import {useEffect,useRef,useState,type PointerEvent as ReactPointerEvent,type ReactNode} from 'react';
const clamp=(value:number,min:number,max:number)=>Math.min(max,Math.max(min,value));
const panelMaxWidth=(minWidth:number)=>Math.max(minWidth,Math.min(576,window.innerWidth*.4));
function storedWidth(key:string,fallback:number,minWidth:number){try{const value=Number(localStorage.getItem(key));return clamp(Number.isFinite(value)&&value>0?value:fallback,minWidth,panelMaxWidth(minWidth));}catch{return clamp(fallback,minWidth,panelMaxWidth(minWidth));}}
export function ResizablePanel({side,storageKey,visible=true,defaultWidth=288,minWidth=224,children,className=''}:{side:'left'|'right';storageKey:string;visible?:boolean;defaultWidth?:number;minWidth?:number;children:ReactNode;className?:string}){const [width,setWidth]=useState(()=>storedWidth(storageKey,defaultWidth,minWidth)),cleanupRef=useRef<()=>void>(()=>{});const update=(next:number)=>{const value=clamp(next,minWidth,panelMaxWidth(minWidth));setWidth(value);try{localStorage.setItem(storageKey,String(value));}catch{/* 无持久化权限时仍可调整 */}};
  useEffect(()=>{const persist=(next:number)=>{const value=clamp(next,minWidth,panelMaxWidth(minWidth));setWidth(value);try{localStorage.setItem(storageKey,String(value));}catch{/* 忽略 */}},resize=()=>setWidth(value=>clamp(value,minWidth,panelMaxWidth(minWidth))),layout=(event:Event)=>{const widths=(event as CustomEvent<{left:number;right:number}>).detail;persist(widths[side]);};window.addEventListener('resize',resize);window.addEventListener('mujoco-layout-widths',layout);return()=>{window.removeEventListener('resize',resize);window.removeEventListener('mujoco-layout-widths',layout);cleanupRef.current();};},[minWidth,side,storageKey]);
  const start=(event:ReactPointerEvent<HTMLButtonElement>)=>{event.preventDefault();cleanupRef.current();const origin=event.clientX,startWidth=width,pointerId=event.pointerId;const move=(moveEvent:PointerEvent)=>{if(moveEvent.pointerId===pointerId)update(startWidth+(moveEvent.clientX-origin)*(side==='left'?1:-1));};const stop=(stopEvent:PointerEvent)=>{if(stopEvent.pointerId!==pointerId)return;cleanup();};const cleanup=()=>{window.removeEventListener('pointermove',move);window.removeEventListener('pointerup',stop);window.removeEventListener('pointercancel',stop);cleanupRef.current=()=>{};};cleanupRef.current=cleanup;window.addEventListener('pointermove',move);window.addEventListener('pointerup',stop);window.addEventListener('pointercancel',stop);};
  return <div hidden={!visible} className={`relative shrink-0 ${className}`} style={{width}}>{children}<button type="button" role="separator" aria-label={side==='left'?'调整工程面板宽度':'调整属性面板宽度'} aria-orientation="vertical" aria-valuemin={minWidth} aria-valuemax={Math.round(panelMaxWidth(minWidth))} aria-valuenow={Math.round(width)} onPointerDown={start} onKeyDown={event=>{if(event.key==='Home')update(minWidth);else if(event.key==='End')update(panelMaxWidth(minWidth));else if(event.key==='ArrowLeft')update(width+(side==='left'?-16:16));else if(event.key==='ArrowRight')update(width+(side==='left'?16:-16));else return;event.preventDefault();}} className={`absolute inset-y-0 z-30 w-2 cursor-col-resize bg-transparent outline-none after:absolute after:inset-y-0 after:left-1/2 after:w-px after:-translate-x-1/2 after:bg-transparent hover:after:bg-accent focus-visible:after:w-0.5 focus-visible:after:bg-accent ${side==='left'?'-right-1':'-left-1'}`}/></div>;}