<?php
/**
 * ImageThumb.inc.php
 * code by strangecode :: www.strangecode.com :: this document contains copyrighted information
 *
 * @author   Quinn Comendant <quinn@strangecode.com>
 * @requires Netpbm <http://sourceforge.net/projects/netpbm/> and libjpeg or GD.
 * @version  2.0
 */

// Image resize options.
define('IMAGETHUMB_FIT_WIDTH', 1);
define('IMAGETHUMB_FIT_HEIGHT', 2);
define('IMAGETHUMB_FIT_LARGER', 3);
define('IMAGETHUMB_STRETCH', 4);
define('IMAGETHUMB_NO_SCALE', 5);
define('IMAGETHUMB_METHOD_NETPBM', 6);
define('IMAGETHUMB_METHOD_GD', 7);

class ImageThumb {
    
    // General object parameters.
    var $_params = array(
        // The location for images to create thumbnails from.
        'source_dir' => null,

        // Existing files will be overwritten when there is a name conflict?
        'allow_overwriting' => false,

        // The file permissions of the uploaded files. Remember, files will be owned by the web server user.
        'dest_file_perms' => 0600,

        // Permissions of autocreated directories. Must be at least 0700 with owner=apache.
        'dest_dir_perms' => 0777,

        // Require file to have one of the following file name extentions.
        'valid_file_extensions' => array('jpg', 'jpeg', 'gif', 'png'),
        
        // Method to use for resizing. (IMAGETHUMB_METHOD_NETPBM or IMAGETHUMB_METHOD_GD)
        'resize_method' => IMAGETHUMB_METHOD_NETPBM,

        // Netpbm and libjpeg binary locations.
        'anytopnm_binary' => '/usr/bin/anytopnm',
        'pnmscale_binary' => '/usr/bin/pnmscale',
        'cjpeg_binary' => '/usr/bin/cjpeg',

        // Which messages do we pass to raiseMsg? Use one of the MSG_* constants or false to disable.
        'display_messages' => MSG_ALL,
    );
    
    // Default image size specs.
    var $default_image_specs = array(
        // The destination for an image thumbnail size. Path relative to source_dir (eg: ../thumbs).
        'dest_dir' => null,
        
        // Destination file types. (IMG_JPG, IMG_PNG, IMG_GIF, IMG_WBMP)
        'dest_file_type' => IMG_JPG,

        // Destination file types. ('jpg', 'png', 'gif', 'wbmp')
        'dest_file_extention' => 'jpg',
        
        // Type of scaling to perform, and sizes used to calculate max dimentions.
        'scaling_type' => IMAGETHUMB_FIT_LARGER,
        'width' => null,
        'height' => null,

        // Percentage quality of image compression output 0-100.
        'quality' => 65,

        // Create progressive jpegs?
        'progressive' => false,

        // If using GD method, apply sharpen filter. Requires PHP > 5.1.
        'sharpen' => true,
        
        // Integers between 1-100, useful values are 65-85.
        'sharpen_value' => 75,

        // If source image is smaller than thumbnail, allow upscaling?
        'allow_upscaling' => false,

        // If thumb exists and filesize is smaller than this, do not overwrite the thumb.
        'keep_filesize' => null,
    );

    // Final specifications for image sizes, set with setSpec().
    var $image_specs = array();

    /**
     * Set (or overwrite existing) parameters by passing an array of new parameters.
     *
     * @access public
     * @param  array    $params     Array of parameters (key => val pairs).
     */
    function setParam($params)
    {
		$app =& App::getInstance();

        if (isset($params) && is_array($params)) {

            // Enforce valid upload_path parameter.
            if (isset($params['source_dir'])) {
                $params['source_dir'] = realpath($params['source_dir']);
                // Must be directory.
                if (!is_dir($params['source_dir'])) {
                    $app->logMsg(sprintf('Source directory invalid: %s', $params['source_dir']), LOG_ERR, __FILE__, __LINE__);
                    trigger_error(sprintf('Source directory invalid: %s', $params['source_dir']), E_USER_ERROR);
                }
                // Must be readable.
                if (!is_readable($params['source_dir'])) {
                    $app->logMsg(sprintf('Source directory not readable: %s', $params['source_dir']), LOG_ERR, __FILE__, __LINE__);
                    trigger_error(sprintf('Source directory not readable: %s', $params['source_dir']), E_USER_ERROR);
                }
            }

