import * as THREE from 'three';
import { CRUSH } from '../../stages/Crush';
import type { EquipmentModel } from '../equipment/EquipmentModels';
import { precompileHidden } from '../equipment/fx/precompileHidden';
type PressSnapshot = {clock:number;phase:'idle'|'down'|'contact'|'up';strikeTime:number};
type Motion = {speed:number;down:number;hold:number;up:number};

/** 컨베이어와 압착기 장면. 받은 압착 모델은 이 장면이 소유·해제하고, 젤리 자원은 PieceStore가 별도로 소유한다. */
export class CrushScene {
  readonly root=new THREE.Group();
  readonly press=new THREE.Group();
  private readonly stripes:THREE.InstancedMesh;
  private readonly materials:THREE.Material[]=[];
  private readonly geometries:THREE.BufferGeometry[]=[];
  /** pressModel: 장착한 압착 장비 모델(원점 = 접촉면 바닥 중앙, 위가 +Y) */
  constructor(private readonly motion:Motion,private readonly pressModel:EquipmentModel) {
    const body=this.material(0x667b7d), belt=this.material(0x334849), metal=this.material(0xe4d9c2), gold=this.material(0xf5bc50);
    this.box(this.root,CRUSH.beltHalfWidth*2,0.15,2.5,body,0,CRUSH.beltY-0.12,0);
    this.box(this.root,CRUSH.beltHalfWidth*2,0.06,2.2,belt,0,CRUSH.beltY-0.03,0);
    // 긴 벨트도 이음선 간격과 드로 콜 수를 유지한다. 매 프레임 전체를 한 칸 안에서만 이동한다.
    const stripeGeometry=new THREE.BoxGeometry(0.025,0.008,2.05);
    this.geometries.push(stripeGeometry);
    this.stripes=new THREE.InstancedMesh(stripeGeometry,body,Math.ceil(CRUSH.beltHalfWidth*2/0.52));
    const matrix=new THREE.Matrix4();
    for(let i=0;i<this.stripes.count;i++)this.stripes.setMatrixAt(i,matrix.makeTranslation(i*0.52-CRUSH.beltHalfWidth,CRUSH.beltY+0.004,0));
    this.stripes.instanceMatrix.needsUpdate=true;
    this.stripes.castShadow=true;this.stripes.receiveShadow=true;
    this.root.add(this.stripes);
    // 벨트 양옆 표시로 압착판에 가리지 않는 타격 중심을 보여 준다.
    for(const z of [-1.17,1.17]) this.box(this.root,CRUSH.halfWidth*2,0.035,0.12,gold,0,CRUSH.beltY,z);
    // 대각선 시점에서 곰과 타격 표시를 가리지 않도록 지지대를 먼 쪽에 둔다.
    for(const x of [-CRUSH.halfWidth-0.35,CRUSH.halfWidth+0.35]) this.box(this.root,0.16,2.1,0.16,metal,x,1.05,1.35);
    this.box(this.root,CRUSH.halfWidth*2+0.86,0.18,0.24,metal,0,2.1,1.35);
    this.press.add(pressModel.object);
    this.root.add(this.press);
    this.press.position.y=CRUSH.hover;
  }
  private material(color:number):THREE.MeshStandardMaterial {
    const m=new THREE.MeshStandardMaterial({color,roughness:0.5,metalness:0.18}); this.materials.push(m); return m;
  }
  private box(parent:THREE.Group,w:number,h:number,d:number,mat:THREE.Material,x:number,y:number,z:number):THREE.Mesh {
    const g=new THREE.BoxGeometry(w,h,d);this.geometries.push(g);
    const m=new THREE.Mesh(g,mat);m.position.set(x,y,z);m.castShadow=true;m.receiveShadow=true;parent.add(m);return m;
  }
  /** dt: 프레임 게임 시간(모델 update 훅에 넘긴다. 준비 직후 첫 배치는 0) */
  update(s:PressSnapshot,dt:number,reducedMotion:boolean) {
    this.stripes.position.x=(s.clock*this.motion.speed)%0.52;
    let k=0;
    if(s.phase==='down') k=Math.min(1,s.strikeTime/this.motion.down);
    else if(s.phase==='contact') k=1;
    else if(s.phase==='up') k=1-(s.strikeTime-this.motion.down-this.motion.hold)/this.motion.up;
    const contactY=CRUSH.beltY+0.55*CRUSH.flat;
    this.press.position.y=CRUSH.hover+(contactY-CRUSH.hover)*k;
    this.pressModel.press?.(k);
    this.pressModel.update?.(dt,0,reducedMotion);
  }
  /** 압착 모델 셰이더를 미리 컴파일한다(장면을 만든 뒤 모드가 부른다. 숨긴 부품 포함) */
  precompile(renderer:THREE.WebGLRenderer,camera:THREE.Camera,scene:THREE.Scene):Promise<void> {
    return precompileHidden(this.pressModel.object,renderer,camera,scene);
  }
  /** 장면 자원을 해제한다. 압착 모델은 보관소(PressModelPool) 것이라 떼기만 한다 */
  dispose() {this.root.removeFromParent();this.stripes.dispose();for(const g of this.geometries)g.dispose();for(const m of this.materials)m.dispose();this.pressModel.object.removeFromParent();}
}