"use client";
import * as React from "react";
import { cn } from "../../lib/utils";
type Datum = {
label?: string;
value: number;
};
export type LineChartProps = {
color?: string;
data: Datum[];
gradientId?: string;
height?: number;
strokeWidth?: number;
width?: number;
} & React.HTMLAttributes<HTMLDivElement>;
const DEFAULT_WIDTH = 320;
const DEFAULT_HEIGHT = 140;
const DEFAULT_STROKE_WIDTH = 2;
type ChartDimensions = { height: number; strokeWidth: number; width: number };
function buildCoordinates(data: Datum[], dimensions: ChartDimensions) {
if (data.length === 0) return [];
const { height, strokeWidth, width } = dimensions;
const values = data.map((point) => point.value);
const minValue = Math.min(...values);
const maxValue = Math.max(...values);
const range = maxValue - minValue || 1;
const safeWidth = Math.max(width - strokeWidth * 2, 0);
const safeHeight = Math.max(height - strokeWidth * 2, 0);
return data.map((point, index) => {
const x =
data.length === 1
? strokeWidth + safeWidth / 2
: strokeWidth + (index / (data.length - 1)) * safeWidth;
const ratio = (point.value - minValue) / range;
const y = safeHeight - ratio * safeHeight + strokeWidth;
return { x, y };
});
}
export const LineChart = React.forwardRef<HTMLDivElement, LineChartProps>(
(
{
className,
color = "currentColor",
data,
gradientId = "line-chart-gradient",
height = DEFAULT_HEIGHT,
strokeWidth = DEFAULT_STROKE_WIDTH,
width = DEFAULT_WIDTH,
...props
},
reference,
) => {
const canvasData = React.useMemo(
() => buildCoordinates(data, { height, strokeWidth, width }),
[data, width, height, strokeWidth],
);
if (canvasData.length === 0) {
return null;
}
const linePath = canvasData
.map((point, index) => `${index === 0 ? "M" : "L"}${point.x},${point.y}`)
.join(" ");
const areaPath =
canvasData.length === 0
? ""
: `M${canvasData[0]?.x ?? 0},${height} ${linePath} L${canvasData.at(-1)?.x ?? 0},${height}Z`;
return (
<div
className={cn(
"rounded-lg border border-border bg-background/40 p-3",
className,
)}
ref={reference}
{...props}
>
<svg
aria-label="Line chart"
className="h-full w-full"
height={height}
role="img"
viewBox={`0 0 ${width} ${height}`}
width={width}
>
<defs>
<linearGradient id={gradientId} x1="0" x2="0" y1="0" y2="1">
<stop offset="0%" stopColor={color} stopOpacity="0.45" />
<stop offset="100%" stopColor={color} stopOpacity="0" />
</linearGradient>
</defs>
<path
d={areaPath}
fill={`url(#${gradientId})`}
stroke="none"
vectorEffect="non-scaling-stroke"
/>
<path
d={linePath}
fill="none"
stroke={color}
strokeLinecap="round"
strokeLinejoin="round"
strokeWidth={strokeWidth}
vectorEffect="non-scaling-stroke"
/>
</svg>
</div>
);
},
);
LineChart.displayName = "LineChart";