/*!
 * Tectum
 * Copyright © 2026 Machiel Heinen.
 * Alle rechten voorbehouden. Gebruik uitsluitend met schriftelijke toestemming.
 * Zie LICENTIE.md.
 */
// IFC4 (STEP, ISO 10303-21) met driehoeksnetten (IfcTriangulatedFaceSet), eenheid mm, Z omhoog.
// Ruimtelijke opbouw: project > terrein > gebouw > bouwlaag; elementen eronder of in een samenstelling.

window.IfcWriter = (() => {
  const B64 = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_$';
  function guid() {
    const b = new Uint8Array(16);
    if (typeof crypto !== 'undefined' && crypto.getRandomValues) crypto.getRandomValues(b);
    else for (let i = 0; i < 16; i++) b[i] = Math.floor(Math.random() * 256);
    b[6] = (b[6] & 0x0f) | 0x40; b[8] = (b[8] & 0x3f) | 0x80;
    let out = B64[b[0] >> 6] + B64[b[0] & 63];
    for (let i = 1; i < 16; i += 3) {
      const n = (b[i] << 16) | (b[i + 1] << 8) | b[i + 2];
      out += B64[(n >> 18) & 63] + B64[(n >> 12) & 63] + B64[(n >> 6) & 63] + B64[n & 63];
    }
    return out;
  }

  // Tekst: ' verdubbelen, \ escapen, alles buiten ASCII als \X2\hhhh\X0\.
  function str(s) {
    if (s === null || s === undefined) return '$';
    let out = '', ext = '';
    const flush = () => { if (ext) { out += '\\X2\\' + ext + '\\X0\\'; ext = ''; } };
    for (const ch of String(s)) {
      const c = ch.codePointAt(0);
      if (c >= 32 && c < 127) {
        flush();
        out += ch === "'" ? "''" : ch === '\\' ? '\\\\' : ch;
      } else if (c >= 127 && c <= 0xffff) ext += c.toString(16).toUpperCase().padStart(4, '0');
      else if (c > 0xffff) ext += '003F';
    }
    flush();
    return `'${out}'`;
  }
  function real(v) {
    const r = Math.round(v * 100) / 100;
    const s = Object.is(r, -0) || !isFinite(r) ? '0' : String(r);
    return /[.eE]/.test(s) ? s : s + '.';
  }
  const list = (a) => `(${a.join(',')})`;
  const ref = (n) => `#${n}`;

  function create(opts) {
    const o = opts || {};
    const lines = [];
    let next = 1;
    const add = (type, args) => { const id = next++; lines.push(`#${id}=${type}(${args.join(',')});`); return id; };

