ImageService.php

<?php
namespace PYSys\Tools;

use Nette\InvalidArgumentException;
use Nette\Object;
use Nette\Utils\Image;

/**
 * Class ImageService
 * @package PYSys\Tools
 */
class ImageService extends Object
{

	/** @var string */
	protected $imagePath;
	/** @var string */
	protected $cachePath;
	/** @var array */
	protected $imageSizes;
	/** @var string */
	protected $cacheUrl;

	/**
	 * @param string $imagePath
	 * @param string $cachePath
	 * @param array $imageSizes
	 * @param string $cacheUrl
	 */
	public function __construct($imagePath, $cachePath, $imageSizes, $cacheUrl) {
		$this->imagePath = $imagePath;
		$this->cachePath = $cachePath;
		$this->imageSizes = $imageSizes;
		$this->cacheUrl = $cacheUrl;
	}

	/**
	 * @param int $id
	 * @param string $filename
	 * @param string $type
	 * @return string
	 */
	public function getThumbnailPath($id, $filename, $type) {
	return $this->cachePath . $this->getThumbnail($id, $filename, $type);
}

	/**
	 * @param int $id
	 * @param string $filename
	 * @param string $type
	 * @return string
	 */
	public function getThumbnailUrl($id, $filename, $type) {
		return $this->cacheUrl . $this->getThumbnail($id, $filename, $type);
	}

	/**
	 * @param int $id
	 * @param string $filename
	 * @param string $type
	 * @return string
	 * @throws \Nette\InvalidArgumentException
	 */
	protected function getThumbnail($id, $filename, $type) {
		if(!array_key_exists($type,$this->imageSizes)) {
			throw new InvalidArgumentException("Neznámý typ obrázku (Není nastaven v configu)");
		}
		$params = $this->imageSizes[$type];
		$thumbnail = $this->getCachePath($id, $filename, $params["width"], $params["height"], $params["flag"]);

		if(!file_exists($this->cachePath . $thumbnail)) {
			$this->generate($id, $filename, $params["width"], $params["height"], $params["flag"]);
		}

		return $thumbnail;
	}

	/**
	 * @param $id
	 * @param $filename
	 * @param $width
	 * @param $height
	 * @param $flag
	 * @throws \Nette\InvalidArgumentException
	 */
	protected function generate($id, $filename, $width, $height, $flag) {
		if(!file_exists($this->imagePath . $filename)) {
			throw new InvalidArgumentException("Obrázek neexistuje");
		}
		$image = Image::fromFile($this->imagePath . $filename);

		switch ($flag) {
			case 'fit': $image->resize($width,$height,Image::FIT); break;
			case 'exact': $image->resize($width,$height,Image::EXACT); break;
			case 'stretch': $image->resize($width,$height,Image::STRETCH); break;
			case 'shrink_only': $image->resize($width,$height,Image::SHRINK_ONLY); break;
			case 'fill': $image->resize($width,$height,Image::FILL); break;
			case 'centered':
				$centered_image = $image->resize($width,$height,Image::SHRINK_ONLY);
				$image = Image::fromBlank($width,$height, Image::rgb(255,255,255));
				$image->place($centered_image,($width - $centered_image->getWidth())/2,($height - $centered_image->getHeight())/2);
				break;
		}

		$thumbnail = $this->getCachePath($id, $filename, $width, $height, $flag);
		list($d1, $d2) = explode('/', $thumbnail);
		@mkdir( $this->cachePath . implode("/",array($d1, $d2)) . "/" , 0777, true);

		$image->save($this->cachePath . $thumbnail);
	}

	/**
	 * @param int $id
	 * @param string $filename
	 * @param int|null $width
	 * @param int|null $height
	 * @param int|null $flag
	 * @return string
	 */
	protected function getCachePath($id, $filename, $width=null, $height=null, $flag=null) {
		$cacheName = $this->getCacheName($id, $filename, $width, $height, $flag);
		return substr($cacheName, 0, 2) . "/" . substr($cacheName, 2, 2) . "/" . $cacheName;
	}

	/**
	 * @param int $id
	 * @param string $filename
	 * @param int|null $width
	 * @param int|null $height
	 * @param int|null $flag
	 * @return string
	 */
	protected function getCacheName($id,$filename, $width=null, $height=null, $flag=null) {
		$hash = md5( $id . $filename );
		return substr($hash,0,12)
			. '-' . $id
			. (!empty($width) ? "-{$width}" : "")
			. (!empty($height) ? "x{$height}" : "")
			. (!empty($flag) ? "-{$flag}" : "")
			. '.' . $this->getExtension($filename);
	}

	/**
	 * @param $filename
	 * @return string
	 */
	protected function getExtension($filename) {
		$name_parts = explode(".",$filename);
		return end($name_parts);
	}

}