/*
 * browser-guest-preload.cjs — runs inside the web page that the Browser tab shows (the Electron
 * <webview> guest). main.cjs forces it onto every webview from will-attach-webview, sandboxed and
 * context-isolated: the page can neither see nor call anything here, and this file can only talk to the
 * Bible app through ipcRenderer.sendToHost (to the <webview> element owned by browser-tab.js) and
 * ipcRenderer.on (from it).
 *
 * Why each piece exists — every one of these is something the app cannot see from outside the page,
 * because input inside a webview never reaches the app's own document:
 *
 *   keyboard   a tapped text field tells the app to bring up its own on-screen keyboard;
 *   scripture  a tap on "Isaiah 41:10" is found with the app's OWN scanner and handed over to open in a
 *              new Bible tab;
 *   scroll     reported so the phone remote and the booth follower can track the page, and carried out
 *              on the app's behalf (phone remote, header nav, OSC);
 *   follower   a script-free copy of the DOM, published only while a booth screen is linked;
 *   activity   touches inside the page count as activity, or the app's idle splash would drop over the
 *              page while pastor is using it — and the five-finger "blank the screen" gesture still works.
 */
'use strict';
const { ipcRenderer, webFrame } = require('electron');

/*
 * No dialog boxes on the stage. alert / confirm / prompt from a page would open a native window over the
 * TV. They are replaced in the PAGE's world (the only one its scripts can see) with silent stand-ins:
 * confirm answers "Cancel", so nothing a page asks permission for can happen by itself.
 */
try {
  webFrame.executeJavaScript('(function(){try{window.alert=function(){};window.confirm=function(){return false;};window.prompt=function(){return null;};}catch(e){}})();');
} catch (_) {}

const OVERLAY_ATTR = 'data-bibleapp-overlay';   // our own tap flash; never published, never observed
const send = (ch, data) => { try { ipcRenderer.sendToHost(ch, data); } catch (_) {} };

// ------------------------------------------------------------------ settings pushed by the app
/*
 * The scanner arrives as SOURCE over IPC instead of being copied into this file: a sandboxed preload
 * cannot require the app's files, and a second copy would drift from the one ProPresenter Sync uses.
 * It is evaluated here, in this isolated world, so the page never sees it.
 */
let Scan = null;
let tapsOn = true;
let wantDom = false;

ipcRenderer.on('bibleapp:init', (_e, cfg) => {
  cfg = cfg || {};
  if (typeof cfg.taps === 'boolean') tapsOn = cfg.taps;
  if (cfg.scanner && !Scan) {
    try {
      const root = {};
      new Function('globalThis', cfg.scanner)(root);
      if (root.ScriptureScan && root.ScriptureScan.scanAll && root.BibleBooks) Scan = root;
    } catch (_) { Scan = null; }
  }
  if (typeof cfg.wantDom === 'boolean') setWantDom(cfg.wantDom);
  reportScroll(true);
});
ipcRenderer.on('bibleapp:taps', (_e, on) => { tapsOn = !!on; });
ipcRenderer.on('bibleapp:want-dom', (_e, on) => setWantDom(!!on));
ipcRenderer.on('bibleapp:dom-now', () => { if (wantDom) publishDom(true); });
ipcRenderer.on('bibleapp:scroll', (_e, cmd) => doScroll(cmd || {}));

