defmodule MaatFeatherWeb.Auth.Plug do
  @moduledoc """
  Plug to user ensure authentication.
  """
  import Plug.Conn
  use Plug.ErrorHandler
  alias MaatFeather.Auth.Token

  def init(default), do: default

  defp send_401(conn) do
    conn
    |> put_resp_header("content-type", "application/json")
    |> send_resp(
      :unauthorized,
      Jason.encode!(%{errors: %{message: "unauthenticated"}})
    )
  end

  @doc """
  Handle
  """
  def call(
        %Plug.Conn{
          remote_ip: _remote_ip
        } = conn,
        _params
      ) do
    with [token] <- get_req_header(conn, "authorization") do
      token = String.slice(token, 7..-1)

      case Token.decode(token) do
        {:ok, claims} ->
          assign(conn, :user, claims)

        {:error, _message} ->
          send_401(conn)
      end
    else
      _ -> send_401(conn)
    end
  end
end