/* Page logic for the pick-and-place sample viewers: camera grid, synchronised playback with
 * autoplay + loop, the state readout, the joint-effort strip and the charts.
 * The instruction header, step timeline and current-step panel come from steps-ui.js, which
 * the older sample pages use as well.  All page data lives in the JSON blocks of the page. */
(function () {
  const J = id => { const e = document.getElementById(id); return e ? JSON.parse(e.textContent) : null; };
  const S = J('series'), STEPS = J('steps') || [], CAMS = J('cams') || [],
        FILES = J('files') || [], TASK = J('task') || {};
  const has = k => S[k] !== undefined;
  const DUR = S.dur != null ? S.dur : (S.t ? S.t[S.n - 1] : (S.n - 1) / S.fps);
  const END_A = S.side === 'L' ? S.end_l : S.end_r;          // active arm, derived
  const cmdDelta = i => {                                    // |command - state|, derived
    let m = 0;
    for (const c of S.joint_idx) m = Math.max(m, Math.abs(S.act_joints[i][c] - S.joints[i][c]));
    return m;
  };
  const frameAt = t => Math.max(0, Math.min(S.n - 1, Math.round(t * S.fps)));
  const SIDE = S.side, SIDEL = SIDE === 'L' ? 'left' : 'right';
  if (window.self !== window.top) {                    // embedded in the gallery shell
    const b = document.getElementById('backlink');
    if (b) b.style.display = 'none';
  }

  // ---- file list
  const fm = document.getElementById('fileManifest');
  FILES.forEach(f => {
    const d = document.createElement('span');
    d.className = 'file-chip';
    d.innerHTML = f.name + '<span class="sz">' + f.size + '</span>';
    fm.appendChild(d);
  });

  // ---- cameras
  const camgrid = document.getElementById('camgrid'), videos = [];
  CAMS.forEach(c => {
    const d = document.createElement('div');
    d.className = 'cam';
    d.innerHTML = `<div class="lbl">${c.label}</div>` +
      `<video muted playsinline preload="auto" src="${c.src}"></video>`;
    camgrid.appendChild(d);
    videos.push(d.querySelector('video'));
  });
  const master = videos[Math.max(0, CAMS.findIndex(c => c.key === 'head_color'))];

  // ---- playback: autoplay once every tile can render, then loop
  const playBtn = document.getElementById('play'), seek = document.getElementById('seek'),
        tlabel = document.getElementById('tlabel');
  let playing = false;
  const seekTo = t => videos.forEach(v => { try { v.currentTime = t; } catch (e) {} });
  function setPlaying(p) {
    playing = p;
    playBtn.textContent = p ? '❚❚' : '▶︎';
    if (p) { videos.forEach(v => v.play().catch(() => {})); requestAnimationFrame(loop); }
    else videos.forEach(v => v.pause());
  }
  playBtn.onclick = () => setPlaying(!playing);
  let started = false, iv = setInterval(tryStart, 400);
  function tryStart() {
    if (started || playing || !videos.length || !videos.every(v => v.readyState >= 2)) return;
    started = true; clearInterval(iv);
    videos.forEach(v => v.muted = true);
    setPlaying(true);
  }
  videos.forEach(v => { v.addEventListener('canplay', tryStart); v.addEventListener('loadeddata', tryStart); });
  window.addEventListener('load', tryStart);
  setTimeout(() => clearInterval(iv), 90000);
  setInterval(() => {
    if (playing && master.currentTime >= DUR - 0.08) {
      seekTo(0); videos.forEach(v => v.play().catch(() => {}));
    }
  }, 200);
  seek.oninput = () => { const t = seek.value / 1000 * DUR; seekTo(t); update(); };
  function resync() {
    const t = master.currentTime;
    videos.forEach(v => { if (v !== master && Math.abs(v.currentTime - t) > 0.2) { try { v.currentTime = t; } catch (e) {} } });
  }
  master.addEventListener('seeked', resync);
  setInterval(() => { if (!master.paused) resync(); }, 1000);
  function loop() { update(); if (playing) requestAnimationFrame(loop); }

  // ---- shared step UI: instruction header, timeline, current-step panel, step list
  const list = document.getElementById('stepList');
  const items = STEPS.map(() => {
    const d = document.createElement('div');
    d.className = 'step-item';
    list.appendChild(d);
    return d;
  });
  const steps = StepsUI.mount({
    series: S, steps: STEPS, task: TASK, colorBy: 'token', listItems: items,
    seek: t => { seekTo(t); update(); },
    hosts: {
      instr: document.getElementById('suInstr'),
      timeline: document.getElementById('suTl'),
      panel: document.getElementById('suPanel'),
    },
  });

  // ---- chart labels that depend on which arm moved
  document.getElementById('lblJoints').textContent =
    SIDEL + '-arm joint positions (rad) · 7 DoF (j1 shoulder → j7 wrist)' +
    (has('act_joints') ? ' · solid = state, dashed = teleop command' : '');
  document.getElementById('lblEnd').innerHTML = SIDEL +
    '-arm end-effector position (m) — <i style="background:#e0616f"></i>x ' +
    '<i style="background:#41c76b"></i>y <i style="background:#4f8ff7"></i>z';
  if (has('act_grip_l')) document.getElementById('lblGrip').innerHTML += ' · dashed = command';

