import type { ColorInput } from "bun";

/** Resolve any ColorInput to a packed 24-bit integer. */
export function packColor(color: ColorInput): number {
	return Bun.color(color, "number") ?? 0;
}

/** Lerp between two colors. Accepts and returns any ColorInput-compatible value. */
export function lerpColor(from: ColorInput, to: ColorInput, t: number): number {
	const fromInt = packColor(from),
		toInt = packColor(to);
	const fromR = (fromInt >> 16) & 0xff,
		fromG = (fromInt >> 8) & 0xff,
		fromB = fromInt & 0xff;
	const toR = (toInt >> 16) & 0xff,
		toG = (toInt >> 8) & 0xff,
		toB = toInt & 0xff;
	return (
		(Math.round(fromR + (toR - fromR) * t) << 16) |
		(Math.round(fromG + (toG - fromG) * t) << 8) |
		Math.round(fromB + (toB - fromB) * t)
	);
}

/** Lighten a color by +30 per channel, clamped to 255. */
export function lighten(color: ColorInput): number {
	const packed = packColor(color);
	const red = Math.min(255, ((packed >> 16) & 0xff) + 30);
	const green = Math.min(255, ((packed >> 8) & 0xff) + 30);
	const blue = Math.min(255, (packed & 0xff) + 30);
	return (red << 16) | (green << 8) | blue;
}