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)

    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)
  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 ->
        # Find all sensors of the specified types
        sensors =
          device.sensors
          |> Enum.filter(&(&1.sensor_type in sensor_types))
          |> Enum.sort_by(& &1.sensor_index)

        if Enum.empty?(sensors) do
          nil
        else
          # Get readings based on range
          since = get_datetime_from_range(range)

          datasets =
            Enum.map(sensors, fn sensor ->
              readings =
                sensor.id
                |> Snmp.get_sensor_readings(
                  since: since,
                  limit: get_limit_for_range(range)
                )
                |> Enum.reverse()

              %{
                label: sensor.sensor_descr,
                data:
                  Enum.map(readings, fn reading ->
                    %{
                      x: DateTime.to_unix(reading.checked_at, :millisecond),
                      y: if(reading.value, do: Float.round(reading.value, 1))
                    }
                  end)
              }
            end)

          Jason.encode!(%{datasets: datasets})
        end
    end
  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 ->
        if Enum.empty?(device.interfaces) do
          nil
        else
          since = get_datetime_from_range(range)
          limit = get_limit_for_range(range)

          # Get all stats for all interfaces
          all_stats =
            device.interfaces
            |> Enum.flat_map(fn interface ->
              stats =
                interface.id
                |> Snmp.get_interface_stats(since: since, limit: limit)
                |> Enum.reverse()

              Enum.map(stats, fn stat ->
                {stat.checked_at, stat.if_in_octets, stat.if_out_octets}
              end)
            end)
            |> Enum.group_by(&elem(&1, 0))
            |> Enum.map(fn {timestamp, stats} ->
              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)
            |> Enum.sort_by(&elem(&1, 0), DateTime)

          if Enum.empty?(all_stats) do
            nil
          else
            # Calculate bits per second from counter differences
            in_data =
              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)

            out_data =
              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)

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

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