defer-next-payment-when-renewing-early-with-discount-code.php

<?php
/**
 * Deferred-payment promo: when a member of the eligible level checks out for
 * the level using the promo discount code, push their first recurring payment
 * out to 1 year after their existing subscription's next payment date.
 * They still pay the initial payment now.
 * 
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */

/**
 * EDIT HERE: the discount code that triggers the promo.
 */
if ( ! defined( 'MY_PMPRO_PROMO_DISCOUNT_CODE' ) ) {
	define( 'MY_PMPRO_PROMO_DISCOUNT_CODE', 'ANNUAL99' );
}

/**
 * EDIT HERE: the membership level ID the promo applies to. The member must
 * already hold this level, and be checking out for it again, to qualify.
 */
if ( ! defined( 'MY_PMPRO_PROMO_LEVEL_ID' ) ) {
	define( 'MY_PMPRO_PROMO_LEVEL_ID', 1 );
}

/**
 * Resolve the discount code applied to a level object.
 *
 * @param object $level Level object.
 * @return string The applied discount code, or '' if none.
 */
function my_pmpro_get_level_discount_code( $level ) {
	if ( ! empty( $level->discount_code ) ) {
		return $level->discount_code;
	}

	if ( ! empty( $level->code_id ) ) {
		global $wpdb;
		return (string) $wpdb->get_var(
			$wpdb->prepare( "SELECT code FROM {$wpdb->pmpro_discount_codes} WHERE id = %d LIMIT 1", $level->code_id )
		);
	}

	return '';
}

/**
 * Determine whether the promo applies to this level for the current user and,
 * if so, return the deferred first-payment date (UTC Y-m-d H:i:s).
 *
 * @param object $level The level being checked out / previewed.
 * @return string|false UTC datetime string, or false if the promo doesn't apply.
 */
function my_pmpro_promo_get_deferred_startdate( $level ) {
	// Bail if PMPro isn't loaded.
	if ( ! function_exists( 'pmpro_getMembershipLevelForUser' ) ) {
		return false;
	}

	// Only applies when checking out for the promo level (MY_PMPRO_PROMO_LEVEL_ID).
	if ( empty( $level ) || (int) $level->id !== (int) MY_PMPRO_PROMO_LEVEL_ID ) {
		return false;
	}

	// Only when the promo discount code is applied. Bail if the constant was
	// overridden with an empty value, otherwise every code-less checkout would match.
	$promo_code = trim( (string) MY_PMPRO_PROMO_DISCOUNT_CODE );
	if ( '' === $promo_code ) {
		return false;
	}
	if ( strcasecmp( my_pmpro_get_level_discount_code( $level ), $promo_code ) !== 0 ) {
		return false;
	}

	// The level being purchased must be recurring for a deferral to mean anything.
	if ( ! pmpro_isLevelRecurring( $level ) ) {
		return false;
	}

	$user_id = get_current_user_id();
	if ( ! $user_id ) {
		return false;
	}

	// Member must currently hold the promo level too (i.e. this is a renewal)...
	$current_level = pmpro_getMembershipLevelForUser( $user_id );
	if ( empty( $current_level ) || (int) $current_level->id !== (int) MY_PMPRO_PROMO_LEVEL_ID ) {
		return false;
	}

	// ...and that current membership must itself be recurring.
	if ( ! pmpro_isLevelRecurring( $current_level ) ) {
		return false;
	}

	// Anchor the deferral to the member's existing subscription next payment date.
	$next_payment = pmpro_next_payment( $user_id, 'success', 'timestamp' );
	if ( empty( $next_payment ) ) {
		// No scheduled next payment to anchor to (e.g. subscription already ended) —
		// fall back to 1 year from checkout so the promo still applies.
		$next_payment = time();
	}

	// Push the first recurring payment to 1 year after the existing next payment date.
	$deferred = strtotime( '+1 year', (int) $next_payment );

	// Gateways limit how far out the first payment can be scheduled: PayPal
	// clamps profile start dates to 1 year from now, and Stripe's maximum
	// trial period is 730 days. Clamp so checkout doesn't fail and the date
	// we display matches what the gateway will actually do.
	if ( in_array( pmpro_getGateway(), array( 'paypal', 'paypalexpress', 'paypalstandard' ), true ) ) {
		$max_deferred = strtotime( '+1 year' );
	} else {
		$max_deferred = time() + 730 * DAY_IN_SECONDS;
	}

	return gmdate( 'Y-m-d H:i:s', min( $deferred, $max_deferred ) );
}

/**
 * Defer the first recurring payment at checkout.
 */
function my_pmpro_promo_defer_checkout_startdate( $checkout_level ) {
	$startdate = my_pmpro_promo_get_deferred_startdate( $checkout_level );
	if ( $startdate ) {
		$checkout_level->profile_start_date = $startdate;
	}
	return $checkout_level;
}
add_filter( 'pmpro_checkout_level', 'my_pmpro_promo_defer_checkout_startdate' );

/**
 * Show the expected next payment date in the level cost text so customers know.
 */
function my_pmpro_promo_show_startdate_in_cost_text( $cost, $level ) {
	// Prefer an already-set profile_start_date (full checkout); otherwise only
	// compute it during the discount-code preview request.
	$startdate = ! empty( $level->profile_start_date ) ? $level->profile_start_date : false;
	if ( empty( $startdate ) && ! empty( $_REQUEST['action'] ) && 'applydiscountcode' === $_REQUEST['action'] ) {
		$startdate = my_pmpro_promo_get_deferred_startdate( $level );
	}

	if ( ! empty( $startdate ) ) {
		// profile_start_date is stored in UTC; convert to local time for display.
		$start_date = get_date_from_gmt( $startdate, get_option( 'date_format' ) );
		$cost      .= sprintf( ' <small>(%s %s)</small>', 'Next payment on', esc_html( $start_date ) );
	}
	return $cost;
}
add_filter( 'pmpro_level_cost_text', 'my_pmpro_promo_show_startdate_in_cost_text', 10, 2 );