user.ex

defmodule Statistik.User do
  use Statistik.Model

  schema "users" do
    field :email, :string
    field :password, :virtual
    field :password_confirmation, :virtual
    field :encrypted_password, :string
  end

  validate user,
    email: present(),
    password: present() when on_create?(user),
    password_confirmation: present() when on_create?(user),
    password: equal_to(user.password_confirmation, message: "must match password confirmation") when on_create?(user)

  def authenticate!(email: email, password: password) do
    Statistik.User
    |> where([u], u.email == ^email)
    |> where([u], u.encrypted_password == ^encrypt_password(password))
    |> Repo.one
  end

  def encrypt_password(user = %__MODULE__{}) do
    struct(user, encrypted_password: encrypt_password(user.password))
  end

  def encrypt_password(password) when is_binary(password) do
    Statistik.Router.config(:secret_key_base)
    |> Plug.Crypto.KeyGenerator.generate(password, iterations: 65536)
    |> Base.encode64
  end
end