Add link from timegate to timemap

lib/Controller/TimeGateController.php

@@ -5,6 +5,7 @@ require_once __DIR__ . '/findMementos.php';
 require_once __DIR__ . '/datetimeConversion.php';
 
 use OCP\IRequest;
+use OCP\IURLGenerator;
 use OCP\IServerContainer;
 use OCP\AppFramework\Controller;
 use OCP\AppFramework\Http\RedirectResponse;
@@ -14,15 +15,18 @@ use findMementos;
 
 class TimeGateController extends Controller {
 	private $userFolder;
+	private $URLGenerator;
 
 	public function __construct(
 		$AppName,
 		IRequest $request,
 		$UserId,
-		IServerContainer $serverContainer
+		IServerContainer $serverContainer,
+		IURLGenerator $URLGenerator
 	) {
 		parent::__construct($AppName, $request);
 		$this->userFolder = $serverContainer->getUserFolder($UserId);
+		$this->URLGenerator = $URLGenerator;
 	}
 
 	/**
@@ -65,7 +69,20 @@ class TimeGateController extends Controller {
 		$response = new RedirectResponse($chosenMemento['mementoUrl']);
 		$response->setStatus(302);
 		$response->addHeader('Vary', 'accept-datetime');
-		$response->addHeader('Link', "<{$chosenMemento['originalUrl']}>; rel=\"original\"");
+
+		// Add a link to the original and to the timemap.
+		$originalLink = "<{$chosenMemento['originalUrl']}>;rel=\"original\"";
+		// XXX hardcoding the route URL.
+		$timeMapUrl = $this->URLGenerator->getAbsoluteUrl("/apps/memento/timemap/$url");
+		$firstDatetime = datetimeTimestampToString($matchingMementos[0]['datetime']);
+		$lastMemento = $matchingMementos[count($matchingMementos)-1];
+		$lastDatetime = datetimeTimestampToString($lastMemento['datetime']);
+		$timeMapLink = "<$timeMapUrl>"
+			. ";rel=\"timemap\""
+			. ";type=\"application/link-format\""
+			. ";from=\"$firstDatetime\";until=\"$lastDatetime\"";
+		$response->addHeader('Link', "$originalLink, $timeMapLink");
+
 		return $response;
 	}
 }