/* isokit-view.js: browser shell for isokit scenes (global IsoKit) */
/*
 * Plain ES2019, no dependencies. The Rust engine renders SVG; this file shows
 * it: levels, four rotations, drag pan, pinch / wheel zoom, tag declutter,
 * tooltips, selection, full screen. Port of the CNXIso / Mooban mount().
 *
 *   var view = IsoKit.mount(el, source, { onPick: function (info) {} });
 *   source = IsoKit.staticSource(data)          // prerendered views (isokit build)
 *          | IsoKit.httpSource("", meta)         // the Studio / dev server
 *   source.meta   = { title, note, levels: [{id, label, title}], defaultLevel, defaultRotation }
 *   source.render(level, rot, cfg) -> view data or a Promise of it:
 *                   { html, info, bbox: [x, y, w, h], focus: [x, y], north, boxes, warnings }
 *
 *   view.update(cfg)  view.refresh()  view.setLevel(id)  view.setRotation(r)  view.rotate(d)
 *   view.select(id)   view.selectObj(id)  view.focus(id | [x, y, z], zoom)  view.fit()
 *   view.toWorld(clientX, clientY, z) -> [x, y]    view.ready() -> Promise
 *   view.info(id)  view.stats()  view.fullscreen(on)  view.destroy()
 */
(function (root) {
  "use strict";

  var VERSION = "0.1.0";
  var C = 4, CZ = 4;

  function esc(s) {
    return String(s).replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;").replace(/"/g, "&quot;");
  }
  function r1(v) { return Math.round(v * 10) / 10; }
  function rotOf(r) { return ((r | 0) % 4 + 4) % 4; }
  // view coordinates -> world plan (inverse of the engine's Proj.r)
  function rInv(rot, vx, vy) {
    switch (rot) { case 0: return [vx, -vy]; case 1: return [-vy, -vx]; case 2: return [-vx, vy]; default: return [vy, vx]; }
  }
  function rFwd(rot, x, y) {
    switch (rot) { case 0: return [x, -y]; case 1: return [-y, -x]; case 2: return [-x, y]; default: return [y, x]; }
  }
  function project(rot, x, y, z) { var v = rFwd(rot, x, y); return [(v[0] - v[1]) * C, (v[0] + v[1]) * C / 2 - (z || 0) * CZ]; }
  function unproject(rot, sx, sy, z) {
    var a = sx / C, b = (sy + (z || 0) * CZ) * 2 / C;
    return rInv(rot, (a + b) / 2, (b - a) / 2);
  }
  function isThen(x) { return x && typeof x.then === "function"; }

  // ------------------------------------------------------------ sources
  function staticSource(data) {
    return {
      meta: data.meta,
      render: function (level, rot) {
        var v = data.views[level + "/" + rot];
        return v || { error: { message: "view " + level + "/" + rot + " was not built" } };
      }
    };
  }
  function httpSource(base, meta) {
    base = base || "";
    return {
      meta: meta,
      dev: true,
      render: function (level, rot, cfg) {
        var q = "level=" + encodeURIComponent(level) + "&rot=" + rot + "&dev=1" + (cfg ? "&cfg=" + encodeURIComponent(JSON.stringify(cfg)) : "");
        return fetch(base + "/api/render?" + q, { cache: "no-store" }).then(function (r) { return r.json(); });
      }
    };
  }

  // ------------------------------------------------------------ mount
  var UID = 0;
  function mount(el, source, opts) {
    if (!el) throw new Error("IsoKit.mount: no container");
    opts = opts || {};
    var meta = source.meta || {};
    var levels = meta.levels && meta.levels.length ? meta.levels : [{ id: "site", label: "Site" }];
    var st = {
      cfg: Object.assign({}, opts.cfg || {}),
      level: opts.level || meta.defaultLevel || levels[0].id,
      rot: rotOf(opts.rotation === undefined ? (meta.defaultRotation === undefined ? 1 : meta.defaultRotation) : opts.rotation),
      sel: null, selObj: null, uid: ++UID
    };
    var wrap = document.createElement("div");
    wrap.className = "iso-wrap";
    var segs = levels.length > 1 ? '<span class="iso-seg" role="group" aria-label="Level">' + levels.map(function (l) {
