towerops/lib/towerops/snmp.ex

defmodule Towerops.Snmp do
  @moduledoc """
  The SNMP context.

  Provides the public API for SNMP discovery and monitoring functionality.
  """

  import Ecto.Query

  alias Towerops.Equipment.Equipment
  alias Towerops.Repo
  alias Towerops.Snmp.Client
  alias Towerops.Snmp.Device
  alias Towerops.Snmp.Discovery
  alias Towerops.Snmp.Interface
  alias Towerops.Snmp.InterfaceStat
  alias Towerops.Snmp.Sensor
  alias Towerops.Snmp.SensorReading

  @doc """
  Tests SNMP connectivity to a device.

  ## Examples

      iex> test_connection("192.168.1.1", "public", "2c")
      {:ok, "Connection successful"}

      iex> test_connection("192.168.1.99", "wrong", "2c")
      {:error, :timeout}
  """
  def test_connection(ip, community, version, port \\ 161) do
    Client.test_connection(
      ip: ip,
      community: community,
      version: version,
      port: port
    )
  end

  @doc """
  Runs SNMP discovery for a piece of equipment.

  Discovers:
  - Device information (manufacturer, model, firmware)
  - Network interfaces
  - Sensors (temperature, power, fans, etc.)

  Updates the database with discovered data.

  ## Examples

      iex> discover_equipment(equipment)
      {:ok, %Device{}}
  """
  def discover_equipment(%Equipment{} = equipment) do
    Discovery.discover_equipment(equipment)
  end

  @doc """
  Runs SNMP discovery for all SNMP-enabled equipment in an organization.

  Returns a summary of successful and failed discoveries.

  ## Examples

      iex> discover_all_for_org(org_id)
      {:ok, %{success: 10, failed: 2, errors: [:timeout, :no_response]}}
  """
  def discover_all_for_org(org_id) do
    Discovery.discover_all(org_id)
  end

  # Device queries

  @doc """
  Gets the SNMP device for a piece of equipment.

  ## Examples

      iex> get_device(equipment_id)
      %Device{}

      iex> get_device(nonexistent_id)
      nil
  """
  def get_device(equipment_id) do
    Repo.get_by(Device, equipment_id: equipment_id)
  end

  @doc """
  Gets the SNMP device for a piece of equipment with preloaded associations.
  """
  def get_device_with_associations(equipment_id) do
    Device
    |> where([d], d.equipment_id == ^equipment_id)
    |> preload([:interfaces, :sensors])
    |> Repo.one()
  end

  # Interface queries

  @doc """
  Lists all interfaces for a device.
  """
  def list_interfaces(device_id) do
    Interface
    |> where([i], i.snmp_device_id == ^device_id)
    |> order_by([i], i.if_index)
    |> Repo.all()
  end

  @doc """
  Lists only monitored interfaces for a device.
  """
  def list_monitored_interfaces(device_id) do
    Interface
    |> where([i], i.snmp_device_id == ^device_id and i.monitored == true)
    |> order_by([i], i.if_index)
    |> Repo.all()
  end

  @doc """
  Gets a specific interface.
  """
  def get_interface(interface_id) do
    Repo.get(Interface, interface_id)
  end

  @doc """
  Updates an interface.
  """
  def update_interface(%Interface{} = interface, attrs) do
    interface
    |> Interface.changeset(attrs)
    |> Repo.update()
  end

  # Sensor queries

  @doc """
  Lists all sensors for a device.
  """
  def list_sensors(device_id) do
    Sensor
    |> where([s], s.snmp_device_id == ^device_id)
    |> order_by([s], [s.sensor_type, s.sensor_index])
    |> Repo.all()
  end

  @doc """
  Lists only monitored sensors for a device.
  """
  def list_monitored_sensors(device_id) do
    Sensor
    |> where([s], s.snmp_device_id == ^device_id and s.monitored == true)
    |> order_by([s], [s.sensor_type, s.sensor_index])
    |> Repo.all()
  end

  @doc """
  Lists sensors grouped by type.
  """
  def list_sensors_by_type(device_id) do
    sensors =
      Sensor
      |> where([s], s.snmp_device_id == ^device_id)
      |> order_by([s], [s.sensor_type, s.sensor_index])
      |> Repo.all()

    Enum.group_by(sensors, & &1.sensor_type)
  end

  @doc """
  Gets a specific sensor.
  """
  def get_sensor(sensor_id) do
    Repo.get(Sensor, sensor_id)
  end

  @doc """
  Updates a sensor.
  """
  def update_sensor(%Sensor{} = sensor, attrs) do
    sensor
    |> Sensor.changeset(attrs)
    |> Repo.update()
  end

  # Sensor readings queries

  @doc """
  Gets recent sensor readings for a sensor.

  ## Options

  - `:limit` - Maximum number of readings to return (default: 100)
  - `:since` - Only return readings after this datetime
  """
  def get_sensor_readings(sensor_id, opts \\ []) do
    limit = Keyword.get(opts, :limit, 100)
    since = Keyword.get(opts, :since)

    query =
      SensorReading
      |> where([r], r.sensor_id == ^sensor_id)
      |> order_by([r], desc: r.checked_at)
      |> limit(^limit)

    query =
      if since do
        where(query, [r], r.checked_at >= ^since)
      else
        query
      end

    Repo.all(query)
  end

  @doc """
  Gets the latest sensor reading for a sensor.
  """
  def get_latest_sensor_reading(sensor_id) do
    SensorReading
    |> where([r], r.sensor_id == ^sensor_id)
    |> order_by([r], desc: r.checked_at)
    |> limit(1)
    |> Repo.one()
  end

  # Interface stats queries

  @doc """
  Gets recent interface statistics for an interface.

  ## Options

  - `:limit` - Maximum number of stats to return (default: 100)
  - `:since` - Only return stats after this datetime
  """
  def get_interface_stats(interface_id, opts \\ []) do
    limit = Keyword.get(opts, :limit, 100)
    since = Keyword.get(opts, :since)

    query =
      InterfaceStat
      |> where([s], s.interface_id == ^interface_id)
      |> order_by([s], desc: s.checked_at)
      |> limit(^limit)

    query =
      if since do
        where(query, [s], s.checked_at >= ^since)
      else
        query
      end

    Repo.all(query)
  end

  @doc """
  Gets the latest interface stat for an interface.
  """
  def get_latest_interface_stat(interface_id) do
    InterfaceStat
    |> where([s], s.interface_id == ^interface_id)
    |> order_by([s], desc: s.checked_at)
    |> limit(1)
    |> Repo.one()
  end

  @doc """
  Records a new sensor reading.
  """
  def create_sensor_reading(attrs) do
    %SensorReading{}
    |> SensorReading.changeset(attrs)
    |> Repo.insert()
  end

  @doc """
  Records a new interface stat.
  """
  def create_interface_stat(attrs) do
    %InterfaceStat{}
    |> InterfaceStat.changeset(attrs)
    |> Repo.insert()
  end
end