// ------------------------------------------------------------------ scroll
function scroller() { return document.scrollingElement || document.documentElement; }
function maxScroll() { const s = scroller(); return s ? Math.max(0, s.scrollHeight - s.clientHeight) : 0; }

function doScroll(cmd) {
  const s = scroller();
  if (!s) return;
  let y = null;
  if (cmd.edge === 'top') y = 0;
  else if (cmd.edge === 'bottom') y = maxScroll();
  else if (typeof cmd.to === 'number') y = cmd.to;
  else if (typeof cmd.by === 'number') y = s.scrollTop + cmd.by;
  else if (typeof cmd.pages === 'number') y = s.scrollTop + cmd.pages * window.innerHeight * 0.85;
  if (y === null || !isFinite(y)) return;
  // 'instant' for a finger dragging on the phone (it restates the position every few ms); smooth for a
  // button press. Explicit either way, so a page's own `scroll-behavior` cannot turn a drag into mush.
  window.scrollTo({ top: Math.max(0, Math.min(maxScroll(), y)), behavior: cmd.smooth ? 'smooth' : 'instant' });
}

let lastY = -1, lastMax = -1, scrollTimer = 0;
function reportScroll(force) {
  const s = scroller();
  if (!s) return;
  const y = Math.round(s.scrollTop), max = Math.round(maxScroll());
  if (!force && y === lastY && max === lastMax) return;
  lastY = y; lastMax = max;
  send('bibleapp:scroll', { y: y, max: max, vh: window.innerHeight });
}
// A timer, not rAF: rAF stops whenever the guest is not painting, and the booth would stop following.
function reportScrollSoon() { if (!scrollTimer) scrollTimer = setTimeout(() => { scrollTimer = 0; reportScroll(false); }, 16); }
window.addEventListener('scroll', reportScrollSoon, { capture: true, passive: true });
window.addEventListener('resize', reportScrollSoon);
window.addEventListener('load', () => reportScroll(true));

// ------------------------------------------------------------------ text fields -> the app's keyboard
function isEditable(el) {
  if (!el || el.nodeType !== 1) return false;
  if (el.isContentEditable) return true;
  if (el.disabled || el.readOnly) return false;
  if (el.tagName === 'TEXTAREA') return true;
  if (el.tagName !== 'INPUT') return false;
  return ['text', 'search', 'email', 'url', 'tel', 'password', 'number'].indexOf(String(el.type || 'text').toLowerCase()) !== -1;
}
function editableFrom(target) {
  if (isEditable(target)) return target;
  const el = target && target.closest ? target.closest('input, textarea, [contenteditable]') : null;
  return isEditable(el) ? el : null;
}

/*
 * The app's keyboard is the only one that should appear. A finger on a field would otherwise also raise
 * the Windows touch keyboard over the stage; inputmode="none" is the browser's own switch for that. It is
 * set just before the field takes focus and put back as it leaves, so the page is never left changed.
 */
const savedInputMode = new WeakMap();
function quietOsKeyboard(el) {
  if (!el || savedInputMode.has(el)) return;
  savedInputMode.set(el, el.getAttribute('inputmode'));
  el.setAttribute('inputmode', 'none');
}
function restoreOsKeyboard(el) {
  if (!el || !savedInputMode.has(el)) return;
  const v = savedInputMode.get(el);
  savedInputMode.delete(el);
  if (v === null) el.removeAttribute('inputmode'); else el.setAttribute('inputmode', v);
}

/*
 * Only a TAP raises the keyboard. A page that focuses its own search box as it loads must not throw a
 * keyboard over the stage while nobody is touching it; focus moving between fields (Tab, the next
 * memorize blank) keeps an open keyboard open; focus moving to anything that is not a field — the site
 * focuses its results heading after a search — puts it away, so the results are not covered.
 */
window.addEventListener('pointerdown', (e) => {
  const el = editableFrom(e.target);
  if (!el) return;
  quietOsKeyboard(el);
  send('bibleapp:editable', { on: true, tap: true });
}, true);
document.addEventListener('focusin', (e) => {
  send('bibleapp:editable', { on: isEditable(e.target), tap: false });
}, true);
document.addEventListener('focusout', (e) => {
  restoreOsKeyboard(e.target);
  setTimeout(() => {
    // The app itself took focus (pastor tapped the tab bar): that is the app's business, not the page's.
    if (!document.hasFocus()) return;
    if (!isEditable(document.activeElement)) send('bibleapp:editable', { on: false, tap: false });
  }, 0);
}, true);

