<?php

abstract class YARPP_Cache {

	protected $core;
	public $score_override = false;
	public $online_limit = false;
	public $last_sql;
	protected $yarpp_time = false;

	function __construct( &$core ) {
		$this->core = &$core;
		$this->name = __($this->name, 'yarpp');
	}
	
	function add_signature( $query ) {
		$query->yarpp_cache_type = $this->name;
	}
	
	/**
	 * GENERAL CACHE CONTROL
	 */
	public function is_yarpp_time() {
		return $this->yarpp_time;
	}

	public function flush() {
	}
	
	public function setup() {
	}
	
	public function upgrade( $last_version ) {
	}
	
	/**
	 * POST CACHE CONTROL
	 */
	// Note: return value changed in 3.4
	// return YARPP_NO_RELATED | YARPP_RELATED | YARPP_DONT_RUN | false if no good input
	function enforce( $reference_ID, $force = false ) {
		// @since 3.5.3: don't compute on revisions
		if ( $the_post = wp_is_post_revision($reference_ID) )
			$reference_ID = $the_post;

		if ( !is_int( $reference_ID ) )
			return false;
	
		$status = $this->is_cached($reference_ID);
		$status = apply_filters( 'yarpp_cache_enforce_status', $status, $reference_ID );
	
		// There's a stop signal:
		if ( YARPP_DONT_RUN === $status )
			return YARPP_DONT_RUN;
	
		// If not cached, process now:
		if ( YARPP_NOT_CACHED == $status || $force )
			$status = $this->update((int) $reference_ID);
			// status now will be YARPP_NO_RELATED | YARPP_RELATED
	
		// There are no related posts
		if ( YARPP_NO_RELATED === $status )
			return YARPP_NO_RELATED;
	
		// There are results
		return YARPP_RELATED;
	}
	
	// @return YARPP_NO_RELATED | YARPP_RELATED | YARPP_NOT_CACHED
	public function is_cached($reference_ID) {
		return YARPP_NOT_CACHED;
	}

	public function clear($reference_ID) {
	}
	
	/**
	 * POST STATUS INTERACTIONS
	 */
	
	// Clear the cache for this entry and for all posts which are "related" to it.
	// New in 3.2: This is called when a post is deleted.
	function delete_post( $post_ID ) {
		// Clear the cache for this post.
		$this->clear((int) $post_ID);
	
		// Find all "peers" which list this post as a related post and clear their caches
		if ( $peers = $this->related(null, (int) $post_ID) )
			$this->clear($peers);
	}
	
	// New in 3.2.1: handle various post_status transitions
	function transition_post_status( $new_status, $old_status, $post ) {
		$post_ID = $post->ID;

		// @since 3.4: don't compute on revisions
		// @since 3.5: compute on the parent instead
		if ( $the_post = wp_is_post_revision($post_ID) )
			$post_ID = $the_post;

		// unpublish
		if ( $old_status == 'publish' && $new_status != 'publish' ) {
			// Find all "peers" which list this post as a related post and clear their caches
			if ( $peers = $this->related(null, (int) $post_ID) )
				$this->clear($peers);
		}
		
		// publish
		if ( $old_status != 'publish' && $new_status == 'publish' ) {
			// find everything which is related to this post, and clear them, so that this
			// post might show up as related to them.
			if ( $related = $this->related($post_ID, null) )
				$this->clear($related);
		}

		// @since 3.4: simply clear the cache on save; don't recompute.
		$this->clear((int) $post_ID);
	}
	
	function set_score_override_flag( $q ) {
		if ( $this->is_yarpp_time() ) {
			$this->score_override = ($q->query_vars['orderby'] == 'score');
	
			if (!empty($q->query_vars['showposts'])) {
				$this->online_limit = $q->query_vars['showposts'];
			} else {
				$this->online_limit = false;
			}
		} else {
			$this->score_override = false;
			$this->online_limit = false;
		}
	}

	/**
	 * SQL!
	 */

	protected function sql( $reference_ID = false, $args = array() ) {
		global $wpdb, $post;
	
		if ( is_object($post) && !$reference_ID ) {
			$reference_ID = $post->ID;
		}
		
		if ( !is_object($post) || $reference_ID != $post->ID ) {
			$reference_post = get_post( $reference_ID );
		} else {
			$reference_post = $post;
		}
	
		$options = array( 'threshold', 'show_pass_post', 'past_only', 'weight', 'require_tax', 'exclude', 'recent', 'limit' );
		extract( $this->core->parse_args($args, $options) );
		// The maximum number of items we'll ever want to cache
		$limit = max($limit, $this->core->get_option('rss_limit'));
	
