Convert ebooks using kepubify on the fly

.env

@@ -50,4 +50,4 @@ BOOK_FILE_NAMING_FORMAT="{serie}-{serieIndex}-{title}"
 KOBO_PROXY_USE_DEV=0
 KOBO_PROXY_USE_EVERYWHERE=0
 KOBO_PROXY_ENABLED=1
-###< kobo/proxy
+###< kobo/proxy

config/services.yaml

@@ -14,6 +14,8 @@ parameters:
     KOBO_API_URL:  '%env(KOBO_API_URL)%'
     env(KOBO_IMAGE_API_URL): "https://cdn.kobo.com/book-images"
     KOBO_IMAGE_API_URL:  '%env(KOBO_IMAGE_API_URL)%'
+    env(KEPUBIFY_BIN): "/usr/bin/kepubify"
+    KEPUBIFY_BIN:  '%env(KEPUBIFY_BIN)%'
 services:
     # default configuration for services in *this* file
     _defaults:

src/Kobo/DownloadHelper.php

@@ -6,11 +6,15 @@
 use App\Entity\KoboDevice;
 use App\Exception\BookFileNotFound;
 use App\Kobo\ImageProcessor\CoverTransformer;
+use App\Kobo\Messenger\KepubifyMessage;
 use App\Service\BookFileSystemManager;
 use Psr\Log\LoggerInterface;
+use Symfony\Component\HttpFoundation\BinaryFileResponse;
+use Symfony\Component\HttpFoundation\HeaderUtils;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpFoundation\StreamedResponse;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+use Symfony\Component\Messenger\MessageBusInterface;
 use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
 
 class DownloadHelper
@@ -19,8 +23,9 @@ public function __construct(
         private readonly BookFileSystemManager $fileSystemManager,
         private readonly CoverTransformer $coverTransformer,
         protected UrlGeneratorInterface $urlGenerator,
-        protected LoggerInterface $logger)
-    {
+        protected LoggerInterface $logger,
+        protected MessageBusInterface $messageBus
+    ) {
     }
 
     protected function getBookFilename(Book $book): string
@@ -86,15 +91,20 @@ public function getCoverResponse(Book $book, int $width, int $height, bool $gray
         return $response;
     }
 
-    public function getResponse(Book $book): StreamedResponse
+    public function getResponse(Book $book): Response
     {
         $bookPath = $this->getBookFilename($book);
         if (false === $this->exists($book)) {
             throw new BookFileNotFound($bookPath);
         }
-        $response = new StreamedResponse(function () use ($bookPath) {
-            readfile($bookPath);
-        }, Response::HTTP_OK);
+
+        // Convert the file to kepub (Kobo's epub format) as a temporary file
+        $temporaryFile = $this->runKepubify($bookPath);
+        $fileToStream = $temporaryFile ?? $bookPath;
+        $fileSize = filesize($fileToStream);
+
+        $response = (new BinaryFileResponse($fileToStream, Response::HTTP_OK))
+            ->deleteFileAfterSend($temporaryFile !== null);
 
         $filename = $book->getBookFilename();
         $encodedFilename = rawurlencode($filename);
@@ -104,10 +114,11 @@ public function getResponse(Book $book): StreamedResponse
             'epub', 'epub3' => 'application/epub+zip',
             default => 'application/octet-stream'
         });
-        $response->headers->set('Content-Disposition',
-            sprintf('attachment; filename="%s"; filename*=UTF-8\'\'%s', $simpleName, $encodedFilename));
+        $response->headers->set('Content-Disposition', HeaderUtils::makeDisposition(HeaderUtils::DISPOSITION_ATTACHMENT, $encodedFilename, $simpleName));
 
