Animated Timeline Playback Scrubber

import { type ChartPoint, defineChart, dot, lineY } from "@tanstack/charts";
import { handleX } from "@tanstack/charts/interaction/handle";
import { controlledSignal } from "@tanstack/charts/interaction/signal";
import { motion } from "@tanstack/charts/motion";
import { tooltip } from "@tanstack/charts/tooltip";
import { Chart } from "@tanstack/react-charts/core";
import { useEffect, useMemo, useState } from "react";

import { scaleLinear, scaleUtc } from "d3-scale";
import { Pause, Play } from "lucide-react";

import { Button } from "@/components/ui/button";
import { Card, CardContent, CardDescription, CardFooter, CardHeader, CardTitle } from "@/components/ui/card";

interface StockDatum {
    date: Date;
    close: number;
}

const motionRenderer = motion({
    initial: "always",
    transition: { type: "spring", stiffness: 170, damping: 18, mass: 1 },
});

function generateDemoData(): StockDatum[] {
    const results: StockDatum[] = [];
    let price = 160;
    const baseDate = new Date(Date.UTC(2024, 0, 1)).getTime();

    for (let i = 0; i < 20; i++) {
        price += Math.sin(i * 0.5) * 5 + (Math.random() - 0.45) * 6;
        results.push({
            date: new Date(baseDate + i * 7 * 24 * 60 * 60 * 1000),
            close: Number(Math.max(100, price).toFixed(2)),
        });
    }
    return results;
}

function shadcnTooltipContent<TDatum>(points: readonly ChartPoint<TDatum>[]) {
    if (points.length === 0) return { title: "", rows: [] };
    const d = points[0].datum as StockDatum;
    if (!d || !d.date) return { title: "", rows: [] };
    const dateObj = d.date instanceof Date ? d.date : new Date(d.date);
    const titleStr = isNaN(dateObj.getTime())
        ? ""
        : dateObj.toLocaleDateString("en-US", { month: "short", day: "numeric", timeZone: "UTC" });
    return {
        title: titleStr,
        rows: [{ label: "Close Price", value: `$${d.close.toFixed(2)}`, color: "var(--chart-1)" }],
    };
}

export function TimelinePlaybackScrubber() {
    const data = useMemo(() => generateDemoData(), []);
    const dates = useMemo(() => data.map((d) => d.date), [data]);

    const [currentFrame, setCurrentFrame] = useState<Date>(dates[0]);
    const [isPlaying, setIsPlaying] = useState<boolean>(false);

    useEffect(() => {
        if (!isPlaying) return;
        const interval = setInterval(() => {
            setCurrentFrame((prev) => {
                const prevTime = prev instanceof Date ? prev.getTime() : new Date(prev).getTime();
                const idx = dates.findIndex(
                    (d) => (d instanceof Date ? d.getTime() : new Date(d).getTime()) === prevTime,
                );
                if (idx < 0 || idx >= dates.length - 1) {
                    setIsPlaying(false);
                    return prev;
                }
                return dates[idx + 1];
            });
        }, 600);

        return () => clearInterval(interval);
    }, [dates, isPlaying]);

    const activeDatum = useMemo(() => {
        const frameTime = currentFrame instanceof Date ? currentFrame.getTime() : new Date(currentFrame).getTime();
        return (
            data.find((d) => (d.date instanceof Date ? d.date.getTime() : new Date(d.date).getTime()) === frameTime) ||
            data[0]
        );
    }, [currentFrame, data]);

