import { DuoLookupDto } from '@registratie/contracts/duo-diplomas.dto';
import { RegistratieMsg } from '@registratie/domain/registratie-wizard.machine';
import { HANDMATIG } from './beroep.step';

/**
 * Resolve the diploma that the user picked into the machine message it implies.
 *
 * The DUO payload maps a diploma id onto a server-derived beroep and the policy
 * questions that apply to it. Reading that map is message construction, so it
 * belongs beside the container, not in the beroep step. The backend stays the
 * authority on both values (ADR-0001) — this function only selects them.
 *
 * Returns null when the id matches no known diploma. The caller then dispatches
 * nothing and the wizard keeps its current state.
 */
export function diplomaMsg(data: DuoLookupDto, id: string): RegistratieMsg | null {
  if (id === HANDMATIG) {
    return { tag: 'KiesHandmatig', vraagIds: data.handmatig.policyQuestions.map((q) => q.id) };
  }
  const diploma = data.diplomas.find((d) => d.id === id);
  if (!diploma) return null;
  return {
    tag: 'KiesDiploma',
    diplomaId: diploma.id,
    beroep: diploma.beroep,
    vraagIds: diploma.policyQuestions.map((q) => q.id),
  };
}