    const mm = add('IFCSIUNIT', ['*', '.LENGTHUNIT.', '.MILLI.', '.METRE.']);
    const m2 = add('IFCSIUNIT', ['*', '.AREAUNIT.', '$', '.SQUARE_METRE.']);
    const m3 = add('IFCSIUNIT', ['*', '.VOLUMEUNIT.', '$', '.CUBIC_METRE.']);
    const rad = add('IFCSIUNIT', ['*', '.PLANEANGLEUNIT.', '$', '.RADIAN.']);
    const units = add('IFCUNITASSIGNMENT', [list([mm, m2, m3, rad].map(ref))]);
    const origin = add('IFCCARTESIANPOINT', [list(['0.', '0.', '0.'])]);
    const axis = add('IFCAXIS2PLACEMENT3D', [ref(origin), '$', '$']);
    const ctx = add('IFCGEOMETRICREPRESENTATIONCONTEXT', ['$', str('Model'), '3', '1.E-05', ref(axis), '$']);
    const body = add('IFCGEOMETRICREPRESENTATIONSUBCONTEXT', [str('Body'), str('Model'), '*', '*', '*', '*', ref(ctx), '$', '.MODEL_VIEW.', '$']);
    const project = add('IFCPROJECT', [str(guid()), '$', str(o.project || 'Woning'), str(o.description || null), '$', '$', '$', list([ref(ctx)]), ref(units)]);
    const sitePl = add('IFCLOCALPLACEMENT', ['$', ref(axis)]);
    const site = add('IFCSITE', [str(guid()), '$', str('Terrein'), '$', '$', ref(sitePl), '$', '$', '.ELEMENT.', '$', '$', '$', '$', '$']);
    const bldPl = add('IFCLOCALPLACEMENT', [ref(sitePl), ref(axis)]);
    const a = o.address || {};
    const addr = a.lines || a.town ? add('IFCPOSTALADDRESS', ['$', '$', '$', '$', a.lines ? list([str(a.lines)]) : '$', '$', str(a.town || null), '$', '$', str('Nederland')]) : null;
    const building = add('IFCBUILDING', [str(guid()), '$', str(o.building || 'Woning'), '$', '$', ref(bldPl), '$', '$', '.ELEMENT.', '$', '$', addr ? ref(addr) : '$']);
    const stPl = add('IFCLOCALPLACEMENT', [ref(bldPl), ref(axis)]);
    const storey = add('IFCBUILDINGSTOREY', [str(guid()), '$', str(o.storey || 'Begane grond'), '$', '$', ref(stPl), '$', '$', '.ELEMENT.', '0.']);
    add('IFCRELAGGREGATES', [str(guid()), '$', '$', '$', ref(project), list([ref(site)])]);
    add('IFCRELAGGREGATES', [str(guid()), '$', '$', '$', ref(site), list([ref(building)])]);
    add('IFCRELAGGREGATES', [str(guid()), '$', '$', '$', ref(building), list([ref(storey)])]);

    // Kleur [r, g, b] (0..1) als oppervlaktestijl, één per kleur.
    const styles = new Map();
    function style(rgb) {
      const k = rgb.map(c => Math.round(c * 1000)).join(',');
      if (!styles.has(k)) {
        const col = add('IFCCOLOURRGB', ['$', ...rgb.map(real)]);
        const shading = add('IFCSURFACESTYLESHADING', [ref(col), '0.']);
        styles.set(k, add('IFCSURFACESTYLE', ['$', '.BOTH.', list([ref(shading)])]));
      }
      return styles.get(k);
    }

    const contained = [];
    const materials = new Map();   // naam -> { id, els: [] }
    const psets = new Map();       // sleutel -> { props, els: [] }

    // Driehoeken als vlakke lijst [x,y,z, x,y,z, x,y,z, ...] in mm; punten worden samengevoegd.
    function shape(tri, rgb) {
      const idx = new Map(), pts = [], faces = [];
      const key = (i) => `${Math.round(tri[i] * 10)},${Math.round(tri[i + 1] * 10)},${Math.round(tri[i + 2] * 10)}`;
      const vid = (i) => {
        const k = key(i);
        if (!idx.has(k)) { idx.set(k, pts.length + 1); pts.push(`(${real(tri[i])},${real(tri[i + 1])},${real(tri[i + 2])})`); }
        return idx.get(k);
      };
      for (let i = 0; i + 8 < tri.length; i += 9) {
        const f = [vid(i), vid(i + 3), vid(i + 6)];
        if (f[0] !== f[1] && f[1] !== f[2] && f[0] !== f[2]) faces.push(`(${f.join(',')})`);
      }
      if (!faces.length) return null;
      const pl = add('IFCCARTESIANPOINTLIST3D', [`(${pts.join(',')})`]);
      const fs = add('IFCTRIANGULATEDFACESET', [ref(pl), '$', '$', `(${faces.join(',')})`, '$']);
      if (rgb) add('IFCSTYLEDITEM', [ref(fs), list([ref(style(rgb))]), '$']);
      const rep = add('IFCSHAPEREPRESENTATION', [ref(body), str('Body'), str('Tessellation'), list([ref(fs)])]);
      return add('IFCPRODUCTDEFINITIONSHAPE', ['$', '$', list([ref(rep)])]);
    }

