'use strict';

// ── Compatibility helpers ─────────────────────────────────────────────────────

// fetch() is available from Safari 10.1 / iOS 10.3 onwards.
// For iOS 9 (iPad 2) we fall back to a minimal XHR wrapper that matches
// the subset of the fetch API we actually use.
function apiFetch(url, opts) {
  if (window.fetch) return fetch(url, opts);
  opts = opts || {};
  return new Promise(function(resolve, reject) {
    var xhr = new XMLHttpRequest();
    xhr.open(opts.method || 'GET', url);
    var headers = opts.headers || {};
    Object.keys(headers).forEach(function(k) { xhr.setRequestHeader(k, headers[k]); });
    xhr.onload = function() {
      var text = xhr.responseText;
      resolve({
        ok:   xhr.status >= 200 && xhr.status < 300,
        json: function() { return JSON.parse(text); },
        text: function() { return text; }
      });
    };
    xhr.onerror = function() { reject(new Error('XHR error')); };
    xhr.send(opts.body || null);
  });
}

// String.prototype.padStart not available in iOS < 10.
function pad2(n) { return n < 10 ? '0' + n : '' + n; }

// iOS version detection — used to pick emoji vs. ASCII symbols.
// Media-control emoji (⏮ ⏸ ⏹ ⏭) and several other glyphs are absent on iOS 9.
var isLegacyIOS = (function() {
  var m = navigator.userAgent.match(/OS (\d+)_/);
  return /iPad|iPhone/.test(navigator.userAgent) && m && parseInt(m[1], 10) <= 9;
}());

// Symbol set: modern emoji for capable browsers, plain text for iOS ≤ 9.
var SYM = isLegacyIOS ? {
  prev:    '<<',
  play:    '►',   // U+25BA — text-presentation pointer (▶ U+25B6 fails as broken emoji on iOS 9)
  pause:   '||',
  stop:    '■',   // U+25A0 — works on iOS 9
  next:    '>>',
  volOn:   'vol',
  volOff:  'mut',
  playlist:'PL',
  skip:    '✕'    // U+2715 — works on iOS 9
} : {
  prev:    '⏮',
  play:    '▶',
  pause:   '⏸',
  stop:    '⏹',
  next:    '⏭',
  volOn:   '🔊',
  volOff:  '🔇',
  playlist:'📋',
  skip:    '🚫'
};

// NodeList.prototype.forEach not available in iOS < 10.
// Wrap querySelectorAll results in a real Array before iterating.
function qsa(selector, root) {
  return Array.prototype.slice.call((root || document).querySelectorAll(selector));
}

// ── DOM refs ──────────────────────────────────────────────────────────────────
var $ = function(id) { return document.getElementById(id); };

var statusDot       = $('winamp-status');
var stateLabel      = $('state-label');
var trackTitle      = $('track-title');
var playlistPos     = $('playlist-pos');
var progressFill    = $('progress-fill');
var timeCurrent     = $('time-current');
var timeLength      = $('time-length');
var volumeFill      = $('volume-fill');
var volumePct       = $('volume-pct');
var btnMute         = $('btn-mute');
var btnPlay         = $('btn-play');
var killistPanel    = $('killist-panel');
var killistItems    = $('killist-items');
var playlistOverlay = $('playlist-overlay');
var playlistList    = $('playlist-list');
var canvas          = $('viz');
var ctx2d           = canvas.getContext('2d');

// ── State ─────────────────────────────────────────────────────────────────────
var currentVolume      = 50;
var currentPlaylistPos = 0;   // 1-based, updated from status
var currentRating      = -1;  // -1 = not yet loaded
var lastRatedTitle     = '';  // track we last fetched rating for
var ws = null;
var reconnectTimer = null;

// Viz state
var NUM_BARS  = 64;
var peaks     = new Float32Array(NUM_BARS);
var lastBars  = new Float32Array(NUM_BARS);
var rafId     = null;
var lastVizAt = 0;       // timestamp of last received viz frame
var winampPlaying = false;

// Canvas display mode — cycles on click: viz → actual → remaining → viz
var VIZ_MODES = ['viz', 'actual', 'remaining'];
var vizMode   = 'viz';
var currentPosition = 0;
var currentLength   = 0;

