defmodule ExAdmin.AssociationController do
  @moduledoc false
  use ExAdmin.Web, :controller
  require Logger

  def update_positions(conn, %{"association_name" => association_name, "positions" => positions} = params) do
    defn = ExAdmin.get_registered_by_controller_route!(params["resource"], conn)
    positions = prepare_positions(defn, positions)
    association_name = String.to_existing_atom(association_name)

    repo.get!(defn.resource_model, params["id"])
    |> repo.preload(association_name)
    |> changeset(association_name, positions)
    |> repo.update!

    conn |> put_status(200) |> json("Ok")
  end


  def toggle_attr(conn, %{"attr_name" => attr_name, "attr_value" => attr_value} = params) do
    defn = ExAdmin.get_registered_by_controller_route!(params["resource"], conn)
    model = repo.get!(defn.resource_model, params["id"])
    attr_name_atom = String.to_existing_atom(attr_name)

    model = model
    |> defn.resource_model.changeset(%{attr_name => attr_value})
    |> repo.update!

    render conn, "toggle_attr.js", attr_name: attr_name, attr_value: Map.get(model, attr_name_atom), id: model.id
  end


  defp prepare_positions(%{position_column: nil}, positions), do: positions
  defp prepare_positions(%{position_column: position_column}, positions) do
    position_column = to_string(position_column)
    positions
    |> Enum.map(fn({idx, %{"id" => id, "position" => position}}) ->
      {idx, %{"id" => id, position_column => position}}
    end)
    |> Enum.into(%{})
  end

  defp changeset(struct, assoc_name, positions) do
    struct
    |> Ecto.Changeset.cast(%{assoc_name => positions}, [], [])
    |> Ecto.Changeset.cast_assoc(assoc_name)
  end

  defp repo, do: Application.get_env(:ex_admin, :repo)
end