      return '<button type="button" data-a="level" data-level="' + esc(l.id) + '" title="' + esc(l.title || l.label || l.id) + '">' + esc(l.label || l.id) + "</button>";
    }).join("") + "</span>" : "";
    wrap.innerHTML = '<div class="iso-stage"><svg class="iso-svg" xmlns="http://www.w3.org/2000/svg" role="img" tabindex="0" aria-label="' + esc(meta.title || "Isometric view") + '"></svg>' +
      '<div class="iso-bar" role="toolbar" aria-label="View">' + segs +
      '<button type="button" data-a="rotl" title="Rotate left" aria-label="Rotate the view left">&#x21BA;</button>' +
      '<button type="button" data-a="rotr" title="Rotate right" aria-label="Rotate the view right">&#x21BB;</button>' +
      '<span class="iso-compass" title="North" aria-hidden="true"><svg viewBox="-10 -10 20 20"><g class="iso-needle"><path d="M0 -8L3 3L0 1.4L-3 3Z"/></g></svg><b>N</b></span>' +
      '<button type="button" data-a="zout" title="Zoom out" aria-label="Zoom out">&#x2212;</button>' +
      '<button type="button" data-a="zin" title="Zoom in" aria-label="Zoom in">+</button>' +
      '<button type="button" data-a="fit" title="Show everything" aria-label="Fit the view">Fit</button>' +
      (opts.fullscreen === false ? "" : '<button type="button" data-a="full" class="iso-fullbtn" title="Full screen (F)" aria-label="Full screen" aria-pressed="false">' +
        '<svg viewBox="0 0 16 16" width="14" height="14" aria-hidden="true"><path class="iso-fs-in" d="M1.5 6V1.5H6M10 1.5h4.5V6M14.5 10v4.5H10M6 14.5H1.5V10"/>' +
        '<path class="iso-fs-out" d="M6 1.5V6H1.5M10 1.5V6h4.5M14.5 10H10v4.5M1.5 10H6v4.5"/></svg></button>') + "</div>" +
      '<div class="iso-tip" role="status" hidden></div><div class="iso-err" hidden></div><div class="iso-busy" hidden></div></div>' +
      (opts.note === false || !meta.note ? "" : '<p class="iso-note">' + esc(meta.note) + "</p>");
    el.appendChild(wrap);
    var stage = wrap.querySelector(".iso-stage"), svg = wrap.querySelector(".iso-svg"), tip = wrap.querySelector(".iso-tip"),
      bar = wrap.querySelector(".iso-bar"), errBox = wrap.querySelector(".iso-err");
    var scn = null, vb = null, fitW = 1, atFit = true, metas = [], declT = 0, alive = true, lastSize = [0, 0], seq = 0, waiting = [];
    var touched = false, first = true;

    // ---------------------------------------------------------- full screen
    var fsEl = opts.fullscreen && opts.fullscreen.nodeType === 1 ? opts.fullscreen : wrap, fsBtn = bar.querySelector('[data-a="full"]');
    function fsNative() { return (document.fullscreenElement || document.webkitFullscreenElement) === fsEl; }
    function isFull() { return fsNative() || fsEl.classList.contains("iso-fs-fake"); }
    function fsSync() {
      var on = isFull();
      fsEl.classList.toggle("iso-fs", on);
      if (fsBtn) { fsBtn.setAttribute("aria-pressed", String(on)); fsBtn.title = on ? "Leave full screen (Esc)" : "Full screen (F)"; }
      call(opts.onFullscreen, on);
    }
    function fsFake(on) { fsEl.classList.toggle("iso-fs-fake", on); document.documentElement.classList.toggle("iso-fs-lock", on); fsSync(); }
    function setFull(on) {
      if (on === isFull()) return;
      if (!on) {
        if (fsEl.classList.contains("iso-fs-fake")) fsFake(false);
        else { var ex = document.exitFullscreen || document.webkitExitFullscreen; if (ex) ex.call(document); }
        return;
      }
      var req = fsEl.requestFullscreen || fsEl.webkitRequestFullscreen;
      if (!req) { fsFake(true); return; }
      try { var p = req.call(fsEl); if (p && p.catch) p.catch(function () { fsFake(true); }); } catch (e) { fsFake(true); }
    }
    function onFsKey(e) { if (e.key === "Escape" && fsEl.classList.contains("iso-fs-fake")) { fsFake(false); svg.focus(); } }
    document.addEventListener("fullscreenchange", fsSync);
