dailies-at-night.php

<?php
namespace PWCC\NightlyCronSchedule;

use DateTime;
use DateTimeZone;
use HM\Cavalcade\Plugin\Job;

/**
 * Register hooks for WordPress.
 */
function bootstrap() {
	if ( ! class_exists( 'HM\Cavalcade\Plugin\Job' ) ) {
		return;
	}

	add_filter( 'pre_get_scheduled_event', __NAMESPACE__ . '\\pre_get_scheduled_event', 5, 4 );
	add_filter( 'schedule_event', __NAMESPACE__ . '\\schedule_event' );
}

function enforced_daily_schedules() {
	/**
	 * Daily cron events to be enforced to run at a
	 * particular hour.
	 *
	 * @param array $daily_events Events scheduled to run daily at particular times.
	 *                            The key is the hook name, the value the hour of day.
	 */
	return apply_filters(
		'pwcc.nightly-cron-scheduled.enforced-daily-schedules',
		[
			'wp_scheduled_delete' => 02,
			'wp_scheduled_auto_draft_delete' => 03,
			'delete_expired_transients' => 04,
		]
	);
}

/**
 * When getting Core daily tasks, ensure they are scheduled for night time.
 *
 * Ensure the following core hooks are scheduled to run within a ten minute window
 * of the specified time.
 * - wp_scheduled_delete: 2am
 * - wp_scheduled_auto_draft_delete: 3am
 * - delete_expired_transients: 4am
 *
 * @param null|bool $pre   Value to return instead. Default null to continue adding the event.
 * @param stdClass  $event {
 *     An object containing an event's data.
 *
 *     @type string       $hook      Action hook to execute when the event is run.
 *     @type int          $timestamp Unix timestamp (UTC) for when to next run the event.
 *     @type string|false $schedule  How often the event should subsequently recur.
 *     @type array        $args      Array containing each separate argument to pass to the hook's callback function.
 *     @type int          $interval  The interval time in seconds for the schedule. Only present for recurring events.
 * }
 * @return null|bool True if event successfully scheduled. False for failure.
 */
function pre_get_scheduled_event( $pre, $hook, $args, $timestamp ) {
	$core_schedules = enforced_daily_schedules();

	if ( ! in_array( $hook, array_keys( $core_schedules ), true ) ) {
		return $pre;
	}

	$jobs = Job::get_jobs_by_query( [
		'hook' => $hook,
		'timestamp' => $timestamp,
		'args' => $args,
	] );

	if ( is_wp_error( $jobs ) || empty( $jobs ) ) {
		return false;
	}

	$job = $jobs[0];

	$date = new DateTime();
	$date->setTimestamp( $job->nextrun );
	$date->setTimezone( new DateTimeZone( get_option('timezone_string') ) );

	$date->modify( '-15 minutes' );
	$start = (int) $date->format( 'Hi' );
	$date->modify( '+30 minutes' );
	$end = (int) $date->format( 'Hi' );

	if (
		( $core_schedules[ $hook ] * 100 ) < $start ||
		( $core_schedules[ $hook ] * 100 ) > $end
	) {
		// Outside window, delete event and return false.
		wp_clear_scheduled_hook( $hook );
		return false;
	}

	/*
	 * Return $pre and allow Cavalcade to deal with object creation and
	 * dealing with any compatibility changes required for core.
	 */
	return $pre;
}

/**
 * Ensure core daily tasks are scheduled for night time.
 *
 * Ensure the following core hooks are scheduled to run at the specified time.
 * - wp_scheduled_delete: 2am
 * - wp_scheduled_auto_draft_delete: 3am
 * - delete_expired_transients: 4am
 *
 * @param stdClass $event {
 *     An object containing an event's data.
 *
 *     @type string       $hook      Action hook to execute when the event is run.
 *     @type int          $timestamp Unix timestamp (UTC) for when to next run the event.
 *     @type string|false $schedule  How often the event should subsequently recur.
 *     @type array        $args      Array containing each separate argument to pass to the hook's callback function.
 *     @type int          $interval  The interval time in seconds for the schedule. Only present for recurring events.
 * }
 */
function schedule_event( $event ) {
	$core_schedules = enforced_daily_schedules();

	if ( ! in_array( $event->hook, array_keys( $core_schedules ), true ) ) {
		return $event;
	}

	$date = new DateTime();
	$date->setTimestamp( $event->timestamp );
	$date->setTimezone( new DateTimeZone( get_option('timezone_string') ));
	$date->modify( sprintf( 'tomorrow %d hours', $core_schedules[ $event->hook ] ) );

	$date->setTime( $core_schedules[ $event->hook ], 0 );
	$event->timestamp = $date->getTimestamp();

	return $event;
}