly cherry cloud darkness
    dawn dew dream dust feather field fire firefly flower
    fog forest frog frost glade glitter grass hamster haze
    hill lake leaf meadow moon morning mountain night paper
    pine pond rain resonance river sea shadow shape silence
    sky smoke snow snowflake sound star sun sun sunset surf
    thunder tree violet voice water water waterfall wave
    wildflower wind wood
  )

  def generate(type) do
    type
    |> initialize()
    |> verify()
  end

  def register(map, type) do
    map
    |> Map.put(:name, generate(type))
  end

  defp initialize(type) do
    %{
      type: type,
      value: create()
    }
  end

  defp create do
    adjective = @adjectives |> Enum.random
    noun = @nouns |> Enum.random

    [adjective, noun] |> Enum.join("-")
  end

  defp verify(%{type: type, value: value}) do
    case duplicates?(type, value) do
      true  -> generate(type)
      false -> value
      _     -> {:error, "An unknown error has occurred in name registry"}
    end
  end

  defp duplicates?(type, value) do
    !Enum.empty?(Repo.all(from x in type, where: x.name == ^value))
  end
end