defmodule CoreUtils.ViewHelper do
  @moduledoc """
  Presentation helpers
  """

  def translate_errors(%{causes: causes}) do
    %{status: :error, code: 1, message: "Validation errors", causes: causes}
  end

  def translate_errors(changeset) do
    %{status: :error, code: 1, message: "Validation errors", causes: Ecto.Changeset.traverse_errors(changeset, &(:erlang.element(1, &1)))}
  end

  defimpl Poison.Encoder, for: Tuple do
    def encode(tuple, _options) do
      tuple
      |> Tuple.to_list()
      |> Poison.encode!()
    end
  end

  defimpl Poison.Encoder, for: Any do
    def encode(%{__struct__: Core.Models.Task} = struct, options) do
      struct =
        if struct.geom do
          {lon, lat} =  struct.geom.coordinates
          %{struct | lon: lon, lat: lat}
        else
          struct
        end
      enconde_model(struct, options)
    end

    def encode(%{__struct__: _} = struct, options) do
      enconde_model(struct, options)
    end

    def encode({lon, lat}, options) when is_float(lon) and is_float(lat) do
      %{lon: lon, lat: lat}
      |> sanitize_map()
      |> Poison.Encoder.Map.encode(options)
    end

    defp enconde_model(model, options) do
      model
      |> Map.from_struct()
      |> sanitize_map()
      |> Poison.Encoder.Map.encode(options)
    end

    defp sanitize_map(map) do
      map
      |> Enum.filter(
        fn({_, %Ecto.Association.NotLoaded{}}) -> false
          ({:__meta__, _}) -> false
          ({:__struct__, _}) -> false
          ({_, _}) -> true
        end)
      |> Map.new()
    end
  end
end