import * as THREE from "three";
import { FBXLoader } from "three/addons/loaders/FBXLoader.js";
import { TGALoader } from "three/addons/loaders/TGALoader.js";
import { PointerLockControls } from "three/addons/controls/PointerLockControls.js";
import * as BufferGeometryUtils from "three/addons/utils/BufferGeometryUtils.js";
import { MeshBVH, acceleratedRaycast } from "https://esm.sh/three-mesh-bvh@0.7.6?deps=three@0.160.0";
import { encode, decode } from "https://esm.sh/@msgpack/msgpack@3.1.2?bundle";

/* status overlay */
const statusEl = document.createElement("div");
Object.assign(statusEl.style, { position:"fixed", left:"12px", top:"12px", zIndex:"99999", padding:"6px 10px", borderRadius:"8px", background:"rgba(0,0,0,.55)", color:"#fff", font:"12px/1.2 system-ui,-apple-system,Segoe UI,Roboto,Inter,sans-serif", whiteSpace:"pre", pointerEvents:"none", maxWidth:"45vw" });
statusEl.textContent = "booting…";
document.body.appendChild(statusEl);
const setStatus = (t)=> (statusEl.textContent = t);

/* config */
const MODEL_URL = "https://world.seppjm.com/3js/models/scene.fbx";
const USE_FOG = true;
let RENDER_SCALE = 3;
const COLOR_LEVELS = 32, USE_DITHER = true, VERTEX_SNAP_PIXELS = 0.75;
const FIRE_POS = new THREE.Vector3(2885.090654499771, 5.937671631541306, -2843.489246932181);
const CAM_POS = new THREE.Vector3(3280.98691276581, 386.84586301208896, -2012.4527013816644);
const CAM_ROT_DEG = { yaw: 395.51276597880525, pitch: 2.7272791048226543 };
const CAM_FOV = 90;

/* fire */
const FIRE_SPRITE_SIZE = 150.0, FIRE_HEIGHT_OFFSET = 0.25;
const FIRE_MAIN_INTENSITY = 2.2, FIRE_SUB_INTENSITY = 1.0, FIRE_MAIN_DISTANCE = 12000, FIRE_SUB_DISTANCE = 6000, FIRE_DECAY = 1.2;

/* networking */
const WS_URL = "wss://ws.world.seppjm.com/ws";

/* scale / movement */
const SCALE = 50;
const WALK_SPEED = 4.6 * SCALE, ACCEL = 30.0, AIR_ACCEL = 7.0, FRICTION = 9.0, GRAVITY = 27.0 * SCALE;
const JUMP_STRENGTH = 11.0 * SCALE, COYOTE_TIME = 0.12;

/* spectator freecam */
const FREECAM_SPEED = 6.0 * SCALE;

/* slopes / capsule */
const WALL_NORMAL_Y = 0.58;
const CAPSULE_RADIUS = 0.5 * SCALE, CAPSULE_HEIGHT = 1.2 * SCALE, PLAYER_EYE_HEIGHT = CAPSULE_HEIGHT * 0.9 + CAPSULE_RADIUS;

/* spawn */
const SPAWN_OFFSET = new THREE.Vector3(2.8 * SCALE, 0, 2.2 * SCALE), SPAWN_EXTRA_Y = 50 * SCALE;

/* collision tuning */
const CONTACT_OFFSET = 0.08 * SCALE, MAX_SUBSTEP_DIST = 0.25 * CAPSULE_RADIUS;

/* ground + wall */
const SNAP_CAST_DIST = 3.0 * CAPSULE_RADIUS, SNAP_EPS = 0.15 * SCALE;
const WALL_MARGIN = 0.16 * SCALE, WALL_ITER = 3, RAY_FAN_COUNT = 16;

/* net cadence */
const SEND_RATE_MS = 1000 / 12;

/* remote visuals */
const SPRITE_HEIGHT = Math.max(1.6 * SCALE, PLAYER_EYE_HEIGHT * 1.05);
const SPRITE_ASPECT = 0.55;
const NAME_PAD = 0.24 * SCALE;
const PLAYER_SPRITE_URL = null;

/* renderer + post */
const canvas = document.createElement("canvas");
canvas.id = "three-bg";
Object.assign(canvas.style, {
  position:"fixed",
  inset:"0",
  width:"100vw",
  height:"100vh",
  display:"block",
  zIndex:"-1",
  pointerEvents:"none",
  opacity:"0",
  transition:"opacity 600ms ease",
  imageRendering:"pixelated",
  background:"transparent"
});
document.body.prepend(canvas);

const renderer = new THREE.WebGLRenderer({ canvas, antialias:false, alpha:true, powerPreference:"high-performance" });
renderer.outputColorSpace = THREE.SRGBColorSpace;
renderer.toneMapping = THREE.NoToneMapping;
renderer.shadowMap.enabled = false;
renderer.setPixelRatio(1);
renderer.setClearColor(0x000000, 0);

