Sales Lead Conversion Step Funnel

import { type ChartPoint, barY, 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 { scaleBand, scaleLinear } from "d3-scale";
import { Filter } from "lucide-react";

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

interface FunnelStageDatum {
    id: string;
    stage: string;
    count: number;
    conversion: number;
}

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

const stages = ["Impressions", "Clicks", "Lead Signup", "Trial User", "Paid Customer"];
const colors = ["var(--chart-1)", "var(--chart-2)", "var(--chart-3)", "var(--chart-4)", "var(--chart-5)"];

function generateDemoData(): FunnelStageDatum[] {
    const rawCounts = [50000, 18000, 6500, 2400, 850];
    const firstCount = rawCounts[0];

    return stages.map((stg, i) => ({
        id: stg,
        stage: stg,
        count: rawCounts[i],
        conversion: Number(((rawCounts[i] / firstCount) * 100).toFixed(1)),
    }));
}

function shadcnTooltipContent<TDatum>(points: readonly ChartPoint<TDatum>[]) {
    if (points.length === 0) return { title: "", rows: [] };
    const d = points[0].datum as FunnelStageDatum;
    if (!d) return { title: "", rows: [] };
    return {
        title: d.stage,
        rows: [
            { label: "Volume Count", value: `${d.count.toLocaleString()} leads`, color: "var(--chart-1)" },
            { label: "Funnel Yield", value: `${d.conversion}% of initial`, color: "var(--chart-2)" },
        ],
    };
}

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

    const definition = useMemo(
        () =>
            defineChart(
                {
                    renderer: motionRenderer,
                    marks: [
                        barY(data, {
                            id: "funnel-bars",
                            x: "stage",
                            y: "count",
                            key: "id",
                            color: "stage",
                            radius: 4,
                        }),
                    ],
                    scales: {
                        x: {
                            scale: scaleBand<string>().domain(stages).padding(0.25),
                            axis: {
                                line: false,
                            },
                        },
                        y: {
                            scale: scaleLinear().domain([0, 55000]),
                            grid: true,
                            axis: { label: "Leads Count" },
                        },
                    },
                    color: {
                        domain: stages,
                        range: colors,
                    },
                    margin: { top: 24, right: 24, bottom: 36, left: 50 },
                    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),
                    },
                },
            ),
        [data],
    );

    return (
        <Card className="w-full max-w-xl">
            <CardHeader>
                <CardTitle>Sales Lead Conversion Step Funnel</CardTitle>
                <CardDescription>
                    Step-down conversion stages tracking user dropoff from awareness to paid conversion
                </CardDescription>
            </CardHeader>
            <CardContent>
                <div className="h-[250px] w-full">
                    <Chart
                        definition={definition}
                        renderer={motionRenderer}
                        height={250}
                        ariaLabel="Sales Lead Conversion Step Funnel Chart"
                    />
                </div>
            </CardContent>
            <CardFooter className="flex-col items-start gap-2 text-sm">
                <div className="flex items-center gap-2 leading-none font-medium">
                    End-to-end conversion rate: 1.7% from impression to paid{" "}
                    <Filter className="h-4 w-4 text-emerald-500" />
                </div>
                <div className="text-muted-foreground leading-none">
                    Sequential stage volume reduction visualized with categorical step bar series
                </div>
            </CardFooter>
        </Card>
    );
}

export default SalesFunnelChart;