    document.addEventListener("webkitfullscreenchange", fsSync);
    document.addEventListener("keydown", onFsKey);

    function call(fn) {
      if (typeof fn !== "function") return undefined;
      try { return fn.apply(null, Array.prototype.slice.call(arguments, 1)); } catch (e) { if (window.console) console.error(e); }
      return undefined;
    }

    // ---------------------------------------------------------- build
    function size() { var r = stage.getBoundingClientRect(); return [Math.max(1, r.width), Math.max(1, r.height)]; }
    function build() {
      var my = ++seq;
      wrap.classList.add("iso-loading");
      var r;
      try { r = source.render(st.level, st.rot, st.cfg); } catch (e) { r = { error: { message: String(e) } }; }
      if (isThen(r)) {
        r.then(function (d) { if (my === seq) applyScene(d); }, function (e) { if (my === seq) applyScene({ error: { message: String(e) } }); });
      } else applyScene(r);
    }
    function applyScene(d) {
      if (!alive) return;
      wrap.classList.remove("iso-loading");
      if (!d || d.error) {
        var e = (d && d.error) || { message: "no data" };
        errBox.innerHTML = "<b>Scene error</b><span>" + esc((e.file ? e.file + (e.line ? ":" + e.line : "") + ": " : "") + e.message) + "</span>" +
          (e.trace && e.trace.length ? "<small>" + e.trace.map(esc).join("<br>") + "</small>" : "");
        errBox.hidden = false;
        call(opts.onRender, d);
        flush();
        return;
      }
      errBox.hidden = true;
      var hadScene = !!scn;
      scn = d;
      svg.innerHTML = d.html;
      wrap.classList.toggle("iso-still", st.cfg.running === false);
      metas = Array.prototype.map.call(svg.querySelectorAll(".iso-tag"), function (g, i) {
        return { el: g, p: +g.getAttribute("data-p"), w: +g.getAttribute("data-w"), x: +g.getAttribute("data-x"), y: +g.getAttribute("data-y"), i: i, hid: false };
      }).sort(function (a, b) { return b.p - a.p || a.i - b.i; });
      Array.prototype.forEach.call(bar.querySelectorAll(".iso-seg button"), function (b) { b.setAttribute("aria-pressed", String(b.getAttribute("data-level") === st.level)); });
      wrap.querySelector(".iso-needle").setAttribute("transform", "rotate(" + (d.north || 0).toFixed(1) + ")");
      if (st.sel) select(st.sel, true);
      if (st.selObj) selectObj(st.selObj);
      if (first || !hadScene) { first = false; lastSize = size(); focusDefault(); }
      else if (pendingFrame) { var f = pendingFrame; pendingFrame = null; f(); }
      else { var wasFit = atFit; computeFit(); if (wasFit) fit(); else { clampVB(); apply(); } }
      call(opts.onRender, d);
      flush();
    }
    var pendingFrame = null;
    function flush() { var w = waiting; waiting = []; w.forEach(function (f) { f(); }); }
    function computeFit() {
      var b = scn.bbox, sz = size(), ar = sz[0] / sz[1], w = b[2] * 1.02, h = b[3] * 1.04;
      if (w / h > ar) h = w / ar; else w = h * ar;
      fitW = w;
      return { x: b[0] + b[2] / 2 - w / 2, y: b[1] + b[3] / 2 - h / 2, w: w, h: h };
    }
    function apply() {
      if (!vb) return;
      svg.setAttribute("viewBox", r1(vb.x) + " " + r1(vb.y) + " " + r1(vb.w) + " " + r1(vb.h));
      var sz = size();
      svg.style.setProperty("--iso-k", (vb.w / sz[0]).toFixed(4));
      atFit = vb.w >= fitW * 0.995;
      svg.style.touchAction = atFit ? "pan-y" : "none";
      wrap.classList.toggle("iso-zoomed", !atFit);
      schedule();
    }
    function fit() { if (!scn) return; vb = computeFit(); apply(); touched = false; }
    function clampVB() {
      var b = scn.bbox, cx = vb.x + vb.w / 2, cy = vb.y + vb.h / 2;
      cx = Math.max(b[0], Math.min(b[0] + b[2], cx)); cy = Math.max(b[1], Math.min(b[1] + b[3], cy));
      vb.x = cx - vb.w / 2; vb.y = cy - vb.h / 2;
    }
    function zoomAt(f, px, py) {
