mepr-restrict-coupons-by-memberships.php

<?php

function mepr_restrict_coupons_by_memberships( $errors ) {
	$coupon = isset( $_POST['mepr_coupon_code'] ) && ! empty( $_POST['mepr_coupon_code'] ) ? $_POST['mepr_coupon_code'] : '';
	$user_id = get_current_user_id();

	if ( $coupon == 'COUPON' && $user_id == 0 ) {
		// User doesn't have an account yet, so turn down their coupon attempt.
		$errors['mepr_coupon_denied'] = 'You cannot use this coupon.';
	}

	$user = new MeprUser( $user_id );

	$prods = $user->active_product_subscriptions( 'products' );
	$user_prod_ids = array();
	$allowed_prod_ids = array( '223' ); // Allowed membership IDs.

	foreach ( $prods as $prod ) {
		$user_prod_ids[] = $prod->ID;
	}

	if ( $coupon == 'COUPON' && ! array_intersect( $user_prod_ids, $allowed_prod_ids ) ) {
		// User tried to use coupon, but doesn't belong to the appropriate membership.
		$errors['mepr_coupon_denied'] = 'You cannot use this coupon.';
	}

	return $errors;
}
add_filter( 'mepr-validate-signup', 'mepr_restrict_coupons_by_memberships', 10, 1 );