1 files changed, 58 insertions, 0 deletions
diff --git a/src/main/java/com/juick/service/WebfingerService.java b/src/main/java/com/juick/service/WebfingerService.java
new file mode 100644
index 00000000..dc978763
--- /dev/null
+++ b/src/main/java/com/juick/service/WebfingerService.java
@@ -0,0 +1,58 @@
+package com.juick.service;
+
+import java.net.URI;
+import java.util.Collections;
+
+import javax.inject.Inject;
+
+import org.apache.commons.lang3.StringUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Component;
+import org.springframework.web.client.RestClientException;
+import org.springframework.web.client.RestTemplate;
+import org.springframework.web.util.UriComponentsBuilder;
+
+import com.juick.www.api.webfinger.model.Account;
+import com.juick.www.api.webfinger.model.Link;
+
+import rocks.xmpp.addr.Jid;
+
+@Component
+public class WebfingerService {
+    private static final Logger logger = LoggerFactory.getLogger("ActivityPub");
+
+    private final RestTemplate restClient;
+    @Inject
+    public WebfingerService(final RestTemplate restClient) {
+        this.restClient = restClient;
+    }
+    public URI discoverAccountURI(String acct, MediaType linkType) {
+        Jid acctId = Jid.of(acct);
+        URI resourceUri = UriComponentsBuilder.fromPath("/.well-known/webfinger").host(acctId.getDomain())
+                .scheme("https").queryParam("resource", "acct:" + acct).build().toUri();
+        HttpHeaders headers = new HttpHeaders();
+        headers.setAccept(Collections.singletonList(MediaType.valueOf("application/jrd+json")));
+        HttpEntity<Void> webfingerRequest = new HttpEntity<>(headers);
+        try {
+            ResponseEntity<Account> response = restClient.exchange(resourceUri, HttpMethod.GET, webfingerRequest,
+                    Account.class);
+            if (response.getStatusCode().is2xxSuccessful()) {
+                var account = response.getBody();
+                for (Link l : account.links()) {
+                    if (l.rel().equals("self") && l.type().equals(linkType.toString())) {
+                        return URI.create(l.href());
+                    }
+                }
+            }
+        } catch (RestClientException e) {
+            logger.warn("Cannot discover person {}: {}", acct, e.getMessage());
+        }
+        return URI.create(StringUtils.EMPTY);
+    }
+}