<?php

/*
Plugin Name: blogroll2email
Plugin URI: https://github.com/petermolnar/blogroll2email
Description: Pulls RSS, Atom and microformats entries from blogroll links and sends them as email
Version: 0.1
Author: Peter Molnar <hello@petermolnar.eu>
Author URI: http://petermolnar.eu/
License: GPLv3
*/

/*  Copyright 2015 Peter Molnar ( hello@petermolnar.eu )

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License, version 3, as
	published by the Free Software Foundation.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

class blogroll2email {
	const revisit_time = 1800;
	const schedule = 'blogroll2email';

	var $schedule = null;

	public function __construct () {
		register_activation_hook( __FILE__ , array( &$this, 'plugin_activate' ) );
		register_deactivation_hook( __FILE__ , array( &$this, 'plugin_deactivate' ) );
		add_action( 'init', array( &$this, 'init'));
		add_filter( 'cron_schedules', array(&$this, 'add_cron_schedule' ));
	}

	public function init () {
		// additional cron schedules
		add_action( static::schedule, array( &$this, 'worker' ) );
		if (!wp_get_schedule( static::schedule ))
			wp_schedule_event ( time(), static::schedule, static::schedule );
		return false;
	}

	public function add_cron_schedule ( $schedules ) {

		$schedules[ static::schedule ] = array(
			'interval' => static::revisit_time,
			'display' => sprintf(__( 'every %d seconds' ), static::revisit_time )
		);

		return $schedules;
	}


	/**
	 * activation hook function, to be extended
	 */
	public function plugin_activate() {
		self::debug('activating');

	}

	/**
	 * deactivation hook function, to be extended
	 */
	public function plugin_deactivate () {
		self::debug('deactivating');
		wp_unschedule_event( time(), static::schedule );
		wp_clear_scheduled_hook( static::schedule );
	}

	public function worker () {
		self::debug('worker started');
		$args = array(
			'orderby' => 'owner',
			'order' => 'ASC',
			'limit' => -1,
		);

		$bookmarks = get_bookmarks( $args );

		$currowner = $owner = false;

		foreach ( $bookmarks as $bookmark ) {
			/* print_r ($bookmark);
				stdClass Object
				(
					[link_id] => 1
					[link_url] => http://devopsreactions.tumblr.com/
					[link_name] => http://devopsreactions.tumblr.com/
					[link_image] =>
					[link_target] =>
					[link_description] =>
					[link_visible] => Y
					[link_owner] => 1
					[link_rating] => 0
					[link_updated] => 0000-00-00 00:00:00
					[link_rel] =>
					[link_notes] =>
					[link_rss] => http://devopsreactions.tumblr.com/rss
				)
			*/

			if ( $currowner != $bookmark->link_owner) {
				$currowner = $bookmark->link_owner;
				$owner = get_userdata($currowner);
				$owner = $owner->data;
				/* print_r ( $owner );
				stdClass Object
				(
					[ID] => 1
					[user_login] => cadeyrn
					[user_pass] => $P$B.QI9GiDNyfXC7S75jJ4pcrQjx3awy/
					[user_nicename] => cadeyrn
					[user_email] => hello@petermolnar.eu
					[user_url] => https://petermolnar.eu/
					[user_registered] => 2014-04-28 21:36:35
					[user_activation_key] =>
					[user_status] => 0
					[display_name] => Peter Molnar
				)
				*/
			}

			if ( empty($bookmark->link_rss))
				$this->parse_mf ( $bookmark, $owner );
			else
				$this->parse_rss( $bookmark, $owner );
		}

		// reschedule the worker
		wp_schedule_single_event ( time() + static::revisit_time, static::schedule );
	}

	/**
	 *
	 */
	public function set_html_content_type() {
		return 'text/html';
	}

	/**
	 *
	 */
	protected function send ( $to, $link, $title, $fromname, $sourceurl, $content ) {

		add_filter( 'wp_mail_content_type', array( $this, 'set_html_content_type') );

		$body = '<html><head></head><h1><a href="'. $link .'">'. $title .'</a></h1><body>'. $content . '<p>URL: <a href="'.$link.'">'.$link.'</a></p></body></html>';

		$sitedomain = parse_url( get_bloginfo('url'), PHP_URL_HOST);

		$headers = array (
			'X-RSS-ID: ' . $link,
			'X-RSS-URL: ' . $link,
			'X-RSS-Feed: ' . $sourceurl,
			'User-Agent: blogroll2email',
			'From: "' . $fromname .'" <'. static::schedule . '@'. $sitedomain .'>',
		);

		self::debug('sending ' . $title . ' to ' . $to );
		wp_mail( $to, $title, $body, $headers );

		remove_filter( 'wp_mail_content_type', array( $this, 'set_html_content_type') );
	}

	/**
	 *
	 */
	protected function parse_rss ( $bookmark, $owner ) {

		if ( empty ($bookmark) || !is_object ($bookmark))
			return false;

		if ( empty ($owner) || !is_object ($owner))
			return false;

		if ( !class_exists('SimplePie') )
			require_once( ABSPATH . WPINC . '/class-simplepie.php' );

		$url = $bookmark->link_rss;
		$last_updated = strtotime( $bookmark->link_updated );

		error_log('Fetching: ' . $url );
		$feed = new SimplePie();
		$feed->set_feed_url( $url );
		$feed->set_cache_duration ( static::revisit_time );
		$feed->set_cache_location( WP_CONTENT_DIR . DIRECTORY_SEPARATOR. 'cache' );
		$feed->force_feed(true);

		// optimization
		$feed->enable_order_by_date(true);
		$feed->remove_div(false);
		$feed->strip_comments(true);
		$feed->strip_htmltags(false);
		$feed->strip_attributes(false);
		$feed->set_image_handler(false);

