<?php
  /*¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯*\
|                Abstract PDO Singleton                 |
|           Writen by Booster2ooo for HWC-Crew          |
|                          ...                          |
 \*___________________________________________________*/

//Abstract Singleton for PDO MySQL
class Engine2
{
        //$sqlCon is our DB unique instance
        private static $sqlCon;
        
        //As Engine is abstract, its contructor can only be called by a child
        protected function __construct($host, $db, $user, $pass)
        {
                //First, we are going to check if the instance $sqlCon of the DB exists. If it doesn't we create one
                if(!isset(self::$sqlCon) || self::$sqlCon == null) {
                        if(empty($host)) $host = 'localhost';
                        if(empty($db)) $db = 'trends';
                        if(empty($user)) $user = 'root';
                                
                        try
                        {
                                //As it's the first time we call Engine2, we create a new(and unique) DB connection
                                self::$sqlCon = new PDO('mysql:host='.$host.';dbname='.$db, $user, $pass);
                                //self::$sqlCon->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_WARNING);
                        }
                        catch(PDOException $e)
                        {
                                echo '<p class="error">';
                                echo 'PDO Error : '.$e->getMessage().'<br />';
                                echo 'N° : '.$e->getCode();
                                echo '</p>';
                        }
                }
        }
        
        //This method provides the mecanism for creating and executing SQL Queries from a child using the unique $sqlCon DB connection instance
        //                - $query represents the SQL query that's going to be executed
        //                - $params is an optinal parameter allowing you to pass the data to bind to the prepared request
        protected function sqlQuery($query,  $params=array(''))
        {
                try
                {
                        $prep_req = self::$sqlCon->prepare($query);
                        $prep_req->execute($params);
                        $reply = $prep_req->fetchAll(PDO::FETCH_OBJ);
                        $prep_req->closeCursor();
                        return $reply;
                }
                catch(PDOException $e)
                {
                        echo '<p class="error">';
                        echo 'Error : '.$e->getMessage().'<br />';
                        echo 'N° : '.$e->getCode().'<br />';
                        echo 'Request: '.$query.'<br />';
                        echo 'Parameters: <br />';
                        var_dump($params);
                        echo '</p>';
                }
        }
}
?>


<?php
//Sample Class inheriting from Engine2
class Sample extends Engine2
{
        //The constructor needs to know the SQL Hostserver, SQL DB, SQL User and SQL Pass (can be null)
        public function __construct($host, $db, $user, $pass)
        {
                try
                {
                        //We call the parent (Engine2) constructor with the same parameters
                        parent::__construct($host, $db, $user, $pass);
                        //We check if the table exists
                        $query = "SHOW TABLES LIKE ?";
                        $params = array('Engine2_Sample');
                        $reply = $this->sqlQuery($query, $params);
                        //If it doesn't, we create it
                        if (empty($reply)) $this->install();
                }
                catch(PDOException $e)
                {
                        echo '<p class="error">';
                        echo 'PDO Error : '.$e->getMessage().'<br />';
                        echo 'N° : '.$e->getCode();
                        echo '</p>';
                }
        }
        
        //Install the table
        private function install()
        {
                $query = "CREATE TABLE IF NOT EXISTS `Engine2_Sample` ("
                                ."`id` int(11) NOT NULL AUTO_INCREMENT,"
                                ."`text` text NOT NULL,"
                                ."PRIMARY KEY (`id`) ) ENGINE=MyISAM  DEFAULT CHARSET=utf8 AUTO_INCREMENT=1";
                $this->sqlQuery($query);
        }
        
        //Check the db for a text entry and add it to the DB if it doesn't exists
        public function add($text)
        {
                if(!empty($text))
                {
                        $query = "SELECT `text` FROM `Engine2_Sample` WHERE `text` = ?";
                        $params = array($text);
                        $result = $this->sqlQuery($query, $params);
                        if(empty($result))
                        {
                                $query = "INSERT INTO `Engine2_Sample` VALUES('',?)";
                                $params = array($text);
                                $this->sqlQuery($query, $params);
                                return true;
                        }
                        else 
                        {
                                return false;
                        }
                }
        }
        }
}
?>