import { Injectable } from '@angular/core';
import { httpResource } from '@angular/common/http';
import { Result, ok, err } from '@shared/kernel/fp';
import { BrpAddressDto } from '@registratie/contracts/brp-address.dto';

/**
 * Infrastructure adapter for the BRP address lookup, reached only through our own
 * ("BFF-lite") endpoint — the anti-corruption boundary. In this POC the endpoint
 * is a static mock; pointing at a real backend touches only this file + the DTO.
 */
@Injectable({ providedIn: 'root' })
export class BrpAdapter {
  // Typed as the DTO for ergonomics, but the value is untrusted JSON until
  // parseBrpAddress validates it.
  adresResource() {
    return httpResource<BrpAddressDto>(() => 'mock/brp-address.json');
  }
}

/** Trust-boundary parse: validate the untrusted response shape. "Geen adres" is a
    valid outcome (gevonden: false), not a malformed response. ponytail: hand-written;
    reach for a schema lib once the contract count grows. */
export function parseBrpAddress(json: unknown): Result<string, BrpAddressDto> {
  if (typeof json !== 'object' || json === null) return err('brp-address: not an object');
  const dto = json as Partial<BrpAddressDto>;
  if (typeof dto.gevonden !== 'boolean') return err('brp-address: missing/invalid gevonden');
  if (dto.gevonden) {
    const a = dto.adres;
    if (!a || typeof a.straat !== 'string' || typeof a.postcode !== 'string' || typeof a.woonplaats !== 'string') {
      return err('brp-address: missing/invalid adres');
    }
  }
  return ok({ gevonden: dto.gevonden, adres: dto.adres });
}