# lib/da_product_app/mqtt/handler.ex
defmodule DaProductApp.MQTT.Handler do
  use Tortoise.Handler
  require Logger

  @impl true
  def init(opts) do
    client_id = Keyword.get(opts, :client_id, "unknown_client")
    {:ok, %{online_devices: %{}, client_id: client_id}}
  end

  @impl true
  def connection(:up, state) do
    device_id = parse_device_id(state.client_id)
    Logger.info("Device #{device_id} connected")
    DaProductApp.DeviceRegistry.track_online(device_id)
    {:ok, put_in(state, [:online_devices, device_id], true)}
  end

  @impl true
  def connection(:down, state) do
    device_id = parse_device_id(state.client_id)
    Logger.info("Device #{device_id} disconnected")
    DaProductApp.DeviceRegistry.track_offline(device_id)
    {:ok, put_in(state, [:online_devices, device_id], false)}
  end

  @impl true
  def handle_message(["", "ack", "qr-device", device_id], payload, state) do
    Logger.info("Received ACK from #{device_id}")
    Logger.info("Received payload from #{payload}")
    DaProductAppWeb.Endpoint.broadcast("qr:ack:#{device_id}", "ack_received", %{})
    {:ok, state}
  end

  defp parse_device_id("qr_" <> rest), do: rest
  defp parse_device_id(client_id), do: client_id
end