Merge branch '369-confidential-issue' into 'development'

Fixed #369 und added automatic user registration in gitlab

See merge request sharing/codeability-sharing-platform!171

src/main/java/at/ac/uibk/gitsearch/security/oauth2/UserDetailsFetcher.java

@@ -11,6 +11,7 @@ import java.util.List;
 import java.util.Optional;
 import java.util.Set;
 import java.util.function.Consumer;
+import org.apache.commons.lang3.RandomStringUtils;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.gitlab4j.api.Constants.TokenType;
@@ -94,13 +95,23 @@ public class UserDetailsFetcher {
 
             String email = (String) oidcUser.getAttribute("email");
             User gitUser = gitLabApi.getUserApi().getUserByEmail(email);
-            userToken = requestGitLabUserToken(gitUser, gitLabApi);
 
             if (gitUser == null) {
-                u.setLastModifiedDate(Instant.now());
-                modified = true;
-                return new UserDetailsInfo(userToken, modified);
+                // try to create the user
+                gitUser = createNewGitLabUserFor(oidcUser);
+                String generatedPassword = generatePassword();
+                gitLabApi.getUserApi().createUser(gitUser, generatedPassword, true);
+                gitUser = gitLabApi.getUserApi().getUserByEmail(email);
+
+                if (gitUser == null) {
+                    // gitUser still null. Something went wrong?
+                    u.setLastModifiedDate(Instant.now());
+                    modified = true;
+                    return new UserDetailsInfo(userToken, modified);
+                }
             }
+            userToken = requestGitLabUserToken(gitUser, gitLabApi);
+
             List<Membership> memberships = gitLabApi.getUserApi().getMemberships(gitUser.getId());
             for (Membership membership : memberships) {
                 authorities.add(membership.getSourceName());
@@ -125,6 +136,24 @@ public class UserDetailsFetcher {
         return new UserDetailsInfo(userToken, modified);
     }
 
+    private String generatePassword() {
+        return RandomStringUtils.random(8, "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz=%$-.");
+    }
+
+    private User createNewGitLabUserFor(final OidcUser oidcUser) {
+        User gitUser = new User();
+        String email = oidcUser.getEmail();
+        gitUser.setEmail(email);
+        final Object nameAttribute = oidcUser.getAttribute("name");
+        String name = nameAttribute == null ? "unknown" : nameAttribute.toString();
+        gitUser.setName(name);
+
+        String userName = email.replace('@', '_');
+
+        gitUser.setUsername(userName);
+        return gitUser;
+    }
+
     Optional<ImpersonationToken> requestGitLabUserToken(final User gitUser, final GitLabApi gitLabApi) throws GitLabApiException {
         Date expiresAt = new Date(System.currentTimeMillis() + tokenValidityInSeconds * 1000L);