/**
 * Extrahiert die Vektorgeometrie aus dem Gartenplan-PDF (Garten Design AG, 1:100)
 * und transformiert sie in ein georeferenziertes, hausachsen-paralleles
 * Koordinatensystem in Metern.
 *
 * Ausgabe: tools/out/plan-raw.json
 *
 * Koordinatensystem (Site-Frame, entspricht three.js X/Z):
 *   X  = Hausachse ENE, Peilung  61.16 deg
 *   Z  = senkrecht dazu SSE, Peilung 151.16 deg
 *   Y  = Hoehe (hier nicht enthalten, kommt aus den Hoehenkoten)
 *   Ursprung = Fixpunkt "0.00" beim Hauseingang, absolut 651.17 m ue. M.
 *
 * Aufruf:  node tools/extract-plan.mjs
 */
import * as mupdf from 'mupdf';
import fs from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const ROOT = path.resolve(__dirname, '..');
const PDF = path.join(ROOT, 'Info Dateien', 'Gartenplan 1 Jasmin und Damian Kellenberger.pdf');
const OUT_DIR = path.join(__dirname, 'out');

/** Massstab 1:100 -> 1 PDF-Punkt entspricht 0.0352778 m in der Realitaet. */
const PT_TO_M = (25.4 / 72 / 1000) * 100;

/** Zeichnungsraster gegenueber Blattkante, aus der Winkelanalyse der Linien. */
const GRID_ANGLE_DEG = -28.8385;

/** Nur dieser Blattausschnitt enthaelt den Situationsplan (PDF-Punkte). */
const PLAN_CLIP = { x0: 600, y0: 150, x1: 1800, y1: 1060 };

const cos = Math.cos((GRID_ANGLE_DEG * Math.PI) / 180);
const sin = Math.sin((GRID_ANGLE_DEG * Math.PI) / 180);

/**
 * PDF-Punkt -> Site-Meter, noch ohne Ursprungsversatz.
 * Auf dem Blatt ist Norden oben, also entspricht (x, y) direkt (Ost, Sued).
 * Projektion auf die beiden Rasterachsen des Plans:
 *   d1 = (cos, sin) bei GRID_ANGLE_DEG  -> Site-X (Hausachse ENE)
 *   d2 = (-sin, cos)                    -> Site-Z (SSE)
 */
function toSite(x, y) {
  return [(x * cos + y * sin) * PT_TO_M, (-x * sin + y * cos) * PT_TO_M];
}

function bboxOf(segs) {
  let x0 = Infinity, y0 = Infinity, x1 = -Infinity, y1 = -Infinity;
  for (const s of segs) {
    for (let i = 1; i + 1 < s.length; i += 2) {
      x0 = Math.min(x0, s[i]); x1 = Math.max(x1, s[i]);
      y0 = Math.min(y0, s[i + 1]); y1 = Math.max(y1, s[i + 1]);
    }
  }
  return [x0, y0, x1, y1];
}

/** Flaeche eines geschlossenen Polygonzugs (Shoelace), in m^2. */
function areaOf(points) {
  let a = 0;
  for (let i = 0; i < points.length; i++) {
    const [x0, z0] = points[i];
    const [x1, z1] = points[(i + 1) % points.length];
    a += x0 * z1 - x1 * z0;
  }
  return Math.abs(a) / 2;
}

/**
 * Erkennt, ob ein Pfad ein Kreis ist (Pflanzensymbole sind Bezier-Kreise).
 * Liefert {cx, cz, r} oder null.
 */
function asCircle(points) {
  if (points.length < 8) return null;
  let cx = 0, cz = 0;
  for (const [x, z] of points) { cx += x; cz += z; }
  cx /= points.length; cz /= points.length;
  let rMin = Infinity, rMax = 0, rSum = 0;
  for (const [x, z] of points) {
    const r = Math.hypot(x - cx, z - cz);
    rMin = Math.min(rMin, r); rMax = Math.max(rMax, r); rSum += r;
  }
  const r = rSum / points.length;
  if (r < 0.05) return null;
  // Toleranz: echte Kreise streuen unter 12 % um den Mittelwert.
  if ((rMax - rMin) / r > 0.12) return null;
  return { cx, cz, r };
}

