<?php
class WebfairyUploadHandler extends UploadHandler
{
    public $realname = '';

    protected function download()
    {
        switch ($this->options['download_via_php']) {
            case 1:
                $redirect_header = null;
                break;
            case 2:
                $redirect_header = 'X-Sendfile';
                break;
            case 3:
                $redirect_header = 'X-Accel-Redirect';
                break;
            default:
                return $this->header('HTTP/1.1 403 Forbidden');
        }
        $file_name = $this->get_file_name_param();
        if (!$this->is_valid_file_object($file_name)) {
            return $this->header('HTTP/1.1 404 Not Found');
        }
        if ($redirect_header) {
            return $this->header(
                $redirect_header.': '.$this->get_download_url(
                    $file_name,
                    $this->get_version_param(),
                    true
                )
            );
        }
        $file_path = $this->get_upload_path($file_name, $this->get_version_param());
        // Prevent browsers from MIME-sniffing the content-type:
        $this->header('X-Content-Type-Options: nosniff');
        if (!preg_match($this->options['inline_file_types'], $file_name)) {
            $this->header('Content-Type: application/octet-stream');
            $this->header('Content-Disposition: attachment; filename="'.$file_name.'"');
        } else {
            $this->header('Content-Type: '.$this->get_file_type($file_path));
            $this->header('Content-Disposition: inline; filename="'.$file_name.'"');
        }
        $this->header('Content-Length: '.$this->get_file_size($file_path));
        $this->header('Last-Modified: '.gmdate('D, d M Y H:i:s T', filemtime($file_path)));
        $this->readfile($file_path);
    }

    protected function get_file_object($file_id)
    {
        if (($file_row = $this->Webfairy->db->files[$file_id]) == false) {
            return false;
        }
        if ($this->is_valid_file_object($file_row['file_physical_name'])) {
            $file = new \stdClass();

            $file->id = $file_row['id'];
            $file->user_id = $file_row['user_id'];
            $file->name = $file->real_name = $file_row['file_real_name'];
            $file->clean_name = $file_row['file_clean_name'];
            $file->physical_name = $file_row['file_physical_name'];
            $file->size = (int) $file_row['file_size'];
            $file->type = $file_row['file_mime_type'];

            $file->url = $this->get_download_url($file_row['file_physical_name']);

            $this->set_additional_file_properties($file);

            return $file;
        }

        return;
    }

    public function delete($print_response = true)
    {
        $file_id = (int) $_REQUEST['file_id'];
        $response = array();
        if ($file_id > 0) {
            $file = $this->get_file_object($file_id);
            if ($this->Webfairy->isManager() == true  || $file->user_id == $this->Webfairy->Userid()) {
                $file_path = $this->get_upload_path($file->physical_name);
                $success = is_file($file_path) && unlink($file_path);
                $response[$file_id] = $success;
            }
        }

        return $this->generate_response($response, $print_response);
    }

    protected function set_additional_file_properties($file)
    {
        if (preg_match($this->options['inline_file_types'], $file->physical_name)) {
            $file->thumbnailUrl = $this->Webfairy->url('resized', 'thumb_'.$file->physical_name);
        } else {
            $mime_type = explode('/', $file->type);
            switch ($mime_type[0]) {
                case 'video':
                    $file->icon = 'file-video-o';
                break;

                case 'audio':
                    $file->icon = 'file-audio-o';
                break;

                case 'image':
                    $file->icon = 'file-picture-o';
                break;

                case 'text':
                    $file->icon = 'file-text';
                break;

                default :
                    $file->icon = 'file';
            }
        }
        if ($this->Webfairy->isManager() == true || $file->user_id == $this->Webfairy->Userid()) {
            $file->deleteUrl = $this->options['script_url']
                .$this->get_query_separator($this->options['script_url'])
                .$this->get_singular_param_name()
                .'='.rawurlencode($file->name)
                .'&file_id='.$file->id;
            $file->deleteType = $this->options['delete_type'];
            if ($file->deleteType !== 'DELETE') {
                $file->deleteUrl .= '&_method=DELETE';
            }
        }

        if ($this->options['access_control_allow_credentials']) {
            $file->deleteWithCredentials = true;
        }
    }

    protected function get_file_objects($iteration_method = 'get_file_object')
    {
        $upload_dir = $this->get_upload_path();
        if (!is_dir($upload_dir)) {
            return array();
        }

        return array_values(
            array_filter(
                array_map(
                    array($this, $iteration_method),
                    $this->get_files_rows()
                )
            )
        );
    }

    public function get_files_rows()
    {
        $params = (array) $this->options['params'];

        $rows =  $this->Webfairy->db->files(
            'file_extension', $this->options['accept_file_types']
        );

        if ($this->Webfairy->isManager() == false) {
            $rows->where('user_id', $this->Webfairy->Userid());
        }

        if (isset($params['group']) == true) {
            $rows->where('file_group', $params['group']);
        }

        return $rows->order('`id` DESC')->limit(25)->fetchPairs('id', 'id');
    }

    protected function trim_file_name($file_path, $name, $size, $type, $error, $index, $content_range)
    {
        $name = parent::trim_file_name($file_path, $name, $size, $type, $error, $index, $content_range);
        $this->realname = $name;

        return md5($name).'.'.pathinfo($name, PATHINFO_EXTENSION);
    }

    protected function handle_form_data($file, $index)
    {
        //$file->title = @$_REQUEST['title'][$index];
        //$file->description = @$_REQUEST['description'][$index];
    }

    public function get_tmp_file($filename)
    {
        return (isset($_SESSION['tmp_files'][$filename]) == true) ? $_SESSION['tmp_files'][$filename] : null;
    }

    public function set_tmp_file($file, $data = array())
    {
        foreach ($data as $key => $value) {
            $_SESSION['tmp_files'][$file][$key] = $value;
        }
    }

    public function clean_tmp_files()
    {
        $_SESSION['tmp_files'] = array();
    }

    public function rename_tmp_file($filename, $realname)
    {
        $extension = pathinfo($realname, PATHINFO_EXTENSION);
        $new_name = substr(md5(time()*rand()), 0, 10).'.'.$extension;
        if (rename(
            $this->get_upload_path($filename),
            $this->get_upload_path($new_name)
        )) {
            return $new_name;
        }

        return false;
    }

    protected function file_save_tmp($file, $uploaded_bytes)
    {
        if ($tmp_file = $this->get_tmp_file($file->name)) {
            $this->set_tmp_file($file->name, array('uploaded_bytes' => $uploaded_bytes));
        } else {
            $this->set_tmp_file(
                $file->name,
                array(
                    'realname' => $this->realname,
                    'cleanname' => preg_replace("/\.[^.]+$/", "", $this->realname),
                    'filename' => $file->name,
                    'extension' => pathinfo($this->realname, PATHINFO_EXTENSION),
                    'size' => $file->size,
                    'uploaded_bytes' => $uploaded_bytes,
                    'type' => $file->type,
                )
            );
        }
    }

    protected function is_file_finished_tmp($file)
    {
        if ($tmp_file = $this->get_tmp_file($file->name)) {
            if ($tmp_file['uploaded_bytes'] == $tmp_file['size']) {
                return true;
            }
        }

        return false;
    }

    protected function is_file_exist_in_tmp($file)
    {
        $answer = array();
        if ($tmp_file = $this->get_tmp_file($file->name)) {
            $answer[0] = $tmp_file['uploaded_bytes'];
            $answer[1] = $tmp_file['size'];
        }

        return $answer;
    }

    protected function handle_file_upload($uploaded_file, $name, $size, $type, $error, $index = null, $content_range = null)
    {
        $file = new \stdClass();
        $file->user_id = $this->Webfairy->Userid();
        $file->real_name = $name;
        $file->name = $this->get_file_name($uploaded_file, $name, $size, $type, $error, $index, $content_range);
        $file->size = $this->fix_integer_overflow(intval($size));
        $file->type = $type;

