# SPDX-FileCopyrightText: 2025 diffo_example contributors <https://github.com/diffo-dev/diffo_example/graphs.contributors>
#
# SPDX-License-Identifier: MIT

defmodule DiffoExample.Nbn.NniGroup do
  @moduledoc """
  Diffo - TMF Service and Resource Management with a difference

  NniGroup - NNI Group Resource Instance

  An NNI Group is the Point of Interconnect (PoI) grouping where a CVC
  terminates. It comprises multiple NNI resources.
  The NNI Group assigns svlan to CVC.
  """

  alias Diffo.Provider.BaseInstance
  alias Diffo.Provider.Assignment

  alias DiffoExample.Nbn

  use Ash.Resource,
    fragments: [BaseInstance],
    domain: Nbn,
    authorizers: [Ash.Policy.Authorizer]

  resource do
    description "An Ash Resource representing an NNI Group"
    plural_name :NniGroups
  end

  provider do
    specification do
      id "e5f6a7b8-9c0d-4e1f-8a2b-4c5d6e7f8a9b"
      name "nniGroup"
      type :resourceSpecification
      description "An NNI Group Resource Instance comprising multiple NNI resources"
      category "Network Resource"
    end

    characteristics do
      characteristic :nni_group, DiffoExample.Nbn.NniGroupCharacteristic
      characteristic :metrics, DiffoExample.Nbn.NniGroupMetrics
    end

    pools do
      pool :svlans, :svlan
    end

    relationships do
      source :all
      target :all
    end

    behaviour do
      actions do
        create :build
      end
    end
  end

  actions do
    create :build do
      description "creates a new NNI Group resource instance"
      accept [:id, :name, :which]
      argument :relationships, {:array, :struct}
      argument :places, {:array, :struct}
      argument :parties, {:array, :struct}

      change set_attribute(:type, :resource)
      change DiffoExample.Nbn.Changes.SetRspId
      change load [:href]
      upsert? false
    end

    update :define do
      description "defines the NNI Group"
      argument :characteristic_value_updates, {:array, :term}

      change set_attribute(:resource_state, :operating)
      change Diffo.Provider.Changes.Define
    end

    update :assign_svlan do
      description "assigns an S-VLAN ID from the NNI Group pool to a CVC"
      argument :assignment, :struct, constraints: [instance_of: Assignment]

      change {Diffo.Provider.Changes.Assign, pool: :svlans}
    end

    update :relate do
      description "relates the NNI Group with other instances (e.g. NNI resources it comprises)"
      argument :relationships, {:array, :struct}

      change Diffo.Provider.Changes.Relate
    end
  end

  attributes do
    attribute :rsp_id, :string do
      description "the owning RSP's id — nil for Perentie-managed infrastructure"
      allow_nil? true
      public? true
    end
  end

  calculations do
    # The NNI characteristic value of every NNI this NniGroup comprises —
    # forward traversal of :contains Relationships (low cardinality).
    calculate :nnis,
              {:array, :map},
              {DiffoExample.Calculations.InheritedCharacteristicViaRelationship,
               [type: :contains, characteristic_module: DiffoExample.Nbn.NniCharacteristic]} do
      public? true
    end
  end

  use DiffoExample.Nbn.RspOwnership
end