<?php
/* 

Thumbnail helper
----------------
original source: Studio Canaria
modifications: nerdnotes.org
 

Example usage, just like $html->image():

echo $thumbnail->image('picture.jpg', array(
 	'alt' => 'test thumbnail',
 	'width' => '100', 
 	'height' => '75'
 	)
 );

This will take the image 'picture.jpg' (/app/webroot/img/picture.jpg) and
returns the following html code:

<img src="/img/thumbs/100x75/picture.jpg"
	alt="test thumbnail" height="75" width="100">


It will make sure the thumbnail is created in /app/webroot/img/thumbs/100x75/ if it didn't exist already.

Notes:
	- tested with cakephp 1.2 and phpthumb 1.7.9
	- place this file (thumbnail.php) in /app/views/helpers/
	- make sure phpthumb is located in one of the vendors directories.
	  ie: vendors/phpthumb/phpthumb.class.php
	- create a directory named /app/webroot/img/thumbs that is writable by
	  the webserver
	- include this helper on the controller level:
	  var $helpers = array('Html', 'Thumbnail');

References:
	- original source of the helper: http://www.studiocanaria.com/articles/cakephp_thumbnail_helper
	- phpthumb: http://phpthumb.sourceforge.net/

*/


class ThumbnailHelper extends AppHelper
{
	/*
	 * Default parameters for phpthumb
	 *
	 */
	var $defaultParameters = array(
		'w' => 320,      // width
		'h' => 200,      // height
		'f' => 'jpeg',   // filetype
		'q' => 80        // jpg quality
	);
	
	var $helpers = array('Html');
	
	
	/***
	 * Generates a thumbnail file and returns the path (uses caching)
	 *
	 * @param string $source_file Absolute path to the original image
	 * @param array $parameters Array of phpthumb parameters, please consult "phpthumb.readme.txt" for more information
	 * @param string $hash If supplied, the hash will be used as filename for the generated thumnail
	 */
	function render($source_file, $parameters = null, $hash = '')
	{
		// merge parameters
		if (is_array($parameters)) {
			$parameters = array_merge($this->defaultParameters, $parameters);
		} else {
			$parameters = $this->defaultParameters;
		}
		
		$path = pathinfo($source_file);
		
		// if hash isn't given, use original file name				
		if ($hash == '') {
			$thumb_file = $path['basename'];
		} else {
			$thumb_file = $hash . '.' . $path['extension'];
		}
		
		// configure 'storage path' as "(webroot/img/)thumbs/{w}x{h}/{hash}.jpg"
		$thumb_url =
			'thumbs' . DS .
			$parameters['w'] . 'x' . $parameters['h'] . DS .
			$thumb_file;
		
		$thumb_file = WWW_ROOT . 'img' . DS . $thumb_url;
		
		// if the file doesn't exist yet, create it
		if (!is_file($thumb_file)) {
			//import phpThumb class
			app::import(
				'Vendor',
				'phpthumb',
				array('file' => 'phpthumb' . DS . 'phpthumb.class.php')
			);
			
			// create destination directory if it doesn't exist yet
			$destdir = dirname($thumb_file);
			if (!is_dir($destdir)) {
				// !!! initially you have to make sure the server can write
				//     the 'storage path' !!!
				mkdir($destdir, 0777, true);
			}
			
			// instantiate and configure phpthumb object
			$thumb = new phpthumb;
			$thumb->setSourceFilename($source_file);
			
			// set the default parameters			
			foreach($this->defaultParameters as $parameter => $value) {
				$thumb->setParameter($parameter, $value);				
			}
			
			// now (over)write given parameters
			if (is_array($parameters)) {
				foreach($parameters as $parameter => $value) {
					$thumb->setParameter($parameter, $value);				
				}
			}
			
			// check if we need to adjust the output format
			if (low($path['extension']) == 'png' or low($path['extension']) == 'gif') {
				$thumb->setParameter('f', $path['extension']);
			}
			
			// generate thumbnail
			if($thumb->GenerateThumbnail()) {
				$thumb->RenderToFile($thumb_file);
			} else {
				debug('phpthumb error: ' . $thumb->fatalerror);
				debug($thumb->debugmessages);
			}
		}
		return $thumb_url;
	}
	
	
	/**
	 * Creates a formatted IMG element
	 *
	 * @param string $path Path to the image file, relative to the app/webroot/img/ directory.
	 * @param array $htmlAttributes Array of HTML attributes.
	 * @return string
	 */
	function image($path, $htmlAttributes = null)
	{
		$picture_path = WWW_ROOT . 'img' . DS . $path;
		$parameters = $this->defaultParameters;
		
		// make sure the parameters for phpthumb and html will match
		if (isset($htmlAttributes['width'])) {
			$parameters['w'] = $htmlAttributes['width'];
		} else {
			$htmlAtributes['width'] = $parameters['w'];
		}
		
		if (isset($htmlAttributes['height'])) {
			$parameters['h'] = $htmlAttributes['height'];
		} else {
			$htmlAttributes['height'] = $parameters['h'];
		}
		
		// get a link to the thumb version
		$thumb = $this->render($picture_path, $parameters);
		
		// generate html for displaying the image
		echo $this->Html->image($thumb, $htmlAttributes);
	}
}

?>