<?php
/* vim: set expandtab sw=4 ts=4 sts=4: */
/**
* Handles plugins that show the upload progress
*
* @package PhpMyAdmin
*/

/**
 * Sets up some variables for upload progress
 *
 * @return array
 *
 */
function PMA_uploadProgressSetup()
{
    /**
     * constant for differentiating array in $_SESSION variable
     */
    $SESSION_KEY = '__upload_status';

    /**
     * sets default plugin for handling the import process
     */
    $_SESSION[$SESSION_KEY]["handler"] = "";

    /**
     * unique ID for each upload
     */
    $upload_id = uniqid("");

    /**
     * list of available plugins
     *
     * Each plugin has own checkfunction in display_import_ajax.lib.php
     * and own file with functions in upload_#KEY#.php
     */
    $plugins = array(
        // PHP 5.4 session-based upload progress is problematic, see bug 3964
        //"session",
        "progress",
        "apc",
        "noplugin"
    );

    // select available plugin
    foreach ($plugins as $plugin) {
        $check = "PMA_Import_" . $plugin . "Check";

        if ($check()) {
            $upload_class = 'PMA\libraries\plugins\import\upload\Upload' . ucwords(
                $plugin
            );
            $_SESSION[$SESSION_KEY]["handler"] = $upload_class;
            break;
        }
    }
    return array($SESSION_KEY, $upload_id, $plugins);
}

/**
  * Checks if APC bar extension is available and configured correctly.
  *
  * @return boolean true if APC extension is available and if rfc1867 is enabled,
  *                      false if it is not
  */
function PMA_Import_apcCheck()
{
    if (! extension_loaded('apc')
        || ! function_exists('apc_fetch')
        || ! function_exists('getallheaders')
    ) {
        return false;
    }
    return (ini_get('apc.enabled') && ini_get('apc.rfc1867'));
}

/**
 * Checks if PMA\libraries\plugins\import\upload\UploadProgress bar extension is
 * available.
 *
 * @return boolean true if PMA\libraries\plugins\import\upload\UploadProgress
 * extension is available, false if it is not
 */
function PMA_Import_progressCheck()
{
    if (! function_exists("uploadprogress_get_info")
        || ! function_exists('getallheaders')
    ) {
        return false;
    }
    return true;
}

/**
  * Checks if PHP 5.4 session upload-progress feature is available.
  *
  * @return boolean true if PHP 5.4 session upload-progress is available,
  *                 false if it is not
  */
function PMA_Import_sessionCheck()
{
    if (! ini_get('session.upload_progress.enabled')) {
        return false;
    }
    return true;
}

/**
  * Default plugin for handling import.
  * If no other plugin is available, noplugin is used.
  *
  * @return boolean true
  */
function PMA_Import_nopluginCheck()
{
    return true;
}

/**
  * The function outputs json encoded status of uploaded.
  * It uses PMA_getUploadStatus, which is defined in plugin's file.
  *
  * @param string $id ID of transfer, usually $upload_id
  *                   from display_import_ajax.lib.php
  *
  * @return void
  */
function PMA_importAjaxStatus($id)
{
    PMA_headerJSON();
    echo json_encode(
        $_SESSION[$GLOBALS['SESSION_KEY']]['handler']::getUploadStatus($id)
    );
}