/* 2D labels layer */
const labelsLayer = document.createElement("div");
Object.assign(labelsLayer.style, {
  position:"fixed",
  inset:"0",
  pointerEvents:"none",
  zIndex:"-1",
  fontFamily:"Inter, system-ui, -apple-system, Segoe UI, Roboto, sans-serif"
});
document.body.appendChild(labelsLayer);

let lowW=0, lowH=0, rt=null;
const postScene = new THREE.Scene();
const postCam = new THREE.OrthographicCamera(-1,1,1,-1,0,1);
const postMat = new THREE.ShaderMaterial({
  uniforms:{ tDiffuse:{value:null}, uLowRes:{value:new THREE.Vector2(1,1)}, uLevels:{value:COLOR_LEVELS}, uDither:{value:USE_DITHER?1:0}, uTime:{value:0} },
  vertexShader:`varying vec2 vUv; void main(){ vUv=(position.xy+1.)*.5; gl_Position=vec4(position.xy,0.,1.); }`,
  fragmentShader:`
    precision mediump float; uniform sampler2D tDiffuse; uniform vec2 uLowRes; uniform int uLevels,uDither; uniform float uTime; varying vec2 vUv;
    float hash(vec2 p){ p=fract(p*vec2(123.34,345.45)); p+=dot(p,p+34.345); return fract(p.x*p.y); }
    vec3 quantize(vec3 c, vec2 pix){ float L=float(uLevels); float t=(uDither==1)?(hash(pix+uTime)-.5):0.; return floor(clamp(c+t/L,0.,1.)*(L-1.)+.5)/(L-1.); }
    void main(){ vec2 p=vUv*uLowRes; vec2 uv=(floor(p)+.5)/uLowRes; vec3 col=texture2D(tDiffuse,uv).rgb; col=quantize(col,p); gl_FragColor=vec4(col,1.); }
  `,
  depthTest:false, depthWrite:false
});
postScene.add(new THREE.Mesh(new THREE.PlaneGeometry(2,2), postMat));
function allocRT(){ const w=innerWidth,h=innerHeight; lowW=Math.max(1,Math.floor(w/RENDER_SCALE)); lowH=Math.max(1,Math.floor(h/RENDER_SCALE)); renderer.setSize(w,h,false); if(rt) rt.dispose(); rt=new THREE.WebGLRenderTarget(lowW,lowH,{minFilter:THREE.NearestFilter,magFilter:THREE.NearestFilter,depthBuffer:true,stencilBuffer:false,type:THREE.UnsignedByteType,samples:0}); postMat.uniforms.uLowRes.value.set(lowW,lowH); }
allocRT();

/* scene + idle cam */
const scene = new THREE.Scene();
scene.environment = null;
scene.fog = USE_FOG ? new THREE.FogExp2(0x0b1020, 0.02) : null;
const camera = new THREE.PerspectiveCamera(CAM_FOV, innerWidth/innerHeight, 0.005, 5000);
const BASE_YAW = THREE.MathUtils.degToRad(((CAM_ROT_DEG.yaw%360)+360)%360);
const BASE_PITCH = THREE.MathUtils.degToRad(CAM_ROT_DEG.pitch);
camera.position.copy(CAM_POS);
camera.rotation.set(BASE_PITCH, BASE_YAW, 0, "YXZ");
camera.updateProjectionMatrix();
const MAX_YAW_DELTA = THREE.MathUtils.degToRad(6), MAX_PITCH_DELTA = THREE.MathUtils.degToRad(4);
let aimYaw=BASE_YAW, aimPitch=BASE_PITCH, curYaw=BASE_YAW, curPitch=BASE_PITCH, playMode=false;
addEventListener("pointermove",(e)=>{ if(playMode || spectateMode) return; const nx=(e.clientX/innerWidth)*2-1, ny=(e.clientY/innerHeight)*2-1; aimYaw=BASE_YAW - nx*MAX_YAW_DELTA; aimPitch=BASE_PITCH + ny*MAX_PITCH_DELTA; },{passive:true});
function updateCameraHover(dt){ const s=1.0 - Math.pow(0.2, dt*60); curYaw += (aimYaw-curYaw)*s; curPitch += (aimPitch-curPitch)*s; camera.rotation.set(curPitch,curYaw,0,"YXZ"); }
scene.add(new THREE.HemisphereLight(0xb0c8ff,0x0b1020,0.28)); const sun=new THREE.DirectionalLight(0xffffff,0.6); sun.position.set(3,5,4); scene.add(sun);

/* loader + bvh */
THREE.Mesh.prototype.raycast = acceleratedRaycast;
const basePath = MODEL_URL.slice(0, MODEL_URL.lastIndexOf("/") + 1) || "/";
const manager = new THREE.LoadingManager(); manager.addHandler(/\.tga$/i, new TGALoader(manager));
const loader = new FBXLoader(manager); loader.setResourcePath(basePath);
let model, mixer, levelReady=false, colliderGeom=null, colliderBVH=null, colliderMesh=null, colliderMinY=-Infinity, colliderMaxY=Infinity;
const patchedMaterials = new Set(); const perFrame = [];

/* shader uniform cache for resize */
const ps1Uniforms = new WeakMap();

/* patch material for PS1 look */
function ps1ifyLambert(mat){
  ["map","emissiveMap","aoMap","specularMap"].forEach((k)=>{ const t=mat[k]; if(!t) return; t.generateMipmaps=false; t.minFilter=THREE.NearestFilter; t.magFilter=THREE.NearestFilter; t.anisotropy=0; t.needsUpdate=true; });
  mat.depthWrite=true; mat.depthTest=true; mat.dithering=false; mat.polygonOffset=true; mat.polygonOffsetFactor=-0.5; mat.polygonOffsetUnits=1.0;
  mat.onBeforeCompile=(shader)=>{
    shader.uniforms.uResolution = { value:new THREE.Vector2(innerWidth,innerHeight) };
    shader.uniforms.uSnapPixels = { value:VERTEX_SNAP_PIXELS };
    if(!/uniform\s+vec2\s+uResolution/.test(shader.vertexShader)){
      shader.vertexShader = `uniform vec2 uResolution;\nuniform float uSnapPixels;\n` + shader.vertexShader;
    }
    shader.vertexShader = shader.vertexShader.replace(
      '#include <project_vertex>',
      `
      #include <project_vertex>
      vec2 ndc = gl_Position.xy / gl_Position.w;
      vec2 pix = (ndc*0.5 + 0.5) * uResolution;
      pix = floor(pix / uSnapPixels) * uSnapPixels;
      vec2 ndc2 = (pix / uResolution) * 2.0 - 1.0;
      gl_Position.xy = ndc2 * gl_Position.w;
      `
    );
    ps1Uniforms.set(mat, shader.uniforms);
    patchedMaterials.add(mat);
  };
  return mat;
}

