prompter.js

const track = document.getElementById('track');
const viewport = document.getElementById('viewport');
const pageTag = document.getElementById('pageTag');
const statusEl = document.getElementById('status');
const emptyEl = document.getElementById('empty');

let cfg = null;
let lines = [];          // Flattened caption lines: {text, pageStart}
let lineEls = [];
let cur = 0;             // Current highlighted line
let offset = 0;          // translateY
let playing = false;
let lastT = 0;
let rafId = null;

function normalizeLocale(language) {
  const lang = (language || '').trim();
  return lang && lang.toLowerCase() !== 'auto' ? lang : undefined;
}

function fallbackSplitSentences(text) {
  const parts = [];
  const normalized = text.replace(/\r\n/g, '\n');
  const chunks = normalized.split(/\n+/).map(s => s.trim()).filter(Boolean);
  const sentencePattern = /[^.!?。！？؛؟।॥…]+(?:[.!?。！？؛؟।॥…]+["')\]\u00bb\u201d\u2019]*)?/g;
  chunks.forEach((chunk) => {
    const matches = chunk.match(sentencePattern);
    if (matches && matches.length) {
      matches.map(s => s.trim()).filter(Boolean).forEach(s => parts.push(s));
    } else {
      parts.push(chunk);
    }
  });
  return parts;
}

function splitSentences(text, locale) {
  const chunks = text.replace(/\r\n/g, '\n').split(/\n+/).map(s => s.trim()).filter(Boolean);
  if (typeof Intl !== 'undefined' && Intl.Segmenter) {
    try {
      const segmenter = new Intl.Segmenter(locale, { granularity: 'sentence' });
      return chunks.flatMap((chunk) =>
        Array.from(segmenter.segment(chunk), s => s.segment.trim()).filter(Boolean)
      );
    } catch {
      // Fall through to the punctuation-based splitter.
    }
  }
  return fallbackSplitSentences(text);
}

function splitScript(text, delimRaw, language) {
  if (!text || !text.trim()) return [];
  let delim;
  try { delim = new RegExp(delimRaw); } catch { delim = /\n\n+/; }
  const pages = text.split(delim).map(s => s.trim()).filter(Boolean);
  const out = [];
  const locale = normalizeLocale(language);
  pages.forEach((p) => {
    const segs = splitSentences(p, locale);
    segs.forEach((s, i) => out.push({ text: s, pageStart: i === 0 }));
  });
  return out;
}

function hexToRgba(hex, a) {
  const m = /^#?([0-9a-f]{6})$/i.exec(hex || '#000000');
  if (!m) return `rgba(0,0,0,${a})`;
  const n = parseInt(m[1], 16);
  return `rgba(${(n>>16)&255},${(n>>8)&255},${n&255},${a})`;
}

function applyStyle() {
  if (!cfg) return;
  const lang = normalizeLocale(cfg.language) || 'en';
  const dir = cfg.direction === 'rtl' || cfg.direction === 'ltr' ? cfg.direction : 'auto';
  document.documentElement.lang = lang;
  document.documentElement.dir = dir === 'auto' ? 'ltr' : dir;
  track.dir = dir;
  document.getElementById('shell').style.background = hexToRgba(cfg.bgColor, cfg.opacity);
  track.style.fontSize = cfg.fontSize + 'px';
  track.style.lineHeight = cfg.lineHeight;
  track.style.color = cfg.textColor;
  track.style.fontFamily = cfg.fontFamily;
  document.body.classList.toggle('mirror', !!cfg.mirror);
}

function render() {
  track.innerHTML = '';
  lineEls = [];
  emptyEl.style.display = lines.length ? 'none' : 'flex';
  lines.forEach((ln, i) => {
    const div = document.createElement('div');
    div.className = 'line dim' + (ln.pageStart && i > 0 ? ' pagestart' : '');
    div.lang = normalizeLocale(cfg && cfg.language) || '';
    div.dir = cfg && (cfg.direction === 'rtl' || cfg.direction === 'ltr') ? cfg.direction : 'auto';
    div.textContent = ln.text;
    track.appendChild(div);
    lineEls.push(div);
  });
  if (cur >= lines.length) cur = Math.max(0, lines.length - 1);
  centerCur(false);
}

function applyOffset(smooth) {
  track.style.transition = smooth ? 'transform .22s ease-out' : 'none';
  const mir = cfg && cfg.mirror ? ' scaleX(-1)' : '';
  track.style.transform = `translateY(${offset}px)${mir}`;
}

