Reworks balloon for sending balloons in freeze

ChangeLog

@@ -2,6 +2,9 @@ DOMjudge Programming Contest Judging System
 
 Version 10.0.0DEV
 ---------------------------
+ - Configuration changes
+   - `show_balloons_postfreeze` configuration variable superseded by
+     `minimum_number_of_balloons` and `any_balloon_postfreeze`.
 
 Version 9.0.0 - 5 October 2025
 ---------------------------

doc/manual/running.rst

@@ -106,9 +106,29 @@ show for submissions after the freeze. It is possible that new
 entries appear for some times after the freeze, if the result of
 a submission before the freeze is only known after (this can also
 happen in case of a :ref:`rejudging`).
-The global configuration option ``show_balloons_postfreeze`` will
+
+.. warning::
+
+  Using the features as described below results in data inconsistencies.
+  e.g. balloon notifications are available through the API while no
+  judgement is available. Using these features can also lead to undesirable
+  information leaking to contestants and observers. Use with caution!
+
+Balloons during frozen scoreboard
+`````````````````````
+The global configuration option ``minimum_number_of_balloons`` will
 ignore a contest freeze for purposes of balloons and new correct
-submissions will trigger a balloon entry in the table.
+submissions will trigger a balloon entry in the table. This only
+happens when the team problem has not received the amount of balloons
+set by the configuration option and the newly solved problem must have
+been solved before the freeze. This is to prevent an information leak.
+
+To hand balloons for any and all correct submissions during the freeze
+set the ``any_balloon_postfreeze`` global configuration option to `true`.
+This sends out balloons as long as ``minimum_number_of_balloons`` has not
+been met. By setting ``minimum_number_of_balloons`` to a value greater or
+equal to the number of problems in the contest ensures any submission
+results in a balloon notification.
 
 Static scoreboard
 -----------------

etc/db-config.yaml

@@ -255,11 +255,16 @@
             default_value: false
             public: true
             description: Show results of TOO-LATE submissions in team interface?
-        -   name: show_balloons_postfreeze
+        -   name: minimum_number_of_balloons
+            type: int
+            default_value: 0
+            public: true
+            description: How many balloons to hand out ignoring freeze time. Only hands out balloons for problems solved pre-freeze.
+        -   name: any_balloon_postfreeze
             type: bool
             default_value: false
             public: true
-            description: Give out balloon notifications after the scoreboard has been frozen?
+            description: Hand out balloons during the freeze for problems that have not been solved pre-freeze.
         -   name: show_relative_time
             type: bool
             default_value: false

webapp/src/Controller/Jury/BalloonController.php

@@ -52,6 +52,10 @@ private function areDefault(array $filters, array $defaultCategories): bool {
     #[Route(path: '', name: 'jury_balloons')]
     public function indexAction(BalloonService $balloonService): Response
     {
+        if (((int)$this->config->get('minimum_number_of_balloons')) !== 0) {
+            $this->addFlash('warning', 'Minimum number of balloons is enabled, this leads to data inconsistencies and/or information leaking during the freeze. Can be disabled in the "Configuration settings".');
+        }
+
         $contest = $this->dj->getCurrentContest();
         if (is_null($contest)) {
             return $this->render('jury/balloons.html.twig');

webapp/src/Controller/Jury/ConfigController.php

@@ -38,6 +38,7 @@ public function indexAction(EventLogService $eventLogService, Request $request):
         foreach ($specs as &$spec) {
             $spec = $this->config->addOptions($spec);
         }
+
         unset($spec);
         /** @var Configuration[] $options */
         $options = $this->em->createQueryBuilder()
@@ -123,6 +124,10 @@ public function indexAction(EventLogService $eventLogService, Request $request):
             }
         }
 
+        if (((int)$this->config->get('minimum_number_of_balloons')) !== 0) {
+            $this->addFlash('warning', 'Minimum number of balloons is enabled, this leads to data inconsistencies and/or information leaking during the freeze. Can be disabled in the "Display" tab.');
+        }
+
         $categories = [];
         foreach ($specs as $spec) {
             if (!in_array($spec->category, $categories)) {

webapp/src/Service/BalloonService.php

@@ -92,15 +92,13 @@ public function updateBalloons(
     public function collectBalloonTable(Contest $contest, bool $todo = false): array
     {
         $em = $this->em;
-        $showPostFreeze = (bool)$this->config->get('show_balloons_postfreeze');
-        if (!$showPostFreeze) {
-            $freezetime = $contest->getFreezeTime();
-        }
 
+        // Retrieve all relevant balloons in 'submit order'. This allows accurate
+        // counts when deciding whether to hand out post-freeze balloons.
         $query = $em->createQueryBuilder()
             ->select('b', 's.submittime', 'p.probid',
                 't.teamid', 's', 't', 't.location',
-                'c.categoryid AS categoryid', 'c.name AS catname',
+                'c.categoryid AS categoryid', 'c.sortorder', 'c.name AS catname',
                 'co.cid', 'co.shortname',
                 'cp.shortname AS probshortname', 'cp.color',
                 'a.affilid AS affilid', 'a.shortname AS affilshort')
@@ -114,28 +112,22 @@ public function collectBalloonTable(Contest $contest, bool $todo = false): array
             ->leftJoin('t.affiliation', 'a')
             ->andWhere('co.cid = :cid')
             ->setParameter('cid', $contest->getCid())
-            ->orderBy('b.done', 'ASC')
-            ->addOrderBy('s.submittime', 'DESC');
+            ->orderBy('b.done', 'DESC')
+            ->addOrderBy('s.submittime', 'ASC');
 
