/**
 * Bauteile: Stuetz- und Sitzmauern, Travertinstelen, Gartenhaus, Spielhaus,
 * Flammengrill, Baenkli, Leuchten.
 */
import {
  BoxGeometry, CylinderGeometry, Group, Mesh, MeshStandardMaterial, PointLight,
  type MeshStandardMaterialParameters,
} from 'three';
import type { Lamp, Prop, Stele, Wall } from '../site';
import { boxGeometry, wallGeometry } from './geometry';
import * as tex from './textures';

function material(belag: tex.Belag, extra: MeshStandardMaterialParameters = {}) {
  return new MeshStandardMaterial({
    map: belag.map, roughness: belag.roughness, metalness: 0, ...extra,
  });
}

const WALL_LOOK: Record<Wall['type'], () => tex.Belag> = {
  travertin: tex.travertinMauer,
  beton: tex.beton,
  holzscheiter: tex.holzscheiter,
  lamellen: tex.fassadeHolz,
};

/** Wertet ein Hoehenprofil (Stuetzelemente) an der Stelle t aus. */
function profileAt(profile: number[] | undefined, t: number, fallback: number): number {
  if (!profile || !profile.length) return fallback;
  const f = t * (profile.length - 1);
  const i = Math.max(0, Math.min(profile.length - 2, Math.floor(f)));
  const u = f - i;
  return profile[i] * (1 - u) + profile[i + 1] * u;
}

export function buildWalls(walls: Wall[], height: (x: number, z: number) => number): Group {
  const group = new Group();
  group.name = 'Mauern und Wände';

  for (const w of walls) {
    const belag = WALL_LOOK[w.type]();
    const top = (t: number, x: number, z: number) =>
      w.crestProfile ? profileAt(w.crestProfile, t, 0) : (w.top ?? height(x, z) + 0.4);
    const base = (t: number, x: number, z: number) =>
      w.footProfile ? profileAt(w.footProfile, t, -1) : (w.base ?? height(x, z) - 0.5);

    if (w.openSlats) {
      // Lamellenwand: senkrechte Bretter im Plan-Rhythmus (10 cm breit,
      // 35 cm tief, rund 90 cm Achsabstand), dazu das schmale Randband.
      const slats = new Group();
      const [a, b] = [w.path[0], w.path[w.path.length - 1]];
      const len = Math.hypot(b[0] - a[0], b[1] - a[1]);
      const n = Math.max(2, Math.round(len / 0.9));
      const mat = material(belag, { roughness: 0.85 });
      const dirX = (b[0] - a[0]) / len, dirZ = (b[1] - a[1]) / len;
      const angle = (Math.atan2(dirZ, dirX) * 180) / Math.PI;
      for (let i = 0; i <= n; i++) {
        const t = i / n;
        const x = a[0] + (b[0] - a[0]) * t;
        const z = a[1] + (b[1] - a[1]) * t;
        const g = boxGeometry(x, z, 0.10, w.t, base(t, x, z), top(t, x, z), angle, 1.2);
        const m = new Mesh(g, mat);
        m.castShadow = true;
        m.receiveShadow = true;
        slats.add(m);
      }
      // durchlaufendes Randband an der Fassadenkante
      const band = new Mesh(
        wallGeometry(w.path, 0.10, top, base, { segments: 6, tile: belag.tile }),
        mat,
      );
      band.castShadow = true;
      band.receiveShadow = true;
      slats.add(band);
      slats.name = w.id;
      slats.userData.note = w.note;
      group.add(slats);
      continue;
    }

    const geo = wallGeometry(w.path, w.t, top, base, {
      segments: w.crestProfile ? w.crestProfile.length - 1 : 16,
      tile: belag.tile,
    });
    const mesh = new Mesh(geo, material(belag));
    mesh.name = w.id;
    mesh.castShadow = true;
    mesh.receiveShadow = true;
    mesh.userData.note = w.note;
    group.add(mesh);
  }

  return group;
}

export function buildStelen(stelen: Stele[], height: (x: number, z: number) => number): Group {
  const group = new Group();
  group.name = 'Travertinstelen';
  const mat = material(tex.travertinMauer(), { roughness: 0.68 });
  for (const s of stelen) {
    const y0 = height(s.x, s.z) - 0.3;
    const geo = boxGeometry(s.x, s.z, 0.22, 0.22, y0, y0 + 0.3 + s.h, 0, 1.6);
    const m = new Mesh(geo, mat);
    m.castShadow = true;
    m.receiveShadow = true;
    group.add(m);
  }
  return group;
}

