// === Daily Satsang Frontend (enhanced) ===

let allSatsangs = [];
let player = null;
let currentVideoId = null;
let userEmail = null;
let saveInterval = null;
let initialLoaderShown = false;

// ---- Helpers ----
const API = "https://bhagvat-mongodb.hf.space";
const timeKey = (vid) => `satsang_time_${vid}`;
const extractId = (y) => (y || "").split("/").pop();

// Debounce utility
function debounce(fn, delay=400){ let t; return (...a)=>{ clearTimeout(t); t=setTimeout(()=>fn(...a), delay); }; }

// Prefer male-ish Hindi/Indian voice when possible
function pickVoice() {
  const voices = speechSynthesis.getVoices();

  // Strong filters first
  const byPref = [
    v => /sa-IN|hi-IN/i.test(v.lang) && /(male|deep|bass)/i.test(v.name),
    v => /sa-IN|hi-IN/i.test(v.lang) && /(google)/i.test(v.name) && /(male|india)/i.test(v.name),
    v => /sa-IN|hi-IN/i.test(v.lang),
    v => /en-IN/i.test(v.lang) && /(male|india)/i.test(v.name),
    v => /en-IN/i.test(v.lang),
  ];

  for (const pick of byPref) {
    const found = voices.find(pick);
    if (found) return found;
  }
  return voices[0]; // fallback
}


// ---- Init ----
window.onload = async () => {
  const token = localStorage.getItem('authToken');
  if (token) {
    try { userEmail = jwt_decode(token)?.email; } catch {}
  }
  await fetchAllSatsangs();
  await fetchUserSaved(); // fills favorites/playlists & counts

  // Show loader while we try to restore last watched
  const il = document.getElementById('initialLoader');
  il.style.display = 'flex';
  initialLoaderShown = true;
  
  await restoreLastOrKeep();

  // If nothing was loaded (user has no last video), hide the loader
  if (initialLoaderShown) il.style.display = 'none';
};

// Fetch satsangs (all)
async function fetchAllSatsangs(){
  try{
    const res = await fetch(`${API}/satsangs?type=all`);
    const data = await res.json();
    allSatsangs = data.satsangs || [];
  }catch(e){ console.error("fetchAllSatsangs", e); }
}

// Restore last watched from backend (if user), else keep last from local lastPlayedVideoId
async function restoreLastOrKeep(){
  let lastId = localStorage.getItem("lastPlayedVideoId");

  if (userEmail){
    try{
      const r = await fetch(`${API}/get_user_saved?email=${encodeURIComponent(userEmail)}`);
      const saved = await r.json();
      if (saved?.last_video_id) lastId = saved.last_video_id;
    }catch(e){ console.warn("get_user_saved last_video_id failed", e); }
  }

  if (lastId){
    const match = allSatsangs.find(s => (extractId(s.youtube) === lastId) || (s.youtube === lastId));
    if (match){
      await showSatsang(match, {autoPlay:true});
      return;
    }
  }
  // If no match, do nothing (user can hit Play Random)
}


function showRandomLoader(){ const el = document.getElementById('randomLoader'); if (el) el.style.display = 'block'; }
function hideRandomLoader(){ const el = document.getElementById('randomLoader'); if (el) el.style.display = 'none'; }

// Load random with filters + exclude previously played local (played list deprecated in favor of DB history)
async function loadNextSatsang(){
  showRandomLoader();
  try {
    const type = document.getElementById('satsangType').value;
    const tagSearch = document.getElementById('tagSearch').value.trim().toLowerCase();
  
    let filtered = allSatsangs.filter(s=>{
      if (!s?.youtube) return false;
      const matchesType = (type==='all') || (s.type===type);
      const matchesTag = !tagSearch || (Array.isArray(s.tags) && s.tags.some(t=>t.toLowerCase().includes(tagSearch)));
      return matchesType && matchesTag;
    });
    if (!filtered.length){ alert("No satsang videos found to play."); return; }
  
    const pick = filtered[Math.floor(Math.random()*filtered.length)];
    await showSatsang(pick, {autoPlay:true});
  } finally {
    // if player starts, we'll also hide in onPlayerStateChange
    setTimeout(()=> hideRandomLoader(), 1200); // safety hide
  }
}

