import toHex from 'colornames';

export const calculateRgba = (input: string, opacity: number) => {
	let color = '';

	const colorNameHex = toHex(input);
	if (colorNameHex !== undefined) {
		// Remove the leading '#'
		color = colorNameHex.slice(1);
	} else if (input.startsWith(`#`)) {
		color = input.slice(1);
	}

	if (color.length === 3) {
		let res = '';
		for (const c of color) {
			res += c;
			res += c;
		}

		color = res;
	}

	const rgbParts = color.match(/.{2}/g);
	if (rgbParts === null) {
		throw new Error(`Could not identify RGB value of color \`${input}\``);
	}

	const rgbValues = rgbParts.map((hex) => Number.parseInt(hex, 16)).join(`, `);

	return `rgba(${rgbValues}, ${opacity})`;
};