// ---------------------------------------------------------------------------
// Freistehende Objekte
// ---------------------------------------------------------------------------

function gartenhaus(p: Prop, y: number): Group {
  const g = new Group();
  const holz = material(tex.fassadeHolz(), { roughness: 0.8 });
  const body = new Mesh(boxGeometry(p.x, p.z, p.w, p.d, y, y + p.h, p.rot, 1.2), holz);
  body.castShadow = true; body.receiveShadow = true;
  g.add(body);
  const roof = new Mesh(
    boxGeometry(p.x, p.z, p.w + 0.16, p.d + 0.16, y + p.h, y + p.h + 0.09, p.rot, 2),
    material(tex.beton(), { color: 0x6a6a66, roughness: 0.9 }),
  );
  roof.castShadow = true;
  g.add(roof);
  // Tuer
  const door = new Mesh(
    new BoxGeometry(0.78, 1.95, 0.04),
    new MeshStandardMaterial({ color: 0x3b3934, roughness: 0.6 }),
  );
  door.position.set(p.x, y + 0.98, p.z - p.d / 2 - 0.02);
  g.add(door);
  return g;
}

/** Spielhaus durch Zimmermann: Podest, Bretterwaende, Gelaender, Pultdach. */
function spielhaus(p: Prop, y: number): Group {
  const g = new Group();
  const holz = material(tex.fassadeHolz(), { color: 0xd8b98c, roughness: 0.85 });
  const dunkel = material(tex.fassadeHolz(), { color: 0xa8895f, roughness: 0.88 });
  const podestTop = y + 0.55;

  const podest = new Mesh(boxGeometry(p.x, p.z, p.w, p.d, y - 0.1, podestTop, p.rot, 1.2), dunkel);
  podest.castShadow = true; podest.receiveShadow = true;
  g.add(podest);

  const hw = p.w / 2, hd = p.d / 2;
  // Rueckwand und zwei Seitenwaende, Vorderseite offen
  const back = new Mesh(boxGeometry(p.x, p.z + hd - 0.05, p.w, 0.09, podestTop, y + p.h, p.rot, 1.2), holz);
  const left = new Mesh(boxGeometry(p.x - hw + 0.05, p.z, 0.09, p.d, podestTop, y + p.h, p.rot, 1.2), holz);
  const right = new Mesh(boxGeometry(p.x + hw - 0.05, p.z - hd / 3, 0.09, p.d / 3, podestTop, y + p.h, p.rot, 1.2), holz);
  for (const m of [back, left, right]) { m.castShadow = true; m.receiveShadow = true; g.add(m); }

  // Bruestung an der offenen Seite
  const rail = new Mesh(boxGeometry(p.x, p.z - hd + 0.05, p.w, 0.07, podestTop + 0.32, podestTop + 0.45, p.rot, 1.2), holz);
  rail.castShadow = true;
  g.add(rail);

  const roof = new Mesh(
    boxGeometry(p.x, p.z, p.w + 0.26, p.d + 0.26, y + p.h, y + p.h + 0.09, p.rot, 2),
    material(tex.fassadeHolz(), { color: 0x7d6549, roughness: 0.9 }),
  );
  roof.castShadow = true;
  g.add(roof);
  return g;
}

function flammengrill(p: Prop, y: number): Group {
  const g = new Group();
  const steel = new MeshStandardMaterial({ color: 0x3a3b3e, roughness: 0.5, metalness: 0.45 });
  const body = new Mesh(boxGeometry(p.x, p.z, p.w, p.d, y + 0.06, y + p.h, p.rot, 1), steel);
  body.castShadow = true; body.receiveShadow = true;
  g.add(body);
  const plate = new Mesh(
    boxGeometry(p.x, p.z, p.w + 0.1, p.d + 0.1, y + p.h, y + p.h + 0.03, p.rot, 1),
    new MeshStandardMaterial({ color: 0x3a3a3c, roughness: 0.35, metalness: 0.7 }),
  );
  plate.castShadow = true;
  g.add(plate);
  return g;
}

function bank(p: Prop, y: number): Group {
  const g = new Group();
  const stein = material(tex.travertinMauer(), { roughness: 0.65 });
  const seat = new Mesh(boxGeometry(p.x, p.z, p.w, p.d, y + p.h - 0.09, y + p.h, p.rot, 1.6), stein);
  seat.castShadow = true; seat.receiveShadow = true;
  g.add(seat);
  for (const s of [-1, 1]) {
    const m = new Mesh(
      boxGeometry(p.x, p.z + (s * (p.d / 2 - 0.22)), p.w - 0.08, 0.14, y, y + p.h - 0.09, p.rot, 1.6),
      stein,
    );
    m.castShadow = true;
    g.add(m);
  }
  return g;
}