        $check_file_exist = $this->is_file_exist_in_tmp($file);
        if (is_array($check_file_exist) && (count($check_file_exist) > 0)) {
            if ($content_range[1] < $check_file_exist[0]) {
                $file->size = $check_file_exist[0];

                return $file;
            }
        }

        if ($this->validate($uploaded_file, $file, $error, $index)) {
            $this->handle_form_data($file, $index);
            $upload_dir = $this->get_upload_path();
            if (!is_dir($upload_dir)) {
                mkdir($upload_dir, $this->options['mkdir_mode'], true);
            }
            $file_path = $this->get_upload_path($file->name);
            $append_file = $content_range && is_file($file_path) &&
                $file->size > $this->get_file_size($file_path);
            if ($uploaded_file && is_uploaded_file($uploaded_file)) {
                // multipart/formdata uploads (POST method uploads)
                if ($append_file) {
                    file_put_contents(
                        $file_path,
                        fopen($uploaded_file, 'r'),
                        FILE_APPEND
                    );
                } else {
                    move_uploaded_file($uploaded_file, $file_path);
                }
            } else {
                // Non-multipart uploads (PUT method support)
                file_put_contents(
                    $file_path,
                    fopen('php://input', 'r'),
                    $append_file ? FILE_APPEND : 0
                );
            }
            $file_size = $this->get_file_size($file_path, $append_file);
            if ($file_size === $file->size) {
                $this->file_save_tmp($file, $file_size);
                if ($this->is_file_finished_tmp($file)) {
                    $file->physical_name = $this->rename_tmp_file($file->name, $this->realname);

                    if ($tmp_file = $this->get_tmp_file($file->name)) {
                        if ($row = $this->Webfairy->db->files()->insert(
                            array(
                                'file_group' => (isset($this->options['params']['group']) == true) ? $this->options['params']['group'] : 1,
                                'user_id' => $file->user_id,
                                'file_real_name' => $tmp_file['realname'],
                                'file_clean_name' => $tmp_file['cleanname'],
                                'file_physical_name' => $file->physical_name,
                                'file_size' => $file->size,
                                'file_mime_type' => $file->type,
                                'file_extension' => $tmp_file['extension'],
                                'file_time' => time(),
                            )
                        )) {
                            $file->id = $row['id'];
                        }
                    }
                    $this->clean_tmp_files();
                }
                $file_path = $this->get_upload_path($file->physical_name);

                if ($this->is_valid_image_file($file_path)) {
                    $file->name = $file->physical_name;
                    $this->handle_image_file($file_path, $file);
                }

                $this->set_additional_file_properties($file);
            } else {
                $this->file_save_tmp($file, $file_size);
                $file->size = $file_size;
                if (!$content_range && $this->options['discard_aborted_uploads']) {
                    unlink($file_path);
                    $file->error = $this->get_error_message('abort');
                }
            }
        }

        return $file;
    }
}

class UploadHandler
{
    protected $Webfairy;
    protected $options;

    // PHP File Upload error message codes:
    // http://php.net/manual/en/features.file-upload.errors.php
    protected $error_messages = array();

    protected $image_objects = array();

    public function __construct($Webfairy, $options = null, $initialize = true, $error_messages = null)
    {
        $this->Webfairy = $Webfairy;

        $this->error_messages = array(
            1 => tr('upload_err_1'),
            2 => tr('upload_err_2'),
            3 => tr('upload_err_3'),
            4 => tr('upload_err_4'),
            6 => tr('upload_err_6'),
            7 => tr('upload_err_7'),
            8 => tr('upload_err_8'),
            'post_max_size' => tr('upload_post_max_size'),
            'max_file_size' => tr('upload_max_file_size'),
            'min_file_size' => tr('upload_min_file_size'),
            'accept_file_types' => tr('upload_accept_types'),
            'max_number_of_files' => tr('upload_max_files'),
            'max_width' => tr('upload_max_width'),
            'min_width' => tr('upload_min_width'),
            'max_height' => tr('upload_max_height'),
            'min_height' => tr('upload_min_height'),
            'abort' => tr('upload_abort'),
            'image_resize' => tr('upload_image_resize'),
        );

        $this->options = array(
            'script_url' => $this->get_full_url().'/',
            'upload_dir' => dirname($this->get_server_var('SCRIPT_FILENAME')).'/files/',
            'upload_url' => $this->get_full_url().'/files/',
            'user_dirs' => false,
            'mkdir_mode' => 0755,
            'param_name' => 'files',
            // Set the following option to 'POST', if your server does not support
            // DELETE requests. This is a parameter sent to the client:
            'delete_type' => 'DELETE',
            'access_control_allow_origin' => '*',
            'access_control_allow_credentials' => false,
            'access_control_allow_methods' => array(
                'OPTIONS',
                'HEAD',
                'GET',
                'POST',
                'PUT',
                'PATCH',
                'DELETE',
            ),
            'access_control_allow_headers' => array(
                'Content-Type',
                'Content-Range',
                'Content-Disposition',
            ),
            // Enable to provide file downloads via GET requests to the PHP script:
            //     1. Set to 1 to download files via readfile method through PHP
            //     2. Set to 2 to send a X-Sendfile header for lighttpd/Apache
            //     3. Set to 3 to send a X-Accel-Redirect header for nginx
            // If set to 2 or 3, adjust the upload_url option to the base path of
            // the redirect parameter, e.g. '/files/'.
            'download_via_php' => false,
            // Read files in chunks to avoid memory limits when download_via_php
            // is enabled, set to 0 to disable chunked reading of files:
            'readfile_chunk_size' => 2 * 1024 * 1024,
            // Defines which files can be displayed inline when downloaded:
            'inline_file_types' => '/\.(gif|jpe?g|png)$/i',
            // Defines which files (based on their names) are accepted for upload:
            'accept_file_types' => array(),
            // The php.ini settings upload_max_filesize and post_max_size
            // take precedence over the following max_file_size setting:
            'max_file_size' => null,
            'min_file_size' => 1,
            // The maximum number of files for the upload directory:
            'max_number_of_files' => null,
            // Defines which files are handled as image files:
            'image_file_types' => '/\.(gif|jpe?g|png)$/i',
            // Image resolution restrictions:
            'max_width' => null,
            'max_height' => null,
            'min_width' => 1,
            'min_height' => 1,
            // Set the following option to false to enable resumable uploads:
            'discard_aborted_uploads' => false,
            // Set to 0 to use the GD library to scale and orient images,
            // set to 1 to use imagick (if installed, falls back to GD),
            // set to 2 to use the ImageMagick convert binary directly:
            'image_library' => 0,
            // Uncomment the following to define an array of resource limits
            // for imagick:
            /*
            'imagick_resource_limits' => array(
                imagick::RESOURCETYPE_MAP => 32,
                imagick::RESOURCETYPE_MEMORY => 32
            ),
            */
            // Command or path for to the ImageMagick convert binary:
            'convert_bin' => 'convert',
            // Uncomment the following to add parameters in front of each
            // ImageMagick convert call (the limit constraints seem only
            // to have an effect if put in front):
            /*
            'convert_params' => '-limit memory 32MiB -limit map 32MiB',
            */
            // Command or path for to the ImageMagick identify binary:
            'identify_bin' => 'identify',
            'image_versions' => array(
                // The empty image version key defines options for the original image:
                '' => array(
                    'auto_orient' => true,
                ),
                // Uncomment the following to create medium sized images:
                /*
                'medium' => array(
                    'max_width' => 800,
                    'max_height' => 600
                ),

