function unquote(v: string): string {
  const m = /^(["'])(.*)\1$/.exec(v);
  return m ? (m[2] ?? "") : v;
}

/**
 * Lit un en-tête YAML simple (--- … ---) : paires `clé: valeur`, valeurs entre guillemets,
 * et blocs `>` / `|` (lignes indentées jointes par des espaces). Pas de YAML imbriqué.
 */
export function parseFrontmatter(raw: string): { data: Record<string, string>; body: string } {
  const text = raw.replace(/\r\n/g, "\n");
  if (!text.startsWith("---\n")) return { data: {}, body: text };
  const end = text.indexOf("\n---", 4);
  if (end === -1) return { data: {}, body: text };

  const lines = text.slice(4, end).split("\n");
  const body = text.slice(end + 4).replace(/^[ \t]*\n?/, "");

  const data: Record<string, string> = {};
  for (let i = 0; i < lines.length; i++) {
    const m = /^([A-Za-z0-9_-]+):\s*(.*)$/.exec(lines[i] ?? "");
    if (!m) continue;
    let value = (m[2] ?? "").trim();
    if (value === "" || /^[>|][+-]?$/.test(value)) {
      const parts: string[] = [];
      while (i + 1 < lines.length && /^\s+\S/.test(lines[i + 1] ?? "")) {
        i++;
        parts.push((lines[i] ?? "").trim());
      }
      value = parts.join(" ");
    }
    data[m[1]!] = unquote(value);
  }
  return { data, body };
}