            // Merge new parameters with old overriding only those passed.
            $this->_params = array_merge($this->_params, $params);
        } else {
            $app->logMsg(sprintf('Parameters are not an array: %s', $params), LOG_ERR, __FILE__, __LINE__);
        }
    }

    /**
     * Return the value of a parameter, if it exists.
     *
     * @access public
     * @param string $param        Which parameter to return.
     * @return mixed               Configured parameter value.
     */
    function getParam($param)
    {
		$app =& App::getInstance();
    
        if (isset($this->_params[$param])) {
            return $this->_params[$param];
        } else {
            $app->logMsg(sprintf('Parameter is not set: %s', $param), LOG_NOTICE, __FILE__, __LINE__);
            return null;
        }
    }

    /**
     * Set the specification of thumbnails.
     *
     * @access  public
     * @param   array $spec The specifications for a size of output image.
     */
    function setSpec($spec, $index=null)
    {
		$app =& App::getInstance();

        // A little sanity checking.
        if (!isset($spec['dest_dir']) || '' == $spec['dest_dir']) {
            $app->logMsg('setSpec error: dest_dir not specified.', LOG_ERR, __FILE__, __LINE__);
        }
        if (isset($spec['dest_file_type'])) {
            switch ($spec['dest_file_type']) {
            case IMG_JPG :
                if (imagetypes() & IMG_JPG == 0) {
                    $app->logMsg(sprintf('IMG_JPG is not supported by this version of PHP GD.', null), LOG_ERR, __FILE__, __LINE__);
                }
                $spec['dest_file_extention'] = 'jpg';
                break;
            case IMG_PNG :
                if (imagetypes() & IMG_PNG == 0) {
                    $app->logMsg(sprintf('IMG_PNG is not supported by this version of PHP GD.', null), LOG_ERR, __FILE__, __LINE__);
                }
                $spec['dest_file_extention'] = 'png';
                break;
            case IMG_GIF :
                if (imagetypes() & IMG_GIF == 0) {
                    $app->logMsg(sprintf('IMG_GIF is not supported by this version of PHP GD.', null), LOG_ERR, __FILE__, __LINE__);
                }
                $spec['dest_file_extention'] = 'gif';
                break;
            case IMG_WBMP :
                if (imagetypes() & IMG_WBMP == 0) {
                    $app->logMsg(sprintf('IMG_WBMP is not supported by this version of PHP GD.', null), LOG_ERR, __FILE__, __LINE__);
                }
                $spec['dest_file_extention'] = 'wbmp';
                break;
            default :
                $app->logMsg(sprintf('Invalid dest_file_type: %s', $spec['dest_file_type']), LOG_ERR, __FILE__, __LINE__);
                break;
            }
        }
        if (!isset($spec['width']) || !is_int($spec['width'])) {
            $app->logMsg('setSpec error: width not specified.', LOG_ERR, __FILE__, __LINE__);
        }
        if (!isset($spec['height']) || !is_int($spec['height'])) {
            $app->logMsg('setSpec error: height not specified.', LOG_ERR, __FILE__, __LINE__);
        }
        if (isset($spec['quality']) && IMG_JPG != $spec['dest_file_type']) {
            $app->logMsg('The "quality" specification is not used unless IMG_JPG is the dest_file_type.', LOG_INFO, __FILE__, __LINE__);
        }
        if (isset($spec['progressive']) && IMG_JPG != $spec['dest_file_type']) {
            $app->logMsg('The "progressive" specification is not used unless IMG_JPG is the dest_file_type.', LOG_INFO, __FILE__, __LINE__);
        }
        
        if (isset($index) && isset($this->image_specs[$index])) {
            // Merge with previous.
            $final_spec = array_merge($this->image_specs[$index], $spec);
            $this->image_specs[$index] = $final_spec;
        } else {
            // Merge with defaults.
            $final_spec = array_merge($this->default_image_specs, $spec);            
            $this->image_specs[] = $final_spec;
        }
        
        return $final_spec;
    }

    /**
     * Process an entire directory of images.
     *
     * @access  public
     * @return  bool true on success, false on failure.
     */
    function processAll($runtime_specs=null)
    {
		$app =& App::getInstance();

