Add username retrieval functionality to LoginController using RecentNamesMapper query

backend/src/main/java/com/alttd/altitudeweb/controllers/login/LoginController.java

@@ -1,18 +1,26 @@
 package com.alttd.altitudeweb.controllers.login;
 
 import com.alttd.altitudeweb.api.LoginApi;
+import com.alttd.altitudeweb.database.litebans.HistoryRecord;
+import com.alttd.altitudeweb.database.litebans.RecentNamesMapper;
+import com.alttd.altitudeweb.database.litebans.UUIDHistoryMapper;
 import com.alttd.altitudeweb.model.PermissionClaimDto;
 import com.alttd.altitudeweb.database.Databases;
 import com.alttd.altitudeweb.database.web_db.PrivilegedUser;
 import com.alttd.altitudeweb.database.web_db.PrivilegedUserMapper;
+import com.alttd.altitudeweb.model.UsernameDto;
 import com.alttd.altitudeweb.setup.Connection;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.autoconfigure.security.oauth2.resource.OAuth2ResourceServerProperties;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.scheduling.annotation.Scheduled;
 import com.alttd.altitudeweb.services.limits.RateLimit;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.context.SecurityContextHolder;
+import org.springframework.security.oauth2.jwt.Jwt;
 import org.springframework.security.oauth2.jwt.JwtClaimsSet;
 import org.springframework.security.oauth2.jwt.JwtEncoder;
 import org.springframework.security.oauth2.jwt.JwtEncoderParameters;
@@ -83,6 +91,47 @@ public class LoginController implements LoginApi {
         return ResponseEntity.ok(loginCode);
     }
 
+    @Override
+    public ResponseEntity<UsernameDto> getUsername() {
+        Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
+
+        if (authentication == null || !(authentication.getPrincipal() instanceof OAuth2ResourceServerProperties.Jwt)) {
+            return ResponseEntity.status(401).build();
+        }
+        Jwt jwt = (Jwt) authentication.getPrincipal();
+        String stringUuid = jwt.getSubject();
+        UUID uuid;
+        try {
+             uuid = UUID.fromString(stringUuid);
+        } catch (IllegalArgumentException e) {
+            return ResponseEntity.badRequest().build();
+        }
+
+        UsernameDto usernameDto = new UsernameDto();
+        usernameDto.setUsername(getUsername(uuid));
+
+        return ResponseEntity.ok(usernameDto);
+    }
+
+    private String getUsername(UUID uuid) {
+        CompletableFuture<String> username = new CompletableFuture<>();
+
+        Connection.getConnection(Databases.LITE_BANS)
+                  .runQuery(sqlSession -> {
+                      log.debug("Loading all history through logged in uuid");
+                      try {
+                          String temp = sqlSession
+                                  .getMapper(RecentNamesMapper.class)
+                                  .getUsername(uuid.toString());
+                          username.complete(temp);
+                      } catch (Exception e) {
+                          log.error("Failed to find username for uuid {}", uuid, e);
+                          username.completeExceptionally(e);
+                      }
+                  });
+        return username.join();
+    }
+
     @RateLimit(limit = 5, timeValue = 1, timeUnit = TimeUnit.MINUTES, key = "login")
     @Override
     public ResponseEntity<String> login(String code) {