import MediaQueryItem from './MediaQueryItem.js';
import MediaQueryTypeEnum from './MediaQueryTypeEnum.js';
import BrowserWindow from '../window/BrowserWindow.js';

/**
 * Media query RegExp.
 *
 * Group 1: "not", "only", "all", "screen", "print".
 * Group 2: Rule.
 * Group 3: Rule end paranthesis (must be present if no value).
 * Group 4: Comma (,).
 * Group 5: "or", "and".
 */
const MEDIA_QUERY_REGEXP = /(not|only|all|screen|print)|\(([^\)]+)(\)){0,1}|(,)| +(or|and) +/g;

/**
 * Check if resolution RegExp.
 */
const IS_RESOLUTION_REGEXP = /[<>]/;

/**
 * Resolution RegExp.
 *
 * Group 1: First resolution value.
 * Group 2: First resolution operator.
 * Group 3: Resolution type.
 * Group 4: Second resolution operator.
 * Group 5: Second resolution value.
 */
const RESOLUTION_REGEXP =
	/(?:([0-9]+[a-z]+) *(<|<=|>|=>)){0,1} *(width|height) *(?:(<|<=|>|=>) *([0-9]+[a-z]+)){0,1}/;

/**
 * Utility for parsing a query string.
 */
export default class MediaQueryParser {
	/**
	 * Parses a media query string.
	 *
	 * @param options Options.
	 * @param options.window Owner window.
	 * @param options.mediaQuery Media query string.
	 * @param [options.rootFontSize] Root font size.
	 * @returns Media query items.
	 */
	public static parse(options: {
		window: BrowserWindow;
		mediaQuery: string;
		rootFontSize?: string | number | null;
	}): MediaQueryItem[] {
		let currentMediaQueryItem: MediaQueryItem = new MediaQueryItem({
			window: options.window,
			rootFontSize: options.rootFontSize
		});
		const mediaQueryItems: MediaQueryItem[] = [currentMediaQueryItem];
		const regexp = new RegExp(MEDIA_QUERY_REGEXP);
		let match: RegExpExecArray | null = null;

		while ((match = regexp.exec(options.mediaQuery.toLowerCase()))) {
			if (match[4] === ',' || match[5] === 'or') {
				currentMediaQueryItem = new MediaQueryItem({
					window: options.window,
					rootFontSize: options.rootFontSize
				});
				mediaQueryItems.push(currentMediaQueryItem);
			} else if (match[1] === 'all' || match[1] === 'screen' || match[1] === 'print') {
				currentMediaQueryItem.mediaTypes.push(<MediaQueryTypeEnum>match[1]);
			} else if (match[1] === 'not') {
				currentMediaQueryItem.not = true;
			} else if (match[2]) {
				const resolutionMatch = IS_RESOLUTION_REGEXP.test(match[2])
					? match[2].match(RESOLUTION_REGEXP)
					: null;
				if (resolutionMatch && (resolutionMatch[1] || resolutionMatch[5])) {
					currentMediaQueryItem.ranges.push({
						before: resolutionMatch[1]
							? {
									value: resolutionMatch[1],
									operator: resolutionMatch[2]
								}
							: null,
						type: resolutionMatch[3],
						after: resolutionMatch[5]
							? {
									value: resolutionMatch[5],
									operator: resolutionMatch[4]
								}
							: null
					});
				} else {
					const [name, value] = match[2].split(':');
					const trimmedValue = value ? value.trim() : null;
					if (!trimmedValue && !match[3]) {
						return [
							new MediaQueryItem({
								window: options.window,
								rootFontSize: options.rootFontSize,
								not: true,
								mediaTypes: [MediaQueryTypeEnum.all]
							})
						];
					}
					currentMediaQueryItem.rules.push({
						name: name.trim(),
						value: trimmedValue
					});
				}
			}
		}

		return mediaQueryItems;
	}
}