        // Ensure we have a source.
        if ('' == $this->getParam('source_dir')) {
            $app->logMsg(sprintf('Source directory not set before processing.'), LOG_ERR, __FILE__, __LINE__);
            return false;
        }

        // Get all files in source directory.
        $dir_handle = opendir($this->getParam('source_dir'));
        while ($dir_handle && ($file = readdir($dir_handle)) !== false) {
            // If the file name does not start with a dot (. or .. or .htaccess).
            if (!preg_match('/^\./', $file) && in_array(strtolower(substr($file, strrpos($file, '.') + 1)), $this->getParam('valid_file_extensions'))) {
                $files[] = $file;
            }
        }

        // Process each found file.
        if (is_array($files) && !empty($files)) {
            $return_val = 0;
            foreach ($files as $file_name) {
                $return_val += $this->processFile($file_name, $runtime_specs);
            }
            $this->_raiseMsg(sprintf(_("Resized %s images."), sizeof($files)), MSG_SUCCESS, __FILE__, __LINE__);
            return 0 === $return_val;
        } else {
            $app->logMsg(sprintf('No images found to thumbnail in directory %s.', $this->getParam('source_dir')), LOG_NOTICE, __FILE__, __LINE__);
            return false;
        }
    }

    /**
     * Generate thumbnails for the specified file.
     *
     * @access  public
     * @param   string $file_name Name of file with extention.
     * @param   array $runtime_specs Array of specifications that will override all configured specifications.
     * @return  bool true on success, false on failure.
     */
    function processFile($file_name, $runtime_specs=null)
    {
		$app =& App::getInstance();

        // Source file determinted by provided file_name.
        $source_file = realpath(sprintf('%s/%s', $this->getParam('source_dir'), $file_name));
        
        // Ensure we have a source.
        if (sizeof($this->image_specs) < 1) {
            if (is_array($runtime_specs)) {
                $this->setSpec($runtime_specs, 0);
            } else {
                $app->logMsg(sprintf('Image specifications not set before processing.'), LOG_ERR, __FILE__, __LINE__);
                return false;                
            }
        }

        // Ensure we have a source.
        if ('' == $this->getParam('source_dir')) {
            $app->logMsg(sprintf('Source directory not set before processing.'), LOG_ERR, __FILE__, __LINE__);
            return false;
        }

        // Confirm source image exists.
        if (!file_exists($source_file)) {
            $this->_raiseMsg(sprintf(_("Image resizing failed: source image %s was not found."), $file_name), MSG_ERR, __FILE__, __LINE__);
            $app->logMsg(sprintf('Source image not found: %s', $source_file), LOG_ALERT, __FILE__, __LINE__);
            return false;
        }

        // Confirm source image is readable.
        if (!is_readable($source_file)) {
            $this->_raiseMsg(sprintf(_("Image resizing failed: source image %s is not readable."), $file_name), MSG_ERR, __FILE__, __LINE__);
            $app->logMsg(sprintf('Source image not readable: %s', $source_file), LOG_ALERT, __FILE__, __LINE__);
            return false;
        }

        // Confirm source image contains data.
        if (filesize($source_file) <= 0) {
            $this->_raiseMsg(sprintf(_("Image resizing failed: source image %s is zero bytes."), $file_name), MSG_ERR, __FILE__, __LINE__);
            $app->logMsg(sprintf('Source image is zero bytes: %s', $source_file), LOG_ALERT, __FILE__, __LINE__);
            return false;
        }

        // Confirm source image has a valid file extension.
        if (!$this->_validFileExtension($file_name)) {
            $this->_raiseMsg(sprintf(_("Image resizing failed: source image %s not a valid type. It must have one of the following file name extensions: %s"), $file_name, join(', ', $this->getParam('valid_file_extensions'))), MSG_ERR, __FILE__, __LINE__);
            $app->logMsg(sprintf('Image resizing failed: source image not of valid type: %s', $source_file), LOG_ERR, __FILE__, __LINE__);
            return false;
        }

        // Ensure destination directories are created. This will only be called once per page load.
        $this->_createDestDirs();
        
