Send notification to members when dripped content available

wpmudev_mp_dripped_content_notifications.php

<?php
/**
 * Plugin Name: Dripped content notifications
 * Version:     1.0
 * Description: Send notification to members when dripped content available
 * Author:      Panos Lyrakis (WPMU DEV)
 * Author URI:  https://premium.wpmudev.org/profile/panoskatws
 * Plugin URI:  https://premium.wpmudev.org/project/membership/
 * License:     GPL2
 * License URI: https://www.gnu.org/licenses/gpl-2.0.html
 */ 

if( ! class_exists( 'WPMUDEV_MS_Dripped_Content_Notification') ){

	class WPMUDEV_MS_Dripped_Content_Notification{

		private static $_instance = null;
		//Number of days
		private static $_closest_range;

		public static function get_instance() {
            if ( is_null( self::$_instance ) ) {
                self::$_instance = new WPMUDEV_MS_Dripped_Content_Notification();
            }

            return self::$_instance;
        }


        private function __construct() {

            if( ! class_exists( 'MS_Model_Membership' ) ){
                return;
            }

        	self::$_closest_range = apply_filters( 'WPMUDEV_MS_Dripped_Content_Notification/closest_range', 0 );        	

        	add_action('init', array( $this, 'shcedule_notifications' ) );
        	add_action( 'ms_set_dripped_content_items', array( $this, 'set_unsent_dripped_notifications' ), 10 );
        	add_action( 'ms_send_dripped_content_notification', array( $this, 'send_notifications' ), 10 );
        	
        }


        public function send_notifications(){

        	$emails_limit = apply_filters( 'WPMUDEV_MS_Dripped_Content_Notification/emails_limit', 50 );

        	$emails_count = 0;

        	$unsent_items = $this->_load_unsent_items();

        	foreach ( $unsent_items as $user_key => $item ) {

        		if( $this->send_notification( $item ) ){                    
        			unset( $unsent_items[ $user_key ] );        			
        		}

        		$emails_count++;
        		if( $emails_count == $emails_limit ){
        			break;
        		}
        		
        	}

        	$this->_update_unsent_notifications( $unsent_items );
            return;
        }


        public function send_notification( $item ){

        	$user = $item[ 'user' ];
        	$pages = $item[ 'pages' ];

        	$subject = apply_filters( 'WPMUDEV_MS_Dripped_Content_Notification/notification_subject', __( 'Brand new stuff to checkout' ) );
        	$message = $this->get_notification_content( $pages, $user );
        	$headers = array();

        	$content_type = apply_filters(
				'ms_model_communication_set_html_content_type',
				'text/html'
			);

			$headers[] = sprintf(
				'Content-Type: %s; charset="UTF-8"',
				$content_type
			);

			$admin_emails = MS_Model_Member::get_admin_user_emails();
			if ( ! empty( $admin_emails[0] ) ) {
				$headers[] = sprintf(
					'From: %s <%s> ',
					get_option( 'blogname' ),
					$admin_emails[0]
				);
			}

        	$headers = apply_filters(
				'ms_model_communication_send_message_headers',
				$headers
			);

			$sent = wp_mail( $user->user_email, $subject, $message, $headers );

            if( $sent ){

                $user_key = 'dripped_pages_list_sent';
                $sent_pages_list = get_user_meta($user->ID, $user_key, true );
                $new_sent_pages_list = array_keys( $pages );

                if( empty( $sent_pages_list ) ){
                    $sent_pages_list = $new_sent_pages_list;
                }
                else{
                    $sent_pages_list = array_merge( $sent_pages_list, $new_sent_pages_list );
                }

                update_user_meta($user->ID, $user_key, $sent_pages_list );

            }
            
            return $sent;

        }


        public function get_notification_content( $pages, $user ){        	

        	$content = __( 'Hi there ' ) . $user->display_name . ',<br />';

        	$content .= __( 'For your eyes only' ) . '<br />';

        	foreach( $pages as $page ){
        		$content .= '<p>';
        			$content .= '<h4>' . $page[ 'page_title' ] . '</h4>';
        			$content .= $page[ 'page_excerpt' ] . '<a href="' . $page[ 'page_link' ] . '">' . __( 'More' ) . '</a>';
        		$content .= '</p>';
        	}

        	return apply_filters( 'WPMUDEV_MS_Dripped_Content_Notification/notification_content', $content, $pages, $user );

        }


        public function set_unsent_dripped_notifications(){
            
			//delete_option( 'ms_unsent_dripped_items_notifications' );
        	$unsent_items = $this->_load_unsent_items();

        	$dripped_items = $this->_get_unsent_notifications();

        	if( is_array( $dripped_items ) && ! empty( $dripped_items ) ){
        		$dripped_items = array_merge( $dripped_items, $unsent_items );	
        	}
        	else{
        		$dripped_items = $unsent_items;
        	}

        	$this->_update_unsent_notifications( $dripped_items );
        	
