<?php
/**
* mpl           by ERB software
* @author       stefan.erb(at)erb-software.com
*/

/**
 * @example
 * Um ein bild nur als Thumb anzuzeigen, kann dieses Script folgendermassen aufgerufen werden
 * Mit den Standartwerten
 * http://domain.com/thumb.php?file=/images/meinBild.jpg
 * Mit einer anderen Grösse
 * http://domain.com/thumb.php?file=/images/meinBild.jpg&size=150
 * 
 * Man kann aber das Thumb auch speichern. Dazu dient der Parameter destfolder
 * http://domain.com/thumb.php?file=/images/meinBild.jpg&destfolder=/images/thumbs
 */

/**
 * Notwendige Packages einbinden
 */
$thumb_path = dirname(__FILE__);
// Sauberes Exception-Handling
require "{$thumb_path}/packages/functions/exceptionErrorHandler.php";
// Hilfsfunktion um Pfade zu erstellen
require "{$thumb_path}/packages/functions/createPath.php";
// Erweiterte Funktion filter_input_array um 'default'
require "{$thumb_path}/packages/functions/filterInputDefaults.php";
// Enum-Klasse
require "{$thumb_path}/packages/enum/include.php";

/**
 * Definitionen
 */
//Art wie das Bild 'geschnitten' wird
class TYPES extends Enum{    
	public static function FIT(){return new self('fit');}           //Proportinen beibehalten. Die längere Seite wird auf die THUMB_SIZE verkleinert    
	public static function STRETCH(){return new self('stretch');}   //Das Bild wird auf das Format THUMB_SIZE x THUMB_SIZE verzerrt
	//public static function CUT(){return new self('cut');}          //Noch nicht richtig definiert
}

//Bildtyp des Thumbs
class IMG_TYPES extends enum{
	protected $paramNames = array('constant', 'function');   
	public static function PNG(){return new self('png',  IMAGETYPE_PNG,  'imagepng');}
	public static function JPG(){return new self('jepg', IMAGETYPE_JPEG, 'imagejpeg');}
	public static function GIF(){return new self('gif',  IMAGETYPE_GIF,  'imagegif');}    
}

//Konstanten
define('C_THUMB_MIN_SIZE', 20);
define('C_THUMB_MAX_SIZE', 200);
define('C_THUMB_FILENAME_SUFFIX', '_thumb');

//Standarts defnieren
define('C_THUMB_DEFAULT_TYPE', TYPES::FIT());
define('C_THUMB_DEFAULT_SIZE', 100);
define('C_THUMB_DEFAULT_IMG_TYPE', IMG_TYPES::PNG());

//GET-Definitionen
$C_THUMB_GET_DEFINITION = 
	array(
		'file'          =>  FILTER_SANITIZE_STRING,
		'size'          =>  array(
			'filter'        => FILTER_VALIDATE_INT,
			'options'       => array(
				'min_range'     => C_THUMB_MIN_SIZE, 
				'max_range'     => C_THUMB_MAX_SIZE),
			'default'       => C_THUMB_DEFAULT_SIZE),
		'type'          =>  array(
			'filter'        => FILTER_VALIDATE_REGEXP,
			'options'       => array(
				'regexp'        => '/^(?:'.TYPES::implode('|').')$/'),
			'default'       => C_THUMB_DEFAULT_TYPE), 
		'imgtype'       =>  array(
			'filter'        => FILTER_VALIDATE_REGEXP,
			'options'       => array(
				'regexp'        => '/^(?:'.IMG_TYPES::implode('|').')$/'),
			'default'       => C_THUMB_DEFAULT_IMG_TYPE),
		'destfolder'    =>  array(
			'filter'        => FILTER_SANITIZE_STRING,
			'default'       => FALSE)
	); 


/**
 * Ausführender Code
 */
try{
	Thumb::createThumb();
}catch(Exception $e){
	echo nl2br($e->getMessage());
	echo "\n<!-- Error Trace\n".$e->getTraceAsString()."\n-->";
}


/**
 * Klasse Thumb
 */
class Thumb{
	
	/**
	 * Singel-Entry
	 * @static
	 */
	public static function createThumb(IMG_TYPES $imgType = NULL){
		$thumb = new self();
		$thumb->createImage($imgType);
	}
	