                'thumbnail' => array(
                    // Uncomment the following to use a defined directory for the thumbnails
                    // instead of a subdirectory based on the version identifier.
                    // Make sure that this directory doesn't allow execution of files if you
                    // don't pose any restrictions on the type of uploaded files, e.g. by
                    // copying the .htaccess file from the files directory for Apache:
                    //'upload_dir' => dirname($this->get_server_var('SCRIPT_FILENAME')).'/thumb/',
                    //'upload_url' => $this->get_full_url().'/thumb/',
                    // Uncomment the following to force the max
                    // dimensions and e.g. create square thumbnails:
                    //'crop' => true,
                    'max_width' => 80,
                    'max_height' => 80
                )
                */
            ),
        );
        if ($options) {
            $this->options = $options + $this->options;
        }
        if ($error_messages) {
            $this->error_messages = $error_messages + $this->error_messages;
        }
        if ($initialize) {
            $this->initialize();
        }
    }

    protected function initialize()
    {
        switch ($this->get_server_var('REQUEST_METHOD')) {
            case 'OPTIONS':
            case 'HEAD':
                $this->head();
                break;
            case 'GET':
                $this->get();
                break;
            case 'PATCH':
            case 'PUT':
            case 'POST':
                $this->post();
                break;
            case 'DELETE':
                $this->delete();
                break;
            default:
                $this->header('HTTP/1.1 405 Method Not Allowed');
        }
    }

    protected function get_full_url()
    {
        $https = !empty($_SERVER['HTTPS']) && strcasecmp($_SERVER['HTTPS'], 'on') === 0 ||
            !empty($_SERVER['HTTP_X_FORWARDED_PROTO']) &&
                strcasecmp($_SERVER['HTTP_X_FORWARDED_PROTO'], 'https') === 0;

        return
            ($https ? 'https://' : 'http://').
            (!empty($_SERVER['REMOTE_USER']) ? $_SERVER['REMOTE_USER'].'@' : '').
            (isset($_SERVER['HTTP_HOST']) ? $_SERVER['HTTP_HOST'] : ($_SERVER['SERVER_NAME'].
            ($https && $_SERVER['SERVER_PORT'] === 443 ||
            $_SERVER['SERVER_PORT'] === 80 ? '' : ':'.$_SERVER['SERVER_PORT']))).
            substr($_SERVER['SCRIPT_NAME'], 0, strrpos($_SERVER['SCRIPT_NAME'], '/'));
    }

    protected function get_user_id()
    {
        @session_start();

        return session_id();
    }

    protected function get_user_path()
    {
        if ($this->options['user_dirs']) {
            return $this->get_user_id().'/';
        }

        return '';
    }

    protected function get_upload_path($file_name = null, $version = null)
    {
        $file_name = $file_name ? $file_name : '';
        if (empty($version)) {
            $version_path = '';
        } else {
            $version_dir = @$this->options['image_versions'][$version]['upload_dir'];
            if ($version_dir) {
                return $version_dir.$this->get_user_path().$file_name;
            }
            $version_path = $version.'/';
        }

        return $this->options['upload_dir'].$this->get_user_path()
            .$version_path.$file_name;
    }

    protected function get_query_separator($url)
    {
        return strpos($url, '?') === false ? '?' : '&';
    }

    protected function get_download_url($file_name, $version = null, $direct = false)
    {
        if (!$direct && $this->options['download_via_php']) {
            $url = $this->options['script_url']
                .$this->get_query_separator($this->options['script_url'])
                .$this->get_singular_param_name()
                .'='.rawurlencode($file_name);
            if ($version) {
                $url .= '&version='.rawurlencode($version);
            }

            return $url.'&download=1';
        }
        if (empty($version)) {
            $version_path = '';
        } else {
            $version_url = @$this->options['image_versions'][$version]['upload_url'];
            if ($version_url) {
                return $version_url.$this->get_user_path().rawurlencode($file_name);
            }
            $version_path = rawurlencode($version).'/';
        }

        return $this->options['upload_url'].$this->get_user_path()
            .$version_path.rawurlencode($file_name);
    }

    protected function set_additional_file_properties($file)
    {
        $file->deleteUrl = $this->options['script_url']
            .$this->get_query_separator($this->options['script_url'])
            .$this->get_singular_param_name()
            .'='.rawurlencode($file->name);
        $file->deleteType = $this->options['delete_type'];
        if ($file->deleteType !== 'DELETE') {
            $file->deleteUrl .= '&_method=DELETE';
        }
        if ($this->options['access_control_allow_credentials']) {
            $file->deleteWithCredentials = true;
        }
    }