    // el: { type: 'IFCMEMBER', predefined: 'STUD', name, tag, tri, color: [r, g, b], material, props: {naam: waarde}, objectType }
    function element(el) {
      const rep = el.tri ? shape(el.tri, el.color) : null;
      if (el.tri && !rep) return null;
      const pl = add('IFCLOCALPLACEMENT', [ref(stPl), ref(axis)]);
      const args = [str(guid()), '$', str(el.name), str(el.description || null), str(el.objectType || null), ref(pl), rep ? ref(rep) : '$', str(el.tag || null)];
      if (el.type === 'IFCELEMENTASSEMBLY') args.push('.FACTORY.', `.${el.predefined || 'NOTDEFINED'}.`);
      else args.push(`.${el.predefined || 'NOTDEFINED'}.`);
      const id = add(el.type, args);
      if (el.material) {
        if (!materials.has(el.material)) {
          const id = add('IFCMATERIAL', [str(el.material), '$', '$']);
          // Ook aan het materiaal, voor viewers die op materiaal kleuren.
          if (el.color) {
            const si = add('IFCSTYLEDITEM', ['$', list([ref(style(el.color))]), '$']);
            const sr = add('IFCSTYLEDREPRESENTATION', [ref(ctx), str('Style'), str('Material'), list([ref(si)])]);
            add('IFCMATERIALDEFINITIONREPRESENTATION', ['$', '$', list([ref(sr)]), ref(id)]);
          }
          materials.set(el.material, { id, els: [] });
        }
        materials.get(el.material).els.push(id);
      }
      if (el.props) {
        const k = JSON.stringify(el.props);
        if (!psets.has(k)) psets.set(k, { props: el.props, els: [] });
        psets.get(k).els.push(id);
      }
      return id;
    }

    function contain(id) { if (id) contained.push(id); }
    function aggregate(parent, children) {
      const c = children.filter(Boolean);
      if (parent && c.length) add('IFCRELAGGREGATES', [str(guid()), '$', '$', '$', ref(parent), list(c.map(ref))]);
    }

    const value = (v) => typeof v === 'number' ? `IFCLENGTHMEASURE(${real(v)})` : `IFCLABEL(${str(v)})`;
    function toString(filename) {
      if (contained.length) add('IFCRELCONTAINEDINSPATIALSTRUCTURE', [str(guid()), '$', '$', '$', list(contained.map(ref)), ref(storey)]);
      materials.forEach(m => add('IFCRELASSOCIATESMATERIAL', [str(guid()), '$', '$', '$', list(m.els.map(ref)), ref(m.id)]));
      psets.forEach(p => {
        const props = Object.entries(p.props).filter(([, v]) => v !== null && v !== undefined && v !== '')
          .map(([n, v]) => add('IFCPROPERTYSINGLEVALUE', [str(n), '$', value(v), '$']));
        if (!props.length) return;
        const ps = add('IFCPROPERTYSET', [str(guid()), '$', str(o.psetName || 'Pset_Tectum'), '$', list(props.map(ref))]);
        add('IFCRELDEFINESBYPROPERTIES', [str(guid()), '$', '$', '$', list(p.els.map(ref)), ref(ps)]);
      });
      contained.length = 0; materials.clear(); psets.clear();
      const now = new Date().toISOString().slice(0, 19);
      return [
        'ISO-10303-21;', 'HEADER;',
        "FILE_DESCRIPTION(('ViewDefinition [ReferenceView_V1.2]'),'2;1');",
        `FILE_NAME(${str(filename || 'woning.ifc')},${str(now)},(${str(o.author || '')}),(${str(o.organization || '')}),${str(o.app || 'Tectum')},${str(o.app || 'Tectum')},'');`,
        "FILE_SCHEMA(('IFC4'));", 'ENDSEC;', 'DATA;', ...lines, 'ENDSEC;', 'END-ISO-10303-21;', ''
      ].join('\n');
    }

    function save(filename) {
      const blob = new Blob([toString(filename)], { type: 'application/x-step' });
      const url = URL.createObjectURL(blob);
      const el = document.createElement('a');
      el.href = url;
      el.download = filename;
      document.body.appendChild(el);
      el.click();
      document.body.removeChild(el);
      URL.revokeObjectURL(url);
    }

    return { element, contain, aggregate, toString, save, count: () => next - 1 };
  }

  return { create, guid };
})();