<?php

/**
 * This software is intended for use with Oxwall Free Community Software http://www.oxwall.org/ and is
 * licensed under The BSD license.

 * ---
 * Copyright (c) 2011, Oxwall Foundation
 * All rights reserved.

 * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
 * following conditions are met:
 *
 *  - Redistributions of source code must retain the above copyright notice, this list of conditions and
 *  the following disclaimer.
 *
 *  - Redistributions in binary form must reproduce the above copyright notice, this list of conditions and
 *  the following disclaimer in the documentation and/or other materials provided with the distribution.
 *
 *  - Neither the name of the Oxwall Foundation nor the names of its contributors may be used to endorse or promote products
 *  derived from this software without specific prior written permission.

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 *
 * @author Sergey Kambalin <greyexpert@gmail.com>
 * @package ow_plugins.newsfeed.classes
 * @since 1.0
 */
class NEWSFEED_CLASS_FormatManager
{
    const FORMAT_EMPTY = "empty";
    
    /**
     * Singleton instance.
     *
     * @var NEWSFEED_CLASS_FormatManager
     */
    private static $classInstance;

    /**
     * Returns an instance of class (singleton pattern implementation).
     *
     * @return NEWSFEED_CLASS_FormatManager
     */
    public static function getInstance()
    {
        if ( self::$classInstance === null )
        {
            self::$classInstance = new self();
        }

        return self::$classInstance;
    }

    private $formats = array();
    
    /**
     *
     * @var OW_Plugin
     */
    private $plugin;
    
    private function __construct()
    {
        $this->plugin = OW::getPluginManager()->getPlugin("newsfeed");
    }
    
    public function getFormatNames() 
    {
        return array_keys($this->formats);
    }
    
    public function renderFormat( $name, $vars )
    {
        $beforeRenderEvent = new OW_Event("feed.before_render_format", array(
            "format" => $name,
            "vars" => $vars
        ), $vars);
        OW::getEventManager()->trigger($beforeRenderEvent);

        $renderEvent = new OW_Event("feed.render_format", array(
            "format" => $name,
            "vars" => $beforeRenderEvent->getData()
        ), null);
        OW::getEventManager()->trigger($renderEvent);
        
        $rendered = $renderEvent->getData();
        
        if ( $rendered === null )
        {
            if ( empty($this->formats[$name]) )
            {
                throw new InvalidArgumentException("Undefined Newsfeed format `$name`");
            }
            
            $formatClass = $this->formats[$name];
            
            /* @var $formatObject NEWSFEED_CLASS_Format */
            $formatObject = new $formatClass($vars, $name);
            $rendered = $formatObject->render();
        }
        
        $afterRenderEvent = new OW_Event("feed.after_render_format", array(
            "format" => $name,
            "vars" => $vars
        ), $rendered);
        OW::getEventManager()->trigger($afterRenderEvent);
        
        return $afterRenderEvent->getData();
    }

    public function addFormat($name, $className)
    {
        $this->formats[$name] = $className;
    }
    
    public function collectFormats()
    {
        $event = new BASE_CLASS_EventCollector("feed.collect_formats");
        OW::getEventManager()->trigger($event);
        
        foreach ( $event->getData() as $format )
        {
            $this->addFormat($format["name"], $format["class"]);
        }
    }
    
    public function init()
    {
        OW::getAutoloader()->addPackagePointer("NEWSFEED_FORMAT", $this->plugin->getRootDir() . "formats" . DS);
        OW::getAutoloader()->addPackagePointer("NEWSFEED_MFORMAT", $this->plugin->getMobileDir() . "formats" . DS);
        
        OW::getEventManager()->bind(OW_EventManager::ON_PLUGINS_INIT, array($this, "collectFormats"));
    }
}