export function matchChannelTemplate(
  template: string,
  candidate: string,
): { params: Record<string, string> } | null {
  // No placeholders: exact match.
  if (!template.includes("{")) {
    return template === candidate ? { params: {} } : null;
  }

  // Build a regex from the template, replacing {name} with named groups.
  const names: string[] = [];
  const escaped = template.replace(/[.+?^${}()|[\]\\]/g, "\\$&"); // escape regex specials
  // The above escapes `{` and `}` too — restore them around placeholders.
  const pattern = escaped.replace(/\\\{([a-zA-Z_][a-zA-Z0-9_]*)\\\}/g, (_m, name) => {
    names.push(name);
    return `([^.]+)`;
  });
  const re = new RegExp(`^${pattern}$`);
  const match = candidate.match(re);
  if (!match) return null;
  const params: Record<string, string> = {};
  names.forEach((name, i) => {
    params[name] = match[i + 1]!;
  });
  return { params };
}