      if (!vb) return;
      touched = true;
      var sz = size(), nw = Math.max(fitW / 20, Math.min(fitW, vb.w / f)), nh = nw * sz[1] / sz[0];
      if (px === undefined) { px = 0.5; py = 0.5; }
      var ux = vb.x + px * vb.w, uy = vb.y + py * vb.h;
      vb = { x: ux - px * nw, y: uy - py * nh, w: nw, h: nh };
      if (nw >= fitW * 0.999) vb = computeFit(); else clampVB();
      apply();
    }
    function zoomClient(f, cx, cy) { var r = stage.getBoundingClientRect(); zoomAt(f, (cx - r.left) / r.width, (cy - r.top) / r.height); }
    function panPx(dx, dy) { if (!vb) return; touched = true; var sz = size(), k = vb.w / sz[0]; vb.x -= dx * k; vb.y -= dy * k; clampVB(); apply(); }
    function focusDefault() {
      fit();
      var sz = size();
      if (sz[0] < 640 && scn && !isFull()) {
        var nw = fitW / 2.4, nh = nw * sz[1] / sz[0];
        vb = { x: scn.focus[0] - nw / 2, y: scn.focus[1] - nh / 2, w: nw, h: nh };
        clampVB(); apply();
      }
      touched = false;
    }
    function schedule() {
      if (declT) return;
      declT = (window.requestAnimationFrame || setTimeout)(function () { declT = 0; declutter(); });
    }
    function declutter() {
      if (!alive || !vb) return;
      var sz = size(), k = vb.w / sz[0], kept = [], i, j, t, x, y, r, vis;
      var bt = bar.offsetTop + bar.offsetHeight + 2, bw = bar.offsetLeft + bar.offsetWidth;
      for (i = 0; i < metas.length; i++) {
        t = metas[i]; x = (t.x - vb.x) / k; y = (t.y - vb.y) / k;
        r = [x - t.w / 2 - 2, y - 23, x + t.w / 2 + 2, y - 4];
        vis = r[0] >= 2 && r[2] <= sz[0] - 2 && r[1] >= 2 && r[3] <= sz[1] - 2 && !(r[1] < bt && r[0] < bw);
        for (j = 0; vis && j < kept.length; j++) if (!(r[2] < kept[j][0] || r[0] > kept[j][2] || r[3] < kept[j][1] || r[1] > kept[j][3])) vis = false;
        if (vis) kept.push(r);
        if (t.hid === vis) { t.hid = !vis; t.el.classList.toggle("iso-hide", !vis); }
      }
    }

    // ---------------------------------------------------------- picking
    function infoOf(id) { return (scn && scn.info && scn.info[id]) || { id: id, name: id, detail: "" }; }
    function showTip(info, cx, cy) {
      var rows = info.rows && info.rows.length ? "<table>" + info.rows.map(function (r) { return "<tr><th>" + esc(r[0]) + "</th><td>" + esc(r[1]) + "</td></tr>"; }).join("") + "</table>" : "";
      tip.innerHTML = "<b>" + esc(info.name) + "</b>" + (info.detail ? "<span>" + esc(info.detail) + "</span>" : "") + rows;
      tip.hidden = false;
      var r = stage.getBoundingClientRect(), tw = tip.offsetWidth, th = tip.offsetHeight, x = cx - r.left + 14, y = cy - r.top + 14;
      if (x + tw > r.width - 6) x = Math.max(6, cx - r.left - tw - 14);
      if (y + th > r.height - 6) y = Math.max(6, cy - r.top - th - 14);
      tip.style.left = x + "px"; tip.style.top = y + "px";
    }
    function hideTip() { tip.hidden = true; }
    function q(attr, id) { return svg.querySelectorAll("[" + attr + '="' + String(id).replace(/["\\]/g, "") + '"]'); }
    function select(id, quiet) {
      Array.prototype.forEach.call(svg.querySelectorAll(".iso-sel"), function (e) { e.classList.remove("iso-sel"); });
      st.sel = id || null;
      if (st.selObj) selectObj(st.selObj);
      if (!id) return;
      Array.prototype.forEach.call(q("data-id", id), function (e) { if (!e.classList.contains("iso-tag")) e.classList.add("iso-sel"); });
    }
    function selectObj(id) {
      Array.prototype.forEach.call(svg.querySelectorAll(".iso-osel"), function (e) { e.classList.remove("iso-osel"); });
      st.selObj = id || null;
      if (id) Array.prototype.forEach.call(q("data-obj", id), function (e) { e.classList.add("iso-osel"); });
    }
    function targetId(t) { var e = t && t.closest ? t.closest("[data-id]") : null; return e && svg.contains(e) ? e.getAttribute("data-id") : null; }