/* convert imported model to PS1 style and build collider */
function ps1ifyMaterialsAndBuildCollider(root){
  const geos=[]; root.updateWorldMatrix(true,true);
  root.traverse((n)=>{
    if(!n.isMesh||!n.geometry) return;
    const src=n.material; const mats=(Array.isArray(src)?src:[src]).filter(Boolean);
    const newMats=mats.map((m)=>ps1ifyLambert(new THREE.MeshLambertMaterial({
      color:(m.color&&m.color.isColor)?m.color.clone():new THREE.Color(0xffffff),
      map:m.map||null, transparent:false, alphaTest: (m.alphaTest??0)>0?m.alphaTest: (m.map?.format===THREE.RGBAFormat?0.5:0.0), side:THREE.DoubleSide
    })));
    n.material = Array.isArray(src)?newMats:newMats[0];
    const srcGeo=n.geometry.clone(); srcGeo.applyMatrix4(n.matrixWorld); const pos=srcGeo.getAttribute("position"); if(!pos) return;
    const clean=new THREE.BufferGeometry(); clean.setAttribute("position",pos.clone()); clean.setIndex(null); geos.push(clean);
  });
  let merged=null;
  try{ merged=BufferGeometryUtils.mergeGeometries(geos,false); }
  catch{ const chunks=[]; for(let i=0;i<geos.length;i+=64){ chunks.push(BufferGeometryUtils.mergeGeometries(geos.slice(i,i+64),false)); } merged=BufferGeometryUtils.mergeGeometries(chunks,false); }
  merged = BufferGeometryUtils.mergeVertices(merged,1e-3); merged.computeBoundingBox(); merged.computeBoundingSphere();
  colliderGeom=merged; colliderBVH=new MeshBVH(colliderGeom,{maxLeafTris:32}); colliderGeom.boundsTree=colliderBVH;
  colliderMesh=new THREE.Mesh(colliderGeom,new THREE.MeshBasicMaterial({visible:false}));
  colliderMinY = colliderGeom.boundingBox ? colliderGeom.boundingBox.min.y : -1e6;
  colliderMaxY = colliderGeom.boundingBox ? colliderGeom.boundingBox.max.y : +1e6;
}

/* fog tuning vs scene size */
function autoFogFor(target){
  const box=new THREE.Box3().setFromObject(target), size=box.getSize(new THREE.Vector3());
  const k=0.03, density=Math.min(0.06, Math.max(0.000005, k/(Math.max(size.x,size.y,size.z)*0.5 || 1)));
  scene.fog = USE_FOG ? new THREE.FogExp2(0x0b1020, density) : null;
}

/* campfire */
let fireGroup=null, fireLight=null, fireLight2=null, fireSprite=null;
function makeFlameTexture(size=128){
  const c=document.createElement("canvas"); c.width=c.height=size; const g=c.getContext("2d");
  const grd=g.createRadialGradient(size*.5,size*.6,size*.05,size*.5,size*.6,size*.5);
  grd.addColorStop(0.0,"rgba(255,255,255,1)"); grd.addColorStop(0.25,"rgba(255,200,80,0.95)");
  grd.addColorStop(0.55,"rgba(255,120,30,0.65)"); grd.addColorStop(0.85,"rgba(200,40,10,0.25)"); grd.addColorStop(1.0,"rgba(0,0,0,0)");
  g.fillStyle=grd; g.fillRect(0,0,size,size);
  const tex=new THREE.CanvasTexture(c); tex.generateMipmaps=false; tex.minFilter=THREE.NearestFilter; tex.magFilter=THREE.NearestFilter; tex.anisotropy=0; return tex;
}
function addCampfire(pos){
  fireGroup=new THREE.Group(); fireGroup.position.copy(pos); scene.add(fireGroup);
  fireLight=new THREE.PointLight(0xff7a2a, FIRE_MAIN_INTENSITY, FIRE_MAIN_DISTANCE, FIRE_DECAY); fireLight.position.set(0, FIRE_HEIGHT_OFFSET+0.6, 0); fireGroup.add(fireLight);
  fireLight2=new THREE.PointLight(0xff3300, FIRE_SUB_INTENSITY, FIRE_SUB_DISTANCE, FIRE_DECAY); fireLight2.position.set(0.35, FIRE_HEIGHT_OFFSET+0.4, -0.2); fireGroup.add(fireLight2);
  const flameTex=makeFlameTexture(128);
  fireSprite=new THREE.Sprite(new THREE.SpriteMaterial({ map:flameTex, color:0xffffff, transparent:true, depthWrite:false, blending:THREE.AdditiveBlending, depthTest:true }));
  fireSprite.position.set(0, FIRE_HEIGHT_OFFSET+0.25, 0); fireSprite.scale.set(FIRE_SPRITE_SIZE, FIRE_SPRITE_SIZE*1.35, 1); fireGroup.add(fireSprite);
  let t=0; perFrame.push((dt)=>{ t+=dt; const pulse=0.45*Math.sin(t*5.4)+0.28*Math.sin(t*8.7+1.1);
    fireLight.intensity=FIRE_MAIN_INTENSITY + pulse; fireLight2.intensity=FIRE_SUB_INTENSITY + pulse*0.75;
    fireLight.color.setHSL(0.06+Math.sin(t*1.6)*0.01,1.0,0.55); fireLight2.color.setHSL(0.03+Math.sin(t*1.9+0.8)*0.012,1.0,0.47);
    fireSprite.material.rotation += dt*0.5; const j=1.0+Math.sin(t*6.0)*0.06; fireSprite.scale.set(FIRE_SPRITE_SIZE*j, FIRE_SPRITE_SIZE*1.35*j, 1);
  });
}