// --- Advanced Search: debounce + backend scoring; loads BEST match automatically
const doSearch = debounce(async ()=>{
  const q = document.getElementById('tagSearch').value.trim();
  if (!q) return;
  const type = document.getElementById('satsangType').value;
  try{
    const res = await fetch(`${API}/satsangs/search?q=${encodeURIComponent(q)}&type=${encodeURIComponent(type)}`);
    const data = await res.json();
    const best = data.results?.[0];
    if (best) await showSatsang(best, {autoPlay:true});
    else alert("No matching satsangs found.");
  }catch(e){
    console.error("search failed", e);
  }
}, 500);

document.addEventListener('input', (e)=>{
  if (e.target && e.target.id === 'tagSearch') doSearch();
});

// ---- Player + state/time ----
function whenYTReady(cb){
  if (window.YT && YT.Player) return cb();
  const prev = window.onYouTubeIframeAPIReady;
  window.onYouTubeIframeAPIReady = function(){ prev && prev(); cb(); };
}

async function showSatsang(data, opts={}){
  document.getElementById("videoTitle").textContent = data.title || "Untitled";
  document.getElementById("videoDescription").textContent = data.description || "";
  document.getElementById("transcriptContent").textContent =
    Array.isArray(data.transcript) ? data.transcript.map(t=>t.text).join(" ") : (data.transcript || "No transcript available.");

  const videoId = extractId(data.youtube);
  currentVideoId = videoId;
  localStorage.setItem("lastPlayedVideoId", videoId);

  // tell backend "this is my last watched" + add to history_ids (no time)
  if (userEmail){
    fetch(`${API}/user/set_last_watched`, {
      method:'POST',
      headers:{'Content-Type':'application/json'},
      body: JSON.stringify({email:userEmail, video_id:videoId})
    }).catch(()=>{});
  }

  const startSeconds = Math.max(0, (parseFloat(localStorage.getItem(timeKey(videoId))) || 0) - 5);

  whenYTReady(()=>{
    const container = document.getElementById('player');
    if (!container){ console.error("Missing #player"); return; }

    const params = { height:'315', width:'100%', videoId, playerVars:{autoplay:1, start:startSeconds, rel:0, controls:1}, events:{ onStateChange:onPlayerStateChange } };
    if (!player) player = new YT.Player('player', params);
    else {
      try { player.loadVideoById({ videoId, startSeconds }); }
      catch { player = new YT.Player('player', params); }
    }
  });
}

function onPlayerStateChange(e){
  if (!currentVideoId) return;

  if (e.data === YT.PlayerState.PLAYING){
    hideRandomLoader();
    const il = document.getElementById('initialLoader');
    if (initialLoaderShown && il) { il.style.display = 'none'; initialLoaderShown = false; }
    clearInterval(saveInterval);
    saveInterval = setInterval(()=>{
      const t = Math.floor(player?.getCurrentTime?.() || 0);
      if (t>0){
        localStorage.setItem(timeKey(currentVideoId), t);
        // Optional: still ping backend to record history (id only)
        if (userEmail){
          fetch(`${API}/update_progress`, {
            method:'POST', headers:{'Content-Type':'application/json'},
            body: JSON.stringify({email:userEmail, video_id: currentVideoId})
          }).catch(()=>{});
        }
      }
    }, 8000);
  }

  if (e.data === YT.PlayerState.PAUSED || e.data === YT.PlayerState.ENDED){
    clearInterval(saveInterval); saveInterval=null;
    const t = Math.floor(player?.getCurrentTime?.() || 0);
    if (t>0) localStorage.setItem(timeKey(currentVideoId), t);
  }
}


function cancelInitialAndPlayRandom(){
  const il = document.getElementById('initialLoader');
  if (il) il.style.display = 'none';
  initialLoaderShown = false;
  loadNextSatsang();
}