  // ---- joint-effort strip
  function heat(v) {
    v = Math.max(0, Math.min(1, v));
    const s = [[30, 40, 120], [40, 140, 200], [60, 200, 120], [230, 210, 60], [220, 60, 50]];
    const x = v * (s.length - 1), i = Math.floor(x), f = x - i,
          a = s[i], b = s[Math.min(i + 1, s.length - 1)];
    return `rgb(${Math.round(a[0] + (b[0] - a[0]) * f)},${Math.round(a[1] + (b[1] - a[1]) * f)},` +
           `${Math.round(a[2] + (b[2] - a[2]) * f)})`;
  }
  const cEff = document.getElementById('cEff');
  if (has('eff')) {
    document.getElementById('effInfo').textContent =
      '(7 joints/arm · both arms shown · peak ' + S.eff_max + ' Nm)';
    document.getElementById('effPeak').textContent = S.eff_max;
  }
  function drawEffort(i) {
    if (!has('eff')) return;
    const ctx = cEff.getContext('2d'), dpr = devicePixelRatio || 1,
          w = cEff.clientWidth, h = cEff.clientHeight || 46;
    cEff.width = w * dpr; cEff.height = h * dpr;
    ctx.setTransform(dpr, 0, 0, dpr, 0, 0); ctx.clearRect(0, 0, w, h);
    const vals = S.eff[i] || [], K = vals.length, gap = 18, cw = (w - gap - 4) / K;
    for (let k = 0; k < K; k++) {
      const x = 2 + k * cw + (k >= 7 ? gap : 0), v = Math.abs(vals[k]) / Math.max(1e-6, S.eff_max);
      ctx.fillStyle = v > 0.02 ? heat(v) : '#1b1f2a';
      ctx.fillRect(x, 4, cw - 1.5, h - 16);
      ctx.strokeStyle = '#0b0d12'; ctx.lineWidth = 1;
      ctx.strokeRect(x, 4, cw - 1.5, h - 16);
    }
    ctx.font = '10px ui-monospace';
    ctx.fillStyle = SIDE === 'L' ? '#41c76b' : '#6b7686'; ctx.fillText('ARM L', 2, h - 3);
    ctx.fillStyle = SIDE === 'R' ? '#e0616f' : '#6b7686'; ctx.fillText('ARM R', 2 + 7 * cw + gap, h - 3);
  }

