'use strict';

const _ = require('lodash');
const declarationValueIndex = require('../../utils/declarationValueIndex');
const getUnitFromValueNode = require('../../utils/getUnitFromValueNode');
const matchesStringOrRegExp = require('../../utils/matchesStringOrRegExp');
const postcss = require('postcss');
const report = require('../../utils/report');
const ruleMessages = require('../../utils/ruleMessages');
const validateOptions = require('../../utils/validateOptions');
const valueParser = require('postcss-value-parser');

const ruleName = 'declaration-property-unit-whitelist';

const messages = ruleMessages(ruleName, {
	rejected: (property, unit) => `Unexpected unit "${unit}" for property "${property}"`,
});

function rule(whitelist) {
	return (root, result) => {
		const validOptions = validateOptions(result, ruleName, {
			actual: whitelist,
			possible: [_.isObject],
		});

		if (!validOptions) {
			return;
		}

		root.walkDecls((decl) => {
			const prop = decl.prop;
			const value = decl.value;

			const unprefixedProp = postcss.vendor.unprefixed(prop);

			const propWhitelist = _.find(whitelist, (list, propIdentifier) =>
				matchesStringOrRegExp(unprefixedProp, propIdentifier),
			);

			if (!propWhitelist) {
				return;
			}

			valueParser(value).walk((node) => {
				// Ignore wrong units within `url` function
				if (node.type === 'function' && node.value.toLowerCase() === 'url') {
					return false;
				}

				if (node.type === 'string') {
					return;
				}

				const unit = getUnitFromValueNode(node);

				if (!unit || (unit && propWhitelist.indexOf(unit.toLowerCase())) !== -1) {
					return;
				}

				report({
					message: messages.rejected(prop, unit),
					node: decl,
					index: declarationValueIndex(decl) + node.sourceIndex,
					result,
					ruleName,
				});
			});
		});
	};
}

rule.ruleName = ruleName;
rule.messages = messages;
module.exports = rule;