// ── WebSocket ─────────────────────────────────────────────────────────────────
function connect() {
  var proto = location.protocol === 'https:' ? 'wss' : 'ws';
  ws = new WebSocket(proto + '://' + location.host + '/ws');

  ws.addEventListener('open', function() {
    statusDot.className = 'ok';
    stateLabel.textContent = 'Verbunden';
    clearTimeout(reconnectTimer);
  });

  ws.addEventListener('close', function() {
    statusDot.className = 'err';
    stateLabel.textContent = 'Verbindung unterbrochen…';
    ws = null;
    reconnectTimer = setTimeout(connect, 3000);
  });

  ws.addEventListener('error', function() { ws.close(); });

  ws.addEventListener('message', function(e) {
    var msg;
    try { msg = JSON.parse(e.data); } catch(_e) { return; }
    if (msg.type === 'status') applyStatus(msg);
    if (msg.type === 'viz')    applyViz(msg.bars);
  });
}

function send(obj) {
  if (ws && ws.readyState === WebSocket.OPEN) {
    ws.send(JSON.stringify(obj));
  }
}

// ── Status handler ────────────────────────────────────────────────────────────
function applyStatus(st) {
  if (!st.running) {
    statusDot.className = 'err';
    stateLabel.textContent = 'Winamp nicht gestartet';
    trackTitle.textContent = '–';
    playlistPos.textContent = '';
    return;
  }

  statusDot.className = 'ok';
  var stateMap = { playing: '▶ Spielt', paused: '⏸ Pause', stopped: '⏹ Stop' };
  stateLabel.textContent = stateMap[st.state] != null ? stateMap[st.state] : st.state;

  trackTitle.textContent = st.title || '–';

  // Fetch rating whenever the track changes.
  if (st.title && st.title !== lastRatedTitle) {
    lastRatedTitle = st.title;
    fetchRating();
  }
  if (!st.title || !st.running) {
    lastRatedTitle = '';
    renderStars(0);
  }

  playlistPos.textContent = st.playlist_length
    ? st.playlist_pos + ' / ' + st.playlist_length : '';

  if (st.playlist_pos !== currentPlaylistPos) {
    currentPlaylistPos = st.playlist_pos;
    updatePlaylistHighlight();
  }

  if (st.length > 0) {
    currentPosition = st.position;
    currentLength   = st.length;
    progressFill.style.width = (st.position / st.length * 100).toFixed(1) + '%';
    timeCurrent.textContent  = fmtTime(st.position);
    timeLength.textContent   = '-' + fmtTime(st.length - st.position);
  } else {
    progressFill.style.width = '0%';
    timeCurrent.textContent  = '0:00';
    timeLength.textContent   = '-0:00';
  }

  btnPlay.textContent = st.state === 'playing' ? SYM.pause : SYM.play;
  winampPlaying = st.state === 'playing';

  if (typeof st.volume === 'number') {
    currentVolume = st.volume;
    updateVolumeFill(st.muted);
    updateMuteBtn(st.muted);
  }
}

// ── Controls ──────────────────────────────────────────────────────────────────
btnPlay.addEventListener('click', function() {
  var playing = btnPlay.textContent === SYM.pause;
  send({ cmd: playing ? 'pause' : 'play' });
});

$('btn-stop').addEventListener('click', function() { send({ cmd: 'stop' }); });
$('btn-next').addEventListener('click', function() { send({ cmd: 'next' }); });
$('btn-prev').addEventListener('click', function() { send({ cmd: 'prev' }); });

qsa('.btn-seek').forEach(function(btn) {
  btn.addEventListener('click', function() {
    send({ cmd: 'seek', delta: parseInt(btn.dataset.delta, 10) });
  });
});

$('progress-bar').addEventListener('click', function(e) {
  var current   = parseTime(timeCurrent.textContent);
  var remaining = parseTime(timeLength.textContent.replace('-', ''));
  var total     = current + remaining;
  if (!total) return;
  var rect   = e.currentTarget.getBoundingClientRect();
  var target = Math.round((e.clientX - rect.left) / rect.width * total);
  send({ cmd: 'seek', delta: target - current });
});

