checking if not already subbmited flag - stub

service/src/main/java/com/telephoners/krakyournet/ctf/repositories/SolutionsRepository.java

 package com.telephoners.krakyournet.ctf.repositories;
 
+import com.telephoners.krakyournet.ctf.beans.Flag;
 import com.telephoners.krakyournet.ctf.beans.Solution;
 import com.telephoners.krakyournet.ctf.beans.Team;
 import com.telephoners.krakyournet.ctf.beans.tasks.Task;
@@ -9,7 +10,9 @@ import javax.inject.Inject;
 import javax.inject.Singleton;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.function.Function;
+import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
 @Singleton
@@ -62,4 +65,22 @@ public class SolutionsRepository implements Repository
                                 .map(solution -> solution.getFlag().getDescription()).collect(Collectors.toList())
                 ));
     }
+
+    //todo: use datastore filter
+    public boolean exists(Solution solution)
+    {
+        //todo: refactor, ugly ;(
+        String value = solution.getFlag().getValue();
+        Optional<Solution> matchedSolution = getAll().stream()
+                .filter(new Predicate<Solution>()
+                {
+                    @Override
+                    public boolean test(Solution solution)
+                    {
+                        return solution.getFlag().getValue().equals(value);
+                    }
+                })
+                .findFirst();
+        return matchedSolution.isPresent();
+    }
 }
\ No newline at end of file

service/src/main/java/com/telephoners/krakyournet/ctf/repositories/TasksRepository.java

@@ -151,6 +151,11 @@ public class TasksRepository implements Repository
         return encodedHash;
     }
 
+    private boolean isAlreadySubmittedSolution(Solution solution)
+    {
+        return solutionsRepository.exists(solution);
+    }
+
     public boolean checkHash(User user, String hashValue)
     {
         //todo: refactor
@@ -161,12 +166,15 @@ public class TasksRepository implements Repository
 
         Pair<Task, Flag> taskFlagPair = taskFlagPairOptional.get();
         Task task = taskFlagPair.getKey();
-        Flag flag = taskFlagPair.getValue();
         Optional<Team> team = teamsRepository.getTeamByUser(user);
         if (team.isPresent()) {
-            solutionsRepository.add(new Solution(team.get(), task, flag)); //todo
+            //todo: combine ifs
+            Solution solution = new Solution(team.get(), task, hashValue); //todo: conflict, solution stores task flag, should store hashValue!!
+            if (!isAlreadySubmittedSolution(solution)) {
+                solutionsRepository.add(solution);
                 return true;
             }
+        }
         return false;
     }