Notification System

// notifications.js:8-22
export let hasNotificationPermission = false;

export async function initNotifications() {
  if (!('Notification' in window)) {
    // Browser doesn't support notifications
    hasNotificationPermission = false;
  } else if (Notification.permission === 'granted') {
    // User has already granted permission
    hasNotificationPermission = true;
  } else if (Notification.permission !== 'denied') {
    // Request permission from user
    const permission = await Notification.requestPermission();
    hasNotificationPermission = permission === 'granted';
  }
}

// app.js:143 - Called during init()
initNotifications();

// 5-second delay allows state to load first
setTimeout(() => {
  startNotificationEngine();
}, 5000);

// Default silent hours: 22:00 (10 PM) to 08:00 (8 AM)
state.config.silentModeStart = 22;  // 24-hour format
state.config.silentModeEnd = 8;

// notifications.js:30-41
function isSilentHour() {
  const horaAtual = new Date().getHours();
  const silenciosoInicio = state.config?.silentModeStart || 22;
  const silenciosoFim = state.config?.silentModeEnd || 8;
  
  if (silenciosoInicio > silenciosoFim) {
    // Wraps around midnight (e.g., 22:00 to 08:00)
    return horaAtual >= silenciosoInicio || horaAtual < silenciosoFim;
  } else {
    // Same day range (e.g., 14:00 to 18:00)
    return horaAtual >= silenciosoInicio && horaAtual < silenciosoFim;
  }
}

// notifications.js:72-80
const revisoesPendentes = getPendingRevisoes();
if (revisoesPendentes && revisoesPendentes.length > 0) {
  const qtVencidas = revisoesPendentes.length;
  fireNotification(
    'Revisões Pendentes!',
    `Você tem ${qtVencidas} assunto(s) pendente(s) de revisão espaçada. Mantenha sua memória fresca!`,
    'alerta_revisao_diaria'
  );
}

// notifications.js:82-101
const metaHoras = state.config?.metas?.horasSemana || 20;
const predStats = getPredictiveStats(metaHoras);

// Alerts only activate Wed-Sat (days remaining ≤ 4)
const isLateWeek = predStats.daysRemaining <= 4 && predStats.daysRemaining > 0;

if (predStats.status === 'vermelho' && isLateWeek) {
  fireNotification(
    'Meta Semanal em Alto Risco ⚠️',
    predStats.suggestion,
    'alerta_risco_metas'
  );
} else if (predStats.status === 'amarelo' && isLateWeek) {
  fireNotification(
    'Atenção ao Ritmo 🟡',
    predStats.suggestion,
    'alerta_aviso_metas'
  );
}

// notifications.js:10, 44-49
let lastNotifiedKeys = new Set();

function fireNotification(title, body, tagKey, requireInteraction = false) {
  const todayStrKey = new Date().toLocaleDateString();
  const uniqueKey = `${todayStrKey}-${tagKey}`;
  
  if (lastNotifiedKeys.has(uniqueKey)) return;  // Already shown today
  
  // ... show notification ...
  
  lastNotifiedKeys.add(uniqueKey);
}

// notifications.js:51-57
if (hasNotificationPermission) {
  new Notification(title, {
    body: body,
    icon: 'favicon.ico',      // PWA icon
    tag: tagKey,              // Replaces same-tag notifications
    requireInteraction: false // Auto-dismiss after timeout
  });
}

// notifications.js:58-63
else {
  document.dispatchEvent(new CustomEvent('app:showToast', {
    detail: { 
      msg: `🔔 ${title}: ${body}`, 
      type: 'info', 
      duration: 8000 
    }
  }));
}

// notifications.js:104-113
export function startNotificationEngine() {
  // Initial check on boot
  checkTriggers();
  
  // Recurring checks every 4 hours (14,400,000 ms)
  if (notificationEngineInterval) clearInterval(notificationEngineInterval);
  notificationEngineInterval = setInterval(() => {
    checkTriggers();
  }, 14400000);
}

// notifications.js:68-102
function checkTriggers() {
  if (isSilentHour()) return;  // Respect silent hours
  
  // 1. Check for pending revisions
  // 2. Check weekly goal status (if Wed-Sat)
}

// 1. App initialization (app.js:143)
initNotifications();
  // ↓ Requests permission
  // ↓ Sets hasNotificationPermission
  // ↓ Starts engine after 5s

// 2. Engine starts (notifications.js:105)
startNotificationEngine();
  // ↓ Immediate checkTriggers()
  // ↓ Sets 4-hour interval

// 3. Each check (notifications.js:68)
checkTriggers();
  // ↓ Check if silent hour → return early
  // ↓ Get pending revisions
  // ↓ Calculate goal predictions
  // ↓ Fire notifications as needed

// 4. Fire notification (notifications.js:43)
fireNotification(title, body, tagKey);
  // ↓ Check if already shown today → return
  // ↓ Check silent hours → return
  // ↓ Show native or fallback
  // ↓ Add to lastNotifiedKeys

// Notification configuration in state.config
{
  silentModeStart: 22,    // Start hour (24h format)
  silentModeEnd: 8,       // End hour (24h format)
  metas: {                // Required for goal notifications
    horasSemana: 20,
    questoesSemana: 150
  },
  frequenciaRevisao: [1, 7, 30, 90]  // Required for revision notifications
}

// Available from notifications.js
export let hasNotificationPermission = false;
export async function initNotifications() { ... }
export function fireNotification(title, body, tagKey, requireInteraction) { ... }
export function startNotificationEngine() { ... }