import { Node } from 'prosemirror-model';

/** Search/preview representation (data-model.md `page_content_cache`). */
export function docToPlainText(doc: Node): string {
  const text = doc.textBetween(0, doc.content.size, '\n\n', (leaf) => {
    if (leaf.type.name === 'image') return (leaf.attrs.alt as string) ?? '';
    // A wikilink contributes its shown text (explicit display or the slug) so
    // search and previews include what the reader sees (issue #46).
    if (leaf.type.name === 'wikilink') {
      return (leaf.attrs.displayText as string | null) ?? (leaf.attrs.targetSlug as string);
    }
    // A mention reads as `@username` (issue #150), so search finds it.
    if (leaf.type.name === 'mention') return `@${leaf.attrs.username as string}`;
    // A date marker contributes its ISO date (issue #152).
    if (leaf.type.name === 'date_marker') return leaf.attrs.date as string;
    return '';
  });
  return text.replace(/\n{3,}/g, '\n\n').trim();
}