    // Fix for overflowing signed 32 bit integers,
    // works for sizes up to 2^32-1 bytes (4 GiB - 1):
    protected function fix_integer_overflow($size)
    {
        if ($size < 0) {
            $size += 2.0 * (PHP_INT_MAX + 1);
        }

        return $size;
    }

    protected function get_file_size($file_path, $clear_stat_cache = false)
    {
        if ($clear_stat_cache) {
            if (version_compare(PHP_VERSION, '5.3.0') >= 0) {
                clearstatcache(true, $file_path);
            } else {
                clearstatcache();
            }
        }

        return $this->fix_integer_overflow(filesize($file_path));
    }

    protected function is_valid_file_object($file_name)
    {
        $file_path = $this->get_upload_path($file_name);
        if (is_file($file_path) && $file_name[0] !== '.') {
            return true;
        }

        return false;
    }

    protected function get_file_object($file_name)
    {
        if ($this->is_valid_file_object($file_name)) {
            $file = new \stdClass();
            $file->name = $file_name;
            $file->size = $this->get_file_size(
                $this->get_upload_path($file_name)
            );
            $file->url = $this->get_download_url($file->name);
            foreach ($this->options['image_versions'] as $version => $options) {
                if (!empty($version)) {
                    if (is_file($this->get_upload_path($file_name, $version))) {
                        $file->{$version.'Url'} = $this->get_download_url(
                            $file->name,
                            $version
                        );
                    }
                }
            }
            $this->set_additional_file_properties($file);

            return $file;
        }

        return;
    }

    protected function get_file_objects($iteration_method = 'get_file_object')
    {
        $upload_dir = $this->get_upload_path();
        if (!is_dir($upload_dir)) {
            return array();
        }

        return array_values(array_filter(array_map(
            array($this, $iteration_method),
            scandir($upload_dir)
        )));
    }

    protected function count_file_objects()
    {
        return count($this->get_file_objects('is_valid_file_object'));
    }

    protected function get_error_message($error)
    {
        return array_key_exists($error, $this->error_messages) ?
            $this->error_messages[$error] : $error;
    }

    public function get_config_bytes($val)
    {
        $val = trim($val);
        $last = strtolower($val[strlen($val)-1]);
        switch ($last) {
            case 'g':
                $val *= 1024;
            case 'm':
                $val *= 1024;
            case 'k':
                $val *= 1024;
        }

        return $this->fix_integer_overflow($val);
    }

    protected function validate($uploaded_file, $file, $error, $index)
    {
        if ($error) {
            $file->error = $this->get_error_message($error);

            return false;
        }
        $content_length = $this->fix_integer_overflow(intval(
            $this->get_server_var('CONTENT_LENGTH')
        ));
        $post_max_size = $this->get_config_bytes(ini_get('post_max_size'));
        if ($post_max_size && ($content_length > $post_max_size)) {
            $file->error = $this->get_error_message('post_max_size');

            return false;
        }
        if (!preg_match('/\.('.implode('|', $this->options['accept_file_types']).')$/i', $file->name)) {
            $file->error = $this->get_error_message('accept_file_types');

            return false;
        }
        if ($uploaded_file && is_uploaded_file($uploaded_file)) {
            $file_size = $this->get_file_size($uploaded_file);
        } else {
            $file_size = $content_length;
        }
        if ($this->options['max_file_size'] && (
                $file_size > $this->options['max_file_size'] ||
                $file->size > $this->options['max_file_size'])
            ) {
            $file->error = $this->get_error_message('max_file_size');

            return false;
        }
        if ($this->options['min_file_size'] &&
            $file_size < $this->options['min_file_size']) {
            $file->error = $this->get_error_message('min_file_size');

            return false;
        }
        if (is_int($this->options['max_number_of_files']) &&
                ($this->count_file_objects() >= $this->options['max_number_of_files']) &&
                // Ignore additional chunks of existing files:
                !is_file($this->get_upload_path($file->name))) {
            $file->error = $this->get_error_message('max_number_of_files');

            return false;
        }
        $max_width = @$this->options['max_width'];
        $max_height = @$this->options['max_height'];
        $min_width = @$this->options['min_width'];
        $min_height = @$this->options['min_height'];
        if (($max_width || $max_height || $min_width || $min_height)
           && preg_match($this->options['image_file_types'], $file->name)) {
            list($img_width, $img_height) = $this->get_image_size($uploaded_file);
        }
        if (!empty($img_width)) {
            if ($max_width && $img_width > $max_width) {
                $file->error = $this->get_error_message('max_width');

                return false;
            }
            if ($max_height && $img_height > $max_height) {
                $file->error = $this->get_error_message('max_height');

                return false;
            }
            if ($min_width && $img_width < $min_width) {
                $file->error = $this->get_error_message('min_width');

                return false;
            }
            if ($min_height && $img_height < $min_height) {
                $file->error = $this->get_error_message('min_height');

                return false;
            }
        }

        return true;
    }

    protected function upcount_name_callback($matches)
    {
        $index = isset($matches[1]) ? intval($matches[1]) + 1 : 1;
        $ext = isset($matches[2]) ? $matches[2] : '';

        return ' ('.$index.')'.$ext;
    }

    protected function upcount_name($name)
    {
        return preg_replace_callback(
            '/(?:(?: \(([\d]+)\))?(\.[^.]+))?$/',
            array($this, 'upcount_name_callback'),
            $name,
            1
        );
    }

    protected function get_unique_filename($file_path, $name, $size, $type, $error,
            $index, $content_range)
    {
        while (is_dir($this->get_upload_path($name))) {
            $name = $this->upcount_name($name);
        }
        // Keep an existing filename if this is part of a chunked upload:
        $uploaded_bytes = $this->fix_integer_overflow(intval($content_range[1]));
        while (is_file($this->get_upload_path($name))) {
            if ($uploaded_bytes === $this->get_file_size(
                    $this->get_upload_path($name))) {
                break;
            }
            $name = $this->upcount_name($name);
        }

        return $name;
    }

    protected function trim_file_name($file_path, $name, $size, $type, $error,
            $index, $content_range)
    {
        // Remove path information and dots around the filename, to prevent uploading
        // into different directories or replacing hidden system files.
        // Also remove control characters and spaces (\x00..\x20) around the filename:
        $name = trim(basename(stripslashes($name)), ".\x00..\x20");
        // Use a timestamp for empty filenames:
        if (!$name) {
            $name = str_replace('.', '-', microtime(true));
        }
        // Add missing file extension for known image types:
        if (strpos($name, '.') === false &&
                preg_match('/^image\/(gif|jpe?g|png)/', $type, $matches)) {
            $name .= '.'.$matches[1];
        }
        if (function_exists('exif_imagetype')) {
            switch (@exif_imagetype($file_path)) {
                case IMAGETYPE_JPEG:
                    $extensions = array('jpg', 'jpeg');
                    break;
                case IMAGETYPE_PNG:
                    $extensions = array('png');
                    break;
                case IMAGETYPE_GIF:
                    $extensions = array('gif');
                    break;
            }
            // Adjust incorrect image file extensions:
            if (!empty($extensions)) {
                $parts = explode('.', $name);
                $extIndex = count($parts) - 1;
                $ext = strtolower(@$parts[$extIndex]);
                if (!in_array($ext, $extensions)) {
                    $parts[$extIndex] = $extensions[0];
                    $name = implode('.', $parts);
                }
            }
        }

        return $name;
    }

    protected function get_file_name($file_path, $name, $size, $type, $error,
            $index, $content_range)
    {
        return $this->get_unique_filename(
            $file_path,
            $this->trim_file_name($file_path, $name, $size, $type, $error,
                $index, $content_range),
            $size,
            $type,
            $error,
            $index,
            $content_range
        );
    }

