point.ex

defmodule Kpsz.Point do
  @behaviour Ecto.Type
  @moduledoc """
  Representation of geological point in the database
  """

  defmodule State do
    defstruct x: 0, y: 0
  end

  @extractor ~r/\(([\d.]+),([\d.]+)\)/

  def type, do: :string

  def cast(%State{} = point), do: point
  def cast({x,y}), do: {:ok, %State{x: x, y: y}  }
  def cast(_) do
    IO.inspect "LOAD crash"
    :error
  end

  def load(string) when is_binary(string) do
    case Regex.run(@extractor, string) do
      [_whole, x, y] -> {:ok, %State{x: x, y: y} }
      _ ->
        :error
    end
  end
  def load(_), do: :error

  def dump(%State{x: x, y: y}), do: {:ok, "(#{x},#{y})" }
  def dump(_),do: :error

end