vendor-wise-individual-use-only-coupons

add_filter('woocommerce_apply_individual_use_coupon', function($keep_coupon, $the_coupon, $applied_coupons) {
    $vendor_wise_coupons = [];
    if( $the_coupon->get_individual_use() ) {
        $coupon_id = $the_coupon->get_id();
        $coupon_vendor = wcfm_get_vendor_id_by_post( $coupon_id );
        if( $coupon_vendor ) {
            foreach ( $applied_coupons as $applied_coupon ) {
                $this_coupon = new WC_Coupon($applied_coupon);
                $this_coupon_vendor = wcfm_get_vendor_id_by_post( $this_coupon->get_id() );
                if( $this_coupon_vendor !== $coupon_vendor) {
                    if( !$this_coupon->get_individual_use()) {
                        $vendor_wise_coupons[$this_coupon_vendor][] = $applied_coupon;
                    } else {
                        $vendor_wise_coupons[$this_coupon_vendor] = [$applied_coupon];
                    }
                }
            }
            foreach($vendor_wise_coupons as $vendor_id => $coupons) {
                $keep_coupon = array_merge($keep_coupon, $coupons);
            }
        }
    }
    return array_unique( $keep_coupon );
}, 10, 3);

add_filter('woocommerce_apply_with_individual_use_coupon', function($is_allowed, $the_coupon, $individual_coupon, $applied_coupons) {
    $coupon_id = $the_coupon->get_id();
    $coupon_vendor = wcfm_get_vendor_id_by_post( $coupon_id );
    $individual_use_coupon_vendor = wcfm_get_vendor_id_by_post( $individual_coupon->get_id() );
    if( $coupon_vendor && $coupon_vendor !== $individual_use_coupon_vendor ) {
        return true;
    }
    return $is_allowed;
}, 10, 4);