/**
 * Routing helpers for sending notifications based on a user's
 * notificationPreference (email | whatsapp | both).
 *
 * Security-critical messages (password reset, login alert, password changed,
 * account closed) always send email regardless of preference, and additionally
 * send a WhatsApp message when preference includes it.
 *
 * Informational messages (registration, payment, tickets) respect the
 * preference fully.
 */

const { isValidZAPhone, sendText, sendPdf } = require('./whatsapp');

/** Returns true when the user should receive a WhatsApp notification. */
function canWhatsApp(user) {
  if (!user) return false;
  const pref = user.notificationPreference || 'email';
  return (pref === 'whatsapp' || pref === 'both') && isValidZAPhone(user.phoneNumber);
}

/** Returns true when the user should receive an email notification. */
function shouldEmail(user) {
  if (!user) return false;
  const pref = user.notificationPreference || 'email';
  return pref === 'email' || pref === 'both';
}

/**
 * Fire-and-forget WhatsApp text to a user.
 * Silently skips if the user can't receive WhatsApp.
 */
async function waText(user, message) {
  if (!canWhatsApp(user)) return;
  try {
    await sendText(user.phoneNumber, message);
  } catch (e) {
    console.warn('[notify] WhatsApp text failed:', e?.response?.data?.message || e.message);
  }
}

/**
 * Fire-and-forget WhatsApp PDF to a user.
 * Silently skips if the user can't receive WhatsApp.
 */
async function waPdf(user, localPdfPath, filename, caption) {
  if (!canWhatsApp(user)) return;
  try {
    await sendPdf(user.phoneNumber, localPdfPath, filename, caption);
  } catch (e) {
    console.warn('[notify] WhatsApp PDF failed:', e?.response?.data?.message || e.message);
  }
}

/**
 * Like waText but bypasses the notification preference check.
 * Use as a fallback when email is not available (guest / no valid email),
 * so the user still receives notifications via WhatsApp if they have a phone.
 */
async function waTextAny(user, message) {
  if (!user || !isValidZAPhone(user.phoneNumber)) return;
  try {
    await sendText(user.phoneNumber, message);
  } catch (e) {
    console.warn('[notify] WhatsApp text (fallback) failed:', e?.response?.data?.message || e.message);
  }
}

/**
 * Like waPdf but bypasses the notification preference check.
 * Use as a fallback when email is not available (guest / no valid email).
 */
async function waPdfAny(user, localPdfPath, filename, caption) {
  if (!user || !isValidZAPhone(user.phoneNumber)) return;
  try {
    await sendPdf(user.phoneNumber, localPdfPath, filename, caption);
  } catch (e) {
    console.warn('[notify] WhatsApp PDF (fallback) failed:', e?.response?.data?.message || e.message);
  }
}

module.exports = { canWhatsApp, shouldEmail, waText, waPdf, waTextAny, waPdfAny };