  // ---- charts
  const fmt = v => (Math.abs(v) >= 100 ? v.toFixed(0) : Math.abs(v) >= 10 ? v.toFixed(1) : v.toFixed(2));
  function mkDraw(canvas, series, cols, yMin, yMax, opt) {
    opt = opt || {};
    const fill = opt.fill, dash = opt.dash || [];
    let off = null, ow = 0, oh = 0;                 // the curves never change: draw them once
    function paint(w, h, dpr) {
      off = document.createElement('canvas');
      off.width = w * dpr; off.height = h * dpr;
      const ctx = off.getContext('2d');
      ctx.setTransform(dpr, 0, 0, dpr, 0, 0);
      STEPS.forEach((st, i) => {
        ctx.fillStyle = steps.colorOf(st, i) + '18';
        ctx.fillRect(st.start_s / DUR * w, 0, (st.end_s - st.start_s) / DUR * w, h);
      });
      ctx.strokeStyle = '#232733'; ctx.lineWidth = 1;
      for (let g = 0; g <= 4; g++) {
        const y = (h - 14) * g / 4 + 7;
        ctx.beginPath(); ctx.moveTo(0, y); ctx.lineTo(w, y); ctx.stroke();
      }
      const X = k => k / (S.n - 1) * w,
            Y = v => (h - 14) - ((v - yMin) / Math.max(1e-9, yMax - yMin)) * (h - 14) + 7;
      series.forEach((c, ci) => {
        ctx.strokeStyle = cols[ci % cols.length];
        ctx.lineWidth = dash[ci] ? 1 : 1.4;
        ctx.setLineDash(dash[ci] ? [3, 3] : []);
        ctx.beginPath();
        c.forEach((v, k) => { const x = X(k), y = Y(v); k ? ctx.lineTo(x, y) : ctx.moveTo(x, y); });
        ctx.stroke();
        ctx.setLineDash([]);
        if (fill) {
          ctx.lineTo(X(c.length - 1), Y(yMin)); ctx.lineTo(X(0), Y(yMin)); ctx.closePath();
          ctx.fillStyle = cols[ci % cols.length] + '33'; ctx.fill();
        }
      });
      ctx.font = '9px ui-monospace'; ctx.fillStyle = '#6b7686'; ctx.textAlign = 'right';
      ctx.fillText(fmt(yMax), w - 3, 10); ctx.fillText(fmt(yMin), w - 3, h - 3);
    }
    return function (t) {
      const dpr = devicePixelRatio || 1;
      const w = canvas.clientWidth, h = canvas.clientHeight || 90;
      if (!off || ow !== w || oh !== h) { paint(w, h, dpr); ow = w; oh = h; }
      canvas.width = w * dpr; canvas.height = h * dpr;
      const ctx = canvas.getContext('2d');
      ctx.setTransform(1, 0, 0, 1, 0, 0);
      ctx.drawImage(off, 0, 0);                     // cached curves
      ctx.setTransform(dpr, 0, 0, dpr, 0, 0);
      const px = (t / DUR) * w;                     // only the cursor is drawn per frame
      ctx.strokeStyle = '#ffffffaa'; ctx.lineWidth = 1;
      ctx.beginPath(); ctx.moveTo(px, 0); ctx.lineTo(px, h); ctx.stroke();
    };
  }
  const rng = ss => {
    let a = Infinity, b = -Infinity;
    ss.forEach(c => c.forEach(v => { a = Math.min(a, v); b = Math.max(b, v); }));
    return [a, b];
  };
  const draws = [];
  const jcols = ['#e0616f', '#e0955f', '#e0d15f', '#7fe05f', '#5fe0c0', '#5f9fe0', '#b46fe0'];
  let jser = S.joint_idx.map(c => S.joints.map(r => r[c])), jdash = jser.map(() => false);
  if (has('act_joints')) S.joint_idx.forEach(c => { jser.push(S.act_joints.map(r => r[c])); jdash.push(true); });
  draws.push(mkDraw(document.getElementById('cJoints'), jser, jcols, ...rng(jser), { dash: jdash }));
  if (has('end_l')) {
    const er = [0, 1, 2].map(c => END_A.map(r => r[c]));
    draws.push(mkDraw(document.getElementById('cEnd'), er, ['#e0616f', '#41c76b', '#4f8ff7'], ...rng(er)));
  }
  if (has('grip_l')) {
    let gs = [S.grip_l, S.grip_r], gd = [false, false];
    if (has('act_grip_l')) { gs.push(S.act_grip_l, S.act_grip_r); gd.push(true, true); }
    draws.push(mkDraw(document.getElementById('cGrip'), gs, ['#41c76b', '#e0616f'], 0, 1, { dash: gd }));
  }
  if (has('fmag_l')) {
    const [, fx] = rng([S.fmag_l, S.fmag_r]);
    draws.push(mkDraw(document.getElementById('cForce'), [S.fmag_l, S.fmag_r], ['#41c76b', '#e0616f'], 0, fx || 1));
  }
  if (has('src')) draws.push(mkDraw(document.getElementById('cSrc'), [S.src], ['#e0a53e'], 0, 1.05, { fill: true }));
  ['cForce', 'cJoints', 'cEnd', 'cGrip', 'cSrc'].forEach(id => {
    const c = document.getElementById(id);
    if (!c) return;
    c.addEventListener('click', e => {
      const r = c.getBoundingClientRect();
      seekTo((e.clientX - r.left) / r.width * DUR); update();
    });
  });

  // ---- per-frame readout
  function update() {
    const t = master.currentTime, i = frameAt(t);
    const si = steps.update(t), st = STEPS[si];
    const set = (id, v) => { const e = document.getElementById(id); if (e) e.textContent = v; };
    set('roTime', t.toFixed(2) + 's');
    set('roFrame', i + ' / ' + (S.n - 1));
    set('roStep', st.id + '. ' + st.token);
    set('roGrip', has('grip_l') ? S.grip_l[i].toFixed(2) + ' / ' + S.grip_r[i].toFixed(2) : '–');
    set('roEndL', has('end_l') ? S.end_l[i].map(x => x.toFixed(3)).join(' / ') : '–');
    set('roEndR', has('end_l') ? S.end_r[i].map(x => x.toFixed(3)).join(' / ') : '–');
    set('roF', has('fmag_l') ? S.fmag_l[i].toFixed(1) + ' / ' + S.fmag_r[i].toFixed(1) : '–');
    set('roSrc', has('src') ? (S.src[i] === 1 ? 'OPERATOR' : 'idle / other') : '–');
    set('roSide', SIDEL + ' arm');
    set('roCmd', has('act_joints') ? cmdDelta(i).toFixed(3) : '–');
    if (has('eff')) {
      const e = S.eff[i];
      let bk = 0;
      for (let k = 0; k < e.length; k++) if (Math.abs(e[k]) > Math.abs(e[bk])) bk = k;
      set('roTau', S.joint_names[bk] + '  ' + e[bk].toFixed(1) + ' Nm');
    }
    set('roProg', Math.round((t - st.start_s) / Math.max(1e-6, st.end_s - st.start_s) * 100) +
        '% of step ' + st.id);
    seek.value = Math.round(t / DUR * 1000);
    tlabel.textContent = t.toFixed(2) + ' / ' + DUR.toFixed(2) + 's';
    drawEffort(i);
    draws.forEach(d => d(t));
  }
  window.addEventListener('resize', update);
  master.addEventListener('loadedmetadata', update);
  master.addEventListener('seeked', update);
  window.addEventListener('load', update);
  update();
})();