<?php

class AutoPlaylistManager {

    /**
     * @var int how often, in seconds, to check for and ingest new podcast episodes
     */
    private static $_AUTOPLAYLIST_POLL_INTERVAL_SECONDS = 60;  // 10 minutes
    
    /**
     * Check whether $_AUTOPLAYLIST_POLL_INTERVAL_SECONDS have passed since the last call to
     * buildAutoPlaylist
     *
     * @return bool true if $_AUTOPLAYLIST_POLL_INTERVAL_SECONDS has passed since the last check
     */
    public static function hasAutoPlaylistPollIntervalPassed() {
        Logging::info("Checking autoplaylist poll");
        $lastPolled = Application_Model_Preference::getAutoPlaylistPollLock();
        return empty($lastPolled) || (microtime(true) > $lastPolled + self::$_AUTOPLAYLIST_POLL_INTERVAL_SECONDS);
    }


    /*
     * This function is copied from the TestUser class and is used to instantiate a user so that
     * the Scheduler model can be utilized by buildAutoPlaylist.
     * Not sure if this is the best strategy but it works.
    */    
    public static function loginUser()
    {
        $authAdapter = Application_Model_Auth::getAuthAdapter();

        //pass to the adapter the submitted username and password
        $authAdapter->setIdentity('admin')
                    ->setCredential('admin');

        $auth = Zend_Auth::getInstance();
        $result = $auth->authenticate($authAdapter);
        if ($result->isValid()) {
            //all info about this user from the login table omit only the password
            $userInfo = $authAdapter->getResultRowObject(null, 'password');

            //the default storage is a session with namespace Zend_Auth
            $authStorage = $auth->getStorage();
            $authStorage->write($userInfo);
        }
    }
     

     /**
     * Find all shows with autoplaylists who have yet to have their playlists built and added to the schedule
     *
     */
    public static function buildAutoPlaylist() {
        // Starting a session so that the User can be created
	Zend_Session::start();
        static::loginUser();
	Logging::info("Checking to run Auto Playlist");
        $autoPlaylists = static::_upcomingAutoPlaylistShows();
       foreach ($autoPlaylists as $autoplaylist) {
       	    // creates a ShowInstance object to build the playlist in from the ShowInstancesQuery Object     
	    $si = new Application_Model_ShowInstance($autoplaylist->getDbId());
	    $playlistid = $si->GetAutoPlaylistId();
            Logging::info("Scheduling $playlistid");
            // call the addPlaylist to show function and don't check for user permission to avoid call to non-existant user object
            $si->addPlaylistToShow($playlistid, false);
            $si->setAutoPlaylistBuilt(true);

            }
        Application_Model_Preference::setAutoPlaylistPollLock(microtime(true));
	Zend_Session::stop();
    }


    /**
     * Find all show instances starting in the next hour with autoplaylists not yet added to the schedule
     *
     * @return PropelObjectCollection collection of ShowInstance objects
     *                                that have unbuilt autoplaylists
     */
    protected static function _upcomingAutoPlaylistShows() {
	    //setting now so that past shows aren't referenced
            $now = new DateTime("now", new DateTimeZone("UTC"));
	    // only build playlists for shows that start up to an hour from now
	    $future = clone $now;
	    $future->add(new DateInterval('PT1H'));
	    
        return CcShowInstancesQuery::create()
            ->filterByDbStarts($now,Criteria::GREATER_THAN) 
          ->filterByDbStarts($future,Criteria::LESS_THAN)
            ->useCcShowQuery('a', 'left join')
                ->filterByDbHasAutoPlaylist(true)
            ->endUse()
            ->filterByDbAutoPlaylistBuilt(false)
            ->find();
    }

}