defmodule SyntropyWeb.SessionController do
  use SyntropyWeb, :controller

  alias SyntropyWeb.OperatorAuth

  plug :put_layout, false

  @spec new(Plug.Conn.t(), map()) :: Plug.Conn.t()
  def new(conn, _params) do
    cond do
      not OperatorAuth.required?() ->
        redirect(conn, to: "/")

      OperatorAuth.authenticated?(conn) ->
        redirect(conn, to: "/")

      true ->
        render_login(conn, nil)
    end
  end

  @spec create(Plug.Conn.t(), map()) :: Plug.Conn.t()
  def create(conn, params) do
    username = params["username"]
    password = params["password"]

    case OperatorAuth.validate_credentials(username, password) do
      :ok ->
        conn
        |> OperatorAuth.sign_in()
        |> redirect(to: "/")

      {:error, :invalid} ->
        conn
        |> put_status(:unauthorized)
        |> render_login("Invalid operator credentials.")
    end
  end

  @spec delete(Plug.Conn.t(), map()) :: Plug.Conn.t()
  def delete(conn, _params) do
    conn
    |> OperatorAuth.sign_out()
    |> redirect(to: "/login")
  end

  defp render_login(conn, error) do
    conn
    |> put_view(html: SyntropyWeb.SessionHTML)
    |> render(:new, error: error, username: OperatorAuth.username())
  end
end