		$feed->init();
		$feed->handle_content_type();
		if ( $feed->error() )
			return new WP_Error( 'simplepie-error', $feed->error() );

		$maxitems = $feed->get_item_quantity( 12 );
		$feed_items = $feed->get_items( 0, $maxitems );
		$feed_title = $feed->get_title();

		if ( !empty($feed_title) && $bookmark->link_name != $feed_title ) {
			global $wpdb;
			$wpdb->update( $wpdb->prefix . 'links', array ( 'link_name' => $feed_title ), array('link_id'=> $bookmark->link_id ) );
		}

		$feed_author = $feed->get_author();

		if ( $maxitems > 0 ) {
			$last_updated_ = 0;
			foreach ( $feed_items as $item ) {
				$date = $item->get_date( 'U' );

				if ( $date > $last_updated ) {
					$from = $feed_title;
					$author = $item->get_author();
					if ($author)
						$from = $from . ': ' . $author->get_name();
					elseif ( $feed_author )
						$from = $from . ': ' . $feed_author->get_name();

					$this->send (
						$owner->user_email,
						$item->get_link(),
						$item->get_title(),
						$from,
						$url,
						$item->get_content()
					);

					if ( $date > $last_updated_ )
						$last_updated_ = $date;
				}
			}
		}

		$this->update_link_date ( $bookmark, $last_updated_ );
	}


	/***
	 *
	 */
	protected function parse_mf ( $bookmark, $owner ) {

		if ( empty ($bookmark) || !is_object ($bookmark))
			return false;

		if ( empty ($owner) || !is_object ($owner))
			return false;

		if ( !class_exists('Mf2') )
			require_once ( dirname(__FILE__) . '/lib/php-mf2/Mf2/Parser.php' );

		$last_updated = strtotime( $bookmark->link_updated );

		$url = $bookmark->link_url;

		//$hash = md5( $url );
		// check cache file and skip this step if exists ?

		$mf = Mf2\fetch($url,  true, $curlInfo);
		error_log('MF2 fetching: ' . $url );

		// check for rss, because it's older and more mature
		// if there is one, register it for the link and skip this run
		// in the next run, we'll parse the RSS
		if ( isset($mf['alternates']) && !empty($mf['alternates'])) {
			foreach ( $mf['alternates'] as $alternate ) {
				if ( 	isset($alternate['type']) &&
						!empty($alternate['type']) &&
						$alternate['type'] == 'application/rss+xml'
						&& isset($altenate['url']) &&
						!empty($alternate['ulr']) &&
						filter_var($alternate['ulr'], FILTER_VALIDATE_URL)
					) {
						global $wpdb;
						$wpdb->update( $wpdb->prefix . 'links', array ( 'link_rss' => $alternate['url'] ), array('link_id'=> $bookmark->link_id ) );
						return false;
					}
			}
		}

		$item = array ();

		foreach ($mf['items'] as $topitem ) {
			if ( in_array( 'h-feed', $topitem['type'])) {
				if ( !empty($topitem['children'])) {
					foreach ( $topitem['children'] as $entry ) {
						if ( in_array( 'h-entry', $entry['type']) ) {

							$properties = $entry['properties'];

							$title = $properties['name'][0];
							$url = $properties['url'][0];

							if ( isset($properties['updated']) && !empty($properties['updated']) )
								$date = $properties['updated'][0];
							else
								$date = $properties['published'][0];

							if ( isset($properties['content'][0]['html']) && !empty($properties['content'][0]['html']) )
								$content = $properties['content'][0]['html'];
							elseif ( isset($properties['summary'][0]['html']) && !empty($properties['summary'][0]['html']))
								$content = $properties['summary'][0]['html'] . '<h2><a href="'.$url.'">Read the full article &raquo;&raquo;</a></h2>';
							else
								$content = '<h1><a href="'.$url.'">'.$title.'</a></h1>';

							$time = strtotime( $date );

							$item = array (
								'url' => $url,
								'content' => $content,
								//'date' => $date,
								'title' => $title,
								//'author' =>
							);

							$items[ $time ] = $item;
						}
					}
				}
			}
		}

		if ( empty( $items ) )
			return false;

		$last_updated_ = 0;
		foreach ( $items as $time => $item ) {

			if ( $time > $last_updated ) {
				$this->send (
					$owner->user_email,
					$item['url'],
					$item['title'],
					$bookmark->link_name,
					$item['url'],
					$item['content']
				);

				if ( $time > $last_updated_ )
					$last_updated_ = $time;
			}
		}

		$this->update_link_date ( $bookmark, $last_updated_ );
	}

	/**
	 *
	 */
	protected function update_link_date ( $bookmark, $last_updated ) {
		$current_updated = strtotime( $bookmark->link_updated );
		if ( $last_updated > $current_updated ) {
			global $wpdb;
			$wpdb->update( $wpdb->prefix . 'links', array ( 'link_updated' => date( 'Y-m-d H:i:s', $last_updated )), array('link_id'=> $bookmark->link_id ) );
		}
	}

	/**
	 *
	 */
	static function debug( $message, $level = LOG_NOTICE ) {
		if ( @is_array( $message ) || @is_object ( $message ) )
			$message = json_encode($message);


		switch ( $level ) {
			case LOG_ERR :
				wp_die( '<h1>Error:</h1>' . '<p>' . $message . '</p>' );
				exit;
			default:
				if ( !defined( 'WP_DEBUG' ) || WP_DEBUG != true )
					return;
				break;
		}

		error_log(  __CLASS__ . ": " . $message );
	}


}

$blogroll2email = new blogroll2email();