    function targetObj(t) { var e = t && t.closest ? t.closest("[data-obj]") : null; return e && svg.contains(e) ? e.getAttribute("data-obj") : null; }
    function targetSrc(t) { var e = t && t.closest ? t.closest("[data-src]") : null; return e && svg.contains(e) ? e.getAttribute("data-src") : null; }
    function pick(t, cx, cy) {
      var id = targetId(t), obj = targetObj(t);
      if (!id && !obj) { select(null); hideTip(); call(opts.onPick, null); return; }
      var info = infoOf(id || obj);
      if (!opts.noSelect) select(id);
      if (!opts.noTip) showTip(info, cx, cy);
      call(opts.onPick, { id: info.id || id, name: info.name, detail: info.detail, rows: info.rows || [], obj: obj, src: targetSrc(t) });
    }
    // client point -> world plan at height z
    function toWorld(cx, cy, z) {
      if (!vb) return null;
      var r = stage.getBoundingClientRect(), sx = vb.x + (cx - r.left) / r.width * vb.w, sy = vb.y + (cy - r.top) / r.height * vb.h;
      return unproject(st.rot, sx, sy, z || 0);
    }
    function screenPx() { var sz = size(); return vb ? vb.w / sz[0] : 1; }

    // ---------------------------------------------------------- pointer
    var ptrs = {}, down = null, moved = false, pinch = null, hoverId = null, claimed = false;
    function npt() { return Object.keys(ptrs).length; }
    svg.addEventListener("pointerdown", function (e) {
      ptrs[e.pointerId] = { x: e.clientX, y: e.clientY };
      if (npt() === 1) {
        down = { x: e.clientX, y: e.clientY, id: e.pointerId, t: e.target }; moved = false;
        claimed = !!(opts.interact && call(opts.interact.down, e, { obj: targetObj(e.target), id: targetId(e.target), world: toWorld(e.clientX, e.clientY, 0) }));
        if (claimed) { try { svg.setPointerCapture(e.pointerId); } catch (er) { /* ignore */ } }
      }
      if (npt() === 2) {
        if (claimed) { call(opts.interact.cancel); claimed = false; }
        var k = Object.keys(ptrs), a = ptrs[k[0]], b = ptrs[k[1]];
        pinch = { d: Math.hypot(a.x - b.x, a.y - b.y) || 1 }; moved = true;
      }
    });
    svg.addEventListener("pointermove", function (e) {
      if (opts.onHover) call(opts.onHover, toWorld(e.clientX, e.clientY, 0), e);
      var p = ptrs[e.pointerId];
      if (p) {
        var dx = e.clientX - p.x, dy = e.clientY - p.y;
        p.x = e.clientX; p.y = e.clientY;
        if (pinch && npt() >= 2) {
          var k = Object.keys(ptrs), a = ptrs[k[0]], b = ptrs[k[1]], d = Math.hypot(a.x - b.x, a.y - b.y) || 1;
          zoomClient(d / pinch.d, (a.x + b.x) / 2, (a.y + b.y) / 2); pinch.d = d; return;
        }
        if (down && !moved && Math.hypot(e.clientX - down.x, e.clientY - down.y) > 4) {
          moved = true; hideTip(); wrap.classList.add("iso-dragging");
          if (!claimed) { try { svg.setPointerCapture(e.pointerId); } catch (er) { /* ignore */ } }
        }
        if (moved) {
          if (claimed) call(opts.interact.move, e, { world: toWorld(e.clientX, e.clientY, 0), dx: e.clientX - down.x, dy: e.clientY - down.y, k: screenPx() });
          else panPx(dx, dy);
          e.preventDefault();
        }
        return;
      }
      if (e.pointerType === "mouse" && !opts.noTip) {
        var id = targetId(e.target);
        if (id) {
          if (id !== hoverId) { if (hoverId) setHover(hoverId, false); setHover(id, true); hoverId = id; }
          showTip(infoOf(id), e.clientX, e.clientY);
        } else if (hoverId) { setHover(hoverId, false); hoverId = null; if (!st.sel) hideTip(); }
      }
    });
    function setHover(id, on) {
      Array.prototype.forEach.call(q("data-id", id), function (e) { if (!e.classList.contains("iso-tag")) e.classList.toggle("iso-hov", on); });
    }
    function up(e) {
      var wasDown = down && down.id === e.pointerId;
