const UUID_RE = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;

export function isUuid(s: string): boolean {
  return UUID_RE.test(s);
}

export function sanitizeBody(text: string): string {
  return text.replace(/[\x00-\x08\x0B\x0C\x0E-\x1F\x7F\u200B-\u200F\u2028-\u202F\uFEFF]/g, "");
}

export function escapeHtml(text: string): string {
  return text
    .replace(/&/g, "&")
    .replace(/</g, "&lt;")
    .replace(/>/g, "&gt;")
    .replace(/"/g, "&quot;")
    .replace(/'/g, "&#x27;");
}

const MENTION_RE = /@([\w-]+)/g;

export function extractMentions(text: string): string[] {
  return [...new Set([...text.matchAll(MENTION_RE)].map((m) => m[1]))];
}

export function highlightMentions(text: string): string {
  const escaped = escapeHtml(text);
  return escaped.replace(MENTION_RE, '<a href="/p/$1" class="mention">@$1</a>');
}