        // To keep this script running even if user tries to stop browser.
        ignore_user_abort(true);
        ini_set('max_execution_time', 300);
        ini_set('max_input_time', 300);

        // This remains zero until something goes wrong.
        $return_val = 0;

        foreach ($this->image_specs as $index => $spec) {
            
            if (is_array($runtime_specs)) {
                // Override with runtime specs.
                $spec = $this->setSpec($runtime_specs, $index);
            }
            
            // Destination filename uses the extention defined by dest_file_extention.
            $dest_file = realpath(sprintf('%s/%s/%s.%s', $this->getParam('source_dir'), $spec['dest_dir'], substr($file_name, 0, strrpos($file_name, '.')), $spec['dest_file_extention']));

            // Skip existing thumbnails with file size below $spec['keep_filesize'].
            if (isset($spec['keep_filesize']) && file_exists($dest_file)) {
                $file_size = filesize($dest_file);
                if (false !== $file_size && $file_size < $spec['keep_filesize']) {
                    $app->logMsg(sprintf('Skipping thumbnail %s. File already exists and file size is less than %s bytes.', $spec['dest_dir'] . '/' . $file_name, $spec['keep_filesize']), LOG_DEBUG, __FILE__, __LINE__);
                    continue;
                }
            }

            // Determine if original file size is smaller than specified thumbnail size. Do not scale-up if $spec['allow_upscaling'] config is set to false.
            $image_size = getimagesize($source_file);
            if ($image_size['0'] <= $spec['width'] && $image_size['1'] <= $spec['height'] && !$spec['allow_upscaling']) {
                $spec['scaling_type'] = IMAGETHUMB_NO_SCALE;
                $app->logMsg(sprintf('Image %s smaller than specified %s thumbnail size. Keeping original size.', $file_name, $spec['dest_dir']), LOG_DEBUG, __FILE__, __LINE__);
            }

            // DO IT! Based on available method.
            if (IMAGETHUMB_METHOD_NETPBM === $this->getParam('resize_method') && file_exists($this->getParam('anytopnm_binary')) && file_exists($this->getParam('pnmscale_binary')) && file_exists($this->getParam('cjpeg_binary'))) {
                // Resize using Netpbm binaries.
                $app->logMsg(sprintf('Resizing with Netpbm...', null), LOG_DEBUG, __FILE__, __LINE__);
                $return_val += $this->_resizeWithNetpbm($source_file, $dest_file, $spec);
            } else if (IMAGETHUMB_METHOD_GD === $this->getParam('resize_method') && extension_loaded('gd')) {
                // Resize with GD.
                $app->logMsg(sprintf('Resizing with GD...', null), LOG_DEBUG, __FILE__, __LINE__);
                $return_val += $this->_resizeWithGD($source_file, $dest_file, $spec);
            } else {
                $app->logMsg(sprintf('Image thumbnailing failed. Neither Netpbm or GD is available.', null), LOG_DEBUG, __FILE__, __LINE__);
                return false;
            }
        }

        // If > 0, there was a problem thumb-nailing.
        return 0 === $return_val;
    }
    
    /*
    * Use the Netpbm and libjpg cjpeg tools to generate a rescaled compressed image.
    * This is the preferred method over GD which has (supposedly) less quality.
    *
    * @access   private
    * @param    string  $source_file    Full path to source image file.
    * @param    string  $dest_file      Full path to destination image file.
    * @param    array   $spec           Array of image size specifications.
    * @return   int                     0 if no error, n > 0 if errors.
    * @author   Quinn Comendant <quinn@strangecode.com>
    * @version  1.0
    * @since    19 May 2006 13:55:46
    */
    function _resizeWithNetpbm($source_file, $dest_file, $spec)
    {
		$app =& App::getInstance();

