<?php
/**
 *	Implements an updater for CBoxManager
 *
 * 
 * 	@version		0.0.1 - dev
 * 	@author			Edoardo Tenani <hide@address.com>
 * 	@license		GNU Public License 2.0 or greater
 * 					<http://opensource.org/licenses/gpl-2.0.php>
 * 	@copyright		Edoardo Tenani
 */
class Updater {

	/**
	 *	The xml file containing the update
	 *
	 * 	@var object
	 */
	protected $xml_file;

	/**
	 *	The SimpleXMLObject with the updates
	 *
	 * 	@var object
	 */
	protected $xml;

	/**
	 * 	The code to be executed to update CBoxManager
	 *
	 * 	@var array
	 */
	protected $code;
	
	function __construct($xml_file) {
		$this->xml_file = $xml_file;
		$this->xml = simplexml_load_file($xml_file);

		$this->load_update();
	}
	
/*	OBJECT FUNCTION OVERRIDE
 ************************************************/

	/**
	 * 	When the class is destroyed this function is called.
	 *
	 * 	@return void
	 */
	public function __destruct() {	}

	/**
	 * 	When an inaccesible method of the class is invoked this function
	 * 	is called.
	 *
	 * 	@return void
	 */
	public function __call($name, $arguments) {
        echo get_class($this)."::Error in calling object method <b>'$name'</b>"."<br>\n";
    }

	/**
	 * 	When an inaccesible static method of the class is invoked this
	 * 	function is called.
	 *
	 * 	@return void
	 */
	public static function __callStatic($name, $arguments) {
        echo get_class($this)."::Error in calling object static method <b>'$name'</b>"."<br>\n";
    }

	/**
	 * 	When the object is converted to a string this function is used to
	 * 	format the result string.
	 * 	Values are separated by "|". If the class var is an array, values
	 * 	in it will be separated by ",", or NULL if is not set.
	 * 	The string starts and ends with "-".
	 *
	 * 	@access public
	 * 	@return a string with all class vars values separated by |
	 */
	public function __toString() {		
		return NULL;
	}

/*	SET & GET FUNCTION
 ************************************************/

	/**
	 * 	The function set a specified class var.
	 * 	Is not case sensitive.
	 *
	 * 	@access public
	 * 	@param	string $var the name of the var to be set
	 * 	@param	mixed $value the new value to set
	 * 
	 *	@return true
	 */
	public function set($var, $value = NULL) {
		$this->{$var} = $value;
		return true;
	}

	/**
	 * 	The function get a specified class var.
	 * 	Is case sensitive.
	 *
	 * 	@access public
	 * 	@param	string $var the name of the var to be get
	 *
	 * 	@return the class var
	 */
	public function get($var) {
		return $this->{$var};
	}


/*	PUBLIC FUNCTION
 ************************************************/

	/**
	 * 	Get attribute's value of xml root element
	 *
	 * 	@param	string $name the name of the attribute'value to be
	 * 		retrieved
	 * 	@return the value on success, false on fail
	 *
	 * 	@link http://it.php.net/manual/en/simplexmlelement.attributes.php
	 * 	@link http://php.net/strcmp
	 */
	public function get_attr($name) {
		foreach ( $this->xml->attributes() as $k => $v ) {
			if ( strcmp($k, $name) == 0 )
				return $this->xml["$k"];
		}

		return false;
	}

	/**
	 * 	Run update
	 *
	 * 	Run update based on $this->code var. Is the main update function,
	 * 	to be called to perform the update.
	 *
	 * 	Rename the update file to {filename}.old to disable update if
	 * 	done.
	 *
	 * 	Actually "file" is not disposable.
	 *
	 * 	@todo	Maybe is better to remove the file?? how to check if the
	 * 		update goes well?
	 *
	 * 	@access public
	 * 	@param	object $db a valid istance of the Database class
	 * 	@param	string $section can be "sql" or "file", to specify which
	 * 		part of the update must be run
	 * 	@return	bool true if code returs true, false if fails
	 *
	 *	@internal if $section is not specified, recursive calls with "sql"
	 * 		and "file" as parameter
	 * 
	 * 	@link http://php.net/eval
	 */
	public function run($db, $section = "") {
		switch ( $section ) {
			case "sql" :
				foreach ( $this->code["sql"]["query"] as $sql ) {
					$sql_results[] = $db->query("$sql") ? true : false;
				}
				$return = (in_array(false, $sql_results) ) ? false : true;
			break;
			case "file" :
				$return = false;
			break;
			default:
				// to be used when file section is completed
				//return ( $this->run($db, "sql") && $this->run($db, "file") ) ? true : false;
				$return = ( $this->run($db, "sql") ) ? true : false;
			break;
		}

		@unlink($this->xml_file);
		
		return  $return;
	}

	public function debug() {
		echo "<pre><b>\$this->xml</b>: <br>", var_dump($this->xml), "</pre>";
		echo "<pre><b>\$this->code</b>: <br>", var_dump($this->code), "</pre>";
	}

	public function _debug($var) {
		echo "<pre><b>var</b>: <br>", var_dump($var), "</pre>";
	}

/*	PRIVATE FUNCTION
 ************************************************/

	/**
	 * 	Loads code from xml
	 *
	 * 	Loads code to be executed as update inside $this->code
	 *
	 * 	@access private
	 * 	@return void
	 *
	 * 	@link http://php.net/trim
	 */
	private function load_update() {
		foreach ( $this->xml as $v ) {
			for ( $i = 0, $count = count($v); $i < $count; $i++ ) {
				$this->code[$v->getName()][$v->children()->getName()][$i] = trim($v->children());
			}
		}
	}

}
?>