function flattenSegments(segs) {
  // Beziers werden linear unterteilt; 8 Stuetzstellen reichen bei Plangroessen.
  const rings = [];
  let cur = null, sx = 0, sy = 0, px = 0, py = 0;
  const push = (x, y) => { cur.push([x, y]); px = x; py = y; };
  for (const s of segs) {
    switch (s[0]) {
      case 'M':
        if (cur && cur.length > 1) rings.push(cur);
        cur = []; sx = s[1]; sy = s[2]; push(s[1], s[2]);
        break;
      case 'L':
        if (!cur) { cur = []; sx = s[1]; sy = s[2]; }
        push(s[1], s[2]);
        break;
      case 'C': {
        if (!cur) { cur = []; sx = px; sy = py; cur.push([px, py]); }
        const [x0, y0] = [px, py];
        for (let i = 1; i <= 8; i++) {
          const t = i / 8, u = 1 - t;
          const x = u * u * u * x0 + 3 * u * u * t * s[1] + 3 * u * t * t * s[3] + t * t * t * s[5];
          const y = u * u * u * y0 + 3 * u * u * t * s[2] + 3 * u * t * t * s[4] + t * t * t * s[6];
          cur.push([x, y]);
        }
        px = s[5]; py = s[6];
        break;
      }
      case 'Z':
        if (cur && cur.length > 1) { rings.push(cur); }
        cur = [[sx, sy]]; px = sx; py = sy;
        break;
    }
  }
  if (cur && cur.length > 1) rings.push(cur);
  return rings;
}

/** Entfernt doppelte und kollineare Stuetzpunkte. */
function simplify(points, eps = 0.004) {
  const out = [];
  for (const p of points) {
    const last = out[out.length - 1];
    if (last && Math.hypot(p[0] - last[0], p[1] - last[1]) < eps) continue;
    out.push(p);
  }
  while (out.length > 1 && Math.hypot(out[0][0] - out[out.length - 1][0], out[0][1] - out[out.length - 1][1]) < eps) {
    out.pop();
  }
  const res = [];
  for (let i = 0; i < out.length; i++) {
    const a = out[(i - 1 + out.length) % out.length], b = out[i], c = out[(i + 1) % out.length];
    const cross = (b[0] - a[0]) * (c[1] - a[1]) - (b[1] - a[1]) * (c[0] - a[0]);
    if (Math.abs(cross) < 1e-5 && out.length > 3) continue;
    res.push(b);
  }
  return res.length >= 3 ? res : out;
}

function main() {
  const doc = mupdf.Document.openDocument(fs.readFileSync(PDF), 'application/pdf');
  const page = doc.loadPage(0);

  // --- 1. Vektor-Operationen mitschneiden -------------------------------
  const raw = [];
  const apply = (m, x, y) => [m[0] * x + m[2] * y + m[4], m[1] * x + m[3] * y + m[5]];
  const walk = (p, m) => {
    const segs = [];
    p.walk({
      moveTo: (x, y) => segs.push(['M', ...apply(m, x, y)]),
      lineTo: (x, y) => segs.push(['L', ...apply(m, x, y)]),
      curveTo: (a, b, c, d, e, f) => segs.push(['C', ...apply(m, a, b), ...apply(m, c, d), ...apply(m, e, f)]),
      closePath: () => segs.push(['Z']),
    });
    return segs;
  };
  const noop = () => {};
  const device = new mupdf.Device({
    fillPath: (p, eo, m, cs, color) => raw.push({ op: 'f', segs: walk(p, m), c: Array.from(color || []) }),
    strokePath: (p, st, m, cs, color) => raw.push({ op: 's', segs: walk(p, m), c: Array.from(color || []), lw: st?.lineWidth ?? 0 }),
    fillShade: noop, fillImage: noop, fillImageMask: noop,
    clipPath: noop, clipStrokePath: noop, clipImageMask: noop, popClip: noop,
    fillText: noop, strokeText: noop, clipText: noop, clipStrokeText: noop, ignoreText: noop,
    beginMask: noop, endMask: noop, beginGroup: noop, endGroup: noop,
    beginTile: () => 0, endTile: noop, beginLayer: noop, endLayer: noop, close: noop,
  });
  page.run(device, mupdf.Matrix.identity);
  device.close();

