<?php

/**
 * VisibilitySettings.php - Group of all possible states of a visibility
 *
 * To be able to edit visibilitysettings as easy as possible we define a state
 * in a class found in the visibilitySettings. To group all the visibilitySetting
 * we use this class. On a verify command this class decides to what class the
 * order should be passed to.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * @author      Florian Bieringer <florian.bieringer@uni-passau.de>
 * @license     http://www.gnu.org/licenses/gpl-2.0.html GPL version 2
 * @category    Stud.IP
 */
require_once 'visibilitySettings/Me.php';
require_once 'visibilitySettings/Buddies.php';
require_once 'visibilitySettings/Domain.php';
require_once 'visibilitySettings/Studip.php';
require_once 'visibilitySettings/Extern.php';

/**
 * Groups all visibilitySettings
 */
class VisibilitySettings
{
    public static $CLASSES = [
        'Visibility_Me',
        'Visibility_Buddies',
        'Visibility_Domain',
        'Visibility_Studip',
        'Visibility_Extern'
    ];

    /**
     * @var array all visibilitystates
     */
    public $states = [];

    /**
     * @var array all names of all states
     */
    private $names = [];

    /**
     * I/O is expensive. Therefore we make the whole class sessionwide singleton
     * to save some I/O.
     *
     * @return VisibilitySettings The sessionwide visibilitySettings
     */
    static public function getInstance()
    {
        static $instance;

        if (!isset($instance)) {
            $instance = new self;
        }

        return $instance;
    }

    /**
     * On first construct we scan the visibilitySettings folder and load all
     * applied visibilitySettings
     */
    public function __construct()
    {
        foreach (self::$CLASSES as $classname) {
            $tmp = new $classname;
            if ($tmp->isActivated()) {
                $this->states[$tmp->getIntRepresentation()] = $tmp;
                $this->names[$tmp->getIntRepresentation()] = $tmp->getDisplayName();
            }
        }
        ksort($this->names);
    }

    /**
     * Passthrou to the specified verify method
     * @param string $user_id The userid
     * @param string $owner_id The owner of the visibility
     * @param int $visibility the visibilityID
     * @return boolean true if the user may see it, false if the user is not
     * allowed to see
     */
    function verify($user_id, $owner_id, $visibility)
    {
        return !empty($this->states[$visibility]) && $this->states[$visibility]->verify($owner_id, $user_id);
    }

    /**
     * Get Description of a specific state
     * @param int $stateid the int representation
     * @return string State description
     */
    function getDescription($stateid)
    {
        return $this->states[$stateid]->getDescription();
    }

    /**
     * Returns all keys of states
     * @return array all keys of states
     */
    function getAllKeys()
    {
        return array_keys($this->names);
    }

    /**
     * Returns all names of states
     * @return array all names of states
     */
    function getAllNames()
    {
        return $this->names;
    }

    /**
     * Returns the number of possible states
     * @return int
     */
    function count()
    {
        return count($this->states);
    }

}