         $balloons = $query->getQuery()->getResult();
-        // Loop once over the results to get totals.
-        $TOTAL_BALLOONS = [];
-        foreach ($balloons as $balloonsData) {
-            if ($balloonsData['color'] === null) {
-                continue;
-            }
 
-            $stime = $balloonsData['submittime'];
+        $minimumNumberOfBalloons = (int)$this->config->get('minimum_number_of_balloons');
+        $ignorePreFreezeSolves = (bool)$this->config->get('any_balloon_postfreeze');
+        $freezetime = $contest->getFreezeTime();
 
-            if (isset($freezetime) && $stime >= $freezetime) {
-                continue;
-            }
+        $balloonsTable = [];
 
-            $TOTAL_BALLOONS[$balloonsData['teamid']][$balloonsData['probshortname']] = $balloonsData[0]->getSubmission()->getContestProblem();
-        }
+        // Total balloons keeps track of the total balloons for a team, will be used to fill the rhs for every row in $balloonsTable.
+        // The same summary is used for every row for a team. References to elements in this array ensure easy updates.
+        /** @var mixed[] $balloonSummaryPerTeam */
+        $balloonSummaryPerTeam = [];
 
-        // Loop again to construct table.
-        $balloons_table = [];
         foreach ($balloons as $balloonsData) {
             if ($balloonsData['color'] === null) {
                 continue;
@@ -144,41 +136,72 @@ public function collectBalloonTable(Contest $contest, bool $todo = false): array
             $balloon = $balloonsData[0];
             $done = $balloon->getDone();
 
-            if ($todo && $done) {
-                continue;
+            // Ensure a summary-row exists for this sortorder and take a reference to these summaries. References are needed to ensure array reuse.
+            // Summaries are used to determine whether a balloon has been handed out so they need to be separated between sortorders.
+            $balloonSummaryPerTeam[$balloonsData['sortorder']] ??= [];
+            $relevantBalloonSummaries = &$balloonSummaryPerTeam[$balloonsData['sortorder']];
+
+            // Commonly no balloons are handed out post freeze.
+            // Underperforming teams' moral can be boosted by handing out balloons post-freeze.
+            // Handing out balloons for problems that have not been solved pre-freeze poses a potential information leak, so these are always excluded.
+            // So to decide whether to skip showing a balloon:
+            //   1. Check whether the scoreboard has been frozen.
+            //   2. Check whether the team has exceeded minimum number of balloons.
+            //   3. Check whether the problem been solved pre-freeze.
+            $stime = $balloonsData['submittime'];
+            if ($ignorePreFreezeSolves === false && isset($freezetime) && $stime >= $freezetime) {
+                if (count($relevantBalloonSummaries[$balloonsData['teamid']] ?? []) >= $minimumNumberOfBalloons) {
+                    continue;
+                }
+
+                // Check if problem has been solved before the freeze by someone in the same sortorder to prevent information leak.
+                // Checking for solved problems in the same sortorder prevent information leaks from teams like DOMjudge that have commonly solved
+                // all problems (jury solutions) but are not in the same sortorder. If a balloon for this problem should've been handed out it is
+                // safe to hand out again since balloons are handled in 'submit order'.
+                if (!array_reduce($relevantBalloonSummaries, fn($c, $i) => $c ||
+                    array_key_exists($balloonsData['probshortname'], $i), false)) {
+                    continue;
+                }
             }
 
-            $balloonId = $balloon->getBalloonId();
+            // Register the balloon that is handed out in the team summary.
+            $relevantBalloonSummaries[$balloonsData['teamid']][$balloonsData['probshortname']] = $balloon->getSubmission()->getContestProblem();
 
-            $stime = $balloonsData['submittime'];
-
-            if (isset($freezetime) && $stime >= $freezetime) {
+            // This balloon might not need to be listed, entire order is needed for counts though.
+            if ($todo && $done) {
                 continue;
             }
 
