Create image generation class to save thumbnails

Added test for complete coverage

Added dropping of thumbnails

Prevent accidential removal of primary image

Signed-off-by: Christian Wolf <github@christianwolf.email>

lib/Helper/ImageService/ImageGenerationHelper.php

@@ -0,0 +1,74 @@
+<?php
+
+namespace OCA\Cookbook\Helper\ImageService;
+
+use OCP\Files\File;
+use OCP\Files\Folder;
+use OCA\Cookbook\Service\ThumbnailService;
+
+/**
+ * This class provides heler function to generate appropriate thumbnails according to the needs.
+ */
+class ImageGenerationHelper {
+	private const MAP = [
+		ImageSize::PRIMARY_IMAGE => 'full.jpg',
+		ImageSize::THUMBNAIL => 'thumb.jpg',
+		ImageSize::MINI_THUMBNAIL => 'thumb16.jpg',
+	];
+
+	/**
+	 * @var ThumbnailService
+	 */
+	private $thumbnailService;
+
+	public function __construct(
+		ThumbnailService $thumbnailService
+	) {
+		$this->thumbnailService = $thumbnailService;
+	}
+
+	/**
+	 * Calculate the image data of a thumbnail of defined size and store it in the nextcloud server storage.
+	 *
+	 * @param File $fullImage The full-sized image to use as a starting point
+	 * @param int $type The requested size of the thunbmail
+	 * @param File $dstFile The name of the file to store the thumbnail to
+	 * @return void
+	 */
+	public function generateThumbnail(File $fullImage, int $type, File $dstFile): void {
+		if ($type === ImageSize::PRIMARY_IMAGE) {
+			return;
+		}
+
+		$fullContent = $fullImage->getContent();
+
+		$thumbContent = $this->thumbnailService->getThumbnail($fullContent, $type);
+		
+		$dstFile->putContent($thumbContent);
+		$dstFile->touch();
+	}
+
+	/**
+	 * Ensure that a thumbnail is not existing in the file system.
+	 *
+	 * This method checks if a certain thumbail size is present in the recipe folder and removes the file accordingly.
+	 * Note: If the thumbnail is not present, this method does nothing.
+	 *
+	 * The main image will not be dropped.
+	 *
+	 * @param Folder $recipeFolder The folder containing the recipe
+	 * @param integer $type The type of the thumbnail to remove
+	 * @return void
+	 */
+	public function drop(Folder $recipeFolder, int $type): void {
+		if ($type === ImageSize::PRIMARY_IMAGE) {
+			return;
+		}
+		
+		$filename = ImageSize::NAME_MAP[$type];
+
+		if ($recipeFolder->nodeExists($filename)) {
+			$recipeFolder->get($filename)->delete();
+		}
+	}
+}

lib/Helper/ImageService/ImageSize.php

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+<?php
+
+namespace OCA\Cookbook\Helper\ImageService;
+
+class ImageSize {
+	public const PRIMARY_IMAGE = 1;
+	public const THUMBNAIL = 2;
+	public const MINI_THUMBNAIL = 3;
+
+	public const NAME_MAP = [
+		self::PRIMARY_IMAGE => 'full.jpg',
+		self::THUMBNAIL => 'thumb.jpg',
+		self::MINI_THUMBNAIL => 'thumb16.jpg',
+	];
+}