		// Fetch keywords
		$keywords = $this->get_keywords($reference_ID);
	
		// SELECT
		$newsql = "SELECT $reference_ID as reference_ID, ID, "; //post_title, post_date, post_content, post_excerpt,
	
		$newsql .= 'ROUND(0';
	
		if ((int) @$weight['body'])
			$newsql .= " + (MATCH (post_content) AGAINST ('".$wpdb->escape($keywords['body'])."')) * ". absint($weight['body']);
		if ((int) @$weight['title'])
			$newsql .= " + (MATCH (post_title) AGAINST ('".$wpdb->escape($keywords['title'])."')) * ". absint($weight['title']);
	
		// Build tax criteria query parts based on the weights
		foreach ( (array) $weight['tax'] as $tax => $tax_weight ) {
			$newsql .= " + " . $this->tax_criteria($reference_ID, $tax) . " * " . intval($tax_weight);
		}
	
		$newsql .= ',1) as score';
	
		$newsql .= "\n from $wpdb->posts \n";
	
		$exclude_tt_ids = wp_parse_id_list( $exclude );
		if ( count($exclude_tt_ids) || count((array) $weight['tax']) || count($require_tax) ) {
			$newsql .= "left join $wpdb->term_relationships as terms on ( terms.object_id = $wpdb->posts.ID ) \n";
		}
	
		// WHERE
	
		$newsql .= " where post_status in ( 'publish', 'static' ) and ID != '$reference_ID'";
	
		if ($past_only) // 3.1.8: revised $past_only option
			$newsql .= " and post_date <= '$reference_post->post_date' ";
		if ( !$show_pass_post )
			$newsql .= " and post_password ='' ";
		if ( !!$recent )
			$newsql .= " and post_date > date_sub(now(), interval {$recent}) ";
	
		$newsql .= " and post_type = 'post'";
	
		// GROUP BY
		$newsql .= "\n group by ID \n";
	
		// HAVING
		// number_format fix suggested by vkovalcik! :)
		$safethreshold = number_format(max($threshold,0.1), 2, '.', '');
		// @since 3.5.3: ID=0 is a special value; never save such a result.
		$newsql .= " having score >= $safethreshold and ID != 0";
		if ( count($exclude_tt_ids) ) {
			$newsql .= " and bit_or(terms.term_taxonomy_id in (" . join(',', $exclude_tt_ids) . ")) = 0";
		}
	
		foreach ( (array) $require_tax as $tax => $number ) {
			$newsql .= ' and ' . $this->tax_criteria($reference_ID, $tax) . ' >= ' . intval($number);
		}
	
		$newsql .= " order by score desc limit $limit";
	
		if ( isset($args['post_type']) )
			$post_types = (array) $args['post_type'];
		else
			$post_types = $this->core->get_post_types();

		$queries = array();
		foreach ( $post_types as $post_type ) {
			$queries[] = '(' . str_replace("post_type = 'post'", "post_type = '{$post_type}'", $newsql) . ')';
		}
		$sql = implode( ' union ', $queries );
	
		if ($this->core->debug) echo "<!--$sql-->";
		
		$this->last_sql = $sql;
		
		return $sql;
	}
	
	private function tax_criteria( $reference_ID, $taxonomy ) {
		// @todo maybe reinforce the object term cache?
		$terms = get_the_terms( $reference_ID, $taxonomy );
		// if there are no terms of that tax
		if ( false === $terms )
			return '(1 = 0)';
		
		$tt_ids = wp_list_pluck($terms, 'term_taxonomy_id');
		return "count(distinct if( terms.term_taxonomy_id in (" . join(',',$tt_ids) .  "), terms.term_taxonomy_id, null ))";
	}

	/**
	 * KEYWORDS
	 */
	 
	// @param $ID (int)
	// @param $type (string) body | title | all
	// @return (string|array) depending on whether "all" were requested or not
	public function get_keywords( $ID, $type = 'all' ) {
		if ( !$ID = absint($ID) )
			return false;

