implement simple getUserTaskFlag endpoint

service/src/main/java/api/TasksResource.java

@@ -6,13 +6,12 @@ import objects.User;
 import repositories.TasksRepository;
 
 import javax.inject.Inject;
-import javax.ws.rs.GET;
-import javax.ws.rs.POST;
-import javax.ws.rs.Path;
-import javax.ws.rs.Produces;
+import javax.ws.rs.*;
 import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
 import java.util.Collection;
 import java.util.List;
+import java.util.Optional;
 
 /**
  * Created by gpietrus on 16.02.16.
@@ -39,6 +38,21 @@ public class TasksResource
         return tasksRepository.getUserFlagsHashes(user.getName()).keySet();
     }
 
+    //todo: merge with upper
+    //todo: user argument
+    //todo: pass username in header via proxy?
+    //todo: post
+    @GET
+    @Path("flags/{task_id}")
+    public Response getUserTaskFlag(final @PathParam("task_id") String taskId) {
+        String temporaryUserName = "gpietrus1";
+        Optional<String> userTaskFlag = tasksRepository.getUserTaskFlag(temporaryUserName, taskId);//todo
+        if(userTaskFlag.isPresent()) {
+            return Response.ok().entity(userTaskFlag.get()).build();
+        }
+        return Response.status(Response.Status.BAD_REQUEST).build();
+    }
+
     @POST
     public boolean submitSolution(@Auth User user,
                                   String flag) throws Exception {

service/src/main/java/repositories/TasksRepository.java

@@ -10,7 +10,10 @@ import org.bson.Document;
 import javax.inject.Inject;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
-import java.util.*;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.UUID;
 import java.util.stream.Collectors;
 
 /**
@@ -90,6 +93,14 @@ public class TasksRepository implements Repository {
     public boolean checkFlag(String username, String flagValue) throws Exception {
         return compareHash(flagValue, username);
     }
+
+    public Optional<String> getUserTaskFlag(String username, String taskId) {
+        //todo: taskId, level, name? discuss
+        return getUserFlagsHashes(username).entrySet().stream()
+                .filter(taskEntry -> taskEntry.getValue().getName().equals(taskId))
+                .map(taskEntry -> calculateHashValue(username, taskEntry.getValue().getFlag().getValue()))
+                .findFirst();
+    }
 }
 
 //todo: generify!
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