-        $response->headers->set('Content-Length', (string) $this->getSize($book));
+        if ($fileSize !== false) {
+            $response->headers->set('Content-Length', (string) $fileSize);
+        }
 
         return $response;
     }
@@ -116,4 +127,12 @@ public function coverExist(Book $book): bool
     {
         return $this->fileSystemManager->coverExist($book);
     }
+
+    private function runKepubify(string $bookPath): ?string
+    {
+        $conversionDto = new KepubifyMessage($bookPath);
+        $this->messageBus->dispatch($conversionDto);
+
+        return $conversionDto->destination;
+    }
 }

src/Kobo/Messenger/KepubifyMessage.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace App\Kobo\Messenger;
+
+/**
+ * Convert an ebook with kepubify binary
+ * The destination property will be set to the path of the converted file,
+ */
+class KepubifyMessage
+{
+    /**
+     * @var string|null Path of the destination file (which aim to be a temporary file). Null if the conversion failed.
+     */
+    public ?string $destination = null;
+
+    public function __construct(
+        /** Path of the source ebook to convert */
+        public string $source
+    ) {
+    }
+}

src/Kobo/Messenger/KepubifyMessageHandler.php

@@ -0,0 +1,74 @@
+<?php
+
+namespace App\Kobo\Messenger;
+
+use Psr\Log\LoggerInterface;
+use Symfony\Component\DependencyInjection\Attribute\Autowire;
+use Symfony\Component\Messenger\Attribute\AsMessageHandler;
+use Symfony\Component\Process\Process;
+
+#[AsMessageHandler]
+class KepubifyMessageHandler
+{
+    public const CACHE_FOLDER = '/kepubify';
+    public const TEMP_NAME_SUFFIX = 'kepub-';
+
+    public function __construct(
+        #[Autowire(param: 'kernel.cache_dir')]
+        private readonly string $cacheDir,
+        private readonly LoggerInterface $logger,
+        #[Autowire(param: 'KEPUBIFY_BIN')]
+        private string $kepubifyBinary
+    ) {
+    }
+
+    public function __invoke(KepubifyMessage $message): void
+    {
+        // Disable kepubify if the path is not set
+        if (trim($this->kepubifyBinary) === '') {
+            return;
+        }
+
+        // Create a temporary file
+        $temporaryFile = $this->getTemporaryFilename();
+        if ($temporaryFile === false) {
+            $this->logger->error('Error while creating temporary file');
+
+            return;
+        }
+
+        // Run the conversion
+        $process = new Process([$this->kepubifyBinary, '--output', $temporaryFile, $message->source]);
+        $this->logger->debug('Run kepubify command: {command}', ['command' => $process->getCommandLine()]);
+        $process->run();
+
+        if (!$process->isSuccessful()) {
+            $this->logger->error('Error while running kepubify: {output}: {error}', [
+                'output' => $process->getOutput(),
+                'error' => $process->getErrorOutput(),
+            ]);
+            @unlink($temporaryFile);
+
+            return;
+        }
+
+        $message->destination = $temporaryFile;
+    }
+
+    /**
+     * Create a temporary file to handle the conversion result.
+     * Note that the name must be unique to handle concurrent requests
+     * because the file will be deleted once the request is served.
+     *
+     * @return string|false
+     */
+    private function getTemporaryFilename(): string|false
+    {
+        $dir = $this->cacheDir.self::CACHE_FOLDER;
+        if (!is_dir($dir) && !mkdir($dir, 0777, true) && !is_dir($dir)) {
+            return false;
+        }
+
+        return tempnam($dir, self::TEMP_NAME_SUFFIX);
+    }
+}

tests/Controller/Kobo/KoboDownloadControllerTest.php

@@ -29,7 +29,7 @@ public function testDownload(): void
         self::assertResponseHeaderSame('Content-Type', 'application/epub+zip');
         self::assertResponseHasHeader('Content-Length');
 
-        $expectedDisposition = "attachment; filename=\"book-1-TheOdysses.epub\"; filename*=UTF-8''TheOdysses.epub";
+        $expectedDisposition = "attachment; filename=book-1-TheOdysses.epub; filename*=utf-8''TheOdysses.epub";
         self::assertResponseHeaderSame('Content-Disposition', $expectedDisposition, 'The Content-Disposition header is not as expected');
 
     }