		$keywords = array(
			'body' => $this->body_keywords($ID),
			'title' => $this->title_keywords($ID)
		);

		if ( empty($keywords) )
			return false;
		
		if ( 'all' == $type )
			return $keywords;
		return $keywords[$type];
	}
	
	protected function title_keywords( $ID, $max = 20 ) {
		return apply_filters( 'yarpp_title_keywords',
			$this->extract_keywords( get_the_title($ID), $max, $ID ), $max, $ID );
	}
	
	protected function body_keywords( $ID, $max = 20 ) {
		$post = get_post( $ID );
		if ( empty($post) )
			return '';
		$content = $this->apply_filters_if_white( 'the_content', $post->post_content );
		return apply_filters( 'yarpp_body_keywords',
			$this->extract_keywords( $content, $max, $ID ), $max, $ID );

	}
	
	private function extract_keywords( $html, $max = 20, $ID = 0 ) {
	
		/**
		 * @filter yarpp_extract_keywords
		 *
		 * Use this filter to override YARPP's built-in keyword computation
		 * Return values should be a string of space-delimited words
		 *
		 * @param $keywords
		 * @param $html unfiltered HTML content
		 * @param (int) $max maximum number of keywords
		 * @param (int) $ID
		 */
		if ( $keywords = apply_filters( 'yarpp_extract_keywords', false, $html, $max, $ID ) )
			return $keywords;
	
		$lang = 'en_US';
		if ( defined('WPLANG') ) {
			switch ( substr(WPLANG, 0, 2) ) {
				case 'de':
					$lang = 'de_DE';
				case 'it':
					$lang = 'it_IT';
				case 'pl':
					$lang = 'pl_PL';
				case 'bg':
					$lang = 'bg_BG';
				case 'fr':
					$lang = 'fr_FR';
				case 'cs':
					$lang = 'cs_CZ';
				case 'nl':
					$lang = 'nl_NL';
				default:
					$lang = 'en_US';
			}
		}
	
		$words_file = YARPP_DIR . '/lang/words-' . $lang . '.php';
		if ( file_exists($words_file) )
			include( $words_file );
		if ( !isset($overusedwords) )
			$overusedwords = array();
	
		// strip tags and html entities
		$text = preg_replace('/&(#x[0-9a-f]+|#[0-9]+|[a-zA-Z]+);/', '', strip_tags($html) );
	
		// 3.2.2: ignore soft hyphens
		// Requires PHP 5: http://bugs.php.net/bug.php?id=25670
		$softhyphen = html_entity_decode('&#173;',ENT_NOQUOTES,'UTF-8');
		$text = str_replace($softhyphen, '', $text);
	
		$charset = get_option('blog_charset');
		if ( function_exists('mb_split') && !empty($charset) ) {
			mb_regex_encoding($charset);
			$wordlist = mb_split('\s*\W+\s*', mb_strtolower($text, $charset));
		} else
			$wordlist = preg_split('%\s*\W+\s*%', strtolower($text));
	
		// Build an array of the unique words and number of times they occur.
		$tokens = array_count_values($wordlist);
	
		// Remove the stop words from the list.
		$overusedwords = apply_filters( 'yarpp_keywords_overused_words', $overusedwords );
		if ( is_array($overusedwords) ) {
			foreach ($overusedwords as $word) {
				 unset($tokens[$word]);
			}
		}
		// Remove words which are only a letter
		foreach (array_keys($tokens) as $word) {
			if ( function_exists('mb_strlen') )
				if (mb_strlen($word) < 2) unset($tokens[$word]);
			else
				if (strlen($word) < 2) unset($tokens[$word]);
		}
	
		arsort($tokens, SORT_NUMERIC);
	
		$types = array_keys($tokens);
	
		if (count($types) > $max)
			$types = array_slice($types, 0, $max);
		return implode(' ', $types);
	}
	
	/* new in 2.0! apply_filters_if_white (previously apply_filters_without) now has a blacklist.
	 * It can be modified via the yarpp_blacklist and yarpp_blackmethods filters.
	 */
	/* blacklisted so far:
		- diggZ-Et
		- reddZ-Et
		- dzoneZ-Et
		- WP-Syntax
		- Viper's Video Quicktags
		- WP-CodeBox
		- WP shortcodes
		- WP Greet Box
		- Jetpack ShareDaddy
		//- Tweet This - could not reproduce problem.
	*/
	function white( $filter ) {
		static $blacklist, $blackmethods;
	
		if ( is_null($blacklist) || is_null($blackmethods) ) {
			$yarpp_blacklist = array('diggZEt_AddBut', 'reddZEt_AddBut', 'dzoneZEt_AddBut', 'wp_syntax_before_filter', 'wp_syntax_after_filter', 'wp_codebox_before_filter', 'wp_codebox_after_filter', 'do_shortcode', 'sharing_display');//,'insert_tweet_this'
			$yarpp_blackmethods = array('addinlinejs', 'replacebbcode', 'filter_content');
		