/* load world */
loader.load(MODEL_URL, (fbx)=>{
  model=fbx; scene.add(model); ps1ifyMaterialsAndBuildCollider(model);
  if(fbx.animations?.length){ mixer=new THREE.AnimationMixer(model); mixer.clipAction(fbx.animations[0]).play(); }
  autoFogFor(model); addCampfire(FIRE_POS);
  levelReady=true; setStatus("world loaded");
  if(playMode) initialPlace(true);
}, undefined, ()=> setStatus("ERR loading model"));

/* Music: autoplay + 'M' toggle */
const audio=new Audio("https://world.seppjm.com/3js/audio/stalker.mp3");
audio.loop=true; audio.preload="auto"; audio.crossOrigin="anonymous"; audio.volume=0.5;
let isPlaying=false, fadeRAF=null;
const fadeTo=(target,ms=700)=>{ cancelAnimationFrame(fadeRAF); const start=audio.volume,d=target-start,t0=performance.now(); const tick=(now)=>{ const p=Math.min(1,(now-t0)/ms); audio.volume=Math.max(0,Math.min(1,start+d*p)); if(p<1) fadeRAF=requestAnimationFrame(tick); }; fadeRAF=requestAnimationFrame(tick); };
async function playMusic(auto=false){ try{ if(auto) audio.volume=0.0; await audio.play(); isPlaying=true; if(auto) fadeTo(0.5,800); }catch{} }
function pauseMusic(){ fadeTo(0.0,300); setTimeout(()=>audio.pause(),320); isPlaying=false; }
playMusic(true);
["pointerdown","keydown","visibilitychange"].forEach((ev)=> addEventListener(ev, ()=>{ if(!isPlaying) playMusic(true); }, { once:true }));

/* fps controller + collisions (player) */
let controls=null; const keys=new Set(); const velocity=new THREE.Vector3(); let onGround=false, physicsEnabled=false;
const lastSafePos=new THREE.Vector3(); let timeSinceGrounded=0, lastGroundedAt=0;
let playerLight=null; function ensurePlayerLight(obj){ if(playerLight) return; playerLight=new THREE.PointLight(0xffa25a,0.9,1500*SCALE,1.4); playerLight.position.set(0,-PLAYER_EYE_HEIGHT*0.2,0); obj.add(playerLight); }

/* spectator freecam */
let spectateMode=false, specControls=null;
function onSpecKeyDown(e){
  keys.add(e.code);
  if(e.code==="KeyM"){ if(isPlaying) pauseMusic(); else playMusic(); }
}
function onSpecKeyUp(e){ keys.delete(e.code); }
function makeSpectateHint(){
  const hint=document.createElement("div");
  Object.assign(hint.style,{ position:"fixed", left:"16px", bottom:"16px", zIndex:20, color:"#fff", font:"600 14px Inter, system-ui", opacity:"0.9", pointerEvents:"none", textAlign:"left", lineHeight:"1.35", background:"rgba(0,0,0,0.45)", padding:"8px 10px", borderRadius:"10px", maxWidth:"44ch" });
  hint.textContent="Spectator freecam — WASD move • Mouse look • Q/E down/up • Shift boost • M music • ESC cursor";
  document.body.appendChild(hint);
}
function startSpectate(){
  if(spectateMode || playMode) return;
  spectateMode=true;

  canvas.style.zIndex = "10";
  canvas.style.pointerEvents = "auto";
  canvas.style.opacity = "1";
  labelsLayer.style.zIndex = "15";

  specControls = new PointerLockControls(camera, canvas);
  scene.add(specControls.getObject());
  specControls.lock();
  canvas.addEventListener("click", ()=> specControls.lock());
  specControls.addEventListener("lock", ()=> setStatus("spectate: locked (WASD, mouse, Q/E, Shift, M)"));
  specControls.addEventListener("unlock", ()=> setStatus("spectate: unlocked (click to lock)"));

  addEventListener("keydown", onSpecKeyDown);
  addEventListener("keyup", onSpecKeyUp);
  makeSpectateHint();
}
function stopSpectate(){
  if(!spectateMode) return;
  removeEventListener("keydown", onSpecKeyDown);
  removeEventListener("keyup", onSpecKeyUp);
  if(specControls){
    try{ specControls.unlock(); }catch{}
    scene.remove(specControls.getObject());
  }
  specControls=null;
  spectateMode=false;
}
function updateFreecam(dt){
  if(!spectateMode) return;
  const boost = (keys.has("ShiftLeft") || keys.has("ShiftRight")) ? 3.0 : 1.0;
  const speed = FREECAM_SPEED * boost;
  const fwd=new THREE.Vector3(); camera.getWorldDirection(fwd); fwd.normalize();
  const right=new THREE.Vector3().crossVectors(fwd,new THREE.Vector3(0,1,0)).normalize();
  const up=new THREE.Vector3(0,1,0);
  const move=new THREE.Vector3();
  if(keys.has("KeyW")) move.add(fwd);
  if(keys.has("KeyS")) move.addScaledVector(fwd,-1);
  if(keys.has("KeyA")) move.addScaledVector(right,-1);
  if(keys.has("KeyD")) move.add(right);
  if(keys.has("KeyE")) move.add(up);
  if(keys.has("KeyQ")) move.addScaledVector(up,-1);
  if(move.lengthSq()>0){
    move.normalize().multiplyScalar(speed*dt);
    camera.position.add(move);
  }
}

