<?php
/**
 *  Copyright (C) 2010  Kai Dorschner
 *
 *  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 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * @author Kai Dorschner <the-hide@address.com>
 * @copyright Copyright 2010, Kai Dorschner
 * @license http://www.gnu.org/licenses/gpl.html GPLv3
 * @package mocovi
 * @subpackage controls
 */

/**
 * Including the abstract dirlist.
 */
ControlFactory::load('dirlist');

/**
 * Image gallery using the {@link image_control}
 *
 * @package mocovi
 * @subpackage controls
 */
class imagegallery_control extends dirlist_control
{
	protected $metafileXPath;
	protected $defaultOptions = array
		( 'source'		=> '/' // sourcepath where the image can be found
		, 'controls'	=> 'yes' // yes|no - Defines if controlling buttons should be shown
		, 'metafile'	=> 'meta.xml' // meta file that should be searched in the sourcepath
		, 'maxelements'	=> 20
		);

	/**
	 * Patterns that must appear in the elements
	 */
	protected $obligations = array
		( '/\.([j|J][p|P][g|G])|([g|G][i|I][f|F])|([t|T][i|I][f|F])|([p|P][n|N][g|G])$/'
		);

	/**
	 * Patterns that must NOT appear in the elements
	 */
	protected $restrictions = array
		( '/^\./' // No dots at the beginning
		);


	/**
	 * @override
	 */
	protected function program()
	{
		$this->options['source'] .= (preg_match('/\/$/', $this->options['source']) ? '' : '/');
		$this->setRules();
		$this->readElementsIn($this->node, $this->getOption('source'));
		if($this->getOption('controls'))
			$this->node->setAttribute('controls', $this->getOption('controls'));
	}

	protected function readElementsIn(DomNode &$container, $dir)
	{
		$elements = $this->readElements($this->getOption('source'));
		$container->setAttribute('elements', count($elements));
		$begin = (isset($_GET['position']) && $_GET['position'] < count($elements) && $_GET['position'] >= 0 ? $_GET['position'] : 0);
		$maxelements = ($this->getOption('maxelements') + $begin < count($elements) ? ($this->getOption('maxelements') + $begin) : count($elements));

		$xpath = new DomXPath($this->dom);

		for($i = $begin; $i < $maxelements; $i++)
		{
			$options = array
			( 'source'		=> preg_replace('#\/{2,}#', '', $dir).$elements[$i]
			, 'description'	=> $elements[$i]
			);
			$this->adoptMetaInformation($elements[$i], $options);
			$image = ControlFactory::createVirtual('image',$options);
			$container->appendChild($image->load($this->node)->run());
		}
		// adds "next" link
		if($begin + $this->getOption('maxelements') < count($elements))
		{
			$next = $this->dom->createElement('next');
			$next->setAttribute('startwith', $i);
			$container->appendChild($next);
			$position = count($elements) - $this->getOption('maxelements');
			$container->setAttribute('last', $position);
		}
		// adds "previous" link
		if($begin - 1 >= 0 && $begin < count($elements))
		{
			$previous = $this->dom->createElement('previous');
			$position = $i - ($this->getOption('maxelements') * 2);
			if($position < 0) $position = 0;
			$previous->setAttribute('startwith', $position);
			$container->appendChild($previous);
		}
	}

	/**
	 * Reads all elements of a physical directory
	 */
	protected function readElements($dir)
	{
		$elements = array();
		if(is_dir($dir) && $handle = @opendir($dir))
		{
			while($elementName = readdir($handle))
				if($this->isValid($elementName))
					$elements[] = $elementName;
			closedir($handle);
		}
		else
			$this->error($dir.' could not be found.');
		return $elements;
	}

	protected function metafile()
	{
		return $this->getOption('source').DIRECTORY_SEPARATOR.$this->getOption('metafile');
	}

	/**
	 * Adopt external saved meta informations about an image gallery element.
	 */
	protected function adoptMetaInformation($file, Array &$array)
	{
		if(is_file($this->metafile()))
		{
			if(!is_object($this->metafileXPath))
			{
				$xml = new DomDocument();
				$xml->load($this->metafile());
				$this->metafileXPath = new DomXpath($xml);
			}
			foreach($this->metafileXPath->query('//file[@name = "'.$file.'"]/@*[name() != "name"]') as $attribute)
				$array[$attribute->nodeName] = $attribute->nodeValue;
		}
	}
}