spiral-loader

1"use client";
2 
3import dynamic from "next/dynamic";
4import type { ComponentType } from "react";
5import { useCallback, useEffect, useRef, useState } from "react";
6import type { LottieRefCurrentProps } from "lottie-react";
7import { cn } from "./utils/cn";
8import { spiralFastData, spiralSlowData } from "./spiral-loader-data";
9import { useTheme } from "next-themes";
10 
11const Lottie = dynamic(() => import("lottie-react"), {
12  ssr: false,
13}) as ComponentType<any>;
14 
15const FAST_REPEATS = 4;
16const SLOW_REPEATS = 2;
17 
18export type SpiralLoaderProps = {
19  size?: number;
20  className?: string;
21};
22 
23export function SpiralLoader({ size = 16, className }: SpiralLoaderProps) {
24  const [isMounted, setIsMounted] = useState(false);
25  const [phase, setPhase] = useState<"fast" | "slow">("fast");
26  const repeatCountRef = useRef(0);
27  const fastRef = useRef<LottieRefCurrentProps | null>(null);
28  const slowRef = useRef<LottieRefCurrentProps | null>(null);
29  const { resolvedTheme } = useTheme();
30 
31  useEffect(() => {
32    setIsMounted(true);
33  }, []);
34 
35  const startFastPhase = useCallback(() => {
36    repeatCountRef.current = 0;
37    setPhase("fast");
38    slowRef.current?.stop();
39    fastRef.current?.goToAndPlay(0, true);
40  }, []);
41 
42  const startSlowPhase = useCallback(() => {
43    repeatCountRef.current = 0;
44    setPhase("slow");
45    fastRef.current?.stop();
46    slowRef.current?.goToAndPlay(0, true);
47  }, []);
48 
49  const handleFastComplete = useCallback(() => {
50    repeatCountRef.current += 1;
51    if (repeatCountRef.current < FAST_REPEATS) {
52      fastRef.current?.goToAndPlay(0, true);
53    } else {
54      startSlowPhase();
55    }
56  }, [startSlowPhase]);
57 
58  const handleSlowComplete = useCallback(() => {
59    repeatCountRef.current += 1;
60    if (repeatCountRef.current < SLOW_REPEATS) {
61      slowRef.current?.goToAndPlay(0, true);
62    } else {
63      startFastPhase();
64    }
65  }, [startFastPhase]);
66 
67  if (!isMounted) return null;
68  const needsInvert = resolvedTheme !== "dark";
69 
70  return (
71    <div
72      className={cn("relative shrink-0", className)}
73      style={{ width: size, height: size }}
74    >
75      <div
76        className={cn(
77          "absolute inset-0 transition-opacity duration-75",
78          needsInvert && "invert",
79          phase === "fast" ? "opacity-100" : "opacity-0",
80        )}
81      >
82        <Lottie
83          lottieRef={fastRef}
84          animationData={spiralFastData}
85          loop={false}
86          autoplay={true}
87          onComplete={handleFastComplete}
88// … truncated