Mini Shell

import ansiStyles from '#ansi-styles';
import supportsColor from '#supports-color';
import { // eslint-disable-line import/order
	stringReplaceAll,
	stringEncaseCRLFWithFirstIndex,
} from './utilities.js';

const {stdout: stdoutColor, stderr: stderrColor} = supportsColor;

const GENERATOR = Symbol('GENERATOR');
const STYLER = Symbol('STYLER');
const IS_EMPTY = Symbol('IS_EMPTY');

// `supportsColor.level` → `ansiStyles.color[name]` mapping
const levelMapping = [
	'ansi',
	'ansi',
	'ansi256',
	'ansi16m',
];

const styles = Object.create(null);

const applyOptions = (object, options = {}) => {
	if (options.level && !(Number.isInteger(options.level) && options.level >= 0 && options.level <= 3)) {
		throw new Error('The `level` option should be an integer from 0 to 3');
	}

	// Detect level if not set manually
	const colorLevel = stdoutColor ? stdoutColor.level : 0;
	object.level = options.level === undefined ? colorLevel : options.level;
};

export class Chalk {
	constructor(options) {
		// eslint-disable-next-line no-constructor-return
		return chalkFactory(options);
	}
}

const chalkFactory = options => {
	const chalk = (...strings) => strings.join(' ');
	applyOptions(chalk, options);

	Object.setPrototypeOf(chalk, createChalk.prototype);

	return chalk;
};

function createChalk(options) {
	return chalkFactory(options);
}

Object.setPrototypeOf(createChalk.prototype, Function.prototype);

for (const [styleName, style] of Object.entries(ansiStyles)) {
	styles[styleName] = {
		get() {
			const builder = createBuilder(this, createStyler(style.open, style.close, this[STYLER]), this[IS_EMPTY]);
			Object.defineProperty(this, styleName, {value: builder});
			return builder;
		},
	};
}

styles.visible = {
	get() {
		const builder = createBuilder(this, this[STYLER], true);
		Object.defineProperty(this, 'visible', {value: builder});
		return builder;
	},
};

const getModelAnsi = (model, level, type, ...arguments_) => {
	if (model === 'rgb') {
		if (level === 'ansi16m') {
			return ansiStyles[type].ansi16m(...arguments_);
		}

		if (level === 'ansi256') {
			return ansiStyles[type].ansi256(ansiStyles.rgbToAnsi256(...arguments_));
		}

		return ansiStyles[type].ansi(ansiStyles.rgbToAnsi(...arguments_));
	}

	if (model === 'hex') {
		return getModelAnsi('rgb', level, type, ...ansiStyles.hexToRgb(...arguments_));
	}

	return ansiStyles[type][model](...arguments_);
};

const usedModels = ['rgb', 'hex', 'ansi256'];

for (const model of usedModels) {
	styles[model] = {
		get() {
			const {level} = this;
			return function (...arguments_) {
				const styler = createStyler(getModelAnsi(model, levelMapping[level], 'color', ...arguments_), ansiStyles.color.close, this[STYLER]);
				return createBuilder(this, styler, this[IS_EMPTY]);
			};
		},
	};

	const bgModel = 'bg' + model[0].toUpperCase() + model.slice(1);
	styles[bgModel] = {
		get() {
			const {level} = this;
			return function (...arguments_) {
				const styler = createStyler(getModelAnsi(model, levelMapping[level], 'bgColor', ...arguments_), ansiStyles.bgColor.close, this[STYLER]);
				return createBuilder(this, styler, this[IS_EMPTY]);
			};
		},
	};
}

const proto = Object.defineProperties(() => {}, {
	...styles,
	level: {
		enumerable: true,
		get() {
			return this[GENERATOR].level;
		},
		set(level) {
			this[GENERATOR].level = level;
		},
	},
});

const createStyler = (open, close, parent) => {
	let openAll;
	let closeAll;
	if (parent === undefined) {
		openAll = open;
		closeAll = close;
	} else {
		openAll = parent.openAll + open;
		closeAll = close + parent.closeAll;
	}

	return {
		open,
		close,
		openAll,
		closeAll,
		parent,
	};
};

const createBuilder = (self, _styler, _isEmpty) => {
	// Single argument is hot path, implicit coercion is faster than anything
	// eslint-disable-next-line no-implicit-coercion
	const builder = (...arguments_) => applyStyle(builder, (arguments_.length === 1) ? ('' + arguments_[0]) : arguments_.join(' '));

	// We alter the prototype because we must return a function, but there is
	// no way to create a function with a different prototype
	Object.setPrototypeOf(builder, proto);

	builder[GENERATOR] = self;
	builder[STYLER] = _styler;
	builder[IS_EMPTY] = _isEmpty;

	return builder;
};

const applyStyle = (self, string) => {
	if (self.level <= 0 || !string) {
		return self[IS_EMPTY] ? '' : string;
	}

	let styler = self[STYLER];

	if (styler === undefined) {
		return string;
	}

	const {openAll, closeAll} = styler;
	if (string.includes('\u001B')) {
		while (styler !== undefined) {
			// Replace any instances already present with a re-opening code
			// otherwise only the part of the string until said closing code
			// will be colored, and the rest will simply be 'plain'.
			string = stringReplaceAll(string, styler.close, styler.open);

			styler = styler.parent;
		}
	}

	// We can move both next actions out of loop, because remaining actions in loop won't have
	// any/visible effect on parts we add here. Close the styling before a linebreak and reopen
	// after next line to fix a bleed issue on macOS: https://github.com/chalk/chalk/pull/92
	const lfIndex = string.indexOf('\n');
	if (lfIndex !== -1) {
		string = stringEncaseCRLFWithFirstIndex(string, closeAll, openAll, lfIndex);
	}

	return openAll + string + closeAll;
};

Object.defineProperties(createChalk.prototype, styles);

const chalk = createChalk();
export const chalkStderr = createChalk({level: stderrColor ? stderrColor.level : 0});

export {
	modifierNames,
	foregroundColorNames,
	backgroundColorNames,
	colorNames,

	// TODO: Remove these aliases in the next major version
	modifierNames as modifiers,
	foregroundColorNames as foregroundColors,
	backgroundColorNames as backgroundColors,
	colorNames as colors,
} from './vendor/ansi-styles/index.js';

export {
	stdoutColor as supportsColor,
	stderrColor as supportsColorStderr,
};

export default chalk;