// ---- Favorites & Playlists (instant UI, titles not ids) ----
async function fetchUserSaved(){
  if (!userEmail) return;
  const res = await fetch(`${API}/get_user_saved?email=${encodeURIComponent(userEmail)}`);
  const data = await res.json();
  const div = document.getElementById("savedContent");
  div.innerHTML = "";

  const idToTitle = {};
  (allSatsangs || []).forEach(s => { idToTitle[extractId(s.youtube)] = s.title || extractId(s.youtube); });

  if (Array.isArray(data.favorites) && data.favorites.length){
    const html = data.favorites.map(v=>{
      const vid = extractId(v);
      const title = idToTitle[vid] || vid;
      return `<li><span class="saved-item" onclick="loadFromId('${vid}')">${title}</span></li>`;
    }).join("");
    div.innerHTML += `<h4>Favorites</h4><ul class="saved-list">${html}</ul>`;
  }

    if (data.playlists){
    for (const [name, videos] of Object.entries(data.playlists)){
      const html = (videos||[]).map(v=>{
        const vid = extractId(v);
        const title = idToTitle[vid] || vid;
        return `<li><span class="saved-item" onclick="loadFromId('${vid}')">${title}</span></li>`;
      }).join("");
      div.innerHTML += `
        <details>
          <summary>${name}</summary>
          <ul class="saved-list">${html || "<li><em>Empty</em></li>"}</ul>
        </details>`;
    }
  }

  // Counts: short & long
  if (Array.isArray(data.history_ids)){
    let short = 0, long = 0;
    const typeMap = {};
    allSatsangs.forEach(s => typeMap[extractId(s.youtube)] = s.type);
    data.history_ids.forEach(id=>{
      const t = typeMap[extractId(id)];
      if (t === 'short') short++;
      if (t === 'long') long++;
    });
    document.getElementById('shortCount').textContent = short;
    document.getElementById('longCount').textContent = long;
  }
}

function viewSaved(){
  document.querySelector('.saved-block')?.scrollIntoView({behavior:'smooth', block:'start'});
}


async function markFavorite(){
  if (!currentVideoId || !userEmail){ alert("Login required to mark favorite."); return; }
  await fetch(`${API}/mark_favorite`, { method:'POST', headers:{'Content-Type':'application/json'},
    body: JSON.stringify({ email:userEmail, video_id: currentVideoId }) });
  // Refresh list instantly
  await fetchUserSaved();
  alert("Added to Favorites");
}

async function addToPlaylist(){
  const playlist = document.getElementById('playlistName').value.trim();
  if (!playlist || !currentVideoId || !userEmail){ alert("Login and playlist name required."); return; }
  await fetch(`${API}/add_to_playlist`, { method:'POST', headers:{'Content-Type':'application/json'},
    body: JSON.stringify({ email:userEmail, playlist_name: playlist, video_id: currentVideoId }) });
  await fetchUserSaved();
  alert(`Added to "${playlist}" playlist.`);
}

async function removeFromPlaylist(){
  const playlist = document.getElementById('playlistName').value.trim();
  if (!playlist || !currentVideoId || !userEmail){ alert("Login and playlist name required."); return; }
  await fetch(`${API}/remove_from_playlist`, { method:'POST', headers:{'Content-Type':'application/json'},
    body: JSON.stringify({ email:userEmail, playlist_name: playlist, video_id: currentVideoId }) });
  await fetchUserSaved();
  alert(`Removed from "${playlist}".`);
}

async function renamePlaylistPrompt(){
  if (!userEmail){ alert("Login required."); return; }
  const oldName = document.getElementById('playlistName').value.trim();
  if (!oldName){ alert("Type the current playlist name first."); return; }

  const newName = prompt("Enter new playlist name:", oldName);
  if (!newName || newName.trim() === oldName) return;

  const res = await fetch(`${API}/rename_playlist`, {
    method:'POST', headers:{'Content-Type':'application/json'},
    body: JSON.stringify({ email:userEmail, old_name: oldName, new_name: newName.trim() })
  });
  const data = await res.json();
  if (res.ok) {
    document.getElementById('playlistName').value = newName.trim();
    await fetchUserSaved();
    alert(`Playlist renamed to "${newName.trim()}"`);
  } else {
    alert(data.error || "Rename failed");
  }
}


function loadFromId(videoId){
  const match = allSatsangs.find(s => extractId(s.youtube) === videoId || s.youtube === videoId);
  if (match) showSatsang(match, {autoPlay:true});
}

