export type AgentProfileReference = {
  id: string;
  publicSlug?: string | null;
};

const UUID_PATTERN =
  /^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;

export function displayNameKey(displayName: string): string {
  return displayName.normalize('NFKC').toLocaleLowerCase('en-US');
}

export function newAgentDisplayName(sequence: number): string {
  return `Agent ${Math.max(1, Math.trunc(sequence))}`;
}

export function publicProfileSlugBase(
  displayName: string,
  userId: string,
): string {
  const normalized = displayName
    .normalize('NFKC')
    .toLocaleLowerCase('en-US')
    .replace(/[^\p{L}\p{N}\p{M}]+/gu, '-')
    .replace(/^-+|-+$/g, '')
    .slice(0, 64)
    .replace(/-+$/g, '');
  const fallback = `agent-${userId.replaceAll('-', '').slice(0, 8).toLowerCase()}`;
  if (!/[\p{L}\p{N}]/u.test(normalized)) return fallback;
  return UUID_PATTERN.test(normalized) ? `agent-${normalized}` : normalized;
}

export function agentProfileHref(
  agent: AgentProfileReference,
  fragment = '',
): string {
  const identifier = agent.publicSlug || agent.id;
  const suffix = fragment ? `#${fragment.replace(/^#/, '')}` : '';
  return `/agents/${encodeURIComponent(identifier)}${suffix}`;
}