// Keep the current line in the upper-middle reading zone.
function centerCur(smooth) {
  const el = lineEls[cur];
  if (!el) { offset = viewport.clientHeight * 0.42; applyOffset(smooth); return; }
  offset = viewport.clientHeight * 0.42 - el.offsetTop - el.offsetHeight / 2;
  applyOffset(smooth);
  highlight();
  updatePageTag();
}

function highlight() {
  lineEls.forEach((el, i) => {
    el.classList.toggle('cur', i === cur);
    el.classList.toggle('dim', i !== cur);
  });
}

function updatePageTag() {
  if (!lines.length) { pageTag.textContent = ''; return; }
  let page = 0;
  for (let i = 0; i <= cur && i < lines.length; i++) if (lines[i].pageStart) page++;
  const total = lines.filter(l => l.pageStart).length;
  pageTag.textContent = `${cur + 1}/${lines.length} lines · Section ${page}/${total}`;
}

function step(d) {
  const n = Math.min(Math.max(cur + d, 0), lines.length - 1);
  if (n === cur) return;
  cur = n;
  centerCur(true);
}

function loop(t) {
  if (!playing) { rafId = null; return; }
  if (!lastT) lastT = t;
  const dt = (t - lastT) / 1000;
  lastT = t;
  offset -= (cfg.scrollSpeed || 40) * dt;
  const last = lineEls[lineEls.length - 1];
  const minOffset = last ? (viewport.clientHeight * 0.42 - last.offsetTop - last.offsetHeight / 2) : 0;
  if (offset <= minOffset) { offset = minOffset; playing = false; updatePlayBtn(); }
  applyOffset(false);
  const center = viewport.clientHeight * 0.42;
  let best = 0, bestD = Infinity;
  for (let i = 0; i < lineEls.length; i++) {
    const mid = lineEls[i].offsetTop + offset + lineEls[i].offsetHeight / 2;
    const dd = Math.abs(mid - center);
    if (dd < bestD) { bestD = dd; best = i; }
  }
  cur = best; highlight(); updatePageTag();
  rafId = requestAnimationFrame(loop);
}

function setPlaying(v) {
  playing = v;
  updatePlayBtn();
  if (v) { lastT = 0; if (!rafId) rafId = requestAnimationFrame(loop); }
  setStatus();
}
function updatePlayBtn() {
  document.getElementById('btnPlay').textContent = playing ? '⏸ Pause' : '▶ Auto';
}
function setStatus() {
  statusEl.textContent = `${playing ? '▶ ' + (cfg ? cfg.scrollSpeed : 0) + 'px/s' : 'Manual'}`;
}

function handleCmd(cmd) {
  switch (cmd) {
    case 'nextLine': if (playing) setPlaying(false); step(1); break;
    case 'prevLine': if (playing) setPlaying(false); step(-1); break;
    case 'togglePlay': setPlaying(!playing); break;
    case 'faster': cfg.scrollSpeed = Math.min(200, (cfg.scrollSpeed || 40) + 8); window.api.setConfig({ scrollSpeed: cfg.scrollSpeed }); setStatus(); break;
    case 'slower': cfg.scrollSpeed = Math.max(8, (cfg.scrollSpeed || 40) - 8); window.api.setConfig({ scrollSpeed: cfg.scrollSpeed }); setStatus(); break;
  }
}

let wheelAcc = 0, wheelLock = false;
viewport.addEventListener('wheel', (e) => {
  if (playing) setPlaying(false);
  wheelAcc += e.deltaY;
  if (wheelLock) return;
  if (Math.abs(wheelAcc) >= 24) {
    step(wheelAcc > 0 ? 1 : -1);
    wheelAcc = 0;
    wheelLock = true;
    setTimeout(() => { wheelLock = false; }, 90);
  }
}, { passive: true });

document.getElementById('btnControl').onclick = () => window.api.openControl();
document.getElementById('btnLock').onclick = () => window.api.toggleLock();
document.getElementById('btnPlay').onclick = () => setPlaying(!playing);
document.getElementById('btnQuit').onclick = () => window.api.quitApp();

function loadCfg(c) {
  const firstLoad = cfg === null;
  cfg = c;
  lines = splitScript(c.script, c.pageDelimiter, c.language);
  applyStyle();
  render();
  if (firstLoad) { cur = 0; centerCur(false); }
  setStatus();
}
window.api.onConfig(loadCfg);
window.api.onCmd(handleCmd);
window.api.onLockChanged((locked) => {
  document.getElementById('btnLock').textContent = locked ? '🔒 Locked' : '🔓 Lock';
});
window.api.getConfig().then(loadCfg);