// ---- Lock / Unlock Overlay ----
function toggleLockScreen(){
  const overlay = document.createElement("div");
  overlay.id = "customLockOverlay";
  Object.assign(overlay.style, {
    position:"fixed", top:"0", left:"0", width:"100vw", height:"100vh",
    background:"transparent", zIndex:"9999", display:"flex",
    justifyContent:"flex-end", alignItems:"flex-start", pointerEvents:"auto"
  });
  const btn = document.createElement("button");
  btn.innerHTML = "🔓"; btn.title = "Unlock Screen";
  Object.assign(btn.style, { margin:"10px", padding:"10px", fontSize:"20px", backgroundColor:"white", borderRadius:"8px", boxShadow:"0 0 10px rgba(0,0,0,0.2)" });
  btn.onclick = ()=>document.body.removeChild(overlay);
  overlay.appendChild(btn);
  document.body.appendChild(overlay);
}

function unlockScreen(e){ e?.stopPropagation?.(); document.getElementById('lockOverlay').style.display='none'; }


/************ TTS: Respect user language, voice, rate, pitch ************/

/** Try to read TTS prefs from your existing popup/menu/state.
 *  We support several sources so we don't break your UI:
 *    - window.ttsPrefs = {lang, voiceName, rate, pitch, engine}
 *    - localStorage keys: tts.lang, tts.voiceName, tts.rate, tts.pitch, tts.engine
 *    - DOM (OPTIONAL): #ttsLang, #voiceSelect, #ttsRate, #ttsPitch, #ttsEngine
 *  engine: 'browser' (default) or 'server' (optional if you also wired server TTS)
 */
function getTTSPrefs() {
  const pick = (domId, lsKey, fallback) => {
    const domEl = document.getElementById(domId);
    if (domEl && domEl.value) return domEl.value;
    const ls = localStorage.getItem(lsKey);
    if (ls !== null && ls !== undefined && ls !== '') return ls;
    return fallback;
  };

  const fromWin = (window.ttsPrefs && typeof window.ttsPrefs === 'object') ? window.ttsPrefs : {};

  const prefs = {
    lang: fromWin.lang || pick('ttsLang', 'tts.lang', 'hi-IN'),         // default Hindi
    voiceName: fromWin.voiceName || pick('voiceSelect', 'tts.voiceName', ''), // exact voice name if saved
    rate: parseFloat(fromWin.rate ?? pick('ttsRate', 'tts.rate', '0.85')) || 0.85,
    pitch: parseFloat(fromWin.pitch ?? pick('ttsPitch', 'tts.pitch', '0.8')) || 0.8,
    engine: (fromWin.engine || pick('ttsEngine', 'tts.engine', 'browser')).toLowerCase()
  };

  return prefs;
}

/** Promise that resolves when voices are loaded (Chrome quirk). */
function loadVoicesOnce() {
  return new Promise(resolve => {
    const have = speechSynthesis.getVoices();
    if (have && have.length) return resolve(have);
    const handler = () => {
      const vs = speechSynthesis.getVoices();
      if (vs && vs.length) {
        speechSynthesis.onvoiceschanged = null;
        resolve(vs);
      }
    };
    speechSynthesis.onvoiceschanged = handler;
    // Edge case: poke the engine to trigger load
    setTimeout(() => handler(), 50);
  });
}

/** Find a voice by exact name if provided; else pick best match for lang; else fallback. */
function resolveVoice(voices, { lang, voiceName }) {
  // exact voice name match first
  if (voiceName) {
    const byName = voices.find(v => v.name === voiceName);
    if (byName) return byName;
  }

