import { startViewer, stopViewer, recenter, setJoystick } from './viewer.js';

const STAGES = [
  ['frames', 'Klatki z wideo'],
  ['colmap', 'Pozycje kamer (COLMAP)'],
  ['reconstruct', 'Rekonstrukcja 3D (GenRecon)'],
  ['glb', 'Składanie sceny (GLB)'],
];
const $ = (id) => document.getElementById(id);
let poll = null;

function show(view) {
  for (const v of document.querySelectorAll('.view')) v.classList.remove('active');
  $(view).classList.add('active');
}

function buildStages() {
  $('stages').innerHTML = STAGES
    .map(([k, label]) => `<li data-stage="${k}"><span class="dot"></span>${label}</li>`).join('');
}

function updateStages(current, status) {
  const order = STAGES.map((s) => s[0]);
  const idx = order.indexOf(current);
  document.querySelectorAll('#stages li').forEach((li, i) => {
    li.classList.toggle('done', status === 'done' || i < idx);
    li.classList.toggle('active', status !== 'done' && i === idx);
  });
}

// The reconstruction runs entirely server-side (a background worker persists
// each job to disk). The client is JUST A VIEW: it remembers the active job id
// (URL + localStorage) so a reload / reconnect / re-open resumes the SAME job,
// and its polling shrugs off transient network drops instead of freezing.
const LAST_JOB_KEY = 'genrecon:lastJob';
let currentJob = null;

function rememberJob(id) {
  currentJob = id;
  try { localStorage.setItem(LAST_JOB_KEY, id); } catch { /* private mode */ }
  const u = new URL(location.href); u.searchParams.set('job', id); history.replaceState(null, '', u);
}
function forgetJob() {
  currentJob = null;
  try { localStorage.removeItem(LAST_JOB_KEY); } catch { /* private mode */ }
  const u = new URL(location.href); u.searchParams.delete('job'); history.replaceState(null, '', u);
}
function stopPolling() { if (poll) { clearInterval(poll); poll = null; } }
function startPolling(id) {
  rememberJob(id);
  stopPolling();
  buildStages(); show('view-progress');
  poll = setInterval(() => refresh(id), 2000);
  refresh(id);
}

async function refresh(id) {
  let st;
  try {
    const r = await fetch(`/api/jobs/${id}`);
    if (r.status === 404) {          // job unknown/expired → back to upload
      stopPolling(); forgetJob(); show('view-upload'); return;
    }
    st = await r.json();
  } catch { return; }                // transient blip (reconnect etc.) → retry next tick, never freeze
  $('bar-fill').style.width = (st.progress || 0) + '%';
  $('progress-msg').textContent = st.message || st.status || '';
  $('progress-msg').classList.toggle('error', st.status === 'error');
  updateStages(st.stage, st.status);
  try {
    const log = await (await fetch(`/api/jobs/${id}/log`)).text();
    const el = $('log'); el.textContent = log; el.scrollTop = el.scrollHeight;
  } catch { /* no log yet */ }

  if (st.status === 'done') {
    stopPolling();
    openViewer(`/api/jobs/${id}/scene.glb`);
  } else if (st.status === 'error') {
    stopPolling();
    $('progress-msg').textContent = '⚠ ' + (st.error || 'błąd rekonstrukcji');
  }
}

async function upload(file) {
  if (!file) return;
  buildStages();
  $('bar-fill').style.width = '0'; $('progress-msg').textContent = 'Wysyłanie filmu…'; $('log').textContent = '';
  show('view-progress');
  const fd = new FormData(); fd.append('video', file);
  let res;
  try { res = await (await fetch('/api/jobs', { method: 'POST', body: fd })).json(); }
  catch (e) { $('progress-msg').classList.add('error'); $('progress-msg').textContent = 'Nie udało się wysłać: ' + e; return; }
  if (res.error) { $('progress-msg').classList.add('error'); $('progress-msg').textContent = res.error; return; }
  // Upload done → hand off to the durable server-side job; the client is now just a view.
  startPolling(res.id);
}

function openViewer(url) {
  show('view-viewer');
  document.body.classList.toggle('touch', matchMedia('(pointer: coarse)').matches);
  startViewer(url).catch((e) => {
    show('view-upload');
    alert('Nie udało się załadować sceny 3D: ' + e);
  });
}

function backToUpload() {
  stopPolling();
  forgetJob();
  stopViewer();
  show('view-upload');
}

// --- mobile joystick ---
function wireJoystick() {
  const stick = $('joystick'), knob = $('joystick-knob');
  let active = null, cx = 0, cy = 0, R = 45;
  const set = (dx, dy) => {
    const len = Math.hypot(dx, dy) || 1, cl = Math.min(len, R);
    dx = dx / len * cl; dy = dy / len * cl;
    knob.style.transform = `translate(${dx}px,${dy}px)`;
    setJoystick(dx / R, -dy / R);   // up = forward
  };
  stick.addEventListener('pointerdown', (e) => {
    active = e.pointerId; const r = stick.getBoundingClientRect();
    cx = r.left + r.width / 2; cy = r.top + r.height / 2;
    stick.setPointerCapture(e.pointerId); set(e.clientX - cx, e.clientY - cy);
  });
  stick.addEventListener('pointermove', (e) => { if (e.pointerId === active) set(e.clientX - cx, e.clientY - cy); });
  const end = (e) => { if (e.pointerId === active) { active = null; knob.style.transform = ''; setJoystick(0, 0); } };
  stick.addEventListener('pointerup', end);
  stick.addEventListener('pointercancel', end);
}

function init() {
  const drop = $('drop'), input = $('file-input');
  input.addEventListener('change', () => upload(input.files[0]));
  ['dragenter', 'dragover'].forEach((ev) => drop.addEventListener(ev, (e) => { e.preventDefault(); drop.classList.add('drag'); }));
  ['dragleave', 'drop'].forEach((ev) => drop.addEventListener(ev, (e) => { e.preventDefault(); drop.classList.remove('drag'); }));
  drop.addEventListener('drop', (e) => upload(e.dataTransfer.files[0]));
  $('btn-demo').addEventListener('click', () => openViewer('./demo.glb'));
  $('btn-cancel').addEventListener('click', backToUpload);
  $('btn-new').addEventListener('click', backToUpload);
  $('btn-recenter').addEventListener('click', recenter);
  wireJoystick();
  if ('serviceWorker' in navigator) navigator.serviceWorker.register('./sw.js').catch(() => {});

  // Resume the active job on load — from the URL (?job=, shareable) or, failing
  // that, from localStorage. So closing the tab, losing signal, or reopening the
  // app hours later drops you right back onto the still-running / finished scan.
  let resumeId = new URLSearchParams(location.search).get('job');
  if (!resumeId) { try { resumeId = localStorage.getItem(LAST_JOB_KEY); } catch { /* private mode */ } }
  if (resumeId) startPolling(resumeId);

  // Mobile browsers freeze timers on a backgrounded tab; re-sync the moment the
  // tab is visible / the network is back, instead of waiting for the next tick.
  const resync = () => {
    if (!currentJob || document.hidden) return;
    if ($('view-viewer').classList.contains('active')) return;  // don't reload the walkthrough mid-explore
    refresh(currentJob);
  };
  document.addEventListener('visibilitychange', resync);
  window.addEventListener('online', resync);
  window.addEventListener('focus', resync);
}

init();