// ------------------------------------------------------------------ activity + five fingers
let lastActivity = 0;
function activity() {
  const now = Date.now();
  if (now - lastActivity < 1000) return;
  lastActivity = now;
  send('bibleapp:activity');
}
['pointerdown', 'wheel', 'keydown', 'touchstart', 'scroll'].forEach((ev) => {
  window.addEventListener(ev, activity, { capture: true, passive: true });
});
const touchIds = new Set();
window.addEventListener('pointerdown', (e) => {
  if (e.pointerType !== 'touch') return;
  touchIds.add(e.pointerId);
  if (touchIds.size >= 5) send('bibleapp:five-finger');
}, true);
['pointerup', 'pointercancel'].forEach((ev) => window.addEventListener(ev, (e) => { if (e.pointerType === 'touch') touchIds.delete(e.pointerId); }, true));
window.addEventListener('blur', () => touchIds.clear());

// ------------------------------------------------------------------ scripture under a tap
const BLOCK = /^(block|flex|inline-flex|grid|inline-grid|list-item|table|table-cell|table-caption|flow-root)$/;
// The nearest block around the tapped text: a reference split across spans ("<b>John</b> 3:16") is still
// one run of text there, where the single text node would only hold half of it.
function blockAround(node) {
  let el = node.nodeType === 1 ? node : node.parentElement;
  for (let i = 0; el && i < 6; i++, el = el.parentElement) {
    if (BLOCK.test(getComputedStyle(el).display)) return el;
  }
  return node.parentElement || document.body;
}
function textOf(block) {
  const walker = document.createTreeWalker(block, NodeFilter.SHOW_TEXT, {
    acceptNode(n) {
      const p = n.parentElement;
      if (!p || /^(SCRIPT|STYLE|NOSCRIPT|TEXTAREA)$/.test(p.tagName) || p.closest('[' + OVERLAY_ATTR + ']')) return NodeFilter.FILTER_REJECT;
      return NodeFilter.FILTER_ACCEPT;
    }
  });
  const nodes = [];
  let text = '';
  for (let n = walker.nextNode(); n && text.length < 6000; n = walker.nextNode()) {
    nodes.push({ node: n, start: text.length });
    text += n.nodeValue;
  }
  return { text, nodes };
}
function rangeOf(map, start, end) {
  const at = (pos) => {
    for (let i = map.nodes.length - 1; i >= 0; i--) {
      const e = map.nodes[i];
      if (pos >= e.start) return { node: e.node, off: Math.min(pos - e.start, e.node.nodeValue.length) };
    }
    return null;
  };
  const a = at(start), b = at(end);
  if (!a || !b) return null;
  const r = document.createRange();
  r.setStart(a.node, a.off);
  r.setEnd(b.node, b.off);
  return r;
}
// "Isaiah 41:10 (NIV)" or a badge beside it, as the site's verse cards have.
function translationNear(text, end, block) {
  const after = Scan.ScriptureScan.translationAfter(text, end);
  if (after) return after;
  let el = block;
  for (let i = 0; el && i < 2; i++, el = el.parentElement) {
    const cands = el.querySelectorAll('span, small, sup, abbr, b, strong, em, i, div');
    for (let k = 0; k < cands.length && k < 60; k++) {
      const c = cands[k];
      if (c.children.length) continue;
      const t = (c.textContent || '').trim();
      if (t && t.length <= 8 && Scan.ScriptureScan.isTranslation(t)) return t.toUpperCase();
    }
  }
  return null;
}
function referenceAt(x, y) {
  const caret = document.caretRangeFromPoint(x, y);
  if (!caret || caret.startContainer.nodeType !== 3) return null;
  const block = blockAround(caret.startContainer);
  const map = textOf(block);
  const entry = map.nodes.find((e) => e.node === caret.startContainer);
  if (!entry) return null;
  const off = entry.start + caret.startOffset;
  const hits = Scan.ScriptureScan.scanAll(map.text);
  for (const h of hits) {
    if (off < h.start || off > h.end) continue;
    const range = rangeOf(map, h.start, h.end);
    if (!range) continue;
    // caretRangeFromPoint snaps to the NEAREST character, even from empty space beside a line. Only a
    // finger actually on the reference counts.
    const pad = 8;
    const onIt = Array.from(range.getClientRects()).some((r) => x >= r.left - pad && x <= r.right + pad && y >= r.top - pad && y <= r.bottom + pad);
    if (onIt) return { ref: h.ref, range: range, translation: translationNear(map.text, h.end, block) };
  }
  return null;
}
function flash(range) {
  try {
    const layer = document.createElement('div');
    layer.setAttribute(OVERLAY_ATTR, '');
    layer.style.cssText = 'position:fixed;left:0;top:0;width:0;height:0;z-index:2147483647;pointer-events:none;';
    Array.from(range.getClientRects()).forEach((r) => {
      const d = document.createElement('div');
      d.style.cssText = 'position:fixed;pointer-events:none;border-radius:6px;background:rgba(255,214,10,.32);' +
        'box-shadow:0 0 0 2px rgba(255,214,10,.85);transition:opacity .45s ease .3s;' +
        'left:' + (r.left - 4) + 'px;top:' + (r.top - 3) + 'px;width:' + (r.width + 8) + 'px;height:' + (r.height + 6) + 'px;';
      layer.appendChild(d);
    });
    (document.body || document.documentElement).appendChild(layer);
    requestAnimationFrame(() => requestAnimationFrame(() => { layer.querySelectorAll('div').forEach((d) => { d.style.opacity = '0'; }); }));
    setTimeout(() => { try { layer.remove(); } catch (_) {} }, 1000);
  } catch (_) {}
}
// Capture on window, so it runs before the page's own handlers — a reference inside a link opens in the
// app instead of navigating the page away. A tap that is not on a reference is left completely alone.
window.addEventListener('click', (e) => {
  if (!tapsOn || !Scan || e.button !== 0) return;
  if (editableFrom(e.target) || (e.target.closest && e.target.closest('select, button[type="submit"]'))) return;
  let found = null;
  try { found = referenceAt(e.clientX, e.clientY); } catch (_) { found = null; }
  if (!found) return;
  e.preventDefault();
  e.stopImmediatePropagation();
  flash(found.range);
  const r = found.ref;
  send('bibleapp:scripture', { book: r.book, chapter: r.chapter, verse: r.verse, verseEnd: r.verseEnd, canonical: r.canonical, translation: found.translation });
}, true);

