Change Arrows

import { type ChartPoint, arrow, defineChart } from "@tanstack/charts";
import { motion } from "@tanstack/charts/motion";
import { tooltip } from "@tanstack/charts/tooltip";
import { Chart } from "@tanstack/react-charts/core";
import { useMemo } from "react";

import { scaleLinear } from "d3-scale";
import { MoveUpRight } from "lucide-react";

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

interface ArrowDatum {
    metro: string;
    pop1980: number;
    ratio1980: number;
    pop2015: number;
    ratio2015: number;
}

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

function generateDemoData(): ArrowDatum[] {
    return [
        { metro: "New York", pop1980: 6.9, ratio1980: 4.5, pop2015: 7.3, ratio2015: 7.8 },
        { metro: "Los Angeles", pop1980: 6.8, ratio1980: 4.2, pop2015: 7.1, ratio2015: 8.2 },
        { metro: "Chicago", pop1980: 6.8, ratio1980: 4.0, pop2015: 6.9, ratio2015: 6.1 },
        { metro: "Houston", pop1980: 6.4, ratio1980: 3.8, pop2015: 6.8, ratio2015: 5.9 },
        { metro: "Phoenix", pop1980: 6.1, ratio1980: 3.6, pop2015: 6.6, ratio2015: 5.2 },
    ];
}

function shadcnTooltipContent<TDatum>(points: readonly ChartPoint<TDatum>[]) {
    if (points.length === 0) return { title: "", rows: [] };
    const d = points[0].datum as ArrowDatum;
    if (!d) return { title: "", rows: [] };
    const diff = d.ratio2015 - d.ratio1980;
    return {
        title: d.metro,
        rows: [
            { label: "1980 Ratio", value: d.ratio1980.toFixed(1), color: "var(--muted-foreground)" },
            { label: "2015 Ratio", value: d.ratio2015.toFixed(1), color: points[0].color || "var(--chart-1)" },
            { label: "Shift", value: `${diff > 0 ? "+" : ""}${diff.toFixed(1)}`, color: "var(--foreground)" },
        ],
    };
}

export function ChangeArrows() {
    const data = useMemo(() => generateDemoData(), []);

    const { increases, decreases } = useMemo(() => {
        return {
            increases: data.filter((d) => d.ratio2015 >= d.ratio1980),
            decreases: data.filter((d) => d.ratio2015 < d.ratio1980),
        };
    }, [data]);

    const definition = useMemo(
        () =>
            defineChart(
                {
                    renderer: motionRenderer,
                    marks: [
                        arrow(increases, {
                            id: "arrow-increases",
                            x1: "pop1980",
                            y1: "ratio1980",
                            x2: "pop2015",
                            y2: "ratio2015",
                            stroke: "var(--chart-1)",
                            headLength: 7,
                        }),
                        arrow(decreases, {
                            id: "arrow-decreases",
                            x1: "pop1980",
                            y1: "ratio1980",
                            x2: "pop2015",
                            y2: "ratio2015",
                            stroke: "var(--chart-2)",
                            headLength: 7,
                        }),
                    ],
                    scales: {
                        x: {
                            scale: scaleLinear().domain([5.8, 7.6]),
                            grid: true,
                            axis: {
                                line: false,
                                label: "Log10 Population",
                                ticks: { size: 0 },
                            },
                        },
                        y: {
                            scale: scaleLinear().domain([3, 9]),
                            grid: true,
                            axis: {
                                line: false,
                                label: "Wage Inequality Ratio",
                                ticks: { size: 0 },
                            },
                        },
                    },
                    margin: { top: 24, right: 24, bottom: 32, left: 45 },
                    theme: {
                        foreground: "var(--muted-foreground)",
                        grid: "var(--border)",
                        background: "transparent",
                    },
                },
                {
                    focus: "group-x",
                    tooltip: {
                        use: tooltip,
                        className:
                            "font-sans shadow-none rounded-md bg-popover text-popover-foreground border p-2 text-xs",
                        anchor: "group-center",
                        placement: "auto",
                        content: (points) => shadcnTooltipContent(points),
                    },
                },
            ),
        [increases, decreases],
    );

    return (
        <Card className="w-full max-w-xl">
            <CardHeader>
                <CardTitle>Population & Wage Vector Shifts</CardTitle>
                <CardDescription>
                    2D vector arrows depicting metro population growth versus wage inequality shift
                </CardDescription>
            </CardHeader>
            <CardContent>
                <div className="h-[250px] w-full">
                    <Chart
                        definition={definition}
                        renderer={motionRenderer}
                        height={250}
                        ariaLabel="Population & Wage Vector Shifts Chart"
                    />
                </div>
            </CardContent>
            <CardFooter className="flex-col items-start gap-2 text-sm">
                <div className="flex items-center gap-2 leading-none font-medium">
                    Vector direction shows simultaneous population expansion and inequality ratio{" "}
                    <MoveUpRight className="h-4 w-4 text-emerald-500" />
                </div>
                <div className="text-muted-foreground leading-none">
                    Green vectors denote increasing inequality; Red vectors denote decreasing inequality
                </div>
            </CardFooter>
        </Card>
    );
}

export default ChangeArrows;