accrue

defmodule Accrue.Billing.SubscriptionSchedule do
  @moduledoc """
  Ecto schema for `accrue_subscription_schedules` (BILL-16).

  Thin projection of Stripe's SubscriptionSchedule resource. Stripe is
  canonical for phase state; we persist only the typed columns
  `accrue_admin` LiveView filters and sorts on, plus a `data` jsonb
  that stores the full Stripe payload (string-keyed) for callers that
  want to inspect the raw shape.

  Follows the D3-17 dual-changeset pattern — `changeset/2` validates
  status transitions on the user path, `force_status_changeset/2`
  bypasses that validation on the webhook path because Stripe is the
  source of truth for schedule state.
  """

  use Ecto.Schema

  import Ecto.Changeset

  alias Accrue.Billing.Metadata

  @primary_key {:id, :binary_id, autogenerate: true}
  @foreign_key_type :binary_id

  @type t :: %__MODULE__{}

  @statuses ~w[not_started active completed released canceled]

  schema "accrue_subscription_schedules" do
    field(:processor, :string, default: "stripe")
    field(:processor_id, :string)
    belongs_to(:customer, Accrue.Billing.Customer)
    belongs_to(:subscription, Accrue.Billing.Subscription)
    field(:status, :string)
    field(:current_phase_index, :integer)
    field(:phases_count, :integer)
    field(:next_phase_at, :utc_datetime_usec)
    field(:released_at, :utc_datetime_usec)
    field(:canceled_at, :utc_datetime_usec)
    field(:data, :map, default: %{})
    field(:metadata, :map, default: %{})
    field(:lock_version, :integer, default: 1)
    field(:last_stripe_event_ts, :utc_datetime_usec)
    field(:last_stripe_event_id, :string)

    timestamps(type: :utc_datetime_usec)
  end

  @cast_fields ~w[
    processor processor_id customer_id subscription_id status
    current_phase_index phases_count next_phase_at
    released_at canceled_at data metadata lock_version
    last_stripe_event_ts last_stripe_event_id
  ]a

  @required_fields ~w[processor processor_id status]a

  @doc "Canonical list of SubscriptionSchedule statuses."
  @spec statuses() :: [String.t()]
  def statuses, do: @statuses

  @doc "User-path changeset with status validation."
  @spec changeset(%__MODULE__{} | Ecto.Changeset.t(), map()) :: Ecto.Changeset.t()
  def changeset(schedule_or_changeset, attrs \\ %{}) do
    schedule_or_changeset
    |> cast(attrs, @cast_fields)
    |> validate_required(@required_fields)
    |> validate_inclusion(:status, @statuses)
    |> Metadata.validate_metadata(:metadata)
    |> optimistic_lock(:lock_version)
    |> unique_constraint(:processor_id)
    |> foreign_key_constraint(:customer_id)
    |> foreign_key_constraint(:subscription_id)
  end

  @doc """
  Webhook-path changeset (D3-17). Stripe is canonical for schedule
  state; this path skips the status allowlist so out-of-order events
  can settle arbitrary state without validation failing.
  """
  @spec force_status_changeset(%__MODULE__{} | Ecto.Changeset.t(), map()) :: Ecto.Changeset.t()
  def force_status_changeset(schedule_or_changeset, attrs \\ %{}) do
    schedule_or_changeset
    |> cast(attrs, @cast_fields)
    |> Metadata.validate_metadata(:metadata)
    |> optimistic_lock(:lock_version)
    |> unique_constraint(:processor_id)
    |> foreign_key_constraint(:customer_id)
    |> foreign_key_constraint(:subscription_id)
  end
end