import type { Chapter, ChapterViewModel, ImageAsset } from './types';

function countByStatus(images: ImageAsset[], status: string): number {
  return images.filter((img) => img.status === status).length;
}

export function toChapterViewModel(chapter: Chapter): ChapterViewModel {
  const images = chapter.images ?? [];
  const cover = chapter.cover_asset ?? null;
  const imagesForStatus = cover ? [cover, ...images] : images;
  const completedCount = countByStatus(imagesForStatus, 'completed');
  const hasContent =
    !!(chapter.canonical_markdown ?? '').trim() ||
    !!(chapter.summary ?? '').trim();
  const wordCountFromMarkdown = (chapter.canonical_markdown ?? '').length;
  const wordCount =
    typeof chapter.word_count === 'number' && chapter.word_count >= 0
      ? chapter.word_count
      : wordCountFromMarkdown;

  return {
    id: chapter.id,
    title: chapter.title,
    category: chapter.category,
    orderIndex: chapter.order_index,
    isEmpty: !hasContent,
    isNew: chapter.is_new,
    hasImages: imagesForStatus.length > 0,
    allImagesReady:
      imagesForStatus.length > 0 && completedCount === imagesForStatus.length,
    pendingImageCount:
      countByStatus(imagesForStatus, 'pending') +
      countByStatus(imagesForStatus, 'processing'),
    failedImageCount: countByStatus(imagesForStatus, 'failed'),
    coverImageUrl: cover?.url ?? null,
    updatedAt: chapter.updated_at,
    wordCount,
  };
}

export function toChapterViewModels(chapters: Chapter[]): ChapterViewModel[] {
  return chapters.map(toChapterViewModel);
}