function simpleBox(p: Prop, y: number, color: number, rough = 0.7): Mesh {
  const m = new Mesh(
    boxGeometry(p.x, p.z, p.w, p.d, y, y + p.h, p.rot, 1),
    new MeshStandardMaterial({ color, roughness: rough }),
  );
  m.castShadow = true;
  m.receiveShadow = true;
  return m;
}

function gartentor(p: Prop, y: number): Group {
  const g = new Group();
  const mat = new MeshStandardMaterial({ color: 0x4a4a4c, roughness: 0.5, metalness: 0.4 });
  const frame = new Mesh(boxGeometry(p.x, p.z, p.w, 0.05, y, y + p.h, p.rot, 1), mat);
  g.add(frame);
  for (let i = 1; i < 6; i++) {
    const bar = new Mesh(
      boxGeometry(p.x - p.w / 2 + (i * p.w) / 6, p.z, 0.03, 0.03, y, y + p.h, p.rot, 1),
      mat,
    );
    g.add(bar);
  }
  g.children.forEach((c) => { (c as Mesh).castShadow = true; });
  return g;
}

export function buildProps(props: Prop[], height: (x: number, z: number) => number): Group {
  const group = new Group();
  group.name = 'Objekte';
  for (const p of props) {
    const y = height(p.x, p.z);
    let obj: Group | Mesh;
    switch (p.type) {
      case 'gartenhaus': obj = gartenhaus(p, y); break;
      case 'spielhaus': obj = spielhaus(p, y); break;
      case 'flammengrill': obj = flammengrill(p, y); break;
      case 'bank': obj = bank(p, y); break;
      case 'tor': obj = gartentor(p, y); break;
      case 'roboter': obj = simpleBox(p, y, 0x33413a, 0.6); break;
      case 'wasserhahn': obj = simpleBox(p, y, 0x8a8d90, 0.4); break;
      case 'schacht': obj = simpleBox(p, y - 0.01, 0x77746e, 0.9); break;
      default: continue;
    }
    obj.name = p.id;
    obj.userData.note = p.note;
    group.add(obj);
  }
  return group;
}

// ---------------------------------------------------------------------------
// Beleuchtung im Garten
// ---------------------------------------------------------------------------

export interface GardenLights {
  group: Group;
  /** Schaltet die Leuchten je nach Tageszeit. */
  setOn(on: boolean): void;
}

export function buildLamps(lamps: Lamp[], height: (x: number, z: number) => number): GardenLights {
  const group = new Group();
  group.name = 'Beleuchtung';
  const bodyMat = new MeshStandardMaterial({ color: 0x33332f, roughness: 0.55, metalness: 0.3 });
  const glowMat = new MeshStandardMaterial({
    color: 0xffd9a0, emissive: 0xffc26e, emissiveIntensity: 0, roughness: 0.4,
  });
  const pointLights: PointLight[] = [];

  for (const l of lamps) {
    const y = height(l.x, l.z);
    const g = new Group();
    if (l.kind === 'poller') {
      const post = new Mesh(new BoxGeometry(0.09, 0.62, 0.09), bodyMat);
      post.position.set(l.x, y + 0.31, l.z);
      post.castShadow = true;
      g.add(post);
      const head = new Mesh(new BoxGeometry(0.11, 0.06, 0.11), glowMat);
      head.position.set(l.x, y + 0.6, l.z);
      g.add(head);
    } else {
      const ring = new Mesh(new CylinderGeometry(0.07, 0.07, 0.03, 16), bodyMat);
      ring.position.set(l.x, y + 0.015, l.z);
      g.add(ring);
      const lens = new Mesh(new CylinderGeometry(0.05, 0.05, 0.035, 16), glowMat);
      lens.position.set(l.x, y + 0.025, l.z);
      g.add(lens);
    }
    const pl = new PointLight(0xffc98a, 0, 6, 2);
    pl.position.set(l.x, y + (l.kind === 'poller' ? 0.6 : 0.1), l.z);
    pointLights.push(pl);
    g.add(pl);
    group.add(g);
  }

  return {
    group,
    setOn(on: boolean) {
      glowMat.emissiveIntensity = on ? 1.6 : 0;
      for (const pl of pointLights) pl.intensity = on ? 2.2 : 0;
    },
  };
}