/* ============================================================
   BAN YARO — Offline-Bereitschafts-Indikator
   5-stufige Pfote im Header, zeigt wie viel der App offline
   verfügbar ist. Klick → Status-Modal mit Nachlade-Button.
   ============================================================ */

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

  // Cache-Namen — müssen mit sw.js übereinstimmen
  const CACHE_STATIC = `by-v${(window.APP_VER || '0')}-static`;
  const CACHE_TILES  = 'ban-yaro-tiles-v1';
  const CACHE_API    = 'ban-yaro-api-v1';
  const TILE_MIN     = 50;          // Mindest-Tiles für Stufe 4

  // 5 Offline-Bereitschafts-Checks, in Reihenfolge der Pfoten-Stufen
  const CHECKS = [
    { step: 1, title: 'App-Grundgerüst',
      detail: 'CSS, Layout und Hauptmodule — die Basis',
      probe:  async () => (await caches.match('/css/design-system.css?v=' + window.APP_VER)) != null
                       || (await caches.match('/css/design-system.css')) != null },

    { step: 2, title: 'Wichtige Seiten',
      detail: 'Tagebuch, Karte, Gassi, Erste Hilfe',
      probe:  async () => {
        const c = await caches.open(CACHE_STATIC).catch(() => null);
        if (!c) return false;
        const must = ['diary.js','map.js','walks.js','erste-hilfe.js'];
        const keys = await c.keys();
        const have = new Set(keys.map(r => r.url));
        return must.every(name => [...have].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 keys = await c.keys();
        const urls = 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;
        const keys = await c.keys();
        return keys.length >= TILE_MIN;
      } },

    { step: 5, title: 'Training & Wissen',
      detail: 'Übungen, Wiki-Rassen, Wetter — Welt-Inhalte',
      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/training/exercises'))
            && urls.some(u => u.includes('/api/wiki/rassen'));
      } },
  ];

  let _btn  = null;
  let _svg  = null;
  let _lastScore = -1;

  // ----------------------------------------------------------
  // Score berechnen + Pfote einfärben
  // ----------------------------------------------------------
  async function refresh() {
    if (!_btn) return;
    if (!('caches' in window)) { _btn.style.display = 'none'; return; }

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

    const score = results.filter(r => r.ok).length;
    _applyScore(score, results);
    _lastScore = score;
    return { score, results };
  }

  function _applyScore(score, results) {
    if (!_svg) return;
    _svg.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);
    });
    _btn.title = `Offline-Bereitschaft: ${score} von 5`;
    _btn.setAttribute('aria-label', `Offline-Bereitschaft: ${score} von 5`);
  }

  // ----------------------------------------------------------
  // Status-Modal beim Klick
  // ----------------------------------------------------------
  async function _openModal() {
    const data = await refresh();
    if (!data) return;
    const { score, results } = data;

    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('');

    const missing = results.filter(r => !r.ok);
    const allOk   = missing.length === 0;

    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)">
          ${allOk
            ? 'Deine App ist voll offline-fähig. Du kannst Tagebuch, Karte und Daten auch ohne Internet nutzen.'
            : 'Je grüner deine Pfote, desto besser klappt die App ohne Internet. 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();
    });
  }

  // ----------------------------------------------------------
  // Fehlende Inhalte aktiv nachladen
  // ----------------------------------------------------------
  async function _fetchMissing(missing) {
    const tasks = [];
    for (const m of missing) {
      if (m.step === 2) {
        // Page-Module fetchen → SW cached sie automatisch
        ['diary.js','map.js','walks.js','erste-hilfe.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) {
        // Karten-Tiles: SW per Message anstoßen
        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) {
        tasks.push(fetch('/api/training/exercises').catch(() => {}));
        tasks.push(fetch('/api/wiki/rassen?limit=50').catch(() => {}));
        tasks.push(fetch('/api/weather').catch(() => {}));
      }
    }
    await Promise.all(tasks);
  }

  // ----------------------------------------------------------
  // Sichtbarkeit an Welten-Overlay koppeln
  // — default sichtbar; nur ausblenden wenn explizit auf Detail-Seite
  // ----------------------------------------------------------
  function _syncVisibility() {
    if (!_btn) return;
    const ov = document.getElementById('worlds-overlay');
    if (!ov) return;                                  // ohne Welten-Overlay sichtbar lassen
    const inWorlds = ov.classList.contains('worlds-visible')
                  || ov.style.display === 'block'
                  || ov.style.display === '';
    _btn.classList.toggle('is-hidden', !inWorlds);
  }

  // ----------------------------------------------------------
  // Init
  // ----------------------------------------------------------
  function init() {
    _btn = document.getElementById('offline-indicator');
    if (!_btn) { console.warn('[OfflineIndicator] #offline-indicator nicht im DOM'); return; }
    _svg = _btn.querySelector('.offline-paw');
    _btn.addEventListener('click', _openModal);

    // MutationObserver: Welten-Overlay Klassenänderung → Indikator zeigen/verstecken
    const ov = document.getElementById('worlds-overlay');
    if (ov) {
      _syncVisibility();
      new MutationObserver(_syncVisibility).observe(ov, { attributes: true, attributeFilter: ['class', 'style'] });
    }

    refresh();

    // bei SW-Updates und alle 60s neu prüfen
    if (navigator.serviceWorker) {
      navigator.serviceWorker.addEventListener('message', e => {
        if (e?.data?.type === 'CACHE_UPDATE') refresh();
      });
    }
    setInterval(refresh, 60_000);
  }

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

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