    protected function handle_form_data($file, $index)
    {
        // Handle form data, e.g. $_REQUEST['description'][$index]
    }

    protected function get_scaled_image_file_paths($file_name, $version)
    {
        $file_path = $this->get_upload_path($file_name);
        if (!empty($version)) {
            $version_dir = $this->get_upload_path(null, $version);
            if (!is_dir($version_dir)) {
                mkdir($version_dir, $this->options['mkdir_mode'], true);
            }
            $new_file_path = $version_dir.'/'.$file_name;
        } else {
            $new_file_path = $file_path;
        }

        return array($file_path, $new_file_path);
    }

    protected function gd_get_image_object($file_path, $func, $no_cache = false)
    {
        if (empty($this->image_objects[$file_path]) || $no_cache) {
            $this->gd_destroy_image_object($file_path);
            $this->image_objects[$file_path] = $func($file_path);
        }

        return $this->image_objects[$file_path];
    }

    protected function gd_set_image_object($file_path, $image)
    {
        $this->gd_destroy_image_object($file_path);
        $this->image_objects[$file_path] = $image;
    }

    protected function gd_destroy_image_object($file_path)
    {
        $image = (isset($this->image_objects[$file_path])) ? $this->image_objects[$file_path] : null;

        return $image && imagedestroy($image);
    }

    protected function gd_imageflip($image, $mode)
    {
        if (function_exists('imageflip')) {
            return imageflip($image, $mode);
        }
        $new_width = $src_width = imagesx($image);
        $new_height = $src_height = imagesy($image);
        $new_img = imagecreatetruecolor($new_width, $new_height);
        $src_x = 0;
        $src_y = 0;
        switch ($mode) {
            case '1': // flip on the horizontal axis
                $src_y = $new_height - 1;
                $src_height = -$new_height;
                break;
            case '2': // flip on the vertical axis
                $src_x  = $new_width - 1;
                $src_width = -$new_width;
                break;
            case '3': // flip on both axes
                $src_y = $new_height - 1;
                $src_height = -$new_height;
                $src_x  = $new_width - 1;
                $src_width = -$new_width;
                break;
            default:
                return $image;
        }
        imagecopyresampled(
            $new_img,
            $image,
            0,
            0,
            $src_x,
            $src_y,
            $new_width,
            $new_height,
            $src_width,
            $src_height
        );

        return $new_img;
    }

    protected function gd_orient_image($file_path, $src_img)
    {
        if (!function_exists('exif_read_data')) {
            return false;
        }
        $exif = @exif_read_data($file_path);
        if ($exif === false) {
            return false;
        }
        $orientation = intval(@$exif['Orientation']);
        if ($orientation < 2 || $orientation > 8) {
            return false;
        }
        switch ($orientation) {
            case 2:
                $new_img = $this->gd_imageflip(
                    $src_img,
                    defined('IMG_FLIP_VERTICAL') ? IMG_FLIP_VERTICAL : 2
                );
                break;
            case 3:
                $new_img = imagerotate($src_img, 180, 0);
                break;
            case 4:
                $new_img = $this->gd_imageflip(
                    $src_img,
                    defined('IMG_FLIP_HORIZONTAL') ? IMG_FLIP_HORIZONTAL : 1
                );
                break;
            case 5:
                $tmp_img = $this->gd_imageflip(
                    $src_img,
                    defined('IMG_FLIP_HORIZONTAL') ? IMG_FLIP_HORIZONTAL : 1
                );
                $new_img = imagerotate($tmp_img, 270, 0);
                imagedestroy($tmp_img);
                break;
            case 6:
                $new_img = imagerotate($src_img, 270, 0);
                break;
            case 7:
                $tmp_img = $this->gd_imageflip(
                    $src_img,
                    defined('IMG_FLIP_VERTICAL') ? IMG_FLIP_VERTICAL : 2
                );
                $new_img = imagerotate($tmp_img, 270, 0);
                imagedestroy($tmp_img);
                break;
            case 8:
                $new_img = imagerotate($src_img, 90, 0);
                break;
            default:
                return false;
        }
        $this->gd_set_image_object($file_path, $new_img);

        return true;
    }

    protected function gd_create_scaled_image($file_name, $version, $options)
    {
        if (!function_exists('imagecreatetruecolor')) {
            error_log('Function not found: imagecreatetruecolor');

            return false;
        }
        list($file_path, $new_file_path) =
            $this->get_scaled_image_file_paths($file_name, $version);
        $type = strtolower(substr(strrchr($file_name, '.'), 1));
        switch ($type) {
            case 'jpg':
            case 'jpeg':
                $src_func = 'imagecreatefromjpeg';
                $write_func = 'imagejpeg';
                $image_quality = isset($options['jpeg_quality']) ?
                    $options['jpeg_quality'] : 75;
                break;
            case 'gif':
                $src_func = 'imagecreatefromgif';
                $write_func = 'imagegif';
                $image_quality = null;
                break;
            case 'png':
                $src_func = 'imagecreatefrompng';
                $write_func = 'imagepng';
                $image_quality = isset($options['png_quality']) ?
                    $options['png_quality'] : 9;
                break;
            default:
                return false;
        }
        $src_img = $this->gd_get_image_object(
            $file_path,
            $src_func,
            !empty($options['no_cache'])
        );
        $image_oriented = false;
        if (!empty($options['auto_orient']) && $this->gd_orient_image(
                $file_path,
                $src_img
            )) {
            $image_oriented = true;
            $src_img = $this->gd_get_image_object(
                $file_path,
                $src_func
            );
        }
        $max_width = $img_width = imagesx($src_img);
        $max_height = $img_height = imagesy($src_img);
        if (!empty($options['max_width'])) {
            $max_width = $options['max_width'];
        }
        if (!empty($options['max_height'])) {
            $max_height = $options['max_height'];
        }
        $scale = min(
            $max_width / $img_width,
            $max_height / $img_height
        );
        if ($scale >= 1) {
            if ($image_oriented) {
                return $write_func($src_img, $new_file_path, $image_quality);
            }
            if ($file_path !== $new_file_path) {
                return copy($file_path, $new_file_path);
            }

            return true;
        }
        if (empty($options['crop'])) {
            $new_width = $img_width * $scale;
            $new_height = $img_height * $scale;
            $dst_x = 0;
            $dst_y = 0;
            $new_img = imagecreatetruecolor($new_width, $new_height);
        } else {
            if (($img_width / $img_height) >= ($max_width / $max_height)) {
                $new_width = $img_width / ($img_height / $max_height);
                $new_height = $max_height;
            } else {
                $new_width = $max_width;
                $new_height = $img_height / ($img_width / $max_width);
            }
            $dst_x = 0 - ($new_width - $max_width) / 2;
            $dst_y = 0 - ($new_height - $max_height) / 2;
            $new_img = imagecreatetruecolor($max_width, $max_height);
        }
        // Handle transparency in GIF and PNG images:
        switch ($type) {
            case 'gif':
            case 'png':
                imagecolortransparent($new_img, imagecolorallocate($new_img, 0, 0, 0));
            case 'png':
                imagealphablending($new_img, false);
                imagesavealpha($new_img, true);
                break;
        }
        $success = imagecopyresampled(
            $new_img,
            $src_img,
            $dst_x,
            $dst_y,
            0,
            0,
            $new_width,
            $new_height,
            $img_width,
            $img_height
        ) && $write_func($new_img, $new_file_path, $image_quality);
        $this->gd_set_image_object($file_path, $new_img);

