/**
 * Kiosk template loader + renderer (display-only).
 * Espone window.kiosk con: loadTemplate, applyInline, patchBox, addBox, removeBox, updateValue.
 */
(function () {
  const COLS = 24, ROWS = 18;
  const canvasEl = document.getElementById('canvas');
  const chip = document.getElementById('statusChip');

  const state = {
    template: null,
    boxes: [],              // array con .el attaccato
    byPath: new Map(),      // path → Set<box>
    sensorCode: null,
    sensorName: null,
    apiUrl: null,
  };

  function setStatus(msg, err) {
    chip.textContent = msg;
    chip.classList.toggle('err', !!err);
  }

  function indexPaths() {
    state.byPath.clear();
    for (const b of state.boxes) {
      if (!b.path) continue;
      if (!state.byPath.has(b.path)) state.byPath.set(b.path, new Set());
      state.byPath.get(b.path).add(b);
    }
  }

  function renderBox(b) {
    const uw = canvasEl.clientWidth / COLS;
    const uh = canvasEl.clientHeight / ROWS;
    b.el.style.left = (b.x * uw) + 'px';
    b.el.style.top = (b.y * uh) + 'px';
    b.el.style.width = (b.w * uw) + 'px';
    b.el.style.height = (b.h * uh) + 'px';
    b.el.style.background = b.color || '#1e293b';
    b.el.style.color = b.textColor || '#fff';
    const titleEl = b.el.querySelector('.title');
    const valEl = b.el.querySelector('.val');
    titleEl.textContent = b.title || (b.path ? b.path.split('.').pop() : '');
    // adatta font-size al box
    valEl.style.fontSize = Math.min(b.w * uw, b.h * uh) * 0.35 + 'px';
    if (b._lastVal !== undefined) renderValue(b, b._lastVal);
    else valEl.innerHTML = '<span style="opacity:.4">—</span>';
  }

  function renderValue(b, value) {
    const valEl = b.el.querySelector('.val');
    if (value == null || (typeof value === 'object' && !('longitude' in value))) {
      valEl.innerHTML = '<span style="opacity:.4">—</span>';
      return;
    }
    let v = value;
    if (typeof v === 'number') {
      const mul = typeof b.multiplier === 'number' ? b.multiplier : 1;
      const dec = typeof b.decimals === 'number' ? b.decimals : 1;
      v = (v * mul).toFixed(dec);
    } else if (v && typeof v === 'object' && 'longitude' in v) {
      v = v.latitude.toFixed(3) + ', ' + v.longitude.toFixed(3);
    }
    valEl.innerHTML = String(v) + (b.unit ? `<span class="unit">${b.unit}</span>` : '');
  }

  function createBoxEl() {
    const el = document.createElement('div');
    el.className = 'box';
    el.innerHTML = '<div class="title"></div><div class="val"></div>';
    canvasEl.appendChild(el);
    return el;
  }

  function clearAll() {
    for (const b of state.boxes) b.el.remove();
    state.boxes = [];
    state.byPath.clear();
  }

  function applyContent(content) {
    clearAll();
    if (content?.background) document.body.style.background = content.background;
    for (const raw of content?.boxes || []) {
      const b = { ...raw, el: createBoxEl() };
      state.boxes.push(b);
      renderBox(b);
    }
    indexPaths();
  }

  async function loadTemplate(templateId) {
    try {
      const url = templateId
        ? `${state.apiUrl}/kiosk/templates/${templateId}`
        : `${state.apiUrl}/kiosk/template/active`;
      const r = await fetch(url);
      if (!r.ok) { setStatus('no template (' + r.status + ')', true); return null; }
      const tpl = await r.json();
      state.template = tpl;
      applyContent(tpl.content);
      setStatus('template ' + tpl.name);
      return tpl;
    } catch (e) {
      setStatus('fetch error', true);
      return null;
    }
  }

  function patchBox(boxId, patch) {
    const b = state.boxes.find(x => x.id === boxId);
    if (!b) return false;
    Object.assign(b, patch);
    indexPaths();
    renderBox(b);
    return true;
  }

  function addBox(boxDef) {
    const b = { ...boxDef, el: createBoxEl() };
    state.boxes.push(b);
    renderBox(b);
    indexPaths();
    return true;
  }

  function removeBox(boxId) {
    const i = state.boxes.findIndex(b => b.id === boxId);
    if (i < 0) return false;
    state.boxes[i].el.remove();
    state.boxes.splice(i, 1);
    indexPaths();
    return true;
  }

  function applyInline(content) {
    applyContent(content);
    return true;
  }

  function updateValue(path, value) {
    const set = state.byPath.get(path);
    if (!set) return;
    for (const b of set) {
      b._lastVal = value;
      renderValue(b, value);
    }
  }

  function init({ apiUrl, sensorCode, sensorName }) {
    state.apiUrl = apiUrl;
    state.sensorCode = sensorCode;
    state.sensorName = sensorName;
  }

  function currentTemplateId() { return state.template?.id || null; }

  let resizeRaf;
  window.addEventListener('resize', () => {
    cancelAnimationFrame(resizeRaf);
    resizeRaf = requestAnimationFrame(() => state.boxes.forEach(renderBox));
  });

  window.kiosk = { init, loadTemplate, patchBox, addBox, removeBox, applyInline, updateValue, currentTemplateId, setStatus };
})();