towerops/lib/towerops_web/live/graph_live/show.ex

defmodule ToweropsWeb.GraphLive.Show do
  @moduledoc false
  use ToweropsWeb, :live_view

  alias Towerops.Equipment
  alias Towerops.Snmp

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

  @impl true
  def handle_params(%{"id" => equipment_id, "sensor_type" => sensor_type} = params, _, socket) do
    if connected?(socket) do
      Phoenix.PubSub.subscribe(Towerops.PubSub, "equipment:#{equipment_id}")
    end

    range = Map.get(params, "range", "24h")

    socket =
      socket
      |> assign(:equipment_id, equipment_id)
      |> assign(:sensor_type, sensor_type)
      |> assign(:range, range)
      |> load_graph_data()

    {:noreply, socket}
  end

  @impl true
  def handle_event("change_range", %{"range" => range}, socket) do
    {:noreply,
     push_patch(socket,
       to:
         ~p"/orgs/#{socket.assigns.current_organization.slug}/equipment/#{socket.assigns.equipment_id}/graph/#{socket.assigns.sensor_type}?range=#{range}"
     )}
  end

  # Private functions

  defp load_graph_data(socket) do
    equipment_id = socket.assigns.equipment_id
    sensor_type = socket.assigns.sensor_type
    range = socket.assigns.range

    equipment = Equipment.get_equipment!(equipment_id)

    chart_data =
      if sensor_type == "traffic" do
        load_traffic_chart_data(equipment_id, range)
      else
        sensor_types = get_sensor_types_for_chart(sensor_type)
        load_sensor_chart_data(equipment_id, sensor_types, range)
      end

    {title, unit, auto_scale} = get_chart_config(sensor_type)
    show_zero_line = sensor_type == "traffic"

    socket
    |> assign(:equipment, equipment)
    |> assign(:page_title, "#{equipment.name} - #{title}")
    |> assign(:chart_title, title)
    |> assign(:chart_data, chart_data)
    |> assign(:unit, unit)
    |> assign(:auto_scale, auto_scale)
    |> assign(:show_zero_line, show_zero_line)
  end

  defp get_sensor_types_for_chart("processors"), do: ["cpu_load"]
  defp get_sensor_types_for_chart("memory"), do: ["memory_usage"]
  defp get_sensor_types_for_chart("storage"), do: ["disk_usage"]
  defp get_sensor_types_for_chart("temperature"), do: ["temperature", "cpu_temperature", "celsius"]
  defp get_sensor_types_for_chart("voltage"), do: ["voltage", "volts"]
  defp get_sensor_types_for_chart("traffic"), do: nil
  defp get_sensor_types_for_chart(_), do: []

  defp get_chart_config("processors"), do: {"Processor Usage", "%", false}
  defp get_chart_config("memory"), do: {"Memory Usage", "%", false}
  defp get_chart_config("storage"), do: {"Storage Usage", "%", false}
  defp get_chart_config("temperature"), do: {"Temperature", "°C", true}
  defp get_chart_config("voltage"), do: {"Voltage", "V", true}
  defp get_chart_config("traffic"), do: {"Overall Traffic", "bps", true}
  defp get_chart_config(_), do: {"Sensor Data", "", false}

  defp load_sensor_chart_data(equipment_id, sensor_types, range) do
    case Snmp.get_device_with_associations(equipment_id) do
      nil ->
        nil

      device ->
        build_sensor_chart_json(device, sensor_types, range)
    end
  end

  defp build_sensor_chart_json(device, sensor_types, range) do
    sensors =
      device.sensors
      |> Enum.filter(&(&1.sensor_type in sensor_types))
      |> Enum.sort_by(& &1.sensor_index)

    if Enum.empty?(sensors) do
      nil
    else
      since = get_datetime_from_range(range)
      limit = get_limit_for_range(range)
      datasets = Enum.map(sensors, &sensor_to_dataset(&1, since, limit))
      Jason.encode!(%{datasets: datasets})
    end
  end

  defp sensor_to_dataset(sensor, since, limit) do
    readings =
      sensor.id
      |> Snmp.get_sensor_readings(since: since, limit: limit)
      |> Enum.reverse()

