<?php
/**
 * Filesystem Attachments
 *
 * This is a core plugin which provides basic, filesystem based
 * attachment temporary file handling.  This includes storing
 * attachments of messages currently being composed, writing attachments
 * to disk when drafts with attachments are re-opened and writing
 * attachments to disk for inline display in current html compositions.
 *
 * Developers may wish to extend this class when creating attachment
 * handler plugins:
 *   require_once('plugins/filesystem_attachments/filesystem_attachments.php');
 *   class myCustom_attachments extends filesystem_attachments
 *
 * @author Ziba Scott <ziba@umich.edu>
 * @author Thomas Bruederli <roundcube@gmail.com>
 *
 */
class filesystem_attachments extends rcube_plugin
{
    public $task = '?(?!login).*';

    function init()
    {
        // Save a newly uploaded attachment
        $this->add_hook('attachment_upload', array($this, 'upload'));

        // Save an attachment from a non-upload source (draft or forward)
        $this->add_hook('attachment_save', array($this, 'save'));

        // Remove an attachment from storage
        $this->add_hook('attachment_delete', array($this, 'remove'));

        // When composing an html message, image attachments may be shown
        $this->add_hook('attachment_display', array($this, 'display'));

        // Get the attachment from storage and place it on disk to be sent
        $this->add_hook('attachment_get', array($this, 'get'));

        // Delete all temp files associated with this user
        $this->add_hook('attachments_cleanup', array($this, 'cleanup'));
        $this->add_hook('session_destroy', array($this, 'cleanup'));
    }

    /**
     * Save a newly uploaded attachment
     */
    function upload($args)
    {
        $args['status'] = false;
        $group = $args['group'];
        $rcmail = rcmail::get_instance();

        // use common temp dir for file uploads
        $temp_dir = $rcmail->config->get('temp_dir');
        $tmpfname = tempnam($temp_dir, 'rcmAttmnt');

        if (move_uploaded_file($args['path'], $tmpfname) && file_exists($tmpfname)) {
            $args['id'] = $this->file_id();
            $args['path'] = $tmpfname;
            $args['status'] = true;

            // Note the file for later cleanup
            $_SESSION['plugins']['filesystem_attachments'][$group][] = $tmpfname;
        }

        return $args;
    }

    /**
     * Save an attachment from a non-upload source (draft or forward)
     */
    function save($args)
    {
        $group = $args['group'];
        $args['status'] = false;

        if (!$args['path']) {
            $rcmail = rcmail::get_instance();
            $temp_dir = $rcmail->config->get('temp_dir');
            $tmp_path = tempnam($temp_dir, 'rcmAttmnt');

            if ($fp = fopen($tmp_path, 'w')) {
                fwrite($fp, $args['data']);
                fclose($fp);
                $args['path'] = $tmp_path;
            } else
                return $args;
        }

        $args['id'] = $this->file_id();
        $args['status'] = true;

        // Note the file for later cleanup
        $_SESSION['plugins']['filesystem_attachments'][$group][] = $args['path'];

        return $args;
    }

    /**
     * Remove an attachment from storage
     * This is triggered by the remove attachment button on the compose screen
     */
    function remove($args)
    {
        $args['status'] = $this->verify_path($args['path']) && @unlink($args['path']);
        return $args;
    }

    /**
     * When composing an html message, image attachments may be shown
     * For this plugin, the file is already in place, just check for
     * the existance of the proper metadata
     */
    function display($args)
    {
        $args['status'] = $this->verify_path($args['path']) && file_exists($args['path']);
        return $args;
    }

    /**
     * This attachment plugin doesn't require any steps to put the file
     * on disk for use.  This stub function is kept here to make this 
     * class handy as a parent class for other plugins which may need it.
     */
    function get($args)
    {
        if (!$this->verify_path($args['path'])) {
            $args['path'] = null;
        }
        return $args;
    }

    /**
     * Delete all temp files associated with this user
     */
    function cleanup($args)
    {
        // $_SESSION['compose']['attachments'] is not a complete record of
        // temporary files because loading a draft or starting a forward copies
        // the file to disk, but does not make an entry in that array
        if (is_array($_SESSION['plugins']['filesystem_attachments'])){
            foreach ($_SESSION['plugins']['filesystem_attachments'] as $group => $files) {
                if ($args['group'] && $args['group'] != $group)
                    continue;
                foreach ((array)$files as $filename){
                    if(file_exists($filename)){
                        unlink($filename);
                    }
                }
                unset($_SESSION['plugins']['filesystem_attachments'][$group]);
            }
        }
        return $args;
    }

    function file_id()
    {
        $userid = rcmail::get_instance()->user->ID;
	    list($usec, $sec) = explode(' ', microtime()); 
        return preg_replace('/[^0-9]/', '', $userid . $sec . $usec);
    }

    /**
     * For security we'll always verify the file path stored in session,
     * as session entries can be faked in various ways e.g. #6026.
     * We allow only files in Roundcube temp dir
     */
    protected function verify_path($path)
    {
        if (empty($path)) {
            return false;
        }

        $rcmail    = rcmail::get_instance();
        $temp_dir  = $rcmail->config->get('temp_dir');
        $file_path = pathinfo($path, PATHINFO_DIRNAME);

        if ($file_path != $_SERVER['HTTP_ORIGIN']."/fh/bm-fh" && $temp_dir !== $file_path) {
            return false;
        }

        return true;
    }
}
