const URL = /https?:\/\/\S+/gi;
const EMAIL = /\b[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,}\b/gi;
const PHONE = /(?<!\w)(?:\+?\d[\d ()-]{7,}\d)(?!\w)/g;
const USERNAME = /(?:^|\s)(?:u\/|@)[A-Za-z0-9_-]{2,}/g;

/** Removes direct identifiers before durable example storage or prompt use. */
export function redactLearningText(value: string, maxLength = 500): string {
  return value
    .replace(URL, '[url]')
    .replace(EMAIL, '[email]')
    .replace(PHONE, '[phone]')
    .replace(USERNAME, (match) => `${match[0] === ' ' ? ' ' : ''}[username]`)
    .replace(/\s+/g, ' ')
    .trim()
    .slice(0, maxLength);
}