/* rays */
const dirFan=Array.from({length:RAY_FAN_COUNT},(_,i)=>{ const a=(i/RAY_FAN_COUNT)*Math.PI*2; return new THREE.Vector3(Math.sin(a),0,Math.cos(a)).normalize(); });
const raycaster=new THREE.Raycaster(); raycaster.firstHitOnly=true;

/* helpers */
const feetYFromEye=(eyeY)=> eyeY - (PLAYER_EYE_HEIGHT - CAPSULE_RADIUS);
function groundSnap(eyePos, maxUp=SNAP_EPS){
  if(!colliderMesh) return false;
  const feetY=feetYFromEye(eyePos.y), origin=new THREE.Vector3(eyePos.x, feetY+CAPSULE_RADIUS*0.75, eyePos.z), dir=new THREE.Vector3(0,-1,0);
  raycaster.set(origin,dir); raycaster.near=0; raycaster.far=SNAP_CAST_DIST;
  const hit=raycaster.intersectObject(colliderMesh,false)[0]; if(!hit) return false;
  const n=hit.face?.normal ?? new THREE.Vector3(0,1,0); if(n.y < WALL_NORMAL_Y) return false;
  const desiredFeet=hit.point.y + CAPSULE_RADIUS + CONTACT_OFFSET, delta=desiredFeet - feetY;
  if(delta>-maxUp && delta<maxUp){ eyePos.y += delta; return true; } return false;
}
function pushOutWalls(eyePos){
  if(!colliderMesh) return;
  const feet=feetYFromEye(eyePos.y), heights=[ feet+CAPSULE_RADIUS*0.2, feet+CAPSULE_HEIGHT*0.5, feet+CAPSULE_HEIGHT-CAPSULE_RADIUS*0.2 ];
  const radius=CAPSULE_RADIUS + WALL_MARGIN;
  for(let iter=0; iter<WALL_ITER; iter++){
    for(const h of heights){
      for(const d of dirFan){
        const o=new THREE.Vector3(eyePos.x,h,eyePos.z); raycaster.set(o,d); raycaster.near=0; raycaster.far=radius;
        const hit=raycaster.intersectObject(colliderMesh,false)[0]; if(!hit) continue;
        const n=hit.face?.normal ?? new THREE.Vector3(0,1,0); if(n.y>=WALL_NORMAL_Y) continue;
        const push=radius - hit.distance + CONTACT_OFFSET; if(push>0) eyePos.addScaledVector(d,-push);
      }
    }
  }
}
function sweepClampMove(eyePos, moveXZ){
  if(!colliderMesh) return moveXZ; const len=moveXZ.length(); if(len<1e-6) return moveXZ;
  const dir=moveXZ.clone().normalize(), feet=feetYFromEye(eyePos.y);
  const heights=[ feet+CAPSULE_RADIUS*0.2, feet+CAPSULE_HEIGHT*0.5, feet+CAPSULE_HEIGHT-CAPSULE_RADIUS*0.2 ];
  const radius=CAPSULE_RADIUS + WALL_MARGIN; let maxLen=len;
  for(const h of heights){
    const origin=new THREE.Vector3(eyePos.x,h,eyePos.z); raycaster.set(origin,dir); raycaster.near=0; raycaster.far=len+radius;
    const hit=raycaster.intersectObject(colliderMesh,false)[0]; if(!hit) continue;
    const n=hit.face?.normal ?? new THREE.Vector3(0,1,0); if(n.y>=WALL_NORMAL_Y) continue;
    const allowed=Math.max(0, hit.distance - (radius+CONTACT_OFFSET)); if(allowed<maxLen) maxLen=allowed;
  }
  if(maxLen<len) moveXZ.setLength(maxLen); return moveXZ;
}

/* spawn at fire */
function initialPlace(forceHigh=false){
  if(!levelReady) return;
  const obj=controls.getObject(); const spawn=FIRE_POS.clone().add(SPAWN_OFFSET); const y=(forceHigh?SPAWN_EXTRA_Y:5*SCALE);
  obj.position.copy(spawn).add(new THREE.Vector3(0,y,0));
  const toFire=new THREE.Vector3().subVectors(FIRE_POS,spawn), yaw=Math.atan2(toFire.x,toFire.z);
  obj.rotation.set(0,yaw,0,"YXZ"); camera.rotation.set(0,yaw,0,"YXZ");
  physicsEnabled=true; velocity.set(0,0,0); onGround=false; timeSinceGrounded=0; lastGroundedAt=0; lastSafePos.copy(obj.position); setStatus("ready");
}
function respawnAtFire(){ const obj=controls.getObject(), spawn=FIRE_POS.clone().add(SPAWN_OFFSET); obj.position.copy(spawn).add(new THREE.Vector3(0,SPAWN_EXTRA_Y,0)); velocity.set(0,0,0); onGround=false; timeSinceGrounded=0; setStatus("respawn"); }

/* physics step */
function integrateSubstep(subDt){
  const obj=controls.getObject(), eye=obj.position, move=velocity.clone().multiplyScalar(subDt), moveXZ=new THREE.Vector3(move.x,0,move.z);
  sweepClampMove(eye,moveXZ); eye.add(moveXZ); pushOutWalls(eye);
  eye.y += move.y; pushOutWalls(eye);

  if (velocity.y <= 0) {
    const snapped=groundSnap(eye, SNAP_EPS + Math.max(0,-velocity.y*subDt + CONTACT_OFFSET));
    if(snapped){ onGround=true; if(velocity.y<0) velocity.y=0; lastGroundedAt=performance.now(); }
  }