  // --- 2. Auf den Planausschnitt beschraenken und transformieren --------
  const shapes = [];
  for (const it of raw) {
    if (!it.segs.length) continue;
    const b = bboxOf(it.segs);
    if (!(b[0] >= PLAN_CLIP.x0 && b[2] <= PLAN_CLIP.x1 && b[1] >= PLAN_CLIP.y0 && b[3] <= PLAN_CLIP.y1)) continue;
    for (const ring of flattenSegments(it.segs)) {
      const pts = simplify(ring.map(([x, y]) => toSite(x, y)));
      if (pts.length < 2) continue;
      const rgb = it.c.length >= 3 ? it.c.slice(0, 3).map((v) => Math.round(v * 255)) : [0, 0, 0];
      shapes.push({
        op: it.op,
        color: rgb,
        hex: '#' + rgb.map((v) => v.toString(16).padStart(2, '0')).join(''),
        pts,
        area: it.op === 'f' ? +areaOf(pts).toFixed(4) : 0,
        circle: asCircle(pts),
        lw: it.lw ? +(it.lw * PT_TO_M).toFixed(3) : 0,
      });
    }
  }

  // --- 3. Beschriftungen mit Position -----------------------------------
  const st = JSON.parse(page.toStructuredText('preserve-whitespace').asJSON());
  const labels = [];
  for (const block of st.blocks ?? []) {
    if (block.type !== 'text') continue;
    for (const line of block.lines ?? []) {
      const t = (line.text ?? '').trim();
      if (!t) continue;
      const { x, y, w, h } = line.bbox;
      if (x < PLAN_CLIP.x0 || x > PLAN_CLIP.x1 || y < PLAN_CLIP.y0 || y > PLAN_CLIP.y1) continue;
      const [sx, sz] = toSite(x + w / 2, y + h / 2);
      labels.push({ text: t, x: +sx.toFixed(3), z: +sz.toFixed(3) });
    }
  }

  // --- 4. Ursprung auf den Fixpunkt legen -------------------------------
  const fix = labels.find((l) => l.text.includes('0.00 Fixpunkt')) ?? labels.find((l) => l.text === 'Eingang');
  const ox = fix ? fix.x : 0;
  const oz = fix ? fix.z : 0;
  const shift = (p) => [+(p[0] - ox).toFixed(4), +(p[1] - oz).toFixed(4)];
  for (const s of shapes) {
    s.pts = s.pts.map(shift);
    if (s.circle) {
      s.circle.cx = +(s.circle.cx - ox).toFixed(4);
      s.circle.cz = +(s.circle.cz - oz).toFixed(4);
      s.circle.r = +s.circle.r.toFixed(4);
    }
  }
  for (const l of labels) { l.x = +(l.x - ox).toFixed(3); l.z = +(l.z - oz).toFixed(3); }

  // --- 5. Hoehenkoten aus den Beschriftungen --------------------------
  const spots = labels
    .filter((l) => /^-?\d\.\d{2}$/.test(l.text))
    .map((l) => ({ x: l.x, z: l.z, y: parseFloat(l.text) }));

  fs.mkdirSync(OUT_DIR, { recursive: true });
  const out = {
    meta: {
      source: path.basename(PDF),
      scale: '1:100',
      ptToM: PT_TO_M,
      gridAngleDeg: GRID_ANGLE_DEG,
      northBearingOfSiteX: 61.1615,
      originLabel: fix?.text ?? null,
      originAbsoluteMasl: 651.17,
      note: 'X = Hausachse ENE, Z = SSE, Ursprung = Fixpunkt 0.00 beim Eingang',
    },
    shapes,
    labels,
    spots,
  };
  fs.writeFileSync(path.join(OUT_DIR, 'plan-raw.json'), JSON.stringify(out));

  const fills = shapes.filter((s) => s.op === 'f');
  console.log(`Formen:  ${shapes.length}  (Fuellungen ${fills.length}, Linien ${shapes.length - fills.length})`);
  console.log(`Kreise:  ${shapes.filter((s) => s.circle).length}`);
  console.log(`Labels:  ${labels.length}   Hoehenkoten: ${spots.length}`);
  const xs = fills.flatMap((s) => s.pts.map((p) => p[0]));
  const zs = fills.flatMap((s) => s.pts.map((p) => p[1]));
  console.log(`Ausdehnung: X ${Math.min(...xs).toFixed(1)} .. ${Math.max(...xs).toFixed(1)} m,  Z ${Math.min(...zs).toFixed(1)} .. ${Math.max(...zs).toFixed(1)} m`);
}

main();