        // Define pnmscale arguments.
        switch ($spec['scaling_type']) {
        case IMAGETHUMB_FIT_WIDTH :
            $pnmscale_args = sprintf(' -width %s ', escapeshellarg($spec['width']));
            break;
        case IMAGETHUMB_FIT_HEIGHT :
            $pnmscale_args = sprintf(' -height %s ', escapeshellarg($spec['height']));
            break;
        case IMAGETHUMB_FIT_LARGER :
            $pnmscale_args = sprintf(' -xysize %s %s ', escapeshellarg($spec['width']), escapeshellarg($spec['height']));
            break;
        case IMAGETHUMB_STRETCH :
            $pnmscale_args = sprintf(' -width %s -height %s ', escapeshellarg($spec['width']), escapeshellarg($spec['height']));
            break;
        case IMAGETHUMB_NO_SCALE :
        default :
            $pnmscale_args = ' 1 ';
            break;
        }

        // Define cjpeg arguments.
        $cjpeg_args = sprintf(' -optimize -quality %s ', escapeshellarg($spec['quality']));
        $cjpeg_args .= (true === $spec['progressive']) ? ' -progressive ' : '';

        // Format the command that creates the thumbnail.
        $command = sprintf('%s %s | %s %s | %s %s > %s/%s',
            escapeshellcmd($this->getParam('anytopnm_binary')),
            escapeshellcmd($source_file),
            escapeshellcmd($this->getParam('pnmscale_binary')),
            escapeshellcmd($pnmscale_args),
            escapeshellcmd($this->getParam('cjpeg_binary')),
            escapeshellcmd($cjpeg_args),
            escapeshellcmd($dest_file),
            escapeshellcmd($file_name)
        );
        $app->logMsg(sprintf('ImageThumb Netpbm command: %s', $command), LOG_DEBUG, __FILE__, __LINE__);
        
        // Execute!
        exec($command, $output, $return_val);

        if (0 === $return_val) {
            // Success!
            // Make the thumbnail writable so the user can delete it over ftp without being 'apache'.
            chmod($dest_file, $this->getParam('dest_file_perms'));
            $app->logMsg(sprintf('Successfully resized image %s', $spec['dest_dir'] . '/' . basename($dest_file), $return_val), LOG_DEBUG, __FILE__, __LINE__);
        } else {
            // An error occurred.
            $app->logMsg(sprintf('Image %s failed resizing with return value: %s%s', $spec['dest_dir'] . '/' . basename($dest_file), $return_val, empty($output) ? '' : ' (' . getDump($output) . ')'), LOG_ERR, __FILE__, __LINE__);
        }

        // Return from the command will be > 0 if there was an error.
        return $return_val;
    }

    /*
    * Use PHP's built-in GD tools to generate a rescaled compressed image.
    *
    * @access   private
    * @param    string  $source_file    Full path to source image file.
    * @param    string  $dest_file      Full path to destination image file.
    * @param    array   $spec           Array of image size specifications.
    * @return   int                     0 if no error, n > 0 if errors.
    * @author   Quinn Comendant <quinn@strangecode.com>
    * @version  1.0
    * @since    19 May 2006 15:46:02
    */
    function _resizeWithGD($source_file, $dest_file, $spec)
    {
		$app =& App::getInstance();

        // Get original file dimensions and type.
        list($source_image_width, $source_image_height, $source_image_type) = getimagesize($source_file);

        // Define destination image dimentions.
        switch ($spec['scaling_type']) {
        case IMAGETHUMB_FIT_WIDTH :
            $dest_image_width = $spec['width'];
            $dest_image_height = $source_image_height * ($spec['width'] / $source_image_width);
            break;
        case IMAGETHUMB_FIT_HEIGHT :
            $dest_image_height = $spec['height'];
            $dest_image_width = $source_image_width * ($spec['height'] / $source_image_height);
            break;
        case IMAGETHUMB_FIT_LARGER :
            if (($source_image_width * ($spec['height'] / $source_image_height)) <= $spec['width']) {
                // Height is larger.
                $dest_image_height = $spec['height'];
                $dest_image_width = $source_image_width * ($spec['height'] / $source_image_height);
            } else {
                // Width is larger.
                $dest_image_width = $spec['width'];
                $dest_image_height = $source_image_height * ($spec['width'] / $source_image_width);
            }
            break;
        case IMAGETHUMB_STRETCH :
            $dest_image_width = $spec['width'];
            $dest_image_height = $spec['height'];
            break;
        case IMAGETHUMB_NO_SCALE :
        default :
            $dest_image_width = $source_image_width;
            $dest_image_height = $source_image_height;
            break;
        }