// ------------------------------------------------------------------ the booth follower's copy
/*
 * The booth screen re-renders the stage rather than receiving video (follower-link.js), so the page goes
 * there as DOM. Only while a booth is linked — the app turns this on and off. Scripts are stripped (the
 * booth must show THIS page, not re-run its search and get different results), and everything a script
 * would have put in place is baked in: form values, which live in properties rather than attributes, and
 * CSS-in-JS rules, which live in the CSSOM rather than in the <style> text.
 */
let domVer = 0, domTimer = 0, domDirty = true, observer = null;

function setWantDom(on) {
  if (on === wantDom) return;
  wantDom = on;
  if (on) { domDirty = true; publishDom(true); }
}
function ours(n) {
  const el = n && (n.nodeType === 1 ? n : n.parentElement);
  return !!(el && el.closest && el.closest('[' + OVERLAY_ATTR + ']'));
}
function startObserver() {
  if (observer || !document.documentElement) return;
  observer = new MutationObserver((muts) => {
    for (const m of muts) {
      if (m.type === 'attributes' && m.attributeName === 'inputmode') continue;   // our own, see quietOsKeyboard
      if (ours(m.target)) continue;
      if (m.type === 'childList' && [...m.addedNodes, ...m.removedNodes].length && [...m.addedNodes, ...m.removedNodes].every(ours)) continue;
      domDirty = true;
      reportScrollSoon();   // new content moves the bottom of the page
      if (wantDom && !domTimer) domTimer = setTimeout(() => { domTimer = 0; publishDom(false); }, 350);
      return;
    }
  });
  observer.observe(document.documentElement, { subtree: true, childList: true, characterData: true, attributes: true });
}