      delete ptrs[e.pointerId];
      if (npt() < 2) pinch = null;
      if (wasDown) {
        if (claimed) call(opts.interact.up, e, { moved: moved, world: toWorld(e.clientX, e.clientY, 0), cancel: e.type !== "pointerup" });
        else if (!moved && e.type === "pointerup") pick(e.target, e.clientX, e.clientY);
      }
      if (npt() === 0) { down = null; claimed = false; wrap.classList.remove("iso-dragging"); }
    }
    svg.addEventListener("pointerup", up);
    svg.addEventListener("pointercancel", up);
    svg.addEventListener("pointerleave", function (e) { if (e.pointerType === "mouse" && hoverId) { setHover(hoverId, false); hoverId = null; if (!st.sel) hideTip(); } });
    svg.addEventListener("wheel", function (e) {
      if (!(e.ctrlKey || e.metaKey || opts.wheelZoom)) return;
      e.preventDefault();
      zoomClient(Math.exp(-e.deltaY * 0.004), e.clientX, e.clientY);
    }, { passive: false });
    svg.addEventListener("dblclick", function (e) { e.preventDefault(); zoomClient(1.8, e.clientX, e.clientY); });
    svg.addEventListener("keydown", function (e) {
      if (opts.onKey && call(opts.onKey, e)) { e.preventDefault(); return; }
      var k = e.key;
      if (k === "+" || k === "=") zoomAt(1.4); else if (k === "-") zoomAt(1 / 1.4); else if (k === "0") fit();
      else if (k === "ArrowLeft") panPx(60, 0); else if (k === "ArrowRight") panPx(-60, 0); else if (k === "ArrowUp") panPx(0, 60); else if (k === "ArrowDown") panPx(0, -60);
      else if (k === "Escape") { select(null); hideTip(); }
      else if ((k === "f" || k === "F") && fsBtn && !e.ctrlKey && !e.metaKey && !e.altKey) setFull(!isFull()); else return;
      e.preventDefault();
    });
    bar.addEventListener("click", function (e) {
      var b = e.target.closest ? e.target.closest("button") : null;
      if (!b) return;
      var a = b.getAttribute("data-a");
      if (a === "level") setLevel(b.getAttribute("data-level"));
      else if (a === "rotl") rotate(-1); else if (a === "rotr") rotate(1);
      else if (a === "zin") zoomAt(1.5); else if (a === "zout") zoomAt(1 / 1.5); else if (a === "fit") fit();
      else if (a === "full") setFull(!isFull());
    });

    function setLevel(l) {
      if (!l || l === st.level || !levels.some(function (x) { return x.id === l; })) return;
      st.level = l; hideTip(); build();
      call(opts.onLevel, l);
    }
    function rotate(d) {
      var keepZoom = vb ? vb.w / fitW : 1;
      st.rot = rotOf(st.rot + (d || 1)); hideTip();
      pendingFrame = function () {
        if (keepZoom >= 0.995) { fit(); return; }
        computeFit();
        var sz = size(), nw = fitW * keepZoom, nh = nw * sz[1] / sz[0], c = scn.focus;
        if (st.selObj && scn.boxes && scn.boxes[st.selObj]) { var b = scn.boxes[st.selObj]; c = project(st.rot, (b[0] + b[3]) / 2, (b[1] + b[4]) / 2, (b[2] + b[5]) / 2); }
        vb = { x: c[0] - nw / 2, y: c[1] - nh / 2, w: nw, h: nh }; clampVB(); apply();
      };
      build();
      call(opts.onRotate, st.rot);
    }
    var ro = null, io = null;
    function onResize() {
      if (!scn) return;
      var sz = size();
      if (Math.abs(sz[0] - lastSize[0]) < 0.5 && Math.abs(sz[1] - lastSize[1]) < 0.5) return;
      var old = lastSize; lastSize = sz;
      if (!vb || !old[0] || !touched) { focusDefault(); return; }
      var wasFit = atFit, k = vb.w / old[0], cx = vb.x + vb.w / 2, cy = vb.y + vb.h / 2;
      computeFit();
      if (wasFit) { fit(); return; }
      var nw = Math.min(fitW, k * sz[0]), nh = nw * sz[1] / sz[0];
      vb = { x: cx - nw / 2, y: cy - nh / 2, w: nw, h: nh }; clampVB(); apply();
    }
    if (window.ResizeObserver) { ro = new ResizeObserver(onResize); ro.observe(stage); }
    else window.addEventListener("resize", onResize);
    if (window.IntersectionObserver) {
