'use strict';

const _ = require('lodash');
const isCustomPropertySet = require('../utils/isCustomPropertySet');
const isStandardSyntaxSelector = require('../utils/isStandardSyntaxSelector');

/**
 * Check whether a Node is a standard rule
 *
 * @param {import('postcss').Rule | import('postcss-less').Rule} rule
 * @returns {boolean}
 */
module.exports = function (rule) {
	if (rule.type !== 'rule') {
		return false;
	}

	// Get full selector
	const selector = _.get(rule, 'raws.selector.raw', rule.selector);

	if (!isStandardSyntaxSelector(rule.selector)) {
		return false;
	}

	// Custom property set (e.g. --custom-property-set: {})
	if (isCustomPropertySet(rule)) {
		return false;
	}

	// Called Less mixin (e.g. a { .mixin() })
	// @ts-ignore TODO TYPES support LESS and SASS types somehow
	if (rule.mixin) {
		return false;
	}

	// Less detached rulesets
	if (selector.startsWith('@') && selector.endsWith(':')) {
		return false;
	}

	// Ignore Less &:extend rule
	if ('extend' in rule && rule.extend) {
		return false;
	}

	// Ignore mixin or &:extend rule
	// https://github.com/shellscape/postcss-less/blob/master/lib/less-parser.js#L52
	// @ts-ignore TODO TYPES support LESS and SASS types somehow
	if (rule.params && rule.params[0]) {
		return false;
	}

	// Non-outputting Less mixin definition (e.g. .mixin() {})
	if (selector.endsWith(')') && !selector.includes(':')) {
		return false;
	}

	// Less guards
	if (/when\s+(not\s+)*\(/.test(selector)) {
		return false;
	}

	// Ignore Scss nested properties
	if (selector.endsWith(':')) {
		return false;
	}

	return true;
};