// ── Volume ────────────────────────────────────────────────────────────────────
$('btn-vol-up').addEventListener('click', function() {
  currentVolume = Math.min(100, currentVolume + 5);
  send({ cmd: 'volume', level: currentVolume });
  updateVolumeFill();
});
$('btn-vol-down').addEventListener('click', function() {
  currentVolume = Math.max(0, currentVolume - 5);
  send({ cmd: 'volume', level: currentVolume });
  updateVolumeFill();
});
$('volume-bar').addEventListener('click', function(e) {
  var rect = e.currentTarget.getBoundingClientRect();
  currentVolume = Math.round((e.clientX - rect.left) / rect.width * 100);
  send({ cmd: 'volume', level: currentVolume });
  updateVolumeFill();
});
btnMute.addEventListener('click', function() {
  var nowMuted = btnMute.classList.contains('muted');
  send({ cmd: 'mute', muted: !nowMuted });
  updateMuteBtn(!nowMuted);
  updateVolumeFill(!nowMuted);
});

function updateVolumeFill(muted) {
  if (muted === undefined) muted = btnMute.classList.contains('muted');
  volumeFill.style.width = currentVolume + '%';
  volumePct.textContent  = currentVolume + ' %';
  volumeFill.classList.toggle('muted', muted);
}
function updateMuteBtn(muted) {
  btnMute.textContent = muted ? SYM.volOff : SYM.volOn;
  if (isLegacyIOS) { btnMute.style.fontSize = '16px'; btnMute.style.fontWeight = 'bold'; }
  btnMute.classList.toggle('muted', muted);
}

// ── Rating (stars) ────────────────────────────────────────────────────────────
var starEls = qsa('.star');

function fetchRating() {
  apiFetch('/api/rating')
    .then(function(r) { return r.json(); })
    .then(function(data) {
      currentRating = data.stars != null ? data.stars : 0;
      renderStars(currentRating);
    })
    .catch(function() { renderStars(0); });
}

function renderStars(n) {
  currentRating = n;
  starEls.forEach(function(s) {
    var v   = parseInt(s.dataset.v, 10);
    var lit = v <= n;
    s.textContent = lit ? '★' : '☆';
    s.classList.toggle('lit', lit);
  });
}

starEls.forEach(function(s) {
  s.addEventListener('click', function() {
    var v          = parseInt(s.dataset.v, 10);
    var newRating  = v === currentRating ? 0 : v;
    var prevRating = currentRating;
    renderStars(newRating);
    apiFetch('/api/rating', {
      method:  'POST',
      headers: { 'Content-Type': 'application/json' },
      body:    JSON.stringify({ stars: newRating }),
    }).catch(function() { renderStars(prevRating); });
  });
});

// ── KillList ──────────────────────────────────────────────────────────────────
$('btn-kill').addEventListener('click', function() {
  send({ cmd: 'killist_add' });
  showToast('🚫 Track zur Skip-Liste hinzugefügt');
});

$('btn-show-killist').addEventListener('click', function() {
  apiFetch('/api/killist')
    .then(function(r) { return r.json(); })
    .then(function(list) { renderKillist(list || []); })
    .catch(function()    { renderKillist([]); });
});

function renderKillist(list) {
  killistItems.innerHTML = '';
  list.forEach(function(title) {
    var li  = document.createElement('li');
    li.innerHTML = '<span>' + escHtml(title) + '</span>';
    var btn = document.createElement('button');
    btn.textContent = '✕';
    btn.onclick = function() {
      send({ cmd: 'killist_remove', title: title });
      li.remove();
    };
    li.appendChild(btn);
    killistItems.appendChild(li);
  });
  killistPanel.classList.remove('hidden');
}

$('btn-close-killist').addEventListener('click', function() {
  killistPanel.classList.add('hidden');
});

// ── Visualisation (Canvas) ────────────────────────────────────────────────────
canvas.addEventListener('click', function() {
  vizMode = VIZ_MODES[(VIZ_MODES.indexOf(vizMode) + 1) % VIZ_MODES.length];
});

function applyViz(bars) {
  if (!bars || bars.length === 0) return;
  lastBars = new Float32Array(bars);
  lastVizAt = performance.now();
}

function renderFrame(ts) {
  ts = ts || 0;
  rafId = requestAnimationFrame(renderFrame);

  // Resize canvas to CSS size (handles window resize / DPR).
  var dpr  = window.devicePixelRatio || 1;
  var cssW = canvas.clientWidth;
  var cssH = canvas.clientHeight;
  if (canvas.width  !== Math.round(cssW * dpr) ||
      canvas.height !== Math.round(cssH * dpr)) {
    canvas.width  = Math.round(cssW * dpr);
    canvas.height = Math.round(cssH * dpr);
    ctx2d.scale(dpr, dpr);
  }

  var w = cssW;
  var h = cssH;
  if (w === 0 || h === 0) return;