      io = new IntersectionObserver(function (es) { es.forEach(function (en) { wrap.classList.toggle("iso-off", !en.isIntersecting); }); });
      io.observe(stage);
    }
    build();

    var view = {
      el: wrap,
      svg: svg,
      stage: stage,
      source: source,
      update: function (c) { st.cfg = Object.assign({}, st.cfg, c || {}); build(); return view; },
      refresh: function () { build(); return view; },
      setSource: function (s) { source = s; build(); return view; },
      setLevel: function (l) { setLevel(l); return view; },
      getLevel: function () { return st.level; },
      rotate: function (d) { rotate(d); return view; },
      setRotation: function (r) { var d = rotOf(r - st.rot); if (d) rotate(d); return view; },
      getRotation: function () { return st.rot; },
      select: function (id) { select(id); return view; },
      selectObj: function (id) { selectObj(id); return view; },
      // centre on an object id / data-id or a world point [x, y, z] at a zoom relative to fit
      focus: function (target, f) {
        if (!scn) return view;
        var c = null;
        if (Array.isArray(target)) c = project(st.rot, target[0], target[1], target[2] || 0);
        else if (target && scn.boxes && scn.boxes[target]) { var b = scn.boxes[target]; c = project(st.rot, (b[0] + b[3]) / 2, (b[1] + b[4]) / 2, (b[2] + b[5]) / 2); }
        else if (target) {
          var bx = [1e9, 1e9, -1e9, -1e9];
          Array.prototype.forEach.call(q("data-id", target), function (e) {
            if (e.classList.contains("iso-tag")) return;
            try { var b = e.getBBox(); if (b.width || b.height) { bx[0] = Math.min(bx[0], b.x); bx[1] = Math.min(bx[1], b.y); bx[2] = Math.max(bx[2], b.x + b.width); bx[3] = Math.max(bx[3], b.y + b.height); } } catch (er) { /* not rendered */ }
          });
          if (bx[0] < 1e9) c = [(bx[0] + bx[2]) / 2, (bx[1] + bx[3]) / 2];
        }
        if (!c) return view;
        computeFit();
        var sz = size(), nw = fitW / Math.max(1, f || 3), nh = nw * sz[1] / sz[0];
        vb = { x: c[0] - nw / 2, y: c[1] - nh / 2, w: nw, h: nh }; clampVB(); apply(); touched = true;
        return view;
      },
      zoom: function (f) { zoomAt(f || 1.5); return view; },
      fit: function () { fit(); return view; },
      fullscreen: function (on) { setFull(on === undefined ? !isFull() : !!on); return view; },
      isFullscreen: function () { return isFull(); },
      toWorld: toWorld,
      screenOf: function (x, y, z) { return project(st.rot, x, y, z); },
      screenPx: screenPx,
      scene: function () { return scn; },
      ready: function () { return new Promise(function (res) { if (!wrap.classList.contains("iso-loading") && scn) res(view); else waiting.push(function () { res(view); }); }); },
      info: function (id) { return id ? infoOf(id) : Object.keys((scn && scn.info) || {}).map(infoOf); },
      config: function () { return Object.assign({}, st.cfg); },
      stats: function () { return { nodes: svg.querySelectorAll("*").length, sprites: scn ? scn.sprites : 0, level: st.level, rotation: st.rot, ms: scn ? scn.ms : 0 }; },
      destroy: function () {
        alive = false;
        if (ro) ro.disconnect(); else window.removeEventListener("resize", onResize);
        if (isFull()) setFull(false);
        document.removeEventListener("fullscreenchange", fsSync);
        document.removeEventListener("webkitfullscreenchange", fsSync);
        document.removeEventListener("keydown", onFsKey);
        if (io) io.disconnect();
        if (wrap.parentNode) wrap.parentNode.removeChild(wrap);
      }
    };
    return view;
  }

  root.IsoKit = { mount: mount, staticSource: staticSource, httpSource: httpSource, project: project, unproject: unproject, version: VERSION };
})(typeof window !== "undefined" ? window : this);