import { type ComponentProps, type ReactNode, useMemo, useRef, useState } from "react"; import { useGSAP } from "@gsap/react"; import gsap from "gsap"; const effectPresets = { slideUp: [ { y: "-100%", }, { y: "100%", }, { y: 0, }, ], slideDown: [ { y: "100%", }, { y: "-100%", }, { y: 0, }, ], opacity: [ { opacity: 0, }, { opacity: 0, }, { opacity: 1, }, ], blur: [ { filter: "blur(12px)", }, { filter: "blur(12px)", }, { filter: "blur(0px)", }, ], grayscale: [ { filter: "grayscale(100%)", }, { filter: "grayscale(100%)", }, { filter: "grayscale(0%)", }, ], } as const; export type SwapProps = Omit, "children"> & { state: T; children: (state: T) => ReactNode; effects?: (keyof typeof effectPresets)[]; duration?: number; }; const mergeVars = (varsArray: Record[]) => { const merged: Record = {}; for (const vars of varsArray) { for (const [key, value] of Object.entries(vars)) { if (key === "filter" && merged.filter) { merged.filter += ` ${value}`; // combine filters } else { merged[key] = value; // last one wins for other props } } } return merged; }; export const Swap = ({ state, children, duration = 0.4, effects = [], ...props }: SwapProps) => { const [currentState, setCurrentState] = useState(state); const containerRef = useRef(null); const contentRef = useRef(null); const [enterVars, exitVars, finalVars] = useMemo( () => Array.from({ length: 3 }, (_, i) => mergeVars(effects.map((e) => effectPresets[e][i]))), [effects], ); useGSAP( () => { if (currentState === state) return; const content = contentRef.current; if (!content) return; gsap.to(content, { ...enterVars, duration, ease: "power2.in", onComplete: () => { setCurrentState(state); gsap.fromTo(content, exitVars, { ...finalVars, duration, ease: "power2.out", }); }, }); }, { dependencies: [state] }, ); useGSAP( () => { if (!containerRef.current || !contentRef.current) return; const box = contentRef.current.getBoundingClientRect(); gsap.to(containerRef.current, { width: box.width, height: box.height, duration: 0.4, ease: "power2.out", }); }, { dependencies: [currentState] }, ); return (

{children(currentState)}

); };