        // Create source image data in memory.
        switch ($source_image_type) {
        case IMAGETYPE_JPEG :
            $source_image_resource = imagecreatefromjpeg($source_file);
            break;
        case IMAGETYPE_PNG :
            $source_image_resource = imagecreatefrompng($source_file);
            break;
        case IMAGETYPE_GIF :
            $source_image_resource = imagecreatefromgif($source_file);
            break;
        case IMAGETYPE_WBMP :
            $source_image_resource = imagecreatefromwbmp($source_file);
        default :
            $app->logMsg(sprintf('Source image type %s not supported.', $source_image_type), LOG_WARNING, __FILE__, __LINE__);
            return 1;
            break;
        }
        if (!$source_image_resource) {
            $app->logMsg(sprintf('Error creating %s image in memory from %s', $source_image_type, $source_file), LOG_WARNING, __FILE__, __LINE__);
            return 1;
        }
        
        // Create destination image data in memory.
        $dest_image_resource = imagecreatetruecolor($dest_image_width, $dest_image_height);

        // Resample!
        if (!imagecopyresampled($dest_image_resource, $source_image_resource, 0, 0, 0, 0, $dest_image_width, $dest_image_height, $source_image_width, $source_image_height)) {
            $app->logMsg(sprintf('Error resampling image %s', $source_file), LOG_WARNING, __FILE__, __LINE__);
            return 1;
        }
        
        // Sharpen image using a custom filter matrix.
        if (phpversion() > '5.1' && true === $spec['sharpen'] && $spec['sharpen_value'] > 0) {
            $sharpen_value = round((((48 - 10) / (100 - 1)) * (100 - $spec['sharpen_value'])) + 10);
            imageconvolution($dest_image_resource, array(array(-1,-1,-1),array(-1,$sharpen_value,-1),array(-1,-1,-1)), ($sharpen_value - 8), 0);
        }

        // Save image.
        $return_val = true;
        switch ($spec['dest_file_type']) {
        case IMG_JPG :
            imageinterlace($dest_image_resource, (true == $spec['progressive'] ? 1 : 0));
            $return_val = imagejpeg($dest_image_resource, $dest_file, $spec['quality']);
            break;
        case IMG_PNG :
            $return_val = imagepng($dest_image_resource, $dest_file);
            break;
        case IMG_GIF :
            $return_val = imagegif($dest_image_resource, $dest_file);
            break;
        case IMG_WBMP :
            $return_val = imagewbmp($dest_image_resource, $dest_file);
            break;
        default :
            $app->logMsg(sprintf('Destination image type %s not supported for image %s.', $spec['dest_file_type'], $dest_file), LOG_WARNING, __FILE__, __LINE__);
            return 1;
            break;
        }

        if ($return_val) {
            // Success!
            // Make the thumbnail writable so the user can delete it over ftp without being 'apache'.
            chmod($dest_file, $this->getParam('dest_file_perms'));
            $app->logMsg(sprintf('Successfully resized image %s', $dest_file), LOG_DEBUG, __FILE__, __LINE__);
            return 0;
        } else {
            // An error occurred.
            $app->logMsg(sprintf('Image %s failed resizing.', $dest_file), LOG_ERR, __FILE__, __LINE__);
            return 1;
        }
    }

    /**
     * Delete the thumbnails for the specified file name.
     *
     * @access  public
     * @param   string $file_name The file name to delete, with extention.
     * @return  bool true on success, false on failure.
     */
    function deleteThumbs($file_name)
    {
		$app =& App::getInstance();

        // Ensure we have a source.
        if ('' == $this->getParam('source_dir')) {
            $app->logMsg(sprintf('Source directory not set before processing.'), LOG_ERR, __FILE__, __LINE__);
            return false;
        }

        $return_val = 0;
        foreach ($this->image_specs as $spec) {
            $dest_file = realpath(sprintf('%s/%s/%s.%s', $this->getParam('source_dir'), $spec['dest_dir'], substr($file_name, 0, strrpos($file_name, '.')), $spec['dest_file_extention']));
            if (file_exists($dest_file)) {
                if (!unlink($dest_file)) {
                    $return_val++;
                    $app->logMsg(sprintf('Delete thumbs failed: %s', $dest_file), LOG_WARNING, __FILE__, __LINE__);
                }
            }
        }
        $this->_raiseMsg(sprintf(_("The thumbnails for file %s have been deleted."), $file_name), MSG_SUCCESS, __FILE__, __LINE__);
        return 0 === $return_val;
    }