  // Background
  ctx2d.fillStyle = '#000';
  ctx2d.fillRect(0, 0, w, h);

  // ── Time display modes ──────────────────────────────────────────────────────
  if (vizMode === 'actual' || vizMode === 'remaining') {
    var isActual = vizMode === 'actual';
    var secs     = isActual ? currentPosition : Math.max(0, currentLength - currentPosition);
    var prefix   = isActual ? '' : '-';
    var timeStr  = prefix + fmtTimeLong(secs);
    var label    = isActual ? 'ELAPSED' : 'REMAINING';

    ctx2d.textAlign    = 'center';
    ctx2d.textBaseline = 'middle';

    ctx2d.font      = 'bold ' + Math.round(h * 0.52) + 'px monospace';
    ctx2d.fillStyle = isActual ? '#e0e0e0' : '#e94560';
    ctx2d.fillText(timeStr, w / 2, h * 0.48);

    ctx2d.font      = Math.round(h * 0.18) + 'px monospace';
    ctx2d.fillStyle = '#444';
    ctx2d.fillText(label, w / 2, h * 0.82);
    return;
  }

  // ── Spectrum mode ───────────────────────────────────────────────────────────
  var hasSignal = winampPlaying && (performance.now() - lastVizAt) < 1500;

  // Classic fixed vertical gradient: green at bottom → yellow → red at top.
  var grad = ctx2d.createLinearGradient(0, h, 0, 0);
  if (hasSignal) {
    grad.addColorStop(0,   '#00aa00');
    grad.addColorStop(0.6, '#aaaa00');
    grad.addColorStop(1,   '#cc0000');
  } else {
    grad.addColorStop(0,   '#003300');
    grad.addColorStop(0.6, '#333300');
    grad.addColorStop(1,   '#330000');
  }

  var n    = NUM_BARS;
  var gap  = 1;
  var barW = Math.max(1, (w - gap * (n - 1)) / n);

  for (var i = 0; i < n; i++) {
    var val;

    if (hasSignal) {
      val = lastBars[i] || 0;
      if (val > peaks[i]) peaks[i] = val;
      else peaks[i] = Math.max(0, peaks[i] - 0.008);
    } else {
      var phase  = (ts / 1800) + (i / n) * Math.PI * 2;
      var breath = (Math.sin(ts / 2000) * 0.5 + 0.5) * 0.08;
      val = Math.max(0, Math.sin(phase) * breath);
      peaks[i] = Math.max(0, peaks[i] - 0.02);
    }

    var x    = Math.round(i * (barW + gap));
    var barH = val * h;

    if (barH > 0.5) {
      ctx2d.fillStyle = grad;
      ctx2d.fillRect(x, h - barH, barW, barH);
    }

    if (peaks[i] > 0.02) {
      var py = Math.round(h - peaks[i] * h) - 1;
      ctx2d.fillStyle = hasSignal ? 'rgba(255,255,255,0.6)' : 'rgba(255,255,255,0.15)';
      ctx2d.fillRect(x, py, barW, 2);
    }
  }

  if (!ws || ws.readyState !== WebSocket.OPEN) {
    drawLabel(ctx2d, w, h, '● NO SIGNAL', '#333');
  } else if (!winampPlaying) {
    drawLabel(ctx2d, w, h, SYM.play + ' PLAY', '#1a3a1a');
  }
}

function drawLabel(ctx, w, h, text, color) {
  ctx.font = 'bold ' + Math.round(h * 0.22) + 'px monospace';
  ctx.textAlign    = 'center';
  ctx.textBaseline = 'middle';
  ctx.fillStyle    = color;
  ctx.fillText(text, w / 2, h / 2);
}

// ── Helpers ───────────────────────────────────────────────────────────────────
function fmtTime(secs) {
  var m = Math.floor(secs / 60);
  var s = Math.floor(secs % 60);
  return m + ':' + pad2(s);
}