  // next: best match inside selected language
  const sameLang = voices.filter(v => (v.lang || '').toLowerCase() === (lang || '').toLowerCase());
  if (sameLang.length) {
    // try to prefer deeper/male-ish names if exist
    const preferred = sameLang.find(v => /(male|deep|bass|baritone)/i.test(v.name)) || sameLang[0];
    return preferred;
  }

  // next: language prefix match (e.g., hi vs hi-IN)
  const langPrefix = (lang || '').split('-')[0];
  if (langPrefix) {
    const pref = voices.filter(v => (v.lang || '').toLowerCase().startsWith(langPrefix.toLowerCase()));
    if (pref.length) return pref[0];
  }

  // final fallback
  return voices[0];
}

/** Split transcript into natural chunks: danda, punctuation, comma, pipe. */
function buildTranscriptChunks(text) {
  const parts = text.split(/[।॥.!?\u0964\u0965,|]\s*/).filter(Boolean);
  const chunks = [];
  let buf = '';
  for (const p of parts) {
    const next = buf ? (buf + ' ' + p) : p;
    if (next.length > 200) { // keep chunks ~180-220 chars
      if (buf) chunks.push(buf.trim());
      buf = p;
    } else {
      buf = next;
    }
  }
  if (buf) chunks.push(buf.trim());
  return chunks;
}

/** Speak an array of chunks with the browser engine. */
async function speakChunksBrowser(chunks, prefs) {
  const voices = await loadVoicesOnce();
  const v = resolveVoice(voices, prefs);

  // clear any residual queue
  try { speechSynthesis.cancel(); } catch {}

  ttsPaused = false;
  ttsUtterances = chunks.map(txt => {
    const u = new SpeechSynthesisUtterance(txt);
    u.voice  = v;
    u.lang   = v?.lang || prefs.lang || 'hi-IN';
    u.rate   = prefs.rate;   // slower
    u.pitch  = prefs.pitch;  // deeper
    u.volume = 1.0;
    return u;
  });

  await new Promise(resolve => {
    const speakNext = () => {
      if (!ttsUtterances.length) return resolve();
      const u = ttsUtterances.shift();
      u.onend = () => { if (!ttsPaused) setTimeout(speakNext, 150); };
      u.onerror = () => { if (!ttsPaused) setTimeout(speakNext, 150); };
      try { speechSynthesis.speak(u); } catch { setTimeout(speakNext, 150); }
    };
    speakNext();
  });
}

/** OPTIONAL: server TTS if you support it (engine === 'server').
 *  Keep this if you already wired a server TTS route; otherwise ignore.
 *  Expects POST /tts_hi_male (or your multi-lang route) {text, lang, rate, pitch, voiceName?}
 */
async function speakChunksServer(chunks, prefs) {
  // Map browser slider to SSML style values roughly
  const ssmlRate  = prefs.rate <= 0.9 ? '-15%' : '-5%';
  const ssmlPitch = prefs.pitch <= 0.85 ? '-4st' : '-2st';

  for (const chunk of chunks) {
    const res = await fetch(`${API.replace('/satsangs','')}/tts_hi_male`, {
      method: 'POST',
      headers: {'Content-Type': 'application/json'},
      body: JSON.stringify({
        text: chunk,
        lang: prefs.lang,        // if your backend supports switching voices per lang
        rate: ssmlRate,
        pitch: ssmlPitch,
        voiceName: prefs.voiceName || '' // optional: exact server voice
      })
    });
    if (!res.ok) throw new Error('Server TTS failed');
    const blob = await res.blob();
    await new Promise(resolve => {
      const url = URL.createObjectURL(blob);
      const audio = new Audio(url);
      audio.onended = () => { URL.revokeObjectURL(url); setTimeout(resolve, 120); };
      audio.onerror = () => { URL.revokeObjectURL(url); setTimeout(resolve, 120); };
      audio.play();
    });
  }
}