        }


        private function _update_unsent_notifications( $dripped_items ){

        	update_option( 'ms_unsent_dripped_items_notifications', '' );
        	//wp_cache_set( 'ms_unsent_dripped_items_notifications', $dripped_items );

        }


        private function _get_unsent_notifications(){

        	//$dripped_items = wp_cache_get( 'ms_unsent_dripped_items_notifications' );

        	//if( ! $dripped_items ){

        		$dripped_items = get_option( 'ms_unsent_dripped_items_notifications' );
        		//wp_cache_set( 'ms_unsent_dripped_items_notifications', $dripped_items );

        	//}

        	return $dripped_items;

        }



        private function _load_unsent_items(){

        	$memberships = MS_Model_Membership::get_memberships();
        	if( empty( $memberships ) ){
        		return;
        	}

        	$unsent_items = array();

        	foreach( $memberships as $membership ){
        		
        		if( $membership->type == 'dripped' ){

        			$members = $membership->get_members();
        			if( empty( $members ) ){
        				continue;
        			}

        			$rules = $membership->_rules;
        			$dripped_pages = $rules['page'];

        			foreach( $dripped_pages->dripped as $page_id => $rule ){

        				foreach ( $members as $member ) {
        					
        					if( $this->_ok_to_add_rule_to_member_list( $rule, $member, $membership->id ) && $this->_ok_to_send_page( $page_id, $member->id ) ){

        						$member_id 				= $member->id;        						
        						$user 					= $member->wp_user;

        						if( ! isset( $unsent_items[ 'user-' . $member_id ][ 'user' ] ) ){
	        						$unsent_items[ 'user-' . $member_id ][ 'user' ] = $user->data;
	        					}

        						$unsent_items[ 'user-' . $member_id ][ 'pages' ][ $page_id ] = array(
        							'page_title' 	=> get_the_title( $page_id ),
        							'page_excerpt'	=> $this->get_page_description( $page_id ),
        							'page_link'		=> get_permalink( $page_id )
        						);

	        				}

        				}
        				
        			}

        		}

        	}

        	return $unsent_items;
        }


        public function get_page_description( $page_id ){

        	$excerpt = get_the_excerpt( $page_id );

        	if( $excerpt != '' ){
        		return $excerpt;
        	}

        	$page = get_post( $page_id );
        	$description_words_count = apply_filters( 'WPMUDEV_MS_Dripped_Content_Notification/page_description_words_count', 50 );
        	return wp_trim_words( strip_tags( $page->post_content ), $description_words_count );
			//return apply_filters( 'the_content', wp_trim_words( strip_tags( $page->post_content ), $description_words_count ) );

        }


        private function _ok_to_add_rule_to_member_list( $rule, $member, $membership_id ){

        	$today_start = new DateTime( date('Y-m-d', time() ) . '00:00:00' ); 			

        	switch( $rule['type'] ){
        		case 'specific_date': 

        			$page_start = new DateTime( $rule['date'] . '00:00:00' );
        			$days_diff = $page_start->diff( $today_start );

        			if( $days_diff->days <= self::$_closest_range ){
        				return true;
        			}

        		break;

        		case 'from_registration': 

        			$subscription = $member->get_subscription( $membership_id );
        			$subscription_start = new DateTime( $subscription->start_date . '00:00:00' );
        			$days_diff = $subscription_start->diff( $today_start );
        			
        			if( $days_diff->days <= self::$_closest_range ){
        				return true;
        			}

        		break;

        		case 'instantly': 
        			return true;
        		break;
        	}

        	return false;

        }


        private function _ok_to_send_page( $page_id, $user_id ){

        	//$page_sent = get_post_meta( $page_id, 'ms_dripped_item_notified', true );
            $user_key = 'dripped_pages_list_sent';
            $sent_pages_list = get_user_meta( $user_id, $user_key, true );

            if( is_array( $sent_pages_list ) && in_array( $page_id, $sent_pages_list ) ){
        		return false;
        	}

        	return true;

        }


        public function shcedule_notifications(){

			$setter_interval = apply_filters( 'WPMUDEV_MS_Dripped_Content_Notification/setter_interval', 'daily' );
			$sender_interval = apply_filters( 'WPMUDEV_MS_Dripped_Content_Notification/sender_interval', 'hourly' );

			if( !wp_next_scheduled( 'ms_set_dripped_content_items' ) ) {  
			   wp_schedule_event( time(), $setter_interval, 'ms_set_dripped_content_items' );  
			}

			if( !wp_next_scheduled( 'ms_send_dripped_content_notification' ) ) {  
			   wp_schedule_event( time(), $sender_interval, 'ms_send_dripped_content_notification' );  
			}

		}

	}

	add_action( 'plugins_loaded', function(){
		$GLOBALS['WPMUDEV_MS_Dripped_Content_Notification'] = WPMUDEV_MS_Dripped_Content_Notification::get_instance();
	} );

}