colorize.ts

import chalk, {type ForegroundColorName, type BackgroundColorName} from 'chalk';

type ColorType = 'foreground' | 'background';

const rgbRegex = /^rgb\(\s?(\d+),\s?(\d+),\s?(\d+)\s?\)$/;
const ansiRegex = /^ansi256\(\s?(\d+)\s?\)$/;

const isNamedColor = (color: string): color is ForegroundColorName => {
	return color in chalk;
};

const colorize = (
	str: string,
	color: string | undefined,
	type: ColorType,
): string => {
	if (!color) {
		return str;
	}

	if (isNamedColor(color)) {
		if (type === 'foreground') {
			return chalk[color](str);
		}

		const methodName = `bg${
			color[0]!.toUpperCase() + color.slice(1)
		}` as BackgroundColorName;

		return chalk[methodName](str);
	}

	if (color.startsWith('#')) {
		return type === 'foreground'
			? chalk.hex(color)(str)
			: chalk.bgHex(color)(str);
	}

	if (color.startsWith('ansi256')) {
		const matches = ansiRegex.exec(color);

		if (!matches) {
			return str;
		}

		const value = Number(matches[1]);

		return type === 'foreground'
			? chalk.ansi256(value)(str)
			: chalk.bgAnsi256(value)(str);
	}

	if (color.startsWith('rgb')) {
		const matches = rgbRegex.exec(color);

		if (!matches) {
			return str;
		}

		const firstValue = Number(matches[1]);
		const secondValue = Number(matches[2]);
		const thirdValue = Number(matches[3]);

		return type === 'foreground'
			? chalk.rgb(firstValue, secondValue, thirdValue)(str)
			: chalk.bgRgb(firstValue, secondValue, thirdValue)(str);
	}

	return str;
};

export default colorize;