        return $success;
    }

    protected function imagick_get_image_object($file_path, $no_cache = false)
    {
        if (empty($this->image_objects[$file_path]) || $no_cache) {
            $this->imagick_destroy_image_object($file_path);
            $image = new \Imagick();
            if (!empty($this->options['imagick_resource_limits'])) {
                foreach ($this->options['imagick_resource_limits'] as $type => $limit) {
                    $image->setResourceLimit($type, $limit);
                }
            }
            $image->readImage($file_path);
            $this->image_objects[$file_path] = $image;
        }

        return $this->image_objects[$file_path];
    }

    protected function imagick_set_image_object($file_path, $image)
    {
        $this->imagick_destroy_image_object($file_path);
        $this->image_objects[$file_path] = $image;
    }

    protected function imagick_destroy_image_object($file_path)
    {
        $image = (isset($this->image_objects[$file_path])) ? $this->image_objects[$file_path] : null;

        return $image && $image->destroy();
    }

    protected function imagick_orient_image($image)
    {
        $orientation = $image->getImageOrientation();
        $background = new \ImagickPixel('none');
        switch ($orientation) {
            case \imagick::ORIENTATION_TOPRIGHT: // 2
                $image->flopImage(); // horizontal flop around y-axis
                break;
            case \imagick::ORIENTATION_BOTTOMRIGHT: // 3
                $image->rotateImage($background, 180);
                break;
            case \imagick::ORIENTATION_BOTTOMLEFT: // 4
                $image->flipImage(); // vertical flip around x-axis
                break;
            case \imagick::ORIENTATION_LEFTTOP: // 5
                $image->flopImage(); // horizontal flop around y-axis
                $image->rotateImage($background, 270);
                break;
            case \imagick::ORIENTATION_RIGHTTOP: // 6
                $image->rotateImage($background, 90);
                break;
            case \imagick::ORIENTATION_RIGHTBOTTOM: // 7
                $image->flipImage(); // vertical flip around x-axis
                $image->rotateImage($background, 270);
                break;
            case \imagick::ORIENTATION_LEFTBOTTOM: // 8
                $image->rotateImage($background, 270);
                break;
            default:
                return false;
        }
        $image->setImageOrientation(\imagick::ORIENTATION_TOPLEFT); // 1
        return true;
    }

    protected function imagick_create_scaled_image($file_name, $version, $options)
    {
        list($file_path, $new_file_path) =
            $this->get_scaled_image_file_paths($file_name, $version);
        $image = $this->imagick_get_image_object(
            $file_path,
            !empty($options['no_cache'])
        );
        if ($image->getImageFormat() === 'GIF') {
            // Handle animated GIFs:
            $images = $image->coalesceImages();
            foreach ($images as $frame) {
                $image = $frame;
                $this->imagick_set_image_object($file_name, $image);
                break;
            }
        }
        $image_oriented = false;
        if (!empty($options['auto_orient'])) {
            $image_oriented = $this->imagick_orient_image($image);
        }
        $new_width = $max_width = $img_width = $image->getImageWidth();
        $new_height = $max_height = $img_height = $image->getImageHeight();
        if (!empty($options['max_width'])) {
            $new_width = $max_width = $options['max_width'];
        }
        if (!empty($options['max_height'])) {
            $new_height = $max_height = $options['max_height'];
        }
        if (!($image_oriented || $max_width < $img_width || $max_height < $img_height)) {
            if ($file_path !== $new_file_path) {
                return copy($file_path, $new_file_path);
            }

            return true;
        }
        $crop = !empty($options['crop']);
        if ($crop) {
            $x = 0;
            $y = 0;
            if (($img_width / $img_height) >= ($max_width / $max_height)) {
                $new_width = 0; // Enables proportional scaling based on max_height
                $x = ($img_width / ($img_height / $max_height) - $max_width) / 2;
            } else {
                $new_height = 0; // Enables proportional scaling based on max_width
                $y = ($img_height / ($img_width / $max_width) - $max_height) / 2;
            }
        }
        $success = $image->resizeImage(
            $new_width,
            $new_height,
            isset($options['filter']) ? $options['filter'] : \imagick::FILTER_LANCZOS,
            isset($options['blur']) ? $options['blur'] : 1,
            $new_width && $new_height // fit image into constraints if not to be cropped
        );
        if ($success && $crop) {
            $success = $image->cropImage(
                $max_width,
                $max_height,
                $x,
                $y
            );
            if ($success) {
                $success = $image->setImagePage($max_width, $max_height, 0, 0);
            }
        }
        $type = strtolower(substr(strrchr($file_name, '.'), 1));
        switch ($type) {
            case 'jpg':
            case 'jpeg':
                if (!empty($options['jpeg_quality'])) {
                    $image->setImageCompression(\imagick::COMPRESSION_JPEG);
                    $image->setImageCompressionQuality($options['jpeg_quality']);
                }
                break;
        }
        if (!empty($options['strip'])) {
            $image->stripImage();
        }

        return $success && $image->writeImage($new_file_path);
    }

    protected function imagemagick_create_scaled_image($file_name, $version, $options)
    {
        list($file_path, $new_file_path) =
            $this->get_scaled_image_file_paths($file_name, $version);
        $resize = @$options['max_width']
            .(empty($options['max_height']) ? '' : 'X'.$options['max_height']);
        if (!$resize && empty($options['auto_orient'])) {
            if ($file_path !== $new_file_path) {
                return copy($file_path, $new_file_path);
            }

            return true;
        }
        $cmd = $this->options['convert_bin'];
        if (!empty($this->options['convert_params'])) {
            $cmd .= ' '.$this->options['convert_params'];
        }
        $cmd .= ' '.escapeshellarg($file_path);
        if (!empty($options['auto_orient'])) {
            $cmd .= ' -auto-orient';
        }
        if ($resize) {
            // Handle animated GIFs:
            $cmd .= ' -coalesce';
            if (empty($options['crop'])) {
                $cmd .= ' -resize '.escapeshellarg($resize.'>');
            } else {
                $cmd .= ' -resize '.escapeshellarg($resize.'^');
                $cmd .= ' -gravity center';
                $cmd .= ' -crop '.escapeshellarg($resize.'+0+0');
            }
            // Make sure the page dimensions are correct (fixes offsets of animated GIFs):
            $cmd .= ' +repage';
        }
        if (!empty($options['convert_params'])) {
            $cmd .= ' '.$options['convert_params'];
        }
        $cmd .= ' '.escapeshellarg($new_file_path);
        exec($cmd, $output, $error);
        if ($error) {
            error_log(implode('\n', $output));

            return false;
        }

        return true;
    }

    protected function get_image_size($file_path)
    {
        if ($this->options['image_library']) {
            if (extension_loaded('imagick')) {
                $image = new \Imagick();
                try {
                    if (@$image->pingImage($file_path)) {
                        $dimensions = array($image->getImageWidth(), $image->getImageHeight());
                        $image->destroy();

