import type { CommonProductItem, CommonResource } from '@prisma/client';

export type ProductMediaDto = {
  mainImageUrl: string | null;
  carouselUrls: string[];
  detailImageUrls: string[];
};

type ProductWithCover = CommonProductItem & {
  coverResource?: { url: string } | null;
};

function urlsFromResources(resources: CommonResource[], bizType: 'CAROUSEL' | 'DETAIL') {
  return resources
    .filter((r) => r.bizType === bizType && r.url)
    .sort((a, b) => a.sortOrder - b.sortOrder)
    .map((r) => r.url);
}

export function mapProductMedia(
  product: ProductWithCover,
  extraResources: CommonResource[] = [],
): ProductMediaDto {
  const mainImageUrl = product.coverResource?.url ?? null;
  const carouselFromDb = urlsFromResources(extraResources, 'CAROUSEL');
  const detailFromDb = urlsFromResources(extraResources, 'DETAIL');

  const detailFromJson = parseDetailContentImages(product.detailContent);

  const carouselUrls =
    carouselFromDb.length > 0
      ? carouselFromDb
      : mainImageUrl
        ? [mainImageUrl]
        : [];

  const detailImageUrls =
    detailFromDb.length > 0
      ? detailFromDb
      : detailFromJson;

  return { mainImageUrl, carouselUrls, detailImageUrls };
}

function parseDetailContentImages(detailContent: unknown): string[] {
  if (!detailContent || typeof detailContent !== 'object') return [];
  const record = detailContent as Record<string, unknown>;
  const images = record.images ?? record.detailImages ?? record.detailImageUrls;
  if (!Array.isArray(images)) return [];
  return images.filter((item): item is string => typeof item === 'string' && item.length > 0);
}

export function groupResourcesByProductId(resources: CommonResource[]) {
  const map = new Map<string, CommonResource[]>();
  for (const resource of resources) {
    const key = resource.ownerId.toString();
    const list = map.get(key) ?? [];
    list.push(resource);
    map.set(key, list);
  }
  return map;
}