import { Refusal } from '@things-factory/shell'

/*
 * **A twin model the kernel refuses is said by name** (ADR-0054).
 *
 * ── What went wrong (2026-10-10) ─────────────────────────────────────────────
 * The MES kernel refuses a model without a production declaration. The engine let that error through
 * as it was, so `twinReplay(miratek)` reached the screen as INTERNAL_SERVER_ERROR with the kernel's
 * English sentence in the shell's notice. The model was what was wrong, not the server.
 *
 * ── The rule ─────────────────────────────────────────────────────────────────
 * The kernel names its refusals: an error that carries a string `code` and an object `params`. The
 * kernel cannot reach the shell, so the host turns that into a shell `Refusal` here, adding which twin
 * it was. The sentence is made where the reader's language is known (`SpeakRefusals`, or the import
 * result's `refusal()`), under `error.<code>`. Anything without a name passes through untouched.
 */
export function asModelRefusal(error: unknown, instanceId: string): unknown {
  if (error instanceof Refusal) return error
  const e = error as { code?: unknown; params?: unknown; message?: unknown } | null
  if (!e || typeof e.code !== 'string' || !e.code || !e.params || typeof e.params !== 'object') return error
  return new Refusal(e.code, { ...(e.params as Record<string, any>), instanceId }, String(e.message ?? e.code))
}

/** Run a step that loads or replays a model; a kernel refusal comes out as a `Refusal`. */
export function refusingModel<T>(instanceId: string, step: () => T): T {
  try {
    return step()
  } catch (error) {
    throw asModelRefusal(error, instanceId)
  }
}