'use strict';

// ── DOM refs ──────────────────────────────────────────────────────────────────
const $ = id => document.getElementById(id);

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

// ── State ─────────────────────────────────────────────────────────────────────
let currentVolume = 50;
let ws = null;
let reconnectTimer = null;

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

// ── WebSocket ─────────────────────────────────────────────────────────────────
function connect() {
  const proto = location.protocol === 'https:' ? 'wss' : 'ws';
  ws = new WebSocket(`${proto}://${location.host}/ws`);

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

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

  ws.addEventListener('error', () => ws.close());

  ws.addEventListener('message', e => {
    let msg;
    try { msg = JSON.parse(e.data); } catch { 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';
  const stateMap = { playing: '▶ Spielt', paused: '⏸ Pause', stopped: '⏹ Stop' };
  stateLabel.textContent = stateMap[st.state] ?? st.state;

  trackTitle.textContent = st.title || '–';
  playlistPos.textContent = st.playlist_length
    ? `${st.playlist_pos} / ${st.playlist_length}` : '';

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

  btnPlay.textContent = st.state === 'playing' ? '⏸' : '▶';
  winampPlaying = st.state === 'playing';

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

// ── Controls ──────────────────────────────────────────────────────────────────
btnPlay.addEventListener('click', () => {
  // Optimistic toggle — server will push the real state back immediately.
  const playing = btnPlay.textContent === '⏸';
  send({ cmd: playing ? 'pause' : 'play' });
});

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

document.querySelectorAll('.btn-seek').forEach(btn => {
  btn.addEventListener('click', () =>
    send({ cmd: 'seek', delta: parseInt(btn.dataset.delta, 10) }));
});

$('progress-bar').addEventListener('click', async e => {
  // We need current length — read from last status (stored in DOM for now via timeLength).
  const total = parseTime(timeLength.textContent);
  if (!total) return;
  const rect = e.currentTarget.getBoundingClientRect();
  const target = Math.round((e.clientX - rect.left) / rect.width * total);
  const current = parseTime(timeCurrent.textContent);
  send({ cmd: 'seek', delta: target - current });
});

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

function updateVolumeFill(muted = btnMute.classList.contains('muted')) {
  volumeFill.style.width  = currentVolume + '%';
  volumePct.textContent   = currentVolume + ' %';
  volumeFill.classList.toggle('muted', muted);
}
function updateMuteBtn(muted) {
  btnMute.textContent = muted ? '🔇' : '🔊';
  btnMute.classList.toggle('muted', muted);
}

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

$('btn-show-killist').addEventListener('click', async () => {
  const list = await fetch('/api/killist').then(r => r.json()).catch(() => []);
  killistItems.innerHTML = '';
  (list || []).forEach(title => {
    const li  = document.createElement('li');
    li.innerHTML = `<span>${escHtml(title)}</span>`;
    const btn = document.createElement('button');
    btn.textContent = '✕';
    btn.onclick = () => {
      send({ cmd: 'killist_remove', title });
      li.remove();
    };
    li.appendChild(btn);
    killistItems.appendChild(li);
  });
  killistPanel.classList.remove('hidden');
});

$('btn-close-killist').addEventListener('click', () =>
  killistPanel.classList.add('hidden'));

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

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

  // Resize canvas to CSS size (handles window resize / DPR).
  // Setting canvas.width resets the transform, so we re-apply scale.
  const dpr  = window.devicePixelRatio || 1;
  const cssW = canvas.clientWidth;
  const 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);
  }

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

  // Check if real viz data is fresh (< 1.5 s old) and Winamp is playing.
  const hasSignal = winampPlaying && (performance.now() - lastVizAt) < 1500;

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

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

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

    if (hasSignal) {
      // Real spectrum data
      val = lastBars[i] || 0;
      if (val > peaks[i]) peaks[i] = val;
      else peaks[i] = Math.max(0, peaks[i] - 0.012);
    } else {
      // Idle animation: slow sine "breathing" across the bars.
      // Amplitude fades out when paused/stopped.
      const phase  = (ts / 1800) + (i / n) * Math.PI * 2;
      const breath = (Math.sin(ts / 2000) * 0.5 + 0.5) * 0.08; // 0..0.08
      val = Math.max(0, Math.sin(phase) * breath);
      peaks[i] = Math.max(0, peaks[i] - 0.02); // let peaks fall quickly
    }

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

    if (barH > 0.5) {
      // Bar colour: green (120°) → yellow (60°) → red (0°)
      const hue = Math.round((1 - val) * 120);
      const lit  = hasSignal ? 42 : 25; // dimmer in idle
      ctx2d.fillStyle = `hsl(${hue},100%,${lit}%)`;
      ctx2d.fillRect(x, h - barH, barW, barH);
    }

    // Peak indicator
    if (peaks[i] > 0.02) {
      const py = Math.round(h - peaks[i] * h) - 1;
      ctx2d.fillStyle = hasSignal ? 'rgba(255,255,255,0.75)' : 'rgba(255,255,255,0.2)';
      ctx2d.fillRect(x, py, barW, 2);
    }
  }

  // "No signal" label when disconnected or stopped
  if (!ws || ws.readyState !== WebSocket.OPEN) {
    drawLabel(ctx2d, w, h, '● NO SIGNAL', '#333');
  } else if (!winampPlaying) {
    drawLabel(ctx2d, w, h, '▶ 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) {
  const m = Math.floor(secs / 60);
  const s = String(Math.floor(secs % 60)).padStart(2, '0');
  return `${m}:${s}`;
}

function parseTime(str) {
  const [m, s] = (str || '0:00').split(':').map(Number);
  return m * 60 + (s || 0);
}

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

let toastTimer;
function showToast(msg) {
  let 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(() => { el.style.opacity = '0'; }, 2500);
}

// ── Boot ──────────────────────────────────────────────────────────────────────
connect();
renderFrame();