    const definition = useMemo(
        () =>
            defineChart(
                {
                    renderer: motionRenderer,
                    marks: [
                        lineY(data, {
                            id: "playback-line",
                            x: "date",
                            y: "close",
                            stroke: "var(--chart-1)",
                            strokeWidth: 2.5,
                        }),
                        dot(data, {
                            id: "playback-points",
                            x: "date",
                            y: "close",
                            fill: "var(--chart-1)",
                            r: 3.5,
                            stroke: "var(--background)",
                            strokeWidth: 1,
                        }),
                    ],
                    scales: {
                        x: {
                            scale: scaleUtc,
                            axis: {
                                ticks: {
                                    format: (v: any) => {
                                        const dateObj = v instanceof Date ? v : new Date(v);
                                        return isNaN(dateObj.getTime())
                                            ? ""
                                            : dateObj.toLocaleDateString("en-US", {
                                                  month: "short",
                                                  day: "numeric",
                                                  timeZone: "UTC",
                                              });
                                    },
                                },
                            },
                        },
                        y: {
                            scale: scaleLinear,
                            grid: true,
                            axis: { label: "Stock Close ($)" },
                        },
                    },
                    controls: [
                        handleX({
                            id: "playback-frame",
                            value: controlledSignal<Date, any>(currentFrame, (next) =>
                                setCurrentFrame(next instanceof Date ? next : new Date(next)),
                            ),
                            values: dates,
                            cross: { edge: "bottom", offset: 24 },
                            ruleStyle: { fill: "var(--chart-2)" },
                            handleStyle: {
                                fill: "var(--chart-2)",
                                stroke: "var(--background)",
                                strokeWidth: 2,
                            },
                            ariaLabel: "Timeline playback frame scrubber",
                        }),
                    ],
                    margin: { top: 24, right: 24, bottom: 45, left: 45 },
                    theme: {
                        foreground: "var(--muted-foreground)",
                        grid: "var(--border)",
                        background: "transparent",
                    },
                },
                {
                    keyboard: true,
                    tooltip: {
                        use: tooltip,
                        className:
                            "font-sans shadow-none rounded-md bg-popover text-popover-foreground border p-2 text-xs",
                        anchor: "pointer",
                        placement: "auto",
                        content: (points) => shadcnTooltipContent(points),
                    },
                },
            ),
        [currentFrame, data, dates],
    );

    const fmtDate = (d: any) => {
        const dateObj = d instanceof Date ? d : new Date(d);
        return isNaN(dateObj.getTime())
            ? ""
            : dateObj.toLocaleDateString("en-US", { month: "short", day: "numeric", timeZone: "UTC" });
    };

    return (
        <Card className="w-full max-w-xl">
            <CardHeader>
                <CardTitle>Animated Timeline Playback Scrubber</CardTitle>
                <CardDescription>
                    Interactive timeline play/pause scrubber stepping through sequential data frames
                </CardDescription>
            </CardHeader>
            <CardContent className="space-y-3">
                <div className="flex items-center justify-between">
                    <Button
                        size="sm"
                        variant="default"
                        className="h-8 text-xs"
                        onClick={() => setIsPlaying((prev) => !prev)}>
                        {isPlaying ? <Pause className="mr-1.5 h-3.5 w-3.5" /> : <Play className="mr-1.5 h-3.5 w-3.5" />}
                        {isPlaying ? "Pause" : "Play Timeline"}
                    </Button>
                    <span className="text-muted-foreground font-mono text-xs">
                        Active: <strong className="text-foreground">{fmtDate(activeDatum.date)}</strong> ($
                        {activeDatum.close.toFixed(2)})
                    </span>
                </div>
                <div className="h-[230px] w-full">
                    <Chart
                        definition={definition}
                        renderer={motionRenderer}
                        height={230}
                        ariaLabel="Animated Timeline Playback Scrubber Chart"
                    />
                </div>
            </CardContent>
            <CardFooter className="flex-col items-start gap-2 text-sm">
                <div className="flex items-center gap-2 leading-none font-medium">
                    {isPlaying
                        ? "Playback active - stepping through timeline..."
                        : "Drag orange handle or click Play to scrub"}
                </div>
                <div className="text-muted-foreground leading-none">
                    `handleX` control provides draggable playhead handle along bottom X axis rail
                </div>
            </CardFooter>
        </Card>
    );
}

export default TimelinePlaybackScrubber;