	/**
	 * Konstrukteur
	 */
	public function __construct(){
		//$_GET auswerten
		$params = (object) filterInputDefaults(INPUT_GET, $GLOBALS['C_THUMB_GET_DEFINITION'] );
		
		//Detailierte Überprüfungen der Parameter
		//if(!file_exists($params->file)) throw new Exception("File '{$params->file}' dosnt exist");
		if($params->size==FALSE) throw new Exception("Size not between ".C_THUMB_MIN_SIZE." AND ".C_THUMB_MAX_SIZE);
		if($params->type==FALSE) throw new Exception("invalid Type '{$params->type}'. Valid Types are ".TYPES::implode(', '));
		
		//Klassenvariablen bescrheiben
		$this->imgType = IMG_TYPES::getEnum($params->imgtype);
		$this->destFolder = $params->destfolder;
		
		//Grössen und Faktoren berechnen
		$info = getimagesize($this->path = $params->file);
		$this->srcH = $info[1];
		$this->srcW = $info[0];
		switch ($params->type){
			case TYPES::FIT():
					$this->factorH = $this->factorW = $params->size/max($this->srcH, $this->srcW);
					$this->h = $this->srcH * $this->factorH;
					$this->w = $this->srcW * $this->factorW;
					break;
				case TYPES::STRETCH():
					$this->h = $this->w =$params->size;
					$this->factorH = $this->srcH/$this->h;
					$this->factorW = $this->srcW/$this->w;
					break;
				case TYPES::CUT():
					$this->factorH = $this->factorW = $params->size/min($this->srcH, $this->srcW);
					$this->h = $this->w =$params->size;
					break;
		}
	}    

	/**
	 * Erstellt das Thumb-image
	 * @param $imgType
	 */
	public function createImage(IMG_TYPES $imgType = NULL, $destFolder = FALSE){
		//Parameters überprüfen und ggf aus de Klasse laden
		if(is_null($imgType)) $imgType = $this->imgType;
		if($destFolder == FALSE) $destFolder = $this->destFolder;
		
		//Thumb-Image erstellen
		$image = $this->getImage();
		//imgecreate-Funktion ermitteln
		$function = $imgType->function;
		//Thumb-Dateiname ermitteln
		$fileName = $this->getThumbFileName();
		
		//Falls ein Destinationsordner angegen wurde, die Datei speichern
		if($this->destFolder != FALSE){
			$function($image, createPath($this->destFolder, $fileName));
		//Anderfalls an den Browser ausgeben
		}else{
			header ('Content-type: '.image_type_to_mime_type($imgType->constant));
			header("Content-disposition: inline; filename=\"{$fileName}\); 
		
			$function($image);            
		}
		
		//Aufräumen
		imagedestroy($image);        
	}
	
	/**
	 * kopiert das Image in das Thumb-Image
	 */
	public function getImage(){
		$srcImg = &$this->getSource();
		$image = imagecreatetruecolor($this->w, $this->h);
		imagecopyresized($image, $srcImg, 0, 0, 0, 0, $this->w, $this->h, $this->srcW, $this->srcH);
		imagedestroy($srcImg);
		return $image;    
	}
	
	/**
	 * erstellt den Namen der Thumb-Datei
	 */
	protected function getThumbFileName(){
		$info = pathinfo($this->path);
		$pattern = "/\.{$info['extension']}$/";
		return preg_replace($pattern, '', $info['basename']) . C_THUMB_FILENAME_SUFFIX .image_type_to_extension($imgType->constant); 
	}
	
	/**
	 * öffnet die Quellgrafik und gibt die Ressource zurück 
	 */
	protected function getSource(){
		//Auswertung des Imagetypes -> http://ch.php.net/manual/de/function.image-type-to-mime-type.php
		switch(exif_imagetype($this->path)){
			case IMAGETYPE_PNG: return imagecreatefrompng($this->path);
			case IMAGETYPE_GIF: return imagecreatefromgif($this->path);
			case IMAGETYPE_JPEG: return imagecreatefromjpeg($this->path);                                
		}
	}       
}
?>