<?php

/**
 * File from http://PrestaShow.pl
 *
 * DISCLAIMER
 * Do not edit or add to this file if you wish to upgrade this module to newer
 * versions in the future.
 *
 *  @authors     PrestaShow.pl <kontakt@prestashow.pl>
 *  @copyright   2015 PrestaShow.pl
 *  @license     http://PrestaShow.pl/license
 */
class PShow_Queue
{

    /**
     * Path to database file
     *
     * @var string
     */
    private $database_filepath;

    /**
     * Array of filenames
     *
     * @var array
     */
    private $queue = array();

    /**
     * @var PShow_Queue
     */
    private static $instance = null;

    /**
     * @return PShow_Queue
     */
    public static function getInstance()
    {
        if (self::$instance === null) {
            self::$instance = new PShow_Queue();
        }

        return self::$instance;
    }

    /**
     * Constructor - get queue from file
     */
    public function __construct()
    {
        $this->database_filepath = getModulePath(__FILE__) . 'import-queue';

        if (file_exists($this->database_filepath)) {
            $this->queue = file($this->database_filepath);

            foreach ($this->queue as &$q)
                $q = str_replace(array("\n", "\s", "\t"), null, $q);
        }
    }

    /**
     * Destructor - save queue to file
     */
    public function __destruct()
    {
        $this->saveToFile();
    }

    /**
     * Save queue to file
     */
    public function saveToFile()
    {
        file_put_contents($this->database_filepath, implode("\n", array_map('trim', $this->queue)));
    }

    /**
     * @return array
     */
    public function getQueue()
    {
        return $this->queue;
    }

    /**
     * Get first element from queue
     *
     * @return string
     */
    public function getFromQueue()
    {
        return array_shift($this->queue);
    }

    /**
     * Add element to the end of queue
     * 
     * @param string $filename
     */
    public function addToQueue($filename)
    {
        $files = glob(_MODULE_UPLOAD_PATH_ . $filename . '.{' . _IMPORT_FILE_EXTENSIONS_ . '}', GLOB_BRACE);
        if (!count($files)) {
            return false;
        }

        array_push($this->queue, $filename);
    }

    /**
     * @param string $filename
     */
    public function delFromQueue($filename)
    {
        $this->queue = array_diff($this->queue, array($filename));
    }
}