    /**
     * Delete the source image with the specified file name.
     *
     * @access  public
     * @param   string $file_name The file name to delete, with extention.
     * @return  bool true on success, false on failure.
     */
    function deleteOriginal($file_name)
    {
		$app =& App::getInstance();

        // Ensure we have a source.
        if ('' == $this->getParam('source_dir')) {
            $app->logMsg(sprintf('Source directory not set before processing.'), LOG_ERR, __FILE__, __LINE__);
            return false;
        }

        $source_file = realpath(sprintf('%s/%s', $this->getParam('source_dir'), $file_name));
        if (!unlink($source_file)) {
            $app->logMsg(sprintf('Delete original failed: %s', $source_file), LOG_WARNING, __FILE__, __LINE__);
            return false;
        }
        $this->_raiseMsg(sprintf(_("The original file %s has been deleted."), $file_name), MSG_SUCCESS, __FILE__, __LINE__);
        return true;
    }

    /**
     * Returns true if file exists.
     *
     * @access  public
     * @param   string $file_name The file name to test, with extention.
     * @return  bool true on success, false on failure.
     */
    function exists($file_name)
    {
		$app =& App::getInstance();

        // Ensure we have a source.
        if ('' == $this->getParam('source_dir')) {
            $app->logMsg(sprintf('Source directory not set before processing.'), LOG_ERR, __FILE__, __LINE__);
            return false;
        }

        $source_file = realpath(sprintf('%s/%s', $this->getParam('source_dir'), $file_name));
        return file_exists($source_file);
    }

    /**
     * Tests if extention of $file_name is in the array valid_file_extensions.
     *
     * @access  public
     * @param   string  $file_name  A file name.
     * @return  bool    True on success, false on failure.
     */
    function _validFileExtension($file_name)
    {
        preg_match('/.*?\.(\w+)$/i', $file_name, $ext);
        return !empty($ext) && in_array(strtolower($ext[1]), $this->getParam('valid_file_extensions'));        
    }

    /**
     * Make directory for each specified thumbnail size, if it doesn't exist.
     *
     * @access  public
     * @return  bool true on success, false on failure.
     */
    function _createDestDirs()
    {
		$app =& App::getInstance();

        static $already_checked = false;

        if (!$already_checked) {
            // Ensure we have a source.
            if ('' == $this->getParam('source_dir')) {
                $app->logMsg(sprintf('Source directory not set before creating destination directories.'), LOG_ERR, __FILE__, __LINE__);
                return false;
            }
        
            // Loop through specs and ensure all dirs are created.
            $return_val = 0;
            foreach ($this->image_specs as $spec) {
                if (!file_exists($this->getParam('source_dir') . '/' . $spec['dest_dir'])) {
                    if (!mkdir($this->getParam('source_dir') . '/' . $spec['dest_dir'], $this->getParam('dest_dir_perms'))) {
                        $return_val++;
                        $app->logMsg(sprintf('mkdir failure: %s', $this->getParam('source_dir') . '/' . $spec['dest_dir']), LOG_ERR, __FILE__, __LINE__);
                    }
                }
            }

            // If > 0, there was a problem creating dest dirs.
            return 0 === $return_val;
        }

        $already_checked = true;
    }

    /**
     * An alias for $app->raiseMsg that only sends messages configured by display_messages.
     *
     * @access public
     *
     * @param string $message The text description of the message.
     * @param int    $type    The type of message: MSG_NOTICE,
     *                        MSG_SUCCESS, MSG_WARNING, or MSG_ERR.
     * @param string $file    __FILE__.
     * @param string $line    __LINE__.
     */
    function _raiseMsg($message, $type, $file, $line)
    {
		$app =& App::getInstance();

        if ($this->getParam('display_messages') === true || (is_int($this->getParam('display_messages')) && $this->getParam('display_messages') & $type > 0)) {
            $app->raiseMsg($message, $type, $file, $line);
        }
    }

} // End of class.
?>