Return fallback file instead of error message for LS to avoid constant pinging of the AutoDJ.

src/Controller/Admin/DebugController.php

@@ -154,11 +154,12 @@ class DebugController extends AbstractLogViewerController
         $this->logger->pushHandler($this->testHandler);
 
         $nextSongAnnotated = $annotations->annotateNextSong(
-            $request->getStation(),
-            false
+            $request->getStation()
         );
 
-        $this->logger->info('Annotated next song: ' . $nextSongAnnotated);
+        $this->logger->info('Annotated next song', [
+            'annotation' => $nextSongAnnotated,
+        ]);
         $this->logger->popHandler();
 
         return $request->getView()->renderToResponse(

src/Event/Radio/AnnotateNextSong.php

@@ -73,10 +73,10 @@ class AnnotateNextSong extends Event
     /**
      * Compile the resulting annotations into one string for Liquidsoap to consume.
      */
-    public function buildAnnotations(): string
+    public function buildAnnotations(): ?string
     {
         if (empty($this->songPath)) {
-            return '';
+            return null;
         }
 
         $this->annotations = array_filter($this->annotations);

src/Radio/AutoDJ/Annotations.php

@@ -27,7 +27,7 @@ class Annotations implements EventSubscriberInterface
     }
 
     /**
-     * @return mixed[]
+     * @inheritDoc
      */
     public static function getSubscribedEvents(): array
     {
@@ -50,7 +50,7 @@ class Annotations implements EventSubscriberInterface
     public function annotateNextSong(
         Entity\Station $station,
         bool $asAutoDj = false,
-    ): string {
+    ): ?string {
         $queueRow = $this->queueRepo->getNextToSendToAutoDj($station);
 
         // Try to rebuild the queue if it's empty.
@@ -64,7 +64,8 @@ class Annotations implements EventSubscriberInterface
                     ],
                 ]
             );
-            return '';
+
+            return null;
         }
 
         $event = new AnnotateNextSong($queueRow, $asAutoDj);

src/Radio/Backend/Liquidsoap/Command/NextSongCommand.php

@@ -6,13 +6,15 @@ namespace App\Radio\Backend\Liquidsoap\Command;
 
 use App\Entity;
 use App\Radio\AutoDJ\Annotations;
+use App\Radio\FallbackFile;
 use Monolog\Logger;
 
 class NextSongCommand extends AbstractCommand
 {
     public function __construct(
         Logger $logger,
-        protected Annotations $annotations
+        protected Annotations $annotations,
+        protected FallbackFile $fallbackFile
     ) {
         parent::__construct($logger);
     }
@@ -25,6 +27,6 @@ class NextSongCommand extends AbstractCommand
         return $this->annotations->annotateNextSong(
             $station,
             $asAutoDj
-        );
+        ) ?? $this->fallbackFile->getFallbackPathForStation($station);
     }
 }

src/Radio/Backend/Liquidsoap/ConfigWriter.php

@@ -14,6 +14,7 @@ use App\Radio\Backend\Liquidsoap;
 use App\Radio\Enums\FrontendAdapters;
 use App\Radio\Enums\StreamFormats;
 use App\Radio\Enums\StreamProtocols;
+use App\Radio\FallbackFile;
 use Carbon\CarbonImmutable;
 use Doctrine\ORM\EntityManagerInterface;
 use League\Flysystem\StorageAttributes;
@@ -34,7 +35,8 @@ class ConfigWriter implements EventSubscriberInterface
         protected Entity\Repository\SettingsRepository $settingsRepo,
         protected Liquidsoap $liquidsoap,
         protected Environment $environment,
-        protected LoggerInterface $logger
+        protected LoggerInterface $logger,
+        protected FallbackFile $fallbackFile
     ) {
     }
 
@@ -998,18 +1000,7 @@ class ConfigWriter implements EventSubscriberInterface
         }
 
         // Write fallback to safety file to ensure infallible source for the broadcast outputs.
-        $errorFile = $this->environment->isDocker()
-            ? '/usr/local/share/icecast/web/error.mp3'
-            : $this->environment->getBaseDirectory() . '/resources/error.mp3';
-
-        // Check for a custom station fallback file.
-        $stationFallback = $station->getFallbackPath();
-        if (!empty($stationFallback)) {
-            $fsConfig = (new StationFilesystems($station))->getConfigFilesystem();
-            if ($fsConfig->fileExists($stationFallback)) {
-                $errorFile = $fsConfig->getLocalPath($stationFallback);
-            }
-        }
+        $errorFile = $this->fallbackFile->getFallbackPathForStation($station);
 
         $event->appendBlock(
             <<<EOF

src/Radio/FallbackFile.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Radio;
+
+use App\Entity;
+use App\Environment;
+use App\Flysystem\StationFilesystems;
+
+class FallbackFile
+{
+    public function __construct(
+        protected Environment $environment
+    ) {
+    }
+
+    public function getFallbackPathForStation(Entity\Station $station): string
+    {
+        $stationFallback = $station->getFallbackPath();
+        if (!empty($stationFallback)) {
+            $fsConfig = (new StationFilesystems($station))->getConfigFilesystem();
+            if ($fsConfig->fileExists($stationFallback)) {
+                return $fsConfig->getLocalPath($stationFallback);
+            }
+        }
+
+        return $this->getDefaultFallbackPath();
+    }
+
+    public function getDefaultFallbackPath(): string
+    {
+        return $this->environment->isDocker()
+            ? '/usr/local/share/icecast/web/error.mp3'
+            : $this->environment->getBaseDirectory() . '/resources/error.mp3';
+    }
+}

src/Sync/Task/CheckRequestsTask.php

@@ -83,6 +83,11 @@ class CheckRequestsTask extends AbstractTask
 
         $track = $event->buildAnnotations();
 
+        if (null === $track) {
+            $this->logger->error('Error building annotation.');
+            return false;
+        }
+
         // Queue request with Liquidsoap.
         if (!$backend->isQueueEmpty($station)) {
             $this->logger->error('Skipping submitting request to Liquidsoap; current queue is occupied.');