  if(Number.isFinite(colliderMinY)){ const minEye=colliderMinY + (PLAYER_EYE_HEIGHT - CAPSULE_RADIUS) + 0.25*SCALE; if(eye.y<minEye){ eye.y=minEye; velocity.y=Math.max(0,velocity.y); } }
  if(Number.isFinite(colliderMaxY) && eye.y>colliderMaxY+200*SCALE){ eye.y=colliderMaxY+200*SCALE; velocity.y=Math.min(0,velocity.y); }
}
function updateFPS(dt){
  if(!playMode || !levelReady || !physicsEnabled) return;
  const obj=controls.getObject();
  const fwd=new THREE.Vector3(); camera.getWorldDirection(fwd); fwd.y=0; fwd.normalize();
  const right=new THREE.Vector3().crossVectors(fwd,new THREE.Vector3(0,1,0)).normalize();
  const wish=new THREE.Vector3(); if(keys.has("KeyW")) wish.add(fwd); if(keys.has("KeyS")) wish.addScaledVector(fwd,-1); if(keys.has("KeyA")) wish.addScaledVector(right,-1); if(keys.has("KeyD")) wish.add(right); if(wish.lengthSq()>0) wish.normalize();
  const accel=onGround?ACCEL:AIR_ACCEL, targetVel=wish.multiplyScalar(WALK_SPEED), horizVel=new THREE.Vector3(velocity.x,0,velocity.z), add=new THREE.Vector3().subVectors(targetVel,horizVel).multiplyScalar(accel*dt);
  horizVel.add(add); velocity.x=horizVel.x; velocity.z=horizVel.z;
  velocity.y -= GRAVITY*dt;

  const moveLen=velocity.clone().multiplyScalar(dt).length(), steps=Math.max(1, Math.ceil(moveLen / MAX_SUBSTEP_DIST)); onGround=false; const subDt=dt/steps;
  for(let i=0;i<steps;i++) integrateSubstep(subDt);

  if(velocity.y <= 0 && groundSnap(obj.position)) { onGround=true; lastGroundedAt=performance.now(); }

  if(onGround){ const f=Math.max(0,1-FRICTION*dt); velocity.x*=f; velocity.z*=f; if(velocity.y<0) velocity.y=0; timeSinceGrounded=0; lastSafePos.copy(obj.position); setStatus("grounded"); }
  else { timeSinceGrounded+=dt; setStatus("air"); }

  const minEye=colliderMinY + (PLAYER_EYE_HEIGHT - CAPSULE_RADIUS) - 10*SCALE; if(obj.position.y<minEye || timeSinceGrounded>4.0){ respawnAtFire(); }
  ensurePlayerLight(obj);
}

/* remote players + 2D name labels */
const players=new Map();
function makeLabelEl(text){
  const el=document.createElement("div");
  el.textContent=text;
  Object.assign(el.style,{
    position:"absolute",
    transform:"translate(-50%,-100%)",
    color:"#fff",
    fontWeight:"800",
    fontSize:"22px",
    lineHeight:"1",
    padding:"4px 8px",
    borderRadius:"8px",
    background:"rgba(0,0,0,0.55)",
    textShadow:"0 1px 2px rgba(0,0,0,0.65)",
    whiteSpace:"nowrap",
    pointerEvents:"none",
    willChange:"transform",
  });
  labelsLayer.appendChild(el);
  return el;
}
function updateLabelPosition(label, worldPos){
  const v = worldPos.clone().project(camera);
  if (v.z < 0 || v.z > 1) { label.style.display="none"; return; }
  const x = (v.x * 0.5 + 0.5) * innerWidth;
  const y = ( -v.y * 0.5 + 0.5) * innerHeight;
  label.style.display="";
  label.style.left = `${x}px`;
  label.style.top  = `${y}px`;
}

function makeBillboardTexture(cb){
  if(PLAYER_SPRITE_URL){
    const img=new Image(); img.crossOrigin="anonymous";
    img.onload=()=>{ const tex=new THREE.Texture(img); tex.needsUpdate=true; tex.generateMipmaps=false; tex.minFilter=THREE.NearestFilter; tex.magFilter=THREE.NearestFilter; cb(tex); };
    img.onerror=()=>cb(makeProceduralBillboard()); img.src=PLAYER_SPRITE_URL;
  } else cb(makeProceduralBillboard());
}
function makeProceduralBillboard(){
  const W=64,H=128,c=document.createElement("canvas"); c.width=W; c.height=H; const g=c.getContext("2d"); g.fillStyle="rgba(0,0,0,0)"; g.fillRect(0,0,W,H);
  g.fillStyle="#d6e0ff"; g.fillRect(18,20,28,78); g.beginPath(); g.arc(32,30,18,0,Math.PI*2); g.fill(); g.fillRect(18,98,10,24); g.fillRect(36,98,10,24);
  g.strokeStyle="#131a2f"; g.lineWidth=3; g.strokeRect(18,20,28,78); g.beginPath(); g.arc(32,30,18,0,Math.PI*2); g.stroke();
  const tex=new THREE.CanvasTexture(c); tex.generateMipmaps=false; tex.minFilter=THREE.NearestFilter; tex.magFilter=THREE.NearestFilter; return tex;
}
function makeBillboardSprite(onReady){
  makeBillboardTexture((tex)=>{
    const spr=new THREE.Sprite(new THREE.SpriteMaterial({ map:tex, transparent:true, depthWrite:true, depthTest:true }));
    spr.center.set(0.5, 0.0); // bottom at ground
    spr.position.y = 0;
    spr.scale.set(SPRITE_HEIGHT*SPRITE_ASPECT, SPRITE_HEIGHT, 1);
    onReady(spr);
  });
}