-            $balloondata = [];
-            $balloondata['balloonid'] = $balloonId;
-            $balloondata['time'] = $stime;
-            $balloondata['problem'] = $balloonsData['probshortname'];
-            $balloondata['contestproblem'] = $balloon->getSubmission()->getContestProblem();
-            $balloondata['team'] = $balloon->getSubmission()->getTeam();
-            $balloondata['teamid'] = $balloonsData['teamid'];
-            $balloondata['location'] = $balloonsData['location'];
-            $balloondata['affiliation'] = $balloonsData['affilshort'];
-            $balloondata['affiliationid'] = $balloonsData['affilid'];
-            $balloondata['category'] = $balloonsData['catname'];
-            $balloondata['categoryid'] = $balloonsData['categoryid'];
-
-            ksort($TOTAL_BALLOONS[$balloonsData['teamid']]);
-            $balloondata['total'] = $TOTAL_BALLOONS[$balloonsData['teamid']];
-
-            $balloondata['done'] = $done;
-
-            $balloons_table[] = [
-                'data' => $balloondata,
+            $balloonsTable[] = [
+                'data' => [
+                    'balloonid' => $balloon->getBalloonId(),
+                    'time' => $stime,
+                    'problem' => $balloonsData['probshortname'],
+                    'contestproblem' => $balloon->getSubmission()->getContestProblem(),
+                    'team' => $balloon->getSubmission()->getTeam(),
+                    'teamid' => $balloonsData['teamid'],
+                    'location' => $balloonsData['location'],
+                    'affiliation' => $balloonsData['affilshort'],
+                    'affiliationid' => $balloonsData['affilid'],
+                    'category' => $balloonsData['catname'],
+                    'categoryid' => $balloonsData['categoryid'],
+                    'done' => $done,
+
+                    // Reuse the same total summary table by taking a reference, makes updates easier.
+                    'total' => &$relevantBalloonSummaries[$balloonsData['teamid']],
+                ]
             ];
         }
-        return $balloons_table;
+
+        // Sort the balloons, since these are handled by reference each summary item only need to be sorted once.
+        foreach ($balloonSummaryPerTeam as $relevantBalloonSummaries) {
+            foreach ($relevantBalloonSummaries as &$balloons) {
+                ksort($balloons);
+            }
+        }
+
+        // Reverse the order so the newest appear first
+        return array_reverse($balloonsTable);
     }
 
     public function setDone(int $balloonId): void

webapp/src/Service/CheckConfigService.php

@@ -67,6 +67,7 @@ public function runAll(): array
             'debugdisabled' => $this->checkDebugDisabled(),
             'tmpdirwritable' => $this->checkTmpdirWritable(),
             'hashtime' => $this->checkHashTime(),
+            'balloonsduringfreeze' => $this->checkBalloonsDuringFreeze(),
         ];
 
         foreach (['affiliations', 'banners', 'countries', 'teams'] as $key) {
@@ -476,6 +477,28 @@ public function checkHashTime(): ConfigCheckItem
         );
     }
 
+    public function checkBalloonsDuringFreeze(): ConfigCheckItem
+    {
+        $balloonsDuringFreeze = (int)$this->config->get('minimum_number_of_balloons');
+
+        $desc = '- Handing out any balloons while the scoreboard is frozen can lead to data inconsistencies and information leaking.'
+            . sprintf("\n - Currently handing out up-to `%d` balloons during the freeze.", $balloonsDuringFreeze);
+
+        if ($balloonsDuringFreeze !== 0) {
+            return new ConfigCheckItem(
+                caption: 'Balloons during freeze',
+                result: 'W',
+                desc: $desc,
+            );
+        }
+
+        return new ConfigCheckItem(
+            caption: 'Balloons during freeze',
+            result: 'O',
+            desc: $desc,
+        );
+    }
+
     public function checkContestActive(): ConfigCheckItem
     {
         $this->stopwatch->start(__FUNCTION__);

webapp/src/Service/DOMJudgeService.php

@@ -101,6 +101,7 @@ class DOMJudgeService
 
     public function __construct(
         protected readonly EntityManagerInterface $em,
+        protected readonly BalloonService $balloonService,
         protected readonly LoggerInterface $logger,
         protected readonly RequestStack $requestStack,
         protected readonly ParameterBagInterface $params,
@@ -437,26 +438,14 @@ public function getUpdates(): array
         }
 
         if ($this->checkrole('balloon') && $contest) {
-            $balloonsQuery = $this->em->createQueryBuilder()
-                ->select('b.balloonid', 't.name', 't.location', 'p.name AS pname')
-                ->from(Balloon::class, 'b')
-                ->leftJoin('b.submission', 's')
-                ->leftJoin('s.problem', 'p')
-                ->leftJoin('s.contest', 'co')
-                ->leftJoin('p.contest_problems', 'cp', Join::WITH, 'co.cid = cp.contest AND p.probid = cp.problem')
-                ->leftJoin('s.team', 't')
-                ->andWhere('co.cid = :cid')
-                ->andWhere('b.done = 0')
-                ->setParameter('cid', $contest->getCid());
-
-            $freezetime = $contest->getFreezeTime();
-            if ($freezetime !== null && !(bool)$this->config->get('show_balloons_postfreeze')) {
-                $balloonsQuery
-                    ->andWhere('s.submittime < :freeze')
-                    ->setParameter('freeze', $freezetime);
-            }
-
-            $balloons = $balloonsQuery->getQuery()->getResult();
+            $balloons = array_map(function ($balloon) {
+                return [
+                    'balloonid' => $balloon['data']['balloonid'],
+                    'name' => $balloon['data']['team']->getName(),
+                    'location' => $balloon['data']['location'],
+                    'pname' => $balloon['data']['contestproblem']->getProblem()->getName(),
+                ];
+            }, $this->balloonService->collectBalloonTable($contest, true));
         }
 
         return [