                        return $dimensions;
                    }

                    return false;
                } catch (Exception $e) {
                    error_log($e->getMessage());
                }
            }
            if ($this->options['image_library'] === 2) {
                $cmd = $this->options['identify_bin'];
                $cmd .= ' -ping '.escapeshellarg($file_path);
                exec($cmd, $output, $error);
                if (!$error && !empty($output)) {
                    // image.jpg JPEG 1920x1080 1920x1080+0+0 8-bit sRGB 465KB 0.000u 0:00.000
                    $infos = preg_split('/\s+/', $output[0]);
                    $dimensions = preg_split('/x/', $infos[2]);

                    return $dimensions;
                }

                return false;
            }
        }
        if (!function_exists('getimagesize')) {
            error_log('Function not found: getimagesize');

            return false;
        }

        return @getimagesize($file_path);
    }

    protected function create_scaled_image($file_name, $version, $options)
    {
        if ($this->options['image_library'] === 2) {
            return $this->imagemagick_create_scaled_image($file_name, $version, $options);
        }
        if ($this->options['image_library'] && extension_loaded('imagick')) {
            return $this->imagick_create_scaled_image($file_name, $version, $options);
        }

        return $this->gd_create_scaled_image($file_name, $version, $options);
    }

    protected function destroy_image_object($file_path)
    {
        if ($this->options['image_library'] && extension_loaded('imagick')) {
            return $this->imagick_destroy_image_object($file_path);
        }
    }

    protected function is_valid_image_file($file_path)
    {
        if (!preg_match($this->options['image_file_types'], $file_path)) {
            return false;
        }
        if (function_exists('exif_imagetype')) {
            return @exif_imagetype($file_path);
        }
        $image_info = $this->get_image_size($file_path);

        return $image_info && $image_info[0] && $image_info[1];
    }

    protected function handle_image_file($file_path, $file)
    {
        $failed_versions = array();
        foreach ($this->options['image_versions'] as $version => $options) {
            if ($this->create_scaled_image($file->name, $version, $options)) {
                if (!empty($version)) {
                    $file->{$version.'Url'} = $this->get_download_url(
                        $file->name,
                        $version
                    );
                } else {
                    $file->size = $this->get_file_size($file_path, true);
                }
            } else {
                $failed_versions[] = $version ? $version : 'original';
            }
        }
        if (count($failed_versions)) {
            $file->error = $this->get_error_message('image_resize')
                    .' ('.implode($failed_versions, ', ').')';
        }
        // Free memory:
        $this->destroy_image_object($file_path);
    }

    protected function handle_file_upload($uploaded_file, $name, $size, $type, $error,
            $index = null, $content_range = null)
    {
        $file = new \stdClass();
        $file->name = $this->get_file_name($uploaded_file, $name, $size, $type, $error,
            $index, $content_range);
        $file->size = $this->fix_integer_overflow(intval($size));
        $file->type = $type;
        if ($this->validate($uploaded_file, $file, $error, $index)) {
            $this->handle_form_data($file, $index);
            $upload_dir = $this->get_upload_path();
            if (!is_dir($upload_dir)) {
                mkdir($upload_dir, $this->options['mkdir_mode'], true);
            }
            $file_path = $this->get_upload_path($file->name);
            $append_file = $content_range && is_file($file_path) &&
                $file->size > $this->get_file_size($file_path);
            if ($uploaded_file && is_uploaded_file($uploaded_file)) {
                // multipart/formdata uploads (POST method uploads)
                if ($append_file) {
                    file_put_contents(
                        $file_path,
                        fopen($uploaded_file, 'r'),
                        FILE_APPEND
                    );
                } else {
                    move_uploaded_file($uploaded_file, $file_path);
                }
            } else {
                // Non-multipart uploads (PUT method support)
                file_put_contents(
                    $file_path,
                    fopen('php://input', 'r'),
                    $append_file ? FILE_APPEND : 0
                );
            }
            $file_size = $this->get_file_size($file_path, $append_file);
            if ($file_size === $file->size) {
                $file->url = $this->get_download_url($file->name);
                if ($this->is_valid_image_file($file_path)) {
                    $this->handle_image_file($file_path, $file);
                }
            } else {
                $file->size = $file_size;
                if (!$content_range && $this->options['discard_aborted_uploads']) {
                    unlink($file_path);
                    $file->error = $this->get_error_message('abort');
                }
            }
            $this->set_additional_file_properties($file);
        }

        return $file;
    }

    protected function readfile($file_path)
    {
        $file_size = $this->get_file_size($file_path);
        $chunk_size = $this->options['readfile_chunk_size'];
        if ($chunk_size && $file_size > $chunk_size) {
            $handle = fopen($file_path, 'rb');
            while (!feof($handle)) {
                echo fread($handle, $chunk_size);
                @ob_flush();
                @flush();
            }
            fclose($handle);

            return $file_size;
        }

        return readfile($file_path);
    }

    protected function body($str)
    {
        echo $str;
    }

    protected function header($str)
    {
        header($str);
    }

    protected function get_server_var($id)
    {
        return isset($_SERVER[$id]) ? $_SERVER[$id] : '';
    }

    protected function generate_response($content, $print_response = true)
    {
        if ($print_response) {
            $json = json_encode($content);
            $redirect = isset($_REQUEST['redirect']) ?
                stripslashes($_REQUEST['redirect']) : null;
            if ($redirect) {
                $this->header('Location: '.sprintf($redirect, rawurlencode($json)));

                return;
            }
            $this->head();
            if ($this->get_server_var('HTTP_CONTENT_RANGE')) {
                $files = isset($content[$this->options['param_name']]) ?
                    $content[$this->options['param_name']] : null;
                if ($files && is_array($files) && is_object($files[0]) && $files[0]->size) {
                    $this->header('Range: 0-'.(
                        $this->fix_integer_overflow(intval($files[0]->size)) - 1
                    ));
                }
            }
            $this->body($json);
        }

        return $content;
    }

    protected function get_version_param()
    {
        return isset($_GET['version']) ? basename(stripslashes($_GET['version'])) : null;
    }

    protected function get_singular_param_name()
    {
        return substr($this->options['param_name'], 0, -1);
    }

    protected function get_file_name_param()
    {
        $name = $this->get_singular_param_name();