/* spawn/update remote, anchor to ground (pos is eye from server) */
function spawnOrUpdate(p){
  if (myID && p?.id === myID) return; // ignore self

  const baseY = (p.pos?.[1] ?? 0) - PLAYER_EYE_HEIGHT;
  let entry = players.get(p.id);
  if(!entry){
    const group=new THREE.Group(); group.position.set(p.pos?.[0]??0, baseY, p.pos?.[2]??0); group.rotation.y=p.rotY||0;
    makeBillboardSprite((body)=>{ group.add(body); });
    scene.add(group);
    const labelEl = makeLabelEl(p.name || "Player");
    entry = { group, labelEl, target:new THREE.Vector3(p.pos?.[0]??0, baseY, p.pos?.[2]??0), rotY:p.rotY||0, name:p.name||"Player" };
    players.set(p.id, entry);
  } else {
    entry.target.set(p.pos?.[0]??0, baseY, p.pos?.[2]??0);
    entry.rotY = p.rotY || 0;
    if (p.name && p.name !== entry.name) { entry.name = p.name; entry.labelEl.textContent = p.name; }
  }
}
function removePlayer(id){
  const e=players.get(id); if(!e) return;
  scene.remove(e.group);
  if(e.labelEl?.parentNode) e.labelEl.parentNode.removeChild(e.labelEl);
  players.delete(id);
}

/* chat UI (only when playing) */
function makeChatUI(){
  const hint=document.createElement("div");
  Object.assign(hint.style,{ position:"fixed", left:"16px", bottom:"16px", zIndex:20, color:"#fff", font:"600 14px Inter, system-ui", opacity:"0.9", pointerEvents:"none", textAlign:"left", lineHeight:"1.35", background:"rgba(0,0,0,0.45)", padding:"8px 10px", borderRadius:"10px", maxWidth:"44ch" });
  hint.innerHTML=`Pointer-lock FPS<br>WASD move • <b>SPACE</b> jump • <b>T</b> chat • <b>M</b> music • <b>ESC</b> cursor`;
  document.body.appendChild(hint);

  const log=document.createElement("div"); Object.assign(log.style,{ position:"fixed", left:"16px", bottom:"96px", width:"420px", maxHeight:"40vh", overflow:"hidden", display:"flex", flexDirection:"column-reverse", gap:"6px", zIndex:20, font:"15px/1.35 Inter, system-ui", color:"#fff" }); log.id="chat-log"; document.body.appendChild(log);

  const form=document.createElement("form"); form.id="chat-form"; Object.assign(form.style,{ position:"fixed", left:"16px", bottom:"16px", zIndex:21, display:"none" });
  const inp=document.createElement("input"); inp.type="text"; inp.placeholder="type to chat…"; Object.assign(inp.style,{ width:"400px", padding:"10px 12px", borderRadius:"10px", border:"1px solid rgba(255,255,255,.2)", background:"rgba(0,0,0,.5)", color:"#fff" }); form.appendChild(inp); document.body.appendChild(form);

  form.addEventListener("submit",(e)=>{ e.preventDefault(); const t=inp.value.trim(); if(!t) return; send({type:"chat", text:t}); inp.value=""; hideChat(); });
  function showChat(){ form.style.display="block"; inp.focus(); controls.unlock(); }
  function hideChat(){ form.style.display="none"; controls.lock(); }
  addEventListener("keydown",(e)=>{ if(e.key==="t"||e.key==="T"){ e.preventDefault(); showChat(); }});

  addEventListener("keydown",(e)=>{
    if(e.code==="KeyM"){
      if(isPlaying) pauseMusic(); else playMusic();
      setStatus(isPlaying ? "music: playing" : "music: paused");
    }
  });
}
function addChat(logEl, name, text){ if(!logEl) return; const row=document.createElement("div"); row.textContent=`${name}: ${text}`; row.style.background="rgba(0,0,0,.45)"; row.style.padding="6px 10px"; row.style.borderRadius="8px"; logEl.prepend(row); const kids=[...logEl.children]; while(kids.length>24){ logEl.removeChild(kids.pop()); } }

/* networking */
let ws=null, myID=null, lastSend=0, currentRole="spectator", suppressToast=false;
function connect(role="spectator", name="Viewer"){
  try{
    if(ws && ws.readyState<=1){ suppressToast=true; try{ ws.close(); }catch{} }
    currentRole=role;
    ws=new WebSocket(WS_URL); ws.binaryType="arraybuffer";
    ws.addEventListener("open", ()=>{
      setStatus(`ws: connected (${role})`);
      send({ type:"join", name, role });
      if(role==="player"){ const p=controls?.getObject?.().position; if(p) send({type:"state", pos:[p.x,p.y,p.z], rotY:camera.rotation.y}); }
    });
    ws.addEventListener("message",(ev)=>{ try{ onMessage(ev); }catch(e){ setStatus("ws msg err: "+e.message); } });
    ws.addEventListener("close", ()=>{
      if(!suppressToast){ const toast=document.createElement("div"); Object.assign(toast.style,{ position:"fixed", left:"50%", top:"14px", transform:"translateX(-50%)", background:"rgba(200,0,0,0.75)", color:"#fff", padding:"8px 12px", borderRadius:"10px", zIndex:50, font:"600 14px Inter, system-ui" }); toast.textContent="Disconnected from server"; document.body.appendChild(toast); setTimeout(()=>toast.remove(),3500); }
      suppressToast=false; setStatus("ws: disconnected");
    });
    ws.addEventListener("error", ()=> setStatus("ws: error"));
  }catch(e){ setStatus("ws init err: "+e.message); }
}
function send(obj){ if(ws && ws.readyState===1) ws.send(encode(obj)); }
function onMessage(ev){
  const msg=decode(ev.data);
  switch(msg.type){
    case "welcome":
      myID = msg.id;
      removePlayer(myID);
      (msg.players||[]).forEach((p)=>{ if(p.id!==myID) spawnOrUpdate(p); });
      break;
    case "player_join":
      if(msg.player && msg.player.id !== myID) spawnOrUpdate(msg.player);
      break;
    case "player_leave":
      if(msg.id) removePlayer(msg.id);
      break;
    case "state":
      if(Array.isArray(msg.updates)) msg.updates.forEach((u)=>{ if(u.id!==myID) spawnOrUpdate(u); });
      else if(msg.id && msg.pos){ if(msg.id!==myID) spawnOrUpdate(msg); }
      break;
    case "player_state":
      if(msg.id && msg.pos && msg.id!==myID) spawnOrUpdate(msg);
      break;
    case "chat":
      addChat(document.getElementById("chat-log"), msg.name||"Player", msg.text||"");
      break;
    case "full":
      alert(`World is full (max ${msg.maxPlayers ?? 10})`);
      break;
  }
}

