<?php
/**
 * Initial implementation of Sitemap support.
 * GoogleSitemap should handle requests to 'sitemap.xml'
 * the other two classes are used to render the sitemap
 */

class GoogleSitemap extends Controller {
	protected $Pages;
	
	function __construct() {
		$this->Pages = Versioned::get_by_stage('SiteTree', 'Live');
	}

	public function Items() {
		$newPages = new DataObjectSet();
		
		foreach($this->Pages as $page) {
			// Only include pages from this host
			if(parse_url($page->AbsoluteLink(), PHP_URL_HOST) == $_SERVER['HTTP_HOST']) {
			
				// If the page has been set to 0 priority, we set a flag so it won't be included
				if(isset($page->Priority) && $page->Priority <= 0) {
					$page->Include = false;
				} else {
					$page->Include = true;
				}
			
				// The one field that isn't easy to deal with in the template is
				// Change frequency, so we set that here.
				$properties = $page->toMap();
				$created = new Datetime($properties['Created']);
				$now = new Datetime();
				$versions = $properties['Version'];
				$timediff = $now->format('U') - $created->format('U');
			
				// Check how many revisions have been made over the lifetime of the
				// Page for a rough estimate of it's changing frequency.
			
				$period = $timediff / ($versions + 1);
			
				if($period > 60*60*24*365) { // > 1 year
					$page->ChangeFreq='yearly';
				} else if($period > 60*60*24*30) { // > ~1 month
					$page->ChangeFreq='monthly';
				} else if($period > 60*60*24*7) { // > 1 week
					$page->ChangeFreq='weekly';
				} else if($period > 60*60*24) { // > 1 day
					$page->ChangeFreq='daily';
				} else if($period > 60*60) { // > 1 hour
					$page->ChangeFreq='hourly';
				} else { // < 1 hour
					$page->ChangeFreq='always';
				}
				
				$newPages->push($page);
			}
		}
		return $newPages;
	}
	
	static function ping() {
		//Don't ping if the site has disabled it, or if the site is in dev mode
		if(!Sitemap::$pings || Director::isDev())
			return;
			
		$location = urlencode(Director::absoluteBaseURL() . '/sitemap.xml');
		
		$response = HTTP::sendRequest("www.google.com", "/webmasters/sitemaps/ping",
			"sitemap=" . $location);
			
		return $response;
	}
	
	protected static $pings = true;
	
	/**
	 * Disables pings to google when the sitemap changes
	 * To use this, in your _config.php file simply include the line
	 * Sitemap::DisableGoogleNotification();
	 */
	static function DisableGoogleNotification() {
		self::$pings = false;
	}
	
	
	function index($url) {
		// We need to override the default content-type
		ContentNegotiator::disable();
		header('Content-type: application/xml; charset="utf-8"');
		
		// But we want to still render.
		return array();
	}
}
?>