Stylesheet::add_rules

	public function add_rules( $selector, $style_rules = null, array $query = null ) {
		$query_hash = 'all';

		if ( $query ) {
			$query_hash = $this->query_to_hash( $query );
		}

		if ( ! isset( $this->rules[ $query_hash ] ) ) {
			$this->add_query_hash( $query_hash );
		}

		if ( null === $style_rules ) {
			preg_match_all( '/([^\s].+?(?=\{))\{((?s:.)+?(?=}))}/', $selector, $parsed_rules );

			foreach ( $parsed_rules[1] as $index => $selector ) {
				$this->add_rules( $selector, $parsed_rules[2][ $index ], $query );
			}

			return $this;
		}

		if ( ! isset( $this->rules[ $query_hash ][ $selector ] ) ) {
			$this->rules[ $query_hash ][ $selector ] = [];
		}

		if ( is_string( $style_rules ) ) {
			$style_rules = array_filter( explode( ';', trim( $style_rules ) ) );

			$ordered_rules = [];

			foreach ( $style_rules as $rule ) {
				$property = explode( ':', $rule, 2 );

				if ( count( $property ) < 2 ) {
					return $this;
				}

				$ordered_rules[ trim( $property[0] ) ] = trim( $property[1], ' ;' );
			}

			$style_rules = $ordered_rules;
		}

		$this->rules[ $query_hash ][ $selector ] = array_merge( $this->rules[ $query_hash ][ $selector ], $style_rules );

		return $this;
	}