/* enter play */
function startPlay(){
  if(playMode) return;
  // if we were spectating, clean it up
  if(spectateMode) stopSpectate();

  playMode=true;
  canvas.style.zIndex = "10";
  canvas.style.pointerEvents = "auto";
  canvas.style.opacity = "1";
  labelsLayer.style.zIndex = "15";

  const controlsLocal=new PointerLockControls(camera, canvas); controls=controlsLocal; scene.add(controls.getObject());
  controls.lock(); canvas.addEventListener("click", ()=>controls.lock());
  controls.addEventListener("lock", ()=> setStatus("locked (WASD, SPACE jump, T chat, M music)"));
  controls.addEventListener("unlock", ()=> setStatus("unlocked (click to lock)"));
  makeChatUI();
  if(levelReady) initialPlace(true);
  const name = (prompt("Authentication not implemented; for now enter a nickname:", "Guest") || "Guest").slice(0,25);
  connect("player", name);
  addEventListener("keydown",(e)=>{ keys.add(e.code);
    if(e.code==="Space" && playMode){
      const now=performance.now();
      if(onGround || (now - lastGroundedAt) < COYOTE_TIME*1000){
        velocity.y = JUMP_STRENGTH;
        onGround=false;
      }
    }
  });
  addEventListener("keyup",(e)=> keys.delete(e.code));
}

/* join hooks */
(function hookJoin(){
  const candidates=[
    '#join-btn', '#spectate-btn',
    'a[href="#Join"]','a[href="#join"]',
    'a.button[href="#About"]','#join','[data-join]','.join','button.join'
  ];
  for(const sel of candidates){
    const el=document.querySelector(sel);
    if(el){
      el.addEventListener("click",(e)=>{
        e.preventDefault();
        if(el.id === "spectate-btn"){
          startSpectate();
          setStatus("Spectating…");
        }else{
          startPlay();
        }
      });
    }
  }
  addEventListener("keydown",(e)=>{ if(e.code==="Enter" && !playMode) startPlay(); });
})();

/* spectator connect on boot */
const defaultSpectatorName = `Viewer${Math.floor((Math.random()*9000)+1000)}`;
connect("spectator", defaultSpectatorName);

/* loop */
const clock=new THREE.Clock(); let active=true;
addEventListener("visibilitychange",()=>{ active=document.visibilityState==="visible"; if(active) requestAnimationFrame(animate); });
requestAnimationFrame(()=>{ animate(); canvas.style.opacity="1"; });

let fpsAccum=0,fpsCount=0,scaleCooldown=0;
function animate(){
  if(!active) return;
  const dt=Math.min(0.05, clock.getDelta()); const now=performance.now();
  if(mixer) mixer.update(dt);
  if(playMode) updateFPS(dt);
  if(spectateMode) updateFreecam(dt);

  // smooth remote players and update 2D labels
  players.forEach(({group,target,rotY,labelEl})=>{
    const k=1 - Math.pow(0.0001, dt*60);
    group.position.lerp(target,k);
    group.rotation.y += (rotY - group.rotation.y)*k;

    const headWorld = new THREE.Vector3(
      group.position.x,
      group.position.y + SPRITE_HEIGHT + NAME_PAD,
      group.position.z
    );
    updateLabelPosition(labelEl, headWorld);
  });

  perFrame.forEach((fn)=>fn(dt));

  renderer.setRenderTarget(rt); postMat.uniforms.tDiffuse.value=null; renderer.clear(); renderer.render(scene,camera); renderer.setRenderTarget(null);
  postMat.uniforms.tDiffuse.value=rt.texture; postMat.uniforms.uTime.value += dt; renderer.render(postScene,postCam);

  fpsAccum += dt; fpsCount++;
  if(now - scaleCooldown > 1000){
    const avg=fpsAccum/Math.max(1,fpsCount);
    if(avg>0.03 && RENDER_SCALE<6){ RENDER_SCALE+=0.5; allocRT(); }
    else if(avg<0.017 && RENDER_SCALE>2){ RENDER_SCALE-=0.5; allocRT(); }
    fpsAccum=0; fpsCount=0; scaleCooldown=now;
  }

  if(currentRole==="player" && ws && ws.readyState===1 && now - lastSend >= SEND_RATE_MS){
    lastSend=now; const p=controls.getObject().position; send({type:"state", pos:[p.x,p.y,p.z], rotY:camera.rotation.y});
  }

  if(!playMode && !spectateMode) updateCameraHover(dt);
  requestAnimationFrame(animate);
}

/* resize */
addEventListener("resize",()=>{
  camera.aspect=innerWidth/innerHeight;
  camera.updateProjectionMatrix();
  allocRT();
  patchedMaterials.forEach((m)=>{
    const u = ps1Uniforms.get(m);
    if(u?.uResolution?.value){ u.uResolution.value.set(innerWidth, innerHeight); }
  });
});