<?php

class CategoryHandler {
	private $pathway;
	
	function __construct($pathway) {
		$this->pathway = $pathway;
	}
	
	/**
	 * Get all categories the pathway belongs to
	 * (As stored in the MediaWiki table)
	 */
	public function getCategories() {
		//Get the categories from mediawiki
		$categories = $this->getMediaWikiCategories();
		return $categories;
	}
	
	/**
	 * Set the given categories for the pathway.
	 * $categories should be an array where the keys are the
	 * category names and the value is 1 when the pathway should
	 * be in the category, and 0 when the pathway should not be in
	 * the category.
	 */
	public function setCategories($categories) {
		$changed = false; //Don't save if nothing changed
		
		$doc = new DOMDocument();
		$gpml = $this->pathway->getGpml();
		$doc->loadXML($gpml);
		$root = $doc->documentElement;
		
		$catnodes = array();
		
		//Find all category nodes
		foreach($root->childNodes as $n) {
			if($n->nodeName == "Comment" && 
				$n->getAttribute('Source') == 'WikiPathways-category') {
				$catnodes[$n->nodeValue] = $n;
			}
		}

		//Remove categories that are set to 0
		foreach(array_keys($categories) as $cat) {
			$value = $categories[$cat];
			if(array_key_exists($cat, $catnodes)) {
				//Remove if value is 0
				if($value == 0) {
					$node = $catnodes[$cat];
					$root->removeChild($node);
					$changed = true;
				}
			} else { //Add if value is 1
				if($value == 1) {
					$node = $doc->createElement("Comment");
					$node->setAttribute("Source", "WikiPathways-category");
					$node->nodeValue = $cat;
					$root->insertBefore($node, $root->firstChild);
					$changed = true;
				}
			}
		}
		
		if($changed) {
			$gpml = $doc->saveXML();
			$this->pathway->updatePathway($gpml, "Modified categories");
		}
	}
	
	public function addToCategory($category) {
		$gpml = $this->pathway->getGPML();
		
		$dom = new DomDocument();
		$dom->loadXML($gpml);

		$node = $dom->createElement("Comment", $category);
		$dom->appendChild($node);
		$source_node = $dom->createAttribute("Source");
		$node->appendChild($source_node);
		$source = $dom->createTextNode("WikiPathways-category");
		$source_node->appendChild($source);

		$xpath = new DomXPath($dom);

		$result = $xpath->query("//*[@BoardWidth]");
		$result_comment = $xpath->query("/Comment");

		$result->item(0)->parentNode->insertBefore($result_comment->item(0), $result->item(0));
		
		$gpml =	$dom->saveXML();
		
		$this->pathway->updatePathway($gpml, 'Added to category $category');
	}
	
	/**
	 * Applies the categories stored in GPML to the
	 * MediaWiki database
	 */
	public function setGpmlCategories() {	
		wfDebug("::setGpmlCategories\n");
			
		$dbw =& wfGetDB( DB_MASTER );
		$clFrom = $this->pathway->getTitleObject()->getArticleID();
		$categorylinks = $dbw->tableName( 'categorylinks' );
		
		$dbw->begin();	
		//Purge old categories
		$dbw->delete( $categorylinks, array( 'cl_from' => $clFrom ) );
		$dbw->commit();
		
		$dbw->begin();
		
		//Add the GPML categories
		foreach($this->getGpmlCategories() as $cat) {
			wfDebug("\tCategory: $cat\n");
						
			//Format to title (replace '_' with ' ');
			$catTitle = Title::makeTitle(NS_CATEGORY, $cat);
			$cat = $catTitle->getDBKey();
			
			$clTo = $dbw->addQuotes($cat);
			$sort = $dbw->addQuotes($this->pathway->getName());
		
			$sql = "INSERT INTO $categorylinks (cl_from, cl_to, cl_sortkey) 
					VALUES ({$dbw->addQuotes($clFrom)}, $clTo, $sort)";
			$dbw->query( $sql, 'SpecialMovepage::doSubmit' );
		}
		$dbw->commit();		
	}
	
	private function getMediaWikiCategories() {
		$categories = array();
		$title = $this->pathway->getTitleObject();
		$id = $title->getArticleID();
		
		$dbr = wfGetDB( DB_SLAVE );
		$res = $dbr->select( "categorylinks", array("cl_to"), array("cl_from" => $id));
		while( $row = $dbr->fetchRow( $res )) {
			if($row[0]) {
				array_push($categories, $row[0]);
			}
		}
		$dbr->freeResult($res);
		return $categories;
	
	}
	
	private function getGpmlCategories() {
		if($this->pathway->isDeleted()) {
			return array();
		} else {
			$cats = $this->pathway->getPathwayData()->getWikiCategories();
			array_push($cats, $this->pathway->species());
			return $cats;
		}
	}
	
	/**
	 * Get all available categories
	 * \param includeSpecies whether to include species categories (e.g. Human) or not
	 */
	public static function getAvailableCategories($includeSpecies = false) {
		$arrayCat = array();
      	        $NScat = NS_CATEGORY;
                $dbr = wfGetDB( DB_SLAVE );
                $categorylinks = $dbr->tableName( 'categorylinks' );
                $implicit_groupby = $dbr->implicitGroupby() ? '1' : 'cl_to';
                $sqlCat= "SELECT 'Categories' as type,
                                {$NScat} as namespace,
                                cl_to as title,
                                $implicit_groupby as value
                           FROM $categorylinks
                           GROUP BY 1,2,3,4";
                $res = $dbr->query($sqlCat);
                while ($obj =  $dbr->fetchObject( $res ) ) {
                        $cat = str_replace('_', ' ', $obj->title);
                        if($cat) {
					array_push($arrayCat, $cat);
			}
		}
		//Exclude species if needed
		if(!$includeSpecies) { 
			$arraySpecies = Pathway::getAvailableSpecies();		
			$arrayCat = array_diff($arrayCat, $arraySpecies);
		}
		return $arrayCat;
	}
}

?>