Line Gaps

import { type ChartPoint, defineChart, lineY } 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, scaleUtc } from "d3-scale";
import { TrendingUp } from "lucide-react";

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

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

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

function generateDemoData(): StockDatum[] {
    const baseDate = new Date(2025, 0, 1);
    return Array.from({ length: 24 }, (_, i) => {
        const d = new Date(baseDate);
        d.setDate(baseDate.getDate() + i * 7);
        // Introduce gaps in Q1 (weeks 4 to 8)
        const isGap = i >= 4 && i <= 7;
        return {
            date: d,
            close: isGap ? null : 150 + Math.sin(i * 0.4) * 25 + i * 2,
        };
    });
}

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

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

    const definition = useMemo(
        () =>
            defineChart(
                {
                    renderer: motionRenderer,
                    marks: [
                        lineY(data, {
                            id: "stock-line",
                            x: "date",
                            y: (row: StockDatum) => row.close,
                            stroke: "var(--chart-1)",
                            strokeWidth: 2.25,
                        }),
                    ],
                    scales: {
                        x: {
                            scale: scaleUtc,
                            axis: {
                                line: false,
                                label: "Week",
                                ticks: {
                                    size: 0,
                                    padding: 10,
                                    format: (d: Date) => d.toLocaleDateString("en-US", { month: "short", day: "numeric" }),
                                },
                            },
                        },
                        y: {
                            scale: scaleLinear().domain([100, 220]),
                            grid: true,
                            axis: {
                                line: false,
                                label: "Close ($)",
                                ticks: { size: 0 },
                            },
                        },
                    },
                    margin: { top: 24, right: 24, bottom: 32, left: 40 },
                    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),
                    },
                },
            ),
        [data],
    );

    return (
        <Card className="w-full max-w-xl">
            <CardHeader>
                <CardTitle>Asset Price with Data Gaps</CardTitle>
                <CardDescription>Weekly closing prices highlighting missing reporting intervals</CardDescription>
            </CardHeader>
            <CardContent>
                <div className="h-[250px] w-full">
                    <Chart
                        definition={definition}
                        renderer={motionRenderer}
                        height={250}
                        ariaLabel="Asset Price with Data Gaps Chart"
                    />
                </div>
            </CardContent>
            <CardFooter className="flex-col items-start gap-2 text-sm">
                <div className="flex items-center gap-2 leading-none font-medium">
                    Market recovery following Q1 gap interval <TrendingUp className="h-4 w-4 text-emerald-500" />
                </div>
                <div className="text-muted-foreground leading-none">
                    Gaps indicate suspended trading sessions during system upgrade
                </div>
            </CardFooter>
        </Card>
    );
}

export default LineGaps;