export interface WikiLink {
  /** Raw target slug as written inside [[...]], left of any `|`. */
  target: string;
  /** Display alias after `|`, or null when absent. */
  alias: string | null;
}

const LINK_RE = /\[\[([^\]]+)\]\]/g;

/**
 * Extract `[[wikilinks]]` from page content.
 * `[[slug]]` → { target: 'slug', alias: null }.
 * `[[slug|Label]]` → { target: 'slug', alias: 'Label' }.
 */
export function extractLinks(content: string): WikiLink[] {
  const links: WikiLink[] = [];
  for (const match of content.matchAll(LINK_RE)) {
    const inner = match[1];
    const pipe = inner.indexOf('|');
    if (pipe === -1) {
      links.push({ target: inner.trim(), alias: null });
    } else {
      links.push({
        target: inner.slice(0, pipe).trim(),
        alias: inner.slice(pipe + 1).trim(),
      });
    }
  }
  return links;
}