Try to do everything with shorter queries

Probably we can even do this with one by using leftJoins and checking if any of
the columns we need become NON NULL but that makes it a lot harder to get right
in the next iteration.

Author: vmcj

webapp/src/Service/DOMJudgeService.php

@@ -879,8 +879,65 @@ public function getSamplesZipStreamedResponse(ContestProblem $contestProblem): S
         return Utils::streamAsBinaryFile($zipFileContent, $outputFilename, 'zip');
     }
 
+    public function checkIfSamplesZipForContest(Contest $contest): bool
+    {
+        // Note, we reload the contest with the problems and attachments, to reduce the number of queries
+        // We do not load the testcases here since addSamplesToZip loads them
+        $contestQuery = $this->em->createQueryBuilder()
+            ->from(Contest::class, 'c')
+            ->innerJoin('c.problems', 'cp')
+            ->innerJoin('cp.problem', 'p')
+            ->leftJoin('p.attachments', 'a')
+            ->leftJoin('p.problemStatementContent', 'content')
+            ->select('c', 'cp', 'p', 'a', 'content')
+            ->andWhere('c.cid = :cid')
+            ->andWhere('cp.allowSubmit = 1') // Do we need this...
+            ->setParameter('cid', $contest->getCid());
+
+        /** @var Contest $contest */
+        $contest = $contestQuery->getQuery()->getSingleResult();
+
+        if ($contest->getContestProblemsetType()) {
+            return true;
+        }
+
+        /** @var Problem[] $nonInteractiveProblems */
+        $nonInteractiveProblems = $contestQuery
+            ->innerJoin('p.testcases', 'tc')
+            ->andWhere('tc.sample = 1')
+            ->andWhere('BIT_AND(p.types, :interactiveType) = 0')
+            ->setParameter('interactiveType', Problem::TYPE_INTERACTIVE)
+            ->getQuery()
+            ->getResult();
+        if (!empty($nonInteractiveProblems)) {
+            return true;
+        }
+
+        /** @var Problem[] $problemsWithProblemStatement */
+        $problemsWithProblemStatement = $contestQuery
+            ->andWhere('p.problemstatementFile IS NOT NULL')
+            ->getQuery()
+            ->getResult();
+        if (!empty($problemsWithProblemStatement)) {
+            return true;
+        }
+
+        /** @var Problem[] $problemsWithAttachments */
+        $problemsWithAttachments = $contestQuery
+            ->innerJoin('p.attachments', 'a')
+            ->getQuery()
+            ->getResult();
+        if (!empty($problemsWithAttachments)) {
+            return true;
+        }
+
+        return false;
+    }
+
     public function getSamplesZipForContest(Contest $contest): StreamedResponse
     {
+        // When updating this, also update checkIfSamplesZipForContest.
+
         // Note, we reload the contest with the problems and attachments, to reduce the number of queries
         // We do not load the testcases here since addSamplesToZip loads them
         /** @var Contest $contest */