import { AanvraagType } from '@registratie/domain/aanvraag';
import { AanvragenAdapter, parseAanvragen } from '@registratie/infrastructure/aanvragen.adapter';

/**
 * Read half of the Concept lookup that `createDraftSync` (`draft-sync.ts`) needs
 * before it can start writing (CQ-001). Free functions that take the adapter
 * as a parameter, not `inject()`, so they get a direct spec without Angular TestBed.
 * `createDraftSync` keeps the closure state (`id`, `resumeGate`) and the write path;
 * these two functions only read.
 */

/** Find the user's existing Concept of a given type (at most one), if any. */
export async function findConcept(
  adapter: AanvragenAdapter,
  type: AanvraagType,
): Promise<string | undefined> {
  try {
    const parsed = parseAanvragen(await adapter.list());
    return parsed.ok
      ? parsed.value.find((a) => a.type === type && a.status.tag === 'Concept')?.id
      : undefined;
  } catch {
    return undefined;
  }
}

/** Outcome of loading one Concept by id: its draft (or null when it has none), or
    `not-concept` when the id is not an editable Concept (submitted/gone) or the
    lookup failed (unknown/deleted id) — the caller treats both the same way, as
    "start fresh". */
export type LoadedConcept = { tag: 'concept'; draft: unknown | null } | { tag: 'not-concept' };

/** Load a specific Concept by id and report whether it is still editable. */
export async function loadConcept(adapter: AanvragenAdapter, id: string): Promise<LoadedConcept> {
  try {
    const dto = await adapter.detail(id);
    if (dto.status && dto.status.tag !== 'Concept') return { tag: 'not-concept' };
    return { tag: 'concept', draft: dto.draft ?? null };
  } catch {
    return { tag: 'not-concept' };
  }
}