// Like fmtTime but always zero-pads to hh:mm:ss for the canvas display.
function fmtTimeLong(secs) {
  secs = Math.floor(secs);
  var h = Math.floor(secs / 3600);
  var m = Math.floor((secs % 3600) / 60);
  var s = secs % 60;
  return pad2(h) + ':' + pad2(m) + ':' + pad2(s);
}

function parseTime(str) {
  var parts = (str || '0:00').split(':').map(Number);
  return parts[0] * 60 + (parts[1] || 0);
}

function escHtml(s) {
  return s.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;');
}

var toastTimer;
function showToast(msg) {
  var el = $('toast');
  if (!el) {
    el = document.createElement('div');
    el.id = 'toast';
    el.style.cssText = [
      'position:fixed', 'bottom:24px', 'left:50%', 'transform:translateX(-50%)',
      'background:#333', 'color:#fff', 'padding:10px 20px', 'border-radius:8px',
      'font-size:14px', 'z-index:999', 'opacity:0', 'transition:opacity .2s',
      'pointer-events:none',
    ].join(';');
    document.body.appendChild(el);
  }
  el.textContent = msg;
  el.style.opacity = '1';
  clearTimeout(toastTimer);
  toastTimer = setTimeout(function() { el.style.opacity = '0'; }, 2500);
}

// ── Playlist ──────────────────────────────────────────────────────────────────
$('btn-show-playlist').addEventListener('click', openPlaylist);
$('btn-close-playlist').addEventListener('click', function() {
  playlistOverlay.classList.add('hidden');
});

function openPlaylist() {
  playlistOverlay.classList.remove('hidden');
  playlistList.innerHTML = '<li id="playlist-loading">Lade…</li>';

  apiFetch('/api/playlist')
    .then(function(r) { return r.json(); })
    .then(function(tracks) {
      if (!tracks || tracks.length === 0) {
        playlistList.innerHTML = '<li id="playlist-loading">Playlist leer</li>';
        return;
      }

      var frag = document.createDocumentFragment();
      tracks.forEach(function(t) {
        var li = document.createElement('li');
        li.dataset.index = t.index - 1; // 0-based for jump
        if (t.index === currentPlaylistPos) li.classList.add('current');

        var idx = document.createElement('span');
        idx.className   = 'pl-idx';
        idx.textContent = t.index;

        var title = document.createElement('span');
        title.className   = 'pl-title';
        title.textContent = t.title || '–';

        li.appendChild(idx);
        li.appendChild(title);
        li.addEventListener('click', function() {
          send({ cmd: 'jump', index: parseInt(li.dataset.index, 10) });
          playlistOverlay.classList.add('hidden');
        });
        frag.appendChild(li);
      });

      playlistList.innerHTML = '';
      playlistList.appendChild(frag);
      scrollToCurrentTrack();
    })
    .catch(function() {
      playlistList.innerHTML = '<li id="playlist-loading">Fehler beim Laden</li>';
    });
}

function updatePlaylistHighlight() {
  if (playlistOverlay.classList.contains('hidden')) return;
  qsa('li', playlistList).forEach(function(li) {
    var isCurrent = parseInt(li.dataset.index, 10) === currentPlaylistPos - 1;
    li.classList.toggle('current', isCurrent);
  });
  scrollToCurrentTrack();
}

function scrollToCurrentTrack() {
  var current = playlistList.querySelector('li.current');
  if (current) current.scrollIntoView(true);
}

// ── Boot ──────────────────────────────────────────────────────────────────────

// Replace text and tune font so the symbol fills ~¾ of the button.
// Centering is already handled by flex on .btn.
// Defined outside if-block — function declarations inside blocks are
// forbidden in strict mode on older engines and can kill the whole script.
function legacySym(id, text, size) {
  var el = $(id);
  el.textContent     = text;
  el.style.fontSize  = size;
  el.style.fontWeight = 'bold';
  el.style.letterSpacing = '2px';
}

// Replace emoji with legacy symbols on iOS 9 where the glyphs are missing.
if (isLegacyIOS) {
  // Transport controls (btn-h = 64px):
  //   two-char symbols (<<, >>) → 26px bold; single-char (■ ▶) → 36px bold.
  legacySym('btn-prev', SYM.prev, '26px');
  legacySym('btn-play', SYM.play, '36px');
  legacySym('btn-stop', SYM.stop, '36px');
  legacySym('btn-next', SYM.next, '26px');

  // Volume mute (48px tall)
  legacySym('btn-mute', SYM.volOn, '16px');

  // Playlist action button (52px tall)
  legacySym('btn-show-playlist', SYM.playlist, '18px');

  // Kill button: drop the emoji, keep the label
  $('btn-kill').textContent = SYM.skip + ' Überspringen';
}

connect();
renderFrame();