/* ============================================================
   BAN YARO — Offline-Bereitschafts-Anzeige IM Welten-FAB
   Färbt die 5 Pfoten-Pfade je nach Cache-Stand grün:
     1 = App-Shell · 2 = Wichtige Seiten · 3 = Hund-/Tagebuchdaten
     4 = Karten-Tiles · 5 = Training & Wissen
   ============================================================ */

window.OfflineIndicator = (() => {
  'use strict';

  // Cache-Namen dynamisch finden — robust gegen Versions-Updates
  const CACHE_TILES  = 'ban-yaro-tiles-v1';
  const CACHE_API    = 'ban-yaro-api-v1';
  const TILE_MIN     = 50;

  async function _staticCache() {
    const names = await caches.keys();
    const found = names.find(n => /^by-v\d+-static$/.test(n));
    return found ? await caches.open(found) : null;
  }

  const CHECKS = [
    { step: 1, title: 'App-Grundgerüst',
      detail: 'CSS, Layout und Hauptmodule — die Basis',
      probe:  async () => {
        const c = await _staticCache();
        if (!c) return false;
        const urls = (await c.keys()).map(r => r.url);
        return urls.some(u => u.includes('/css/design-system.css'))
            && urls.some(u => u.includes('/js/app.js'));
      } },

    { step: 2, title: 'Wichtige Seiten',
      detail: 'Tagebuch, Karte, Gassi, Erste Hilfe, Notizblock, Ausgaben, Routen',
      probe:  async () => {
        const c = await _staticCache();
        if (!c) return false;
        const must = ['diary.js','map.js','walks.js','erste-hilfe.js','notes.js','expenses.js','routes.js'];
        const urls = (await c.keys()).map(r => r.url);
        return must.every(name => urls.some(u => u.includes('/js/pages/' + name)));
      } },

    { step: 3, title: 'Hund- und Tagebuchdaten',
      detail: 'Letzte Einträge und Hund-Profil',
      probe:  async () => {
        const c = await caches.open(CACHE_API).catch(() => null);
        if (!c) return false;
        const urls = (await c.keys()).map(r => r.url);
        return urls.some(u => /\/api\/dogs\/\d+/.test(u))
            && urls.some(u => /\/api\/dogs\/\d+\/diary/.test(u));
      } },

    { step: 4, title: 'Karten-Kacheln',
      detail: `Mindestens ${TILE_MIN} Tiles im Umkreis`,
      probe:  async () => {
        const c = await caches.open(CACHE_TILES).catch(() => null);
        if (!c) return false;
        return (await c.keys()).length >= TILE_MIN;
      } },

    { step: 5, title: 'Welt-Daten',
      detail: 'Streak, Wetter, Hundepass — kommt beim Welten-Aufruf',
      probe:  async () => {
        const c = await caches.open(CACHE_API).catch(() => null);
        if (!c) return false;
        const urls = (await c.keys()).map(r => r.url);
        return urls.some(u => u.includes('/api/streak/'))
            && urls.some(u => u.includes('/api/weather'));
      } },
  ];

  // Tile-Prefetch-Konfiguration
  const TILE_PREFETCH = [
    { zoom: 14, radius: 3 },   // 7x7 = 49 Tiles im Nahbereich
    { zoom: 13, radius: 1 },   // 3x3 = 9 Tiles für Übersicht
  ];

  let _fab = null;

  async function refresh() {
    _fab = document.getElementById('worlds-fab');
    if (!_fab || !('caches' in window)) return null;

    const results = await Promise.all(CHECKS.map(async c => {
      try { return { ...c, ok: await c.probe() }; }
      catch { return { ...c, ok: false }; }
    }));

    _fab.querySelectorAll('.paw-elem').forEach(el => {
      const step = Number(el.dataset.step);
      const isOk = results.find(r => r.step === step)?.ok;
      el.classList.toggle('filled', !!isOk);
    });

    const score = results.filter(r => r.ok).length;
    _fab.setAttribute('data-offline-score', `${score}/5`);
    return { score, results };
  }

  // Optional aufrufbar: zeigt das Status-Modal mit Nachlade-Button
  async function openStatus() {
    const data = await refresh();
    if (!data) return;
    const { score, results } = data;
    const missing = results.filter(r => !r.ok);
    const rows = results.map(r => `
      <div class="offline-status-row ${r.ok ? 'ok' : 'miss'}">
        <div class="osr-check">${r.ok ? '✓' : '○'}</div>
        <div class="osr-text">
          <div class="osr-title">${r.title}</div>
          <div class="osr-detail">${r.detail}</div>
        </div>
      </div>
    `).join('');

