Cancel the membership at the end of the month, not immediately.

e20r-end-of-month-membership-cancellation.php

/*
  Change cancellation to set expiration date et expiration date to be the end of the current month, instead of cancelling immediately.
	
  Assumes orders are generated for each payment (i.e. your webhooks/etc are setup correctly).
  
*/

//give users their level back with an expiration
function e20r_pmpro_after_change_ml($level_id, $user_id)
{
	//are we on the cancel page?
	global $pmpro_pages, $wpdb, $pmpro_next_payment_timestamp;
	if($level_id == 0 && (is_page($pmpro_pages['cancel']) || (is_admin() && (empty($_REQUEST['from']) || $_REQUEST['from'] != 'profile'))))
	{
		/*
			okay, let's give the user his old level back with an expiration based on his subscription date
		*/
		//get last order
		$order = new MemberOrder();
		$order->getLastMemberOrder($user_id, "cancelled");
		
		//can't do this if we can't find the order
		if(empty($order->id))
			return false;

		//get the last level they had		
		$level = $wpdb->get_row("SELECT * FROM $wpdb->pmpro_memberships_users WHERE membership_id = '" . $order->membership_id . "' AND user_id = '" . $user_id . "' ORDER BY id DESC LIMIT 1");

		//can't do this if the level isn't recurring
		if(empty($level->cycle_number))
			return false;
				
		//can't do if we can't find an old level
		if(empty($level))
			return false;
			
		//last payment date
		$lastdate = date("Y-m-d", $order->timestamp);
				
		/*
			next payment date
		*/
		$nextdate = strtotime( date('Y-m-t', current_time('timestamp') ), current_time('timestamp') ); 

		//if the date in the future?
		if($nextdate - time() > 0)
		{						
			//give them their level back with the expiration date set
			$old_level = $wpdb->get_row("SELECT * FROM $wpdb->pmpro_memberships_users WHERE membership_id = '" . $order->membership_id . "' AND user_id = '" . $user_id . "' ORDER BY id DESC LIMIT 1", ARRAY_A);
			$old_level['enddate'] = date("Y-m-d H:i:s", $nextdate);

			//disable this hook so we don't loop
			remove_action("pmpro_after_change_membership_level", "e20r_pmpro_after_change_ml", 10, 2);
			remove_filter('pmpro_cancel_previous_subscriptions', 'my_pmpro_cancel_previous_subscriptions');

			//change level
			pmpro_changeMembershipLevel($old_level, $user_id);
			
			//add the action back just in case
			add_action("pmpro_after_change_membership_level", "e20r_pmpro_after_change_ml", 10, 2);
			add_filter('pmpro_cancel_previous_subscriptions', 'my_pmpro_cancel_previous_subscriptions');

			//change message shown on cancel page
			add_filter("gettext", "e20r_cancel_text", 10, 3);
		}
	}
}
add_action("pmpro_after_change_membership_level", "e20r_pmpro_after_change_ml", 10, 2);
 
//this replaces the cancellation text so people know they'll still have access for a certain amount of time
function e20r_cancel_text($translated_text, $text, $domain)
{
	if($domain == "pmpro" && $text == "Your membership has been cancelled.")
	{
		global $current_user;
		$translated_text = "Your recurring subscription has been cancelled. Your active membership will expire on " . date(get_option("date_format"), pmpro_next_payment($current_user->ID, "cancelled")) . ".";
	}
	
	return $translated_text;
}
 
//want to update the cancellation email as well
function e20r_email_body($body, $email)
{
	if($email->template == "cancel")
	{
		global $wpdb;
		$user_id = $wpdb->get_var("SELECT ID FROM $wpdb->users WHERE user_email = '" . esc_sql($email->email) . "' LIMIT 1");
		if(!empty($user_id))
		{
			$expiration_date = pmpro_next_payment($user_id);
			
			//if the date in the future?
			if($expiration_date - time() > 0)
			{						
				$body .= "<p>Your access will expire on " . date(get_option("date_format"), $expiration_date) . ".</p>";
			}
		}
	}
	
	return $body;
}
add_filter("pmpro_email_body", "e20r_email_body", 10, 2);