defmodule PrymnWeb.ServerLive.Show do
  use PrymnWeb, :live_view

  alias Prymn.{Agents, Servers}

  @impl true
  def mount(_params, _session, socket) do
    {:ok, socket}
  end

  @impl true
  def handle_params(%{"id" => id}, _, socket) do
    server = Servers.get_server!(id)
    pid = self()

    if connected?(socket) do
      Agents.start_connection_or_keep_alive(server.public_ip)
      Task.start_link(fn -> get_sys_info(pid, server.public_ip) end)
    end

    {:noreply,
     socket
     |> assign(:page_title, server.name)
     |> assign(:server, server)
     |> assign(:uptime, 0)
     |> assign(:cpus, [])
     |> assign(:total_memory, 0)
     |> assign(:used_memory, 0)
     |> assign(:registration_command, Servers.create_setup_command(server))}
  end

  @impl true
  def handle_info(%PrymnProto.Prymn.SysInfoResponse{} = response, socket) do
    {:noreply,
     socket
     |> assign(:uptime, response.uptime)
     |> assign(
       :used_memory,
       bytes_to_gigabytes(response.mem_total_bytes - response.mem_avail_bytes)
     )
     |> assign(:total_memory, bytes_to_gigabytes(response.mem_total_bytes))
     |> assign(:cpus, response.cpus)}
  end

  defp bytes_to_gigabytes(bytes) do
    Float.round(bytes / Integer.pow(1024, 3), 2)
  end

  defp get_sys_info(from, host_address) do
    channel = Agents.get_channel(host_address)
    {:ok, reply} = PrymnProto.Prymn.Agent.Stub.get_sys_info(channel, %Google.Protobuf.Empty{})
    send(from, reply)
    Process.sleep(:timer.seconds(2))
    get_sys_info(from, host_address)
  end
end