--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/server/src/app/Services/ViafResolver.php	Thu Dec 10 16:05:53 2015 +0100
@@ -0,0 +1,114 @@
+<?php
+namespace CorpusParole\Services;
+
+use CorpusParole\Services\ViafResolverInterface;
+
+use Cache;
+use Config;
+use EasyRdf\Graph;
+use GuzzleHttp\Client;
+use GuzzleHttp\Exception\RequestException;
+use GuzzleHttp\Exception\ClientException;
+use GuzzleHttp\Exception\GuzzleException;
+use Illuminate\Contracts\Cache\Repository as CacheRepository;
+
+class ViafResolver implements ViafResolverInterface {
+
+    private $client = null;
+
+    public function __construct(Client $httpClient) {
+        $this->client = $httpClient;
+    }
+
+    /**
+     * make the viaf query.
+     */
+    public function queryName($id) {
+
+        $url = config('corpusparole.viaf_base_url').$id;
+
+        try {
+            $response = $this->client->get($url."/", ['headers'=>['Accept' => 'application/rdf+xml'],]);
+        }
+        catch(ClientException $e) {
+            if($e->getResponse()->getStatusCode() === 404) {
+                return null;
+            } else {
+                throw new ViafResolverException(
+                    $e->getMessage(),
+                    $e->getResponse()->getStatusCode(),
+                    $e
+                );
+            }
+        }
+        catch(RequestException $e) {
+            throw new ViafResolverException(
+                $e->getMessage(),
+                $e->hasResponse()?$e->getResponse()->getStatusCode():500,
+                $e
+            );
+        }
+
+        $graph = new Graph($url, $response->getBody());
+        $names = [];
+        foreach ($graph->allLiterals("<$url>", "schema:name") as $nameLit) {
+            $lang = $nameLit->getLang();
+            if(!$lang && !isset($names[''])) {
+                $names[''] = $nameLit->getvalue();
+            }
+            elseif (strpos($lang, 'fr') === 0 && !isset($names['fr'])) {
+                $names['fr'] = $nameLit->getvalue();
+            }
+            elseif (strpos($lang, 'en') === 0 && !isset($names['en'])) {
+                $names['en'] = $nameLit->getvalue();
+            }
+        }
+
+        return (isset($names['fr'])) ? $names['fr'] : ((isset($names['en'])) ? $names['en'] : ((isset($names['']))? $names[''] : null));
+
+    }
+
+    /**
+     * Check viaf id format
+     */
+    private function checkViafIdFormat($viafid) {
+        return ctype_digit($viafid);
+    }
+
+    /**
+     * Get name from Viaf id
+     * @param string $id The id to resolve. Can be an url starting with http://viaf.org/viaf/
+     * @return a string with the name
+     */
+    public function getName($id) {
+        $viafid = $id;
+        if(strpos($id, config('corpusparole.viaf_base_url')) === 0) {
+            $viafid = substr($id, strlen(config('corpusparole.viaf_base_url')));
+        }
+        $viafid = rtrim($viafid, '/');
+
+        if(!$this->checkViafIdFormat($viafid)) {
+            throw new ViafResolverException("ViafId not in correct format", 400);
+        }
+
+        $that = $this;
+
+        return Cache::remember("viaf:$viafid", config('corpusparole.viaf_cache_expiration'), function() use ($that, $viafid)  {
+
+            return $that->queryName($viafid);
+
+        });
+
+    }
+
+    /**
+     * Get a list of names from an array of viaf ids.
+     * @param array $ids The array of ids to resolve.
+     *                   Each id can be an url starting with http://viaf.org/viaf/
+     */
+    public function getNames(array $ids) {
+        return array_combine($ids, array_map([$this,'getName'], $ids));
+    }
+
+
+}