    UI.modal.open({
      title: `🐾 Offline-Bereitschaft ${score}/5`,
      body: `
        <p style="font-size:var(--text-sm);color:var(--c-text-secondary);margin:0 0 var(--space-3)">
          ${missing.length === 0
            ? 'Voll offline-fähig — Tagebuch, Karte und Daten funktionieren auch ohne Internet.'
            : 'Je grüner deine Pfote im FAB, desto mehr klappt offline. Fehlende Inhalte werden beim nächsten Online-Aufruf automatisch geladen.'}
        </p>
        ${rows}
      `,
      footer: `
        <div style="display:flex;flex-direction:column;gap:var(--space-2);width:100%">
          ${missing.length ? `<button class="btn btn-primary" id="offline-fill-btn" style="width:100%">
            ${UI.icon('cloud-arrow-down')} Fehlende jetzt nachladen
          </button>` : ''}
          <button class="btn btn-secondary" data-modal-close style="width:100%">Schließen</button>
        </div>
      `,
    });

    document.getElementById('offline-fill-btn')?.addEventListener('click', async () => {
      const btn = document.getElementById('offline-fill-btn');
      btn.disabled = true; btn.textContent = 'Lade …';
      await _fetchMissing(missing);
      UI.modal.close();
      UI.toast.success('Offline-Inhalte aktualisiert.');
      refresh();
    });
  }

  async function _fetchMissing(missing) {
    const tasks = [];
    for (const m of missing) {
      if (m.step === 2) {
        ['diary.js','map.js','walks.js','erste-hilfe.js','notes.js','expenses.js','routes.js'].forEach(p =>
          tasks.push(fetch(`/js/pages/${p}?v=${window.APP_VER}`).catch(() => {})));
      } else if (m.step === 3) {
        const dogId = window._appState?.activeDog?.id;
        if (dogId) {
          tasks.push(fetch(`/api/dogs/${dogId}`).catch(() => {}));
          tasks.push(fetch(`/api/dogs/${dogId}/diary?limit=20`).catch(() => {}));
        }
      } else if (m.step === 4) {
        if (navigator.serviceWorker?.controller) {
          const pos = await new Promise(res =>
            navigator.geolocation?.getCurrentPosition(p => res(p), () => res(null), { timeout: 4000 }));
          if (pos) {
            navigator.serviceWorker.controller.postMessage({
              type: 'CACHE_TILES', lat: pos.coords.latitude, lon: pos.coords.longitude,
              zoom: 14, radius: 2,
            });
          }
        }
      } else if (m.step === 5) {
        // Welt-Daten: Streak braucht Hund-ID, Wetter braucht GPS
        tasks.push(fetch('/api/weather').catch(() => {}));
        const dogId = window._appState?.activeDog?.id;
        if (dogId) tasks.push(fetch(`/api/streak/${dogId}`).catch(() => {}));
      }
    }
    await Promise.all(tasks);
  }

  // ----------------------------------------------------------
  // Tile-URL-Berechnung (OSM, Subdomain 'a')
  // ----------------------------------------------------------
  function _tile(lat, lon, z) {
    const n = Math.pow(2, z);
    const x = Math.floor((lon + 180) / 360 * n);
    const latRad = lat * Math.PI / 180;
    const y = Math.floor((1 - Math.log(Math.tan(latRad) + 1/Math.cos(latRad)) / Math.PI) / 2 * n);
    return { x, y };
  }
  function _tileUrls(lat, lon, zoom, radius) {
    const center = _tile(lat, lon, zoom);
    const out = [];
    for (let dx = -radius; dx <= radius; dx++) {
      for (let dy = -radius; dy <= radius; dy++) {
        out.push(`https://a.tile.openstreetmap.org/${zoom}/${center.x + dx}/${center.y + dy}.png`);
      }
    }
    return out;
  }

  // Tile-Prefetch im Umkreis der aktuellen GPS-Position (nur wenn Permission schon da)
  async function _prefetchTiles() {
    if (!navigator.serviceWorker?.controller) return;
    if (!navigator.permissions || !navigator.geolocation) return;
    try {
      const perm = await navigator.permissions.query({ name: 'geolocation' });
      if (perm.state !== 'granted') return;                    // kein Popup wenn nicht schon erlaubt
      const pos = await new Promise(res =>
        navigator.geolocation.getCurrentPosition(p => res(p), () => res(null), { timeout: 5000 }));
      if (!pos) return;
      const urls = [];
      TILE_PREFETCH.forEach(({ zoom, radius }) =>
        urls.push(..._tileUrls(pos.coords.latitude, pos.coords.longitude, zoom, radius)));
      navigator.serviceWorker.controller.postMessage({ type: 'CACHE_TILES', urls });
    } catch {}
  }

  function init() {
    refresh();
    _prefetchTiles();                                          // im Hintergrund
    if (navigator.serviceWorker) {
      navigator.serviceWorker.addEventListener('message', e => {
        if (e?.data?.type === 'CACHE_UPDATE')          refresh();
        if (e?.data?.type === 'CACHE_TILES_PROGRESS')  refresh();
      });
    }
    setInterval(refresh, 60_000);
  }

  return { init, refresh, openStatus };
})();

if (document.readyState !== 'loading') {
  window.OfflineIndicator.init();
} else {
  document.addEventListener('DOMContentLoaded', () => window.OfflineIndicator.init());
}