/** Public controls */
function pauseTranscriptTTS(){ try{ speechSynthesis.pause(); ttsPaused = true; }catch{} }
function resumeTranscriptTTS(){ try{ speechSynthesis.resume(); ttsPaused = false; }catch{} }
function stopTranscriptTTS(silent=false){
  try{ speechSynthesis.cancel(); }catch{}
  ttsPaused = false; ttsUtterances = [];
  if (!silent) {/* noop */}
}

/** Main entry: follows user’s selected language, voice, rate, pitch, engine. */
async function playTranscriptTTS() {
  const textEl = document.getElementById('transcriptContent');
  if (!textEl) return alert('Transcript element not found.');
  const text = textEl.textContent.trim();
  if (!text) return alert('No transcript to play.');

  stopTranscriptTTS(true);

  const prefs = getTTSPrefs(); // <- read from your popup/menu/localStorage
  const chunks = buildTranscriptChunks(text);

  try {
    if (prefs.engine === 'server') {
      // if you have server engine wired per language/voice
      await speakChunksServer(chunks, prefs);
    } else {
      await speakChunksBrowser(chunks, prefs);
    }
  } catch (e) {
    console.warn('TTS failed, trying browser fallback…', e);
    try { await speakChunksBrowser(chunks, prefs); } catch {}
  }
}

// // ---- Transcript TTS (male-ish, slow, resonant) ----
// let ttsUtterances = [];
// let ttsPaused = false;

// function buildTranscriptChunks(text){
//   // Split on Sanskrit danda, punctuation, comma, and pipe with spaces optionally after
//   const parts = text.split(/[।॥.!?,|]\s*/).filter(Boolean);

//   // Merge into ~180-220 char chunks for natural pacing
//   const chunks = [];
//   let buffer = "";
//   for (const p of parts){
//     if ((buffer + " " + p).length > 200){
//       if (buffer) chunks.push(buffer.trim());
//       buffer = p;
//     } else buffer = (buffer ? buffer + " " : "") + p;
//   }
//   if (buffer) chunks.push(buffer.trim());
//   return chunks;
// }

// function playTranscriptTTS(){
//   const text = document.getElementById('transcriptContent').textContent.trim();
//   if (!text){ alert("No transcript to play."); return; }
//   stopTranscriptTTS(true); // clear any existing
//   const rate = parseFloat(document.getElementById('ttsRate').value || "0.85");
//   const pitch = parseFloat(document.getElementById('ttsPitch').value || "0.8");

//   const voice = pickVoice();
//   const chunks = buildTranscriptChunks(text);

//   ttsUtterances = chunks.map(chunk=>{
//     const u = new SpeechSynthesisUtterance(chunk);
//     u.voice = voice;
//     u.lang = (voice?.lang || "hi-IN");
//     u.rate = rate; // slower
//     u.pitch = pitch; // slightly deeper
//     u.volume = 1.0; // loud
//     // add small pause between chunks
//     u.onend = ()=>{ if (ttsUtterances.length) setTimeout(()=>{}, 250); };
//     return u;
//   });

//   // Some browsers need async voice load
//   const startSpeaking = () => {
//     // Chain play
//     function speakNext(){
//       if (!ttsUtterances.length) return;
//       const u = ttsUtterances.shift();
//       u.onend = ()=>{ if (!ttsPaused) speakNext(); };
//       try { speechSynthesis.speak(u); } catch {}
//     }
//     speakNext();
//   };

//   if (speechSynthesis.getVoices().length === 0) {
//     speechSynthesis.onvoiceschanged = () => startSpeaking();
//   } else {
//     startSpeaking();
//   }
// }

// function pauseTranscriptTTS(){ try{ speechSynthesis.pause(); ttsPaused = true; }catch{} }
// function resumeTranscriptTTS(){ try{ speechSynthesis.resume(); ttsPaused = false; }catch{} }
// function stopTranscriptTTS(silent=false){
//   try{ speechSynthesis.cancel(); }catch{}
//   ttsPaused = false; ttsUtterances = [];
//   if (!silent) { /* noop */ }
// }

// Logout helper (if you ever need)
function logout(){ localStorage.removeItem("authToken"); window.location.href = "login.html"; }