JetSmartFilters Relation AND for checkbox filter (meta field)

jsf-checkbox-and.php

<?php

add_filter( 'jet-smart-filters/query/final-query', function ($query) {

	if ( ! isset( $query['meta_query'] ) || ! function_exists( 'jet_engine' ) ) {
		return $query;
	}

	foreach ( $query['meta_query'] as $index => $meta_query_item ) {

		if ( false !== strpos( $query['meta_query'][ $index ]['key'], 'checkbox_and__' ) ) {

			$meta_key = explode( '__', $query['meta_query'][ $index ]['key'] )[1];

			$query['meta_query'][ $index ]['key'] = $meta_key;

		} else {
			continue;
		}



		if ( ! is_array( $query['meta_query'][ $index ]['value'] ) ) {
			$values = array( $query['meta_query'][ $index ]['value'] );
		} else {
			$values = $query['meta_query'][ $index ]['value'];
		}

		$regexp_query['relation'] = 'AND';

		$i = 0;

		foreach ( $values as $value ) {

			$value = preg_quote( $value );

			$regexp = '\:[\'\"]?' . $value . '[\'\"]?;s:4:"true"|\:[\'\"]?' . $value . '[\'\"]?;[^s]';

			$regexp_query[ $i ] = array(

				'key' => $meta_key,

				'value' => $regexp,

				'compare' => 'REGEXP',

			);

			$i = $i + 1;

		}

		$query['meta_query'][ $index ] = $regexp_query;

	}

	return $query;

}, 999 );