defmodule Mv.ApplicationTest do
  @moduledoc """
  Guards the AshAuthentication supervisor wiring in `Mv.Application`.

  The auth children (token Expunger, audit-log batcher/expunger) resolve their
  configuration via `Spark.sparks(otp_app, Ash.Resource)`. With the wrong
  `otp_app` they silently start against an empty resource set: the token
  Expunger then runs against no token resources and becomes a no-op. This test
  pins the corrected `:mv` wiring against the *running* application tree: the
  supervisor and all three children are present, and the token Expunger booted
  live and resolved the real `:mv` token resource.

  The two audit-log children legitimately report an `:undefined` pid because no
  `AuditLogResource` resources exist under `:mv` (their init returns `:ignore`);
  that is a successful start, not a crash, so they are only asserted present.
  """
  use ExUnit.Case, async: false

  alias AshAuthentication.TokenResource.Expunger

  test "AshAuthentication children boot under the :mv otp_app and resolve real config" do
    # Locate the running AshAuthentication.Supervisor inside the live app tree.
    auth_sup =
      Mv.Supervisor
      |> Supervisor.which_children()
      |> Enum.find_value(fn
        {AshAuthentication.Supervisor, pid, _type, _mods} when is_pid(pid) -> pid
        _ -> nil
      end)

    assert is_pid(auth_sup), "AshAuthentication.Supervisor is not running in Mv.Supervisor"

    children = Supervisor.which_children(auth_sup)
    child_ids = children |> Enum.map(&elem(&1, 0)) |> Enum.sort()

    # All three auth children are present in the supervision tree.
    assert child_ids ==
             Enum.sort([
               AshAuthentication.TokenResource.Expunger,
               AshAuthentication.AuditLogResource.Batcher,
               AshAuthentication.AuditLogResource.Expunger
             ])

    # The token Expunger booted as a live process and resolved the real :mv
    # token resource — proving the children run against non-empty :mv config
    # rather than the empty set the wrong otp_app produced.
    expunger_pid =
      Enum.find_value(children, fn
        {Expunger, pid, _, _} when is_pid(pid) -> pid
        _ -> nil
      end)

    assert is_pid(expunger_pid), "token Expunger did not boot as a live process under :mv"
    assert Process.alive?(expunger_pid)
    assert %{otp_app: :mv, resources: resources} = :sys.get_state(expunger_pid)
    assert Map.has_key?(resources, Mv.Accounts.Token)
  end
end