<?php

/**
 * Used to search the database for results
 *
 * @since      1.0.0
 *
 * @package    @package Ajax Live Search
 * @subpackage Als/includes
 */

 
/**
 * The main search class
 * @since      1.0.0
 *
 * @package    Als
 * @subpackage Als/includes
 */
 

class Als_Search {

	/**
	 * Search cache
	 *
	 * @since    2.3.3
	 * @access   private
	 * @var      array
	 */
	private $cache = array();


	/**
	 * Class constructor
	 *
	 * @param $s the query string to search for
	 * @since    1.0.0
	 */
	public function __construct() {		
		$this->cache = array();
	} 

	/**
	 * Search for the user query
	 *
	 * 1. Sanitize the string
	 * 2. Strip stop words
	 * 3. Fetch the posts using the new string
	 *
	 * @since    1.0.0
	 * @param    string               $q            The phrase to search for
	 */
	public function search( $q ){
		global $wpdb;
		
		//Is it in the cache?
		If (array_key_exists( $q, $this->cache )){
			return $this->cache[$q];
		}


		$s = $wpdb->prepare('%s', $q);
		$post_ids =  apply_filters( 'als_found_post_ids', $this->posts_with( $s, $q ), $s);

		if (!is_array($post_ids)){
			$post_ids = array();
		}
		
		if( 3 < strlen($s)){
			$this->log_query( $s, count($post_ids));
		}
		
		$this->cache[$s] = $post_ids;
		return $post_ids;
		
	}
	
	/**
	 * Uses MySQL's fulltext to search for posts containing the search string
	 *
	 *
	 * @since    1.0.0
	 * @param    string               $s           sanitised string to search for
	 * @param    string               $q           unsanitised string to search for
	 * @return array with ids of posts arranged according to relevance
	 */
	private function posts_with( $s ){
		global $wpdb;

		$posts 			= array();	
		$post_types 	= array_unique(als_index_post_types());
		$title_weight 	= intval(get_option('als_title_weight',15));
		$content_weight = intval(get_option('als_content_weight',1));
		$q 				= $wpdb->prepare('%s', als_remove_punct(als_remove_modifiers($s)));
		$order_by 		= 'post__in';
		$order 			= 'ORDER BY score DESC';
		$score_field 	= "(((MATCH(post_title) AGAINST($q) * $title_weight) + 
		(MATCH(post_title,post_content) AGAINST($q) * $content_weight)) + 
		(IF(comment_count = 0, 0, log(comment_count)+0.5)) + 
		(log(DATEDIFF(NOW(), post_modified)+1))
		";

				
		// Weight based on post types			
		$score_field .= '+(';				
		foreach($post_types as $type){
			$type 			= strtolower($type);
			$weight 		= "als_{$type}_weight";
			$weight 		= get_option($weight, 1);
			$score_field 	.= "((post_type IN('$type'))*$weight)+";					
		}				
		$score_field .= '0)) as score'; //Simple way to take care of final +

		//Filter by post type
		$new_array = array();
		foreach( $post_types as $type ){
			$new_array[] = "'$type'";
		}		
		$post_types = implode(',', $new_array);
		$restrictions = "WHERE MATCH(post_title, post_content) AGAINST ($q IN BOOLEAN MODE) ";
		$restrictions .= "AND post_type in($post_types) AND post_status='publish'";
		
		//The final sql statement
        $sql = "SELECT ID, $score_field FROM {$wpdb->posts} $restrictions ORDER BY score DESC LIMIT 100";	
		$results = $wpdb->query($sql);
		$results = $wpdb->last_result; //Here is a workaround(for the time being)
		
		foreach($results as $single){
			$posts[] = $single->ID;
		}
		return $posts;
			

	}
	
	/**
	 * Save the search term with its results
	 *
	 *
	 * @since    1.0.0
	 * @param    string               $s            array of words
	 * @param    int               $count            number of results
	 */
	private function log_query( $s, $count = 0 ){
		global $wpdb;
		$searches_log_table = $wpdb->prefix . "als_log";
		$count = intval($count);
		$modified = $wpdb->prepare("(%s)", als_remove_punct(als_remove_modifiers($s)));
		$original = $wpdb->prepare("(%s)", $s);

		$exists = "SELECT searches as searches FROM $searches_log_table WHERE LOWER(query)=LOWER($original)";	
		$exists = $wpdb->get_results($exists);
		
		if(count($exists) < 1) {
			$sql = "INSERT IGNORE INTO $searches_log_table (query, modified, hits)
			VALUES ($original, $modified,$count)";
			
			return $wpdb->query($sql);
		} else {
			$searches = intval($exists[0]->searches) + 1;
			$sql = "UPDATE $searches_log_table SET searches=$searches, hits=$count WHERE LOWER(query)=LOWER($original)";
			
			return $wpdb->query($sql);
		}
	}

}