<?php
class Database
{
	public function __construct($servername, $dbusername, $dbpassword, $dbname)
	{
		$this->mysqli = new mysqli($servername, $dbusername, $dbpassword, $dbname);

		if ( mysqli_connect_errno() )
		{
			die(mysqli_connect_error());
		}
	}

	public function query($sql)
	{
		return $this->mysqli->query($sql);
	}

	public function insert_id()
	{
		return $this->mysqli->insert_id;
	}

	public function affected_rows($sql)
	{
		$this->query($sql);

		return $this->mysqli->affected_rows;
	}

	public function fetch_array($query)
	{
		return mysqli_fetch_array($query);
	}

	public function fetch_one_array($query)
	{
		return $this->fetch_array($this->query($query));
	}

	public function fetch_one($query)
	{
		$record = $this->fetch_one_array($query);

		Return $record[0];
	}

	public function close()
	{
		return $this->mysqli->close();
	}

	private function compile_db_insert_string($data)
	{
		$field_names = "";

		$field_values = "";

		foreach ($data as $k => $v)
		{
			$field_names .= "$k,";

			$field_values .= "'$v',";
		}

		$field_names = preg_replace( "/,$/" , "" , $field_names );

		$field_values = preg_replace( "/,$/" , "" , $field_values );

		return array('FIELD_NAMES' => $field_names, 'FIELD_VALUES' => $field_values);
	}

	private function compile_db_update_string($data)
	{
		$return_string = "";

		foreach ($data as $k => $v)
		{
			if(is_array($v))
			{
				$return_string .= $k . "=".$v['0'].",";
			}
			else
			{
				$return_string .= $k . "='".$v."',";
			}
		}

		return preg_replace( "/,$/" , "" , $return_string );
	}

	public function insert_sql( $tbl , $arr ,$action="INSERT")
	{
		$dba = $this->compile_db_insert_string( $arr );

		$sql = "{$action} INTO {$tbl} ({$dba['FIELD_NAMES']}) VALUES ({$dba['FIELD_VALUES']})";
		
		return $sql;
	}

	public function update_sql($tbl , $arr , $where='')
	{
		$dba	=	$this->compile_db_update_string( $arr );

    	$query = "UPDATE {$tbl} SET $dba";
    	
    	if ( $where )
    	{
    		$query .= " WHERE ".$where;
    	}

		return $query;
	}
}
?>