<?php
defined( 'ABSPATH' ) || exit;

/**
 * Quick and dirty way to mostly minify CSS.
 */
if ( ! class_exists( 'Medizin_Minify' ) ) {
	class Medizin_Minify {

		public static function css( $css ) {
			// Normalize whitespace.
			$css = preg_replace( '/\s+/', ' ', $css );

			// Remove spaces before and after comment.
			$css = preg_replace( '/(\s+)(\/\*(.*?)\*\/)(\s+)/', '$2', $css );
			// Remove comment blocks, everything between /* and */, unless.
			// preserved with /*! ... */ or /** ... */
			$css = preg_replace( '~/\*(?![\!|\*])(.*?)\*/~', '', $css );
			// Remove ; before }.
			$css = preg_replace( '/;(?=\s*})/', '', $css );
			// Remove space after , : ; { } */ >.
			$css = preg_replace( '/(,|:|;|\{|}|\*\/|>) /', '$1', $css );
			// Remove space before , ; { } ( ) >.
			$css = preg_replace( '/ (,|;|\{|}|\(|\)|>)/', '$1', $css );
			// Strips leading 0 on decimal values (converts 0.5px into .5px).
			$css = preg_replace( '/(:| )0\.([0-9]+)(%|em|ex|px|in|cm|mm|pt|pc)/i', '${1}.${2}${3}', $css );
			// Strips units if value is 0 (converts 0px to 0).
			$css = preg_replace( '/(:| )(\.?)0(%|em|ex|px|in|cm|mm|pt|pc)/i', '${1}0', $css );
			// Converts all zeros value into short-hand.
			$css = preg_replace( '/0 0 0 0/', '0', $css );
			// Shorten 6-character hex color codes to 3-character where possible.
			$css = preg_replace( '/#([a-f0-9])\\1([a-f0-9])\\2([a-f0-9])\\3/i', '#\1\2\3', $css );

			return trim( $css );
		}
	}
}
