<?php

/**
 * Search Engine : Search through all types of databap documents
 *
 * Procedure to add a new type in the search
 * - Add type in Databap->getItemTables()
 * - Add type in searched fields : SearchEngine->setResults()
 * - Add type in Databap->getItemList() and create a Databap->get<type>info()
 * - Add type text in Databap->getProfile()
 * - Consider the message types : add + edit in Databap->getMessages() and in chat.html
 */
class SearchEngine extends PhpObject
{
	/**
	 * DB Handle
	 * @var MySqlManager
	 */
	private $oMySql;

	//variables
	private $sWords;
	private $asItems;

	function __construct($oMySql)
	{
		parent::__construct(__CLASS__, Settings::DEBUG);
		$this->oMySql = $oMySql;
		$this->sWords = '';
		$this->asItems = array();
	}

	public function setWords($sSearchWords)
	{
		$this->oMySql->cleanSql($sSearchWords);
		$this->sWords = $sSearchWords;
		$this->setResults();
	}

	private function setResults()
	{
		$this->asItems = array();
		if($this->sWords != '')
		{
			$asSearches = array(
				Databap::CODE_TYPE	=> array(
					Databap::CODE_TABLE => array(MySqlManager::getText(Databap::CODE_TABLE), 'description')
				),
				Databap::PROC_TYPE	=> array(
					Databap::PROC_TABLE	=> array('title', 'description'),
					Databap::STEP_TABLE	=> array('description')
				),
				Databap::ART_TYPE	=> array(
					Databap::ART_TABLE	=> array('title')
				),
				Databap::DOC_TYPE	=> array(
					Databap::DOC_TABLE	=> array('title', 'description'),
					Databap::FILE_TABLE	=> array('description')
				),
				Databap::TABLE_TYPE=> array(
					Databap::TABL_TABLE	=> array('title', 'description', 'keywords')
				)
			);
			
			foreach($asSearches as $sType=>$asTables) {
				$sMainTableName = $sJoin = '';
				$asMatchAgainst = array();
				foreach($asTables as $sTableName=>$asFields) {
					if($sMainTableName=='')	{	//First table contains main object
						$sMainTableName = $sTableName;
						$sMainTableIdCol = MySqlManager::getId($sMainTableName);
						$sMainTableIdColFull = MySqlManager::getId($sMainTableName, true);
					}
					else {						//Other tables must be joined
						$sJoin .= "LEFT JOIN {$sTableName} ";
						if($this->oMySql->isColumnInTable($sTableName, $sMainTableIdCol))	$sJoin .= "USING({$sMainTableIdCol}) ";
						else 																$sJoin .= "ON {$sTableName}.id_item = {$sMainTableIdColFull} ";
					}
					
					$asMatchFields = array();
					foreach($asFields as $sField) $asMatchFields[] = MySqlManager::getFullColumnName($sTableName, $sField);
					$asMatchAgainst[] = "MATCH (".implode(',', $asMatchFields).") AGAINST ('".$this->sWords."' IN BOOLEAN MODE)";
				}
				
				$sGroupByCol = $this->oMySql->isColumnInTable($sMainTableName, 'refer_id')?'refer_id':$sMainTableIdColFull;
				
				$sQuery =	"SELECT MAX({$sMainTableIdColFull}) AS id_item, '{$sType}' AS type, (".(implode(" + ", $asMatchAgainst)).") AS rank ".
    						"FROM {$sMainTableName} ".
    						$sJoin.
    						"WHERE ".implode(" OR ", $asMatchAgainst)." ".
							"GROUP BY {$sGroupByCol}";

    			$asItems = $this->oMySql->getArrayQuery($sQuery, true);
    			foreach($asItems as $asItem) {
    				$asItem['rank'] = round($asItem['rank'] * 100);
    				$this->asItems[] = $asItem;
    			}
			}
		}
		
		
	}

	public function getResults()
	{
		usort($this->asItems, function($a, $b) {return ($a['rank'] < $b['rank']);});
		return $this->asItems;
	}
}

?>