			$blacklist = (array) apply_filters( 'yarpp_blacklist', $yarpp_blacklist );
			$blackmethods = (array) apply_filters( 'yarpp_blackmethods', $yarpp_blackmethods );
		}
		
		if ( is_array($filter) && is_a( $filter[0], 'YARPP' ) )
			return false;
		if ( is_array($filter) && in_array( $filter[1], $blackmethods ) )
			return false;
		return !in_array( $filter, $blacklist );
	}
	
	/* FYI, apply_filters_if_white was used here to avoid a loop in apply_filters('the_content') > YARPP::the_content() > YARPP::related() > YARPP_Cache::body_keywords() > apply_filters('the_content').*/
	function apply_filters_if_white($tag, $value) {
		global $wp_filter, $merged_filters, $wp_current_filter;
	
		$args = array();
	
		// Do 'all' actions first
		if ( isset($wp_filter['all']) ) {
			$wp_current_filter[] = $tag;
			$args = func_get_args();
			_wp_call_all_hook($args);
		}
	
		if ( !isset($wp_filter[$tag]) ) {
			if ( isset($wp_filter['all']) )
				array_pop($wp_current_filter);
			return $value;
		}
	
		if ( !isset($wp_filter['all']) )
			$wp_current_filter[] = $tag;
	
		// Sort
		if ( !isset( $merged_filters[ $tag ] ) ) {
			ksort($wp_filter[$tag]);
			$merged_filters[ $tag ] = true;
		}
	
		reset( $wp_filter[ $tag ] );
	
		if ( empty($args) )
			$args = func_get_args();
	
		do {
			foreach( (array) current($wp_filter[$tag]) as $the_ )
				if ( !is_null($the_['function'])
				and $this->white($the_['function'])){ // HACK
					$args[1] = $value;
					$value = call_user_func_array($the_['function'], array_slice($args, 1, (int) $the_['accepted_args']));
				}
	
		} while ( next($wp_filter[$tag]) !== false );
	
		array_pop( $wp_current_filter );
	
		return $value;
	}
}

class YARPP_Cache_Bypass extends YARPP_Cache {

	public $name = "bypass";

	// variables used for lookup
	private $related_postdata = array();
	private $related_IDs = array();

	public $demo_time = false;
	private $demo_limit = 0;

	/**
	 * SETUP/STATUS
	 */
	function __construct( &$core ) {
		parent::__construct( $core );
	}

	public function is_enabled() {
		return true; // always enabled.
	}

	public function cache_status() {
		return 0; // always uncached
	}

	public function stats() {
		return array(); // always unknown
	}

	public function uncached($limit = 20, $offset = 0) {
		return array(); // nothing to cache
	}

	/**
	 * MAGIC FILTERS
	 */
	public function where_filter($arg) {
		global $wpdb;
		// modify the where clause to use the related ID list.
		if (!count($this->related_IDs))
			$this->related_IDs = array(0);
		$arg = preg_replace("!{$wpdb->posts}.ID = \d+!","{$wpdb->posts}.ID in (".join(',',$this->related_IDs).")",$arg);

		// if we have recent set, add an additional condition
		if ( !!$this->args['recent'] )
			$arg .= " and post_date > date_sub(now(), interval {$this->args['recent']}) ";
		return $arg;
	}

	public function orderby_filter($arg) {
		global $wpdb;
		// only order by score if the score function is added in fields_filter, which only happens
		// if there are related posts in the postdata
		if ($this->score_override &&
		    is_array($this->related_postdata) && count($this->related_postdata))
			return str_replace("$wpdb->posts.post_date","score",$arg);
		return $arg;
	}

	public function fields_filter($arg) {
		global $wpdb;
		if (is_array($this->related_postdata) && count($this->related_postdata)) {
			$scores = array();
			foreach ($this->related_postdata as $related_entry) {
				$scores[] = " WHEN {$related_entry['ID']} THEN {$related_entry['score']}";
			}
			$arg .= ", CASE {$wpdb->posts}.ID" . join('',$scores) ." END as score";
		}
		return $arg;
	}

	public function demo_request_filter($arg) {
		global $wpdb;
		$wpdb->query("set @count = 0;");