        return isset($_REQUEST[$name]) ? basename(stripslashes($_REQUEST[$name])) : null;
    }

    protected function get_file_names_params()
    {
        $params = isset($_REQUEST[$this->options['param_name']]) ?
            $_REQUEST[$this->options['param_name']] : array();
        foreach ($params as $key => $value) {
            $params[$key] = basename(stripslashes($value));
        }

        return $params;
    }

    protected function get_file_type($file_path)
    {
        switch (strtolower(pathinfo($file_path, PATHINFO_EXTENSION))) {
            case 'jpeg':
            case 'jpg':
                return 'image/jpeg';
            case 'png':
                return 'image/png';
            case 'gif':
                return 'image/gif';
            default:
                return '';
        }
    }

    protected function download()
    {
        switch ($this->options['download_via_php']) {
            case 1:
                $redirect_header = null;
                break;
            case 2:
                $redirect_header = 'X-Sendfile';
                break;
            case 3:
                $redirect_header = 'X-Accel-Redirect';
                break;
            default:
                return $this->header('HTTP/1.1 403 Forbidden');
        }
        $file_name = $this->get_file_name_param();
        if (!$this->is_valid_file_object($file_name)) {
            return $this->header('HTTP/1.1 404 Not Found');
        }
        if ($redirect_header) {
            return $this->header(
                $redirect_header.': '.$this->get_download_url(
                    $file_name,
                    $this->get_version_param(),
                    true
                )
            );
        }
        $file_path = $this->get_upload_path($file_name, $this->get_version_param());
        // Prevent browsers from MIME-sniffing the content-type:
        $this->header('X-Content-Type-Options: nosniff');
        if (!preg_match($this->options['inline_file_types'], $file_name)) {
            $this->header('Content-Type: application/octet-stream');
            $this->header('Content-Disposition: attachment; filename="'.$file_name.'"');
        } else {
            $this->header('Content-Type: '.$this->get_file_type($file_path));
            $this->header('Content-Disposition: inline; filename="'.$file_name.'"');
        }
        $this->header('Content-Length: '.$this->get_file_size($file_path));
        $this->header('Last-Modified: '.gmdate('D, d M Y H:i:s T', filemtime($file_path)));
        $this->readfile($file_path);
    }

    protected function send_content_type_header()
    {
        $this->header('Vary: Accept');
        if (strpos($this->get_server_var('HTTP_ACCEPT'), 'application/json') !== false) {
            $this->header('Content-type: application/json');
        } else {
            $this->header('Content-type: text/plain');
        }
    }

    protected function send_access_control_headers()
    {
        $this->header('Access-Control-Allow-Origin: '.$this->options['access_control_allow_origin']);
        $this->header('Access-Control-Allow-Credentials: '
            .($this->options['access_control_allow_credentials'] ? 'true' : 'false'));
        $this->header('Access-Control-Allow-Methods: '
            .implode(', ', $this->options['access_control_allow_methods']));
        $this->header('Access-Control-Allow-Headers: '
            .implode(', ', $this->options['access_control_allow_headers']));
    }

    public function head()
    {
        $this->header('Pragma: no-cache');
        $this->header('Cache-Control: no-store, no-cache, must-revalidate');
        $this->header('Content-Disposition: inline; filename="files.json"');
        // Prevent Internet Explorer from MIME-sniffing the content-type:
        $this->header('X-Content-Type-Options: nosniff');
        if ($this->options['access_control_allow_origin']) {
            $this->send_access_control_headers();
        }
        $this->send_content_type_header();
    }

    public function get($print_response = true)
    {
        if ($print_response && isset($_GET['download'])) {
            return $this->download();
        }
        $file_name = $this->get_file_name_param();

        if ($file_name) {
            $response = array(
                $this->get_singular_param_name() => $this->get_file_object($file_name),
            );
        } else {
            $response = array(
                $this->options['param_name'] => $this->get_file_objects(),
            );
        }

        return $this->generate_response($response, $print_response);
    }

    public function post($print_response = true)
    {
        if (isset($_REQUEST['_method']) && $_REQUEST['_method'] === 'DELETE') {
            return $this->delete($print_response);
        }
        $upload = isset($_FILES[$this->options['param_name']]) ?
            $_FILES[$this->options['param_name']] : null;
        // Parse the Content-Disposition header, if available:
        $file_name = $this->get_server_var('HTTP_CONTENT_DISPOSITION') ?
            rawurldecode(preg_replace(
                '/(^[^"]+")|("$)/',
                '',
                $this->get_server_var('HTTP_CONTENT_DISPOSITION')
            )) : null;
        // Parse the Content-Range header, which has the following form:
        // Content-Range: bytes 0-524287/2000000
        $content_range = $this->get_server_var('HTTP_CONTENT_RANGE') ?
            preg_split('/[^0-9]+/', $this->get_server_var('HTTP_CONTENT_RANGE')) : null;
        $size =  $content_range ? $content_range[3] : null;
        $files = array();
        if ($upload && is_array($upload['tmp_name'])) {
            // param_name is an array identifier like "files[]",
            // $_FILES is a multi-dimensional array:
            foreach ($upload['tmp_name'] as $index => $value) {
                $files[] = $this->handle_file_upload(
                    $upload['tmp_name'][$index],
                    $file_name ? $file_name : $upload['name'][$index],
                    $size ? $size : $upload['size'][$index],
                    $upload['type'][$index],
                    $upload['error'][$index],
                    $index,
                    $content_range
                );
            }
        } else {
            // param_name is a single object identifier like "file",
            // $_FILES is a one-dimensional array:
            $files[] = $this->handle_file_upload(
                isset($upload['tmp_name']) ? $upload['tmp_name'] : null,
                $file_name ? $file_name : (isset($upload['name']) ?
                        $upload['name'] : null),
                $size ? $size : (isset($upload['size']) ?
                        $upload['size'] : $this->get_server_var('CONTENT_LENGTH')),
                isset($upload['type']) ?
                        $upload['type'] : $this->get_server_var('CONTENT_TYPE'),
                isset($upload['error']) ? $upload['error'] : null,
                null,
                $content_range
            );
        }

        return $this->generate_response(
            array($this->options['param_name'] => $files),
            $print_response
        );
    }

    public function delete($print_response = true)
    {
        $file_names = $this->get_file_names_params();
        if (empty($file_names)) {
            $file_names = array($this->get_file_name_param());
        }
        $response = array();
        foreach ($file_names as $file_name) {
            $file_path = $this->get_upload_path($file_name);
            $success = is_file($file_path) && $file_name[0] !== '.' && unlink($file_path);
            if ($success) {
                foreach ($this->options['image_versions'] as $version => $options) {
                    if (!empty($version)) {
                        $file = $this->get_upload_path($file_name, $version);
                        if (is_file($file)) {
                            unlink($file);
                        }
                    }
                }
            }
            $response[$file_name] = $success;
        }

        return $this->generate_response($response, $print_response);
    }
}
