// Pure transform: Ghost post object → site.standard.document payload.
// No I/O, no client state — caller passes the publication AT-URI and (optionally)
// an already-uploaded cover-image blob ref.

import { convert as htmlToText } from 'html-to-text';
import type { BlobRef } from '@atproto/api';
import { buildMarkpubContent } from './content-shape.js';

export const DOCUMENT_COLLECTION = 'site.standard.document';

export type { BlobRef };

export interface GhostPostLike {
  id: string;
  title: string;
  slug: string;
  status: string;
  published_at: string;
  updated_at?: string | null;
  custom_excerpt?: string | null;
  excerpt?: string | null;
  html?: string | null;
  feature_image?: string | null;
  tags?: { name: string }[];
}

export function ghostPostToRecord(
  post: GhostPostLike,
  publicationUri: string,
  coverImageBlob: BlobRef | null,
): Record<string, unknown> {
  const tags = (post.tags ?? [])
    .map((t) => t.name)
    .filter((name): name is string => !!name && !name.startsWith('#'));

  const textContent = post.html
    ? htmlToText(post.html, {
        wordwrap: false,
        selectors: [
          { selector: 'a', options: { ignoreHref: true } },
          { selector: 'img', format: 'skip' },
        ],
      })
    : '';

  const record: Record<string, unknown> = {
    $type:       DOCUMENT_COLLECTION,
    site:        publicationUri,
    title:       post.title,
    publishedAt: post.published_at,
    path:        `/${post.slug}/`,
  };

  const description = post.custom_excerpt || post.excerpt;
  if (description)              record.description = description.slice(0, 3000);
  if (tags.length)              record.tags        = tags;
  if (textContent)              record.textContent = textContent;
  if (post.updated_at && post.updated_at !== post.published_at) {
    record.updatedAt = post.updated_at;
  }
  if (coverImageBlob)           record.coverImage  = coverImageBlob;

  // Post body as at.markpub.markdown — the document content union is open
  // (`closed: false`), so no lexicon registration is needed; the shared $type
  // is what markpub-aware readers key on.
  const content = buildMarkpubContent(post.html ?? '');
  if (content)                  record.content     = content;

  return record;
}