		$loremipsum = 'Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Cras tincidunt justo a urna. Ut turpis. Phasellus convallis, odio sit amet cursus convallis, eros orci scelerisque velit, ut sodales neque nisl at ante. Suspendisse metus. Curabitur auctor pede quis mi. Pellentesque lorem justo, condimentum ac, dapibus sit amet, ornare et, erat. Quisque velit. Etiam sodales dui feugiat neque suscipit bibendum. Integer mattis. Nullam et ante non sem commodo malesuada. Pellentesque ultrices fermentum lectus. Maecenas hendrerit neque ac est. Fusce tortor mi, tristique sed, cursus at, pellentesque non, dui. Suspendisse potenti.';

		return "SELECT SQL_CALC_FOUND_ROWS ID + {$this->demo_limit} as ID, post_author, post_date, post_date_gmt, '{$loremipsum}' as post_content,
		concat('".__('Example post ','yarpp')."',@count:=@count+1) as post_title, 0 as post_category, '' as post_excerpt, 'publish' as post_status, 'open' as comment_status, 'open' as ping_status, '' as post_password, concat('example-post-',@count) as post_name, '' as to_ping, '' as pinged, post_modified, post_modified_gmt, '' as post_content_filtered, 0 as post_parent, concat('PERMALINK',@count) as guid, 0 as menu_order, 'post' as post_type, '' as post_mime_type, 0 as comment_count, 'SCORE' as score
		FROM $wpdb->posts
		ORDER BY ID DESC LIMIT 0, {$this->demo_limit}";
	}

	public function limit_filter($arg) {
		global $wpdb;
		if ($this->online_limit)
			return " limit {$this->online_limit} ";
		return $arg;
	}

	/**
	 * RELATEDNESS CACHE CONTROL
	 */	 
	public function begin_yarpp_time( $reference_ID, $args ) {
		global $wpdb;

		$this->yarpp_time = true;
		$options = array( 'threshold', 'show_pass_post', 'past_only', 'weight', 'require_tax', 'exclude', 'recent', 'limit' );
		$this->args = $this->core->parse_args($args, $options);

		$this->related_postdata = $wpdb->get_results($this->sql($reference_ID, $args), ARRAY_A);
		$this->related_IDs = wp_list_pluck( $this->related_postdata, 'ID' );

		add_filter('posts_where',array(&$this,'where_filter'));
		add_filter('posts_orderby',array(&$this,'orderby_filter'));
		add_filter('posts_fields',array(&$this,'fields_filter'));
		add_filter('post_limits',array(&$this,'limit_filter'));
		add_action('pre_get_posts',array(&$this,'add_signature'));
		// sets the score override flag.
		add_action('parse_query',array(&$this,'set_score_override_flag'));
	}
	
	public function begin_demo_time( $limit ) {
		$this->demo_time = true;
		$this->demo_limit = $limit;
		add_action('pre_get_posts',array(&$this,'add_signature'));
		add_filter('posts_request',array(&$this,'demo_request_filter'));
	}

	public function end_yarpp_time() {
		$this->yarpp_time = false;
		remove_filter('posts_where',array(&$this,'where_filter'));
		remove_filter('posts_orderby',array(&$this,'orderby_filter'));
		remove_filter('posts_fields',array(&$this,'fields_filter'));
		remove_filter('post_limits',array(&$this,'limit_filter'));
		remove_action('pre_get_posts',array(&$this,'add_signature'));
		remove_action('parse_query',array(&$this,'set_score_override_flag'));
	}
	
	public function end_demo_time() {
		$this->demo_time = false;
		remove_action('pre_get_posts',array(&$this,'add_signature'));
		remove_filter('posts_request',array(&$this,'demo_request_filter'));
	}

	// @return YARPP_NO_RELATED | YARPP_RELATED
	// @used by enforce
	protected function update($reference_ID) {
		global $wpdb;

		return YARPP_RELATED;
	}

	public function related($reference_ID = null, $related_ID = null) {
		global $wpdb;

		if ( !is_int( $reference_ID ) && !is_int( $related_ID ) ) {
			_doing_it_wrong( __METHOD__, 'reference ID and/or related ID must be set', '3.4' );
			return;
		}

		// reverse lookup
		if ( is_int($related_ID) && is_null($reference_ID) ) {
			_doing_it_wrong( __METHOD__, 'YARPP_Cache_Bypass::related cannot do a reverse lookup', '3.4' );
			return;
		}

		$results = $wpdb->get_results($this->sql($reference_ID), ARRAY_A);
		if ( !$results || !count($results) )
			return false;
			
		$results_ids = wp_list_pluck( $results, 'ID' );
		if ( is_null($related_ID) ) {
			return $results_ids;
		} else {
			return in_array( $related_ID, $results_ids );
		}
	}
}