function fields(root) { return root.querySelectorAll('input, textarea, select'); }
function fieldValue(el) {
  if (el.tagName === 'SELECT') return el.selectedIndex;
  if (el.type === 'checkbox' || el.type === 'radio') return !!el.checked;
  if (el.type === 'password' || el.type === 'file') return '';   // never put a password on the program feed
  return el.value;
}
function serialize() {
  const live = document.documentElement;
  const clone = live.cloneNode(true);
  const ls = live.querySelectorAll('style'), cs = clone.querySelectorAll('style');
  for (let i = 0; i < ls.length && i < cs.length; i++) {
    try {
      const rules = ls[i].sheet && ls[i].sheet.cssRules;
      if (rules && rules.length) { let t = ''; for (const r of rules) t += r.cssText + '\n'; cs[i].textContent = t; }
    } catch (_) {}
  }
  try {
    const adopted = document.adoptedStyleSheets || [];
    if (adopted.length) {
      let t = '';
      adopted.forEach((sh) => { for (const r of sh.cssRules) t += r.cssText + '\n'; });
      const st = document.createElement('style');
      st.textContent = t;
      (clone.querySelector('head') || clone).appendChild(st);
    }
  } catch (_) {}
  const lf = fields(live), cf = fields(clone);
  for (let i = 0; i < lf.length && i < cf.length; i++) {
    const a = lf[i], b = cf[i], v = fieldValue(a);
    try {
      if (a.tagName === 'TEXTAREA') b.textContent = v;
      else if (a.tagName === 'SELECT') Array.from(b.options).forEach((o, k) => { if (k === v) o.setAttribute('selected', ''); else o.removeAttribute('selected'); });
      else if (a.type === 'checkbox' || a.type === 'radio') { if (v) b.setAttribute('checked', ''); else b.removeAttribute('checked'); }
      else b.setAttribute('value', v);
    } catch (_) {}
  }
  clone.querySelectorAll('script, noscript, base, meta[http-equiv], [' + OVERLAY_ATTR + ']').forEach((n) => n.remove());
  let head = clone.querySelector('head');
  if (!head) { head = document.createElement('head'); clone.insertBefore(head, clone.firstChild); }
  const base = document.createElement('base');
  base.setAttribute('href', location.href);
  head.insertBefore(base, head.firstChild);
  return '<!DOCTYPE html>' + clone.outerHTML;
}
function sendInputs() {
  try { send('bibleapp:inputs', { values: Array.from(fields(document), fieldValue) }); } catch (_) {}
}
function publishDom(force) {
  if (!wantDom || (!domDirty && !force) || !document.documentElement) return;
  domDirty = false;
  let html;
  try { html = serialize(); } catch (_) { return; }
  domVer++;
  send('bibleapp:dom', { ver: domVer, html: html });
  sendInputs();
}
// Typing changes a property, not the DOM, so it never wakes the observer: field values travel on their own,
// a few bytes per keystroke instead of the whole page.
let inputsTimer = 0;
function inputsSoon() { if (wantDom && !inputsTimer) inputsTimer = setTimeout(() => { inputsTimer = 0; sendInputs(); }, 60); }
document.addEventListener('input', inputsSoon, true);
document.addEventListener('change', inputsSoon, true);

window.addEventListener('DOMContentLoaded', () => {
  startObserver();
  reportScroll(true);
  send('bibleapp:ready', { url: location.href, title: document.title });
});