New Feature: Low Quality Image Placeholder

app/Actions/Diagnostics/Errors.php

@@ -15,6 +15,7 @@
 use App\Actions\Diagnostics\Pipes\Checks\IniSettingsCheck;
 use App\Actions\Diagnostics\Pipes\Checks\MigrationCheck;
 use App\Actions\Diagnostics\Pipes\Checks\PHPVersionCheck;
+use App\Actions\Diagnostics\Pipes\Checks\PlaceholderExistsCheck;
 use App\Actions\Diagnostics\Pipes\Checks\SmallMediumExistsCheck;
 use App\Actions\Diagnostics\Pipes\Checks\SupporterCheck;
 use App\Actions\Diagnostics\Pipes\Checks\TimezoneCheck;
@@ -44,6 +45,7 @@ class Errors
 		ForeignKeyListInfo::class,
 		DBIntegrityCheck::class,
 		SmallMediumExistsCheck::class,
+		PlaceholderExistsCheck::class,
 		CountSizeVariantsCheck::class,
 		SupporterCheck::class,
 	];

app/Actions/Diagnostics/Pipes/Checks/PlaceholderExistsCheck.php

@@ -0,0 +1,76 @@
+<?php
+
+namespace App\Actions\Diagnostics\Pipes\Checks;
+
+use App\Contracts\DiagnosticPipe;
+use App\Enum\SizeVariantType;
+use App\Image\SizeVariantDimensionHelpers;
+use App\Models\SizeVariant;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Schema;
+
+/**
+ * Check if there are placeholders that can be generated or encoded.
+ */
+class PlaceholderExistsCheck implements DiagnosticPipe
+{
+	public const NUM_PLACEHOLDER = 'num_placeholder';
+	public const MAX_NUM_PLACEHOLDER = 'max_num_placeholder';
+	public const NUM_UNENCODED_PLACEHOLDER = 'num_unencoded_placeholder';
+	public const INFO_MSG_MISSING = 'Info: Found %d placeholders that could be generated.';
+	public const INFO_LINE_MISSING = '