tests/Unit/Helper/ImageService/ImageGenerationHelperTest.php

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+<?php
+
+namespace OCA\Cookbook\tests\Unit\Helper\ImageService;
+
+use OCA\Cookbook\Helper\ImageService\ImageGenerationHelper;
+use PHPUnit\Framework\TestCase;
+use OCA\Cookbook\Helper\ImageService\ImageSize;
+use OCA\Cookbook\Service\ThumbnailService;
+use OCP\Files\File;
+use OCP\Files\Folder;
+use OCP\Files\NotFoundException;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\MockObject\Stub;
+
+/**
+ * @covers OCA\Cookbook\Helper\ImageService\ImageGenerationHelper
+ */
+class ImageGenerationHelperTest extends TestCase {
+
+	/**
+	 * @var ThumbnailService|MockObject
+	 */
+	private $thumbnailService;
+
+	/**
+	 * @var ImageGenerationHelper
+	 */
+	private $dut;
+
+	protected function setUp(): void {
+		$this->thumbnailService = $this->createMock(ThumbnailService::class);
+
+		$this->dut = new ImageGenerationHelper($this->thumbnailService);
+	}
+
+	public function dpThumbnails() {
+		yield [ImageSize::THUMBNAIL];
+		yield [ImageSize::MINI_THUMBNAIL];
+	}
+
+	/**
+	 * @dataProvider dpThumbnails
+	 */
+	public function testThumbnailGeneration($type) {
+		/**
+		 * @var Stub|File $fullImage
+		 */
+		$fullImage = $this->createStub(File::class);
+		/**
+		 * @var MockObject|File
+		 */
+		$dstFile = $this->createMock(File::class);
+
+		$fullContent = 'The content of the full image';
+		$thumbContent = 'The content of the thumb file';
+
+		$fullImage->method('getContent')->willReturn($fullContent);
+
+		$fileWasSaved = true;
+
+		$dstFile->expects($this->once())->method('putContent')->with($thumbContent)->will(
+			$this->returnCallback(function ($content) use (&$fileWasSaved) {
+				$fileWasSaved = false;
+			})
+		);
+		$dstFile->expects($this->once())->method('touch')->will($this->returnCallback(
+			function () use (&$fileWasSaved) {
+				$fileWasSaved = true;
+			}
+		));
+
+		$this->thumbnailService->method('getThumbnail')->with($fullContent, $type)
+			->willReturn($thumbContent);
+
+		$this->dut->generateThumbnail($fullImage, $type, $dstFile);
+
+		$this->assertTrue($fileWasSaved, 'File was not touched after modifications.');
+	}
+
+	public function testFullSizeImage() {
+		$fullImage = $this->createStub(File::class);
+		/**
+		 * @var MockObject|File $dstFile
+		 */
+		$dstFile = $this->createMock(File::class);
+
+		$dstFile->expects($this->never())->method('putContent');
+
+		$this->dut->generateThumbnail($fullImage, ImageSize::PRIMARY_IMAGE, $dstFile);
+	}
+
+	public function dpDropExisting() {
+		yield [ImageSize::THUMBNAIL, 'thumb.jpg'];
+		yield [ImageSize::MINI_THUMBNAIL, 'thumb16.jpg'];
+	}
+
+	/**
+	 * @dataProvider dpDropExisting
+	 */
+	public function testDropThumbnailExisting($type, $filename) {
+		/**
+		 * @var MockObject|Folder $folder
+		 */
+		$folder = $this->createMock(Folder::class);
+		/**
+		 * @var MockObject|File $thumbnail
+		 */
+		$thumbnail = $this->createMock(File::class);
+
+		$folder->method('get')->with($filename)->willReturn($thumbnail);
+		$folder->method('nodeExists')->willReturn(true);
+
+		$thumbnail->expects($this->once())->method('delete');
+
+		$this->dut->drop($folder, $type);
+	}
+
+	/**
+	 * @dataProvider dpDropExisting
+	 */
+	public function testDropThumbnailNonExisting($type, $filename) {
+		/**
+		 * @var MockObject|Folder $folder
+		 */
+		$folder = $this->createMock(Folder::class);
+
+		$folder->method('get')->with($filename)->willThrowException(new NotFoundException());
+		$folder->method('nodeExists')->willReturn(false);
+
+		$this->dut->drop($folder, $type);
+		$this->assertTrue(true, 'No Exception was thrown');
+	}
+
+	public function testDropThumbnailMainImage() {
+		/**
+		 * @var MockObject|Folder $folder
+		 */
+		$folder = $this->createMock(Folder::class);
+		/**
+		 * @var MockObject|Folder $image
+		 */
+		$image = $this->createMock(File::class);
+
+		$folder->method('get')->with('full.jpg')->willReturn($image);
+		$folder->method('nodeExists')->willReturn(true);
+
+		$image->expects($this->never())->method('delete');
+
+		$this->dut->drop($folder, ImageSize::PRIMARY_IMAGE);
+		$this->assertTrue(true, 'No Exception was thrown');
+	}
+}