dotfiles/app/lib/prymn_web/components/system_info.ex

defmodule PrymnWeb.SystemInfo do
  use PrymnWeb, :live_component

  require Logger
  alias Phoenix.LiveView.AsyncResult

  @impl true
  def update(assigns, socket) do
    {:ok,
     socket
     |> assign(:agent, assigns.agent)
     |> assign(:sys_info, AsyncResult.loading())}

    # |> start_async(:get_sys_info, fn ->
    #   Prymn.Agents.get_sys_info(assigns.agent)
    # end)}
  end

  @impl true
  def render(assigns) do
    ~H"""
    <div class="flex justify-between space-x-4 rounded bg-gray-800 p-5 text-white">
      <.async_result :let={sys_info} assign={@sys_info}>
        <:loading>
          <div>
            <.spinner size="sm" />
            <p class="text-xl">Loading system statistics...</p>
          </div>
        </:loading>
        <div>
          <p class="text-xl"><%= sys_info.uptime || "" %>s</p>
          <p class="text-sm">Uptime</p>
        </div>
        <div>
          <p class="text-xl"><%= Enum.count(sys_info.cpus || []) %></p>
          <p class="text-sm">CPUs</p>
        </div>
        <div>
          <p class="text-xl"><%= calculate_cpu_usage(sys_info.cpus) %></p>
          <p class="text-sm">CPU%</p>
        </div>
        <div>
          <p class="text-xl">
            <%= bytes_to_gigabytes(sys_info.mem_total_bytes - sys_info.mem_avail_bytes) %>
            <span>/</span>
            <%= bytes_to_gigabytes(sys_info.mem_total_bytes) %>
            <span>GiB</span>
          </p>
          <p class="text-sm">Memory</p>
        </div>
        <div>
          <p class="text-xl">
            <%= calculate_disk_used_percent(sys_info.disks) %>
            <span>%</span>
          </p>
          <p class="text-sm">Used Disk</p>
        </div>
      </.async_result>
    </div>
    """
  end

  # @impl true
  # def handle_async(:get_sys_info, {:ok, %SysInfoResponse{} = sys_info}, socket) do
  #   %{sys_info: sys_info_result, agent: agent} = socket.assigns

  #   {:noreply,
  #    socket
  #    |> assign(:sys_info, AsyncResult.ok(sys_info_result, sys_info))
  #    |> start_async(:get_sys_info, fn ->
  #      # 10 seconds is >5 which is gun's timeout duration (which might have a race
  #      # condition if they are equal)
  #      Process.sleep(:timer.seconds(10))
  #      Prymn.Agents.get_sys_info(agent)
  #    end)}
  # end

  # def handle_async(:get_sys_info, {:ok, {:error, grpc_error}}, socket) do
  #   %{sys_info: sys_info_result} = socket.assigns

  #   {:noreply,
  #    socket
  #    |> assign(:sys_info, AsyncResult.failed(sys_info_result, grpc_error))}
  # end

  # def handle_async(:get_sys_info, {:exit, _reason}, socket) do
  #   {:noreply, socket}
  # end

  defp calculate_cpu_usage(cpus) do
    (Enum.reduce(cpus, 0, fn x, acc -> x.usage + acc end) / Enum.count(cpus))
    |> Float.round(2)
  end

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

  defp calculate_disk_used_percent(disks) do
    0
    # alias PrymnProto.Prymn.SysInfoResponse.Disk

    # {used, total} =
    #   Enum.reduce(disks, {0, 0}, fn %Disk{} = disk, {used, total} ->
    #     {used + disk.total_bytes - disk.avail_bytes, total + disk.total_bytes}
    #   end)

    # Float.round(100 * used / total, 2)
  end
end