<?php
/**
 *
 * Abstract class Database
 * Provide methods to handle database communication
 * @author NetanelEdri
 * @date 04/09/2011
 *
**/

abstract class Database
{
    /**
     * current instance var ( singleton pattren )
     * @object
    **/
    public static $objInstance;

    /**
     * connection resource var
     * @object
    **/
    protected $connection;

    /**
     * last query var
     * @string
    **/
    protected $lastQuery;

    /**
     * connection mode
     * @bool
    **/
    protected $connectionMode;

    /**
     * get instance of the database
     * @object
    **/
    public static function getInstance($dbInfo)
    {
        if(!isset($this->objInstance) || !is_object($this->objInstance))
        {
            $Class = __CLASS__;
            self::$objInstance = new $Class($dbInfo);
        }
        return self::$objInstance;
    }

    /**
     * contructror function
    **/
    protected function __construct($dbInfo)
    {
        $this->Connect($dbInfo);
    }

    /**
     * get affected rows
     * @int
    **/
    public function affRows($query = null)
    {
        return $this->connection->affected_rows;
    }

    /**
     * clone function ( singleton pattren )
    **/
    final private function clone()
    {
        die('Clone is not allowed !');
    }

    /**
     * destruct function
    **/
    public function __destruct()
    {
        if($this->connectionMode)
            $this->connection->close();
    }

    /**
     * commit the last transactions
    **/
    public function commit()
    {
        $this->connection->query("COMMIT");
        $this->connection->query("SET AUTOCOMMIT=1");
    }

    /**
     * rollback the last transactions
    **/
    public function rollback()
    {
        $this->connection->query("ROLLBACK");
        $this->connection->query("SET AUTOCOMMIT=1");
    }

    /**
     * get the last insert_id
    **/
    public function insert_id()
    {
        return $this->connection->insert_id;
    }

    /**
     * abstract functions
    **/
    abstract function Connect(array $dbInfo);
    abstract function query(string $string);
    abstract function fetch($query = null);
    abstract function update(array $array);
    abstract function insert(array $array);
}

class DatabaseDriver extends Database
{
    /**
     * connect function
    **/
    public function Connect($dbInfo)
    {
        $this->connection = new mysqli($dbInfo['hostname'],$dbInfo['dbuser'],$dbInfo['dbpass'],$dbInfo['dbname']);
        if($this->connection->connect_error)
            die($this->connection->connect_error);
        else {
            $this->connection->set_charset($dbInfo['charset']);
            $this->connectionMode = true;
        }
    }

    /**
     * execute a query
    **/
    public function query($string)
    {
        $this->lastQuery = $string;
        return ($this->objInstance->query($string)) ? true : false;
    }

    /**
     * fetch query results
     * @object
    **/
    public function fetch($query = null)
    {
        if(is_null($query))
        {
            $q = $this->query($this->lastQuery);
            return $this->connection->$q->fetch_object();
        }else {
            return $this->connection->$query->fetch_object();
        }
    }

    /**
     * execute a update query
     * @bool
    **/
    public function update($array)
    {
        $table = $array['table'];
        $where = (isset($array['where'])) ? " WHERE ".$array['where'] : null;
        $data = null;
        foreach($array as $col => $value)
        {
            if($col != "table")
                $data .= "`'".$col."'` = '" .$value. "',";
        }
        $data = substr($data,0,-1);
        $queryString = "UPDATE `".$table."` SET ".$data.$where;
        return ($this->query($queryString)) ? true : false;
    }

    /**
     * execute a insert query
    **/
    public function insert($array)
    {
        $table = $array['table'];
        $cols = null;
        $values = null;
        foreach($array as $col => $value)
        {
            if($col != "table")
            {
                $cols .= "`".$col."`,";
                $values .= "'" .$value. "',";
            }
        }
        $cols = substr($cols,0,-1);
        $values = substr($values,0,-1);
        $queryString = "INSERT INTO `".$table."` (" .$cols. ") VALUES(" .$values. ")";
        return ($this->query($queryString)) ? true : false;
    }
}


?>