    %{
      label: sensor.sensor_descr,
      data: Enum.map(readings, &reading_to_chart_point/1)
    }
  end

  defp reading_to_chart_point(reading) do
    %{
      x: DateTime.to_unix(reading.checked_at, :millisecond),
      y: if(reading.value, do: Float.round(reading.value, 1))
    }
  end

  defp get_datetime_from_range("1h"), do: DateTime.add(DateTime.utc_now(), -1, :hour)
  defp get_datetime_from_range("6h"), do: DateTime.add(DateTime.utc_now(), -6, :hour)
  defp get_datetime_from_range("12h"), do: DateTime.add(DateTime.utc_now(), -12, :hour)
  defp get_datetime_from_range("24h"), do: DateTime.add(DateTime.utc_now(), -24, :hour)
  defp get_datetime_from_range("7d"), do: DateTime.add(DateTime.utc_now(), -7, :day)
  defp get_datetime_from_range("30d"), do: DateTime.add(DateTime.utc_now(), -30, :day)
  defp get_datetime_from_range(_), do: DateTime.add(DateTime.utc_now(), -24, :hour)

  defp get_limit_for_range("1h"), do: 360
  defp get_limit_for_range("6h"), do: 720
  defp get_limit_for_range("12h"), do: 1440
  defp get_limit_for_range("24h"), do: 2880
  defp get_limit_for_range("7d"), do: 10_080
  defp get_limit_for_range("30d"), do: 43_200
  defp get_limit_for_range(_), do: 2880

  defp load_traffic_chart_data(equipment_id, range) do
    case Snmp.get_device_with_associations(equipment_id) do
      nil -> nil
      device -> build_traffic_chart_json(device, range)
    end
  end

  defp build_traffic_chart_json(device, range) do
    if Enum.empty?(device.interfaces) do
      nil
    else
      since = get_datetime_from_range(range)
      limit = get_limit_for_range(range)
      all_stats = aggregate_interface_stats(device.interfaces, since, limit)

      if Enum.empty?(all_stats) do
        nil
      else
        build_traffic_datasets(all_stats)
      end
    end
  end

  defp aggregate_interface_stats(interfaces, since, limit) do
    interfaces
    |> Enum.flat_map(fn interface ->
      stats =
        interface.id
        |> Snmp.get_interface_stats(since: since, limit: limit)
        |> Enum.reverse()

      Enum.map(stats, &stat_to_tuple/1)
    end)
    |> Enum.group_by(&elem(&1, 0))
    |> Enum.map(&sum_stats_by_timestamp/1)
    |> Enum.sort_by(&elem(&1, 0), DateTime)
  end

  defp stat_to_tuple(stat) do
    {stat.checked_at, stat.if_in_octets, stat.if_out_octets}
  end

  defp sum_stats_by_timestamp({timestamp, stats}) do
    total_in = Enum.reduce(stats, 0, fn {_, in_octets, _}, acc -> acc + (in_octets || 0) end)
    total_out = Enum.reduce(stats, 0, fn {_, _, out_octets}, acc -> acc + (out_octets || 0) end)
    {timestamp, total_in, total_out}
  end

  defp build_traffic_datasets(all_stats) do
    in_data = calculate_traffic_data(all_stats, :inbound)
    out_data = calculate_traffic_data(all_stats, :outbound)

    datasets = [
      %{label: "Outbound", data: out_data},
      %{label: "Inbound", data: in_data}
    ]

    Jason.encode!(%{datasets: datasets})
  end

  defp calculate_traffic_data(all_stats, :inbound) do
    all_stats
    |> Enum.chunk_every(2, 1, :discard)
    |> Enum.map(fn [{t1, in1, _out1}, {t2, in2, _out2}] ->
      time_diff = t2 |> DateTime.diff(t1, :second) |> max(1)
      bps = ((in2 - in1) * 8 / time_diff) |> max(0) |> :erlang.float() |> Float.round(2)

      %{
        x: DateTime.to_unix(t2, :millisecond),
        y: -bps
      }
    end)
  end

  defp calculate_traffic_data(all_stats, :outbound) do
    all_stats
    |> Enum.chunk_every(2, 1, :discard)
    |> Enum.map(fn [{t1, _in1, out1}, {t2, _in2, out2}] ->
      time_diff = t2 |> DateTime.diff(t1, :second) |> max(1)
      bps = ((out2 - out1) * 8 / time_diff) |> max(0) |> :erlang.float() |> Float.round(2)

      %{
        x: DateTime.to_unix(t2, :millisecond),
        y: bps
      }
    end)
  end
end