defmodule Pulsar.Consumer do
  use GenServer

  # 1. Topic Discovery
  # 2. Partition Discovery
  # 3. Connect to Broker
  # 4. Subscribe
  # 5. Flow
  # 6. Consume, Forward, ACK and NACK
  
  defstruct connection: nil,
    module: nil,
    topic: "",
    subscription_type: "",
    subscription_name: "",
    consumer_id: 0
  
  def start_link(connection, module, topic, subscription_type, subscription_name) do
    GenServer.start_link(__MODULE__, [connection, module, topic, subscription_type, subscription_name])
  end

  @impl true
  def init(args) do
    [connection, module, topic, subscription_type, subscription_name] = args
    consumer_id = System.unique_integer([:monotonic, :positive])
    
    state = %__MODULE__{
      connection: connection,
      module: module,
      topic: topic,
      subscription_type: subscription_type,
      subscription_name: subscription_name,
      consumer_id: consumer_id
    }
    
    {:ok, state, {:continue, :subscribe}}
  end

  @impl true
  def handle_continue(:subscribe, state) do
    %__MODULE__{
      connection: conn,
      topic: topic,
      subscription_type: subscription_type,
      subscription_name: subscription_name,
      consumer_id: consumer_id
    } = state

    Pulsar.Connection.subscribe(conn, consumer_id, topic, subscription_type, subscription_name)
    Process.sleep(5_000)
    Pulsar.Connection.flow(conn, consumer_id, 5)

    {:noreply, state}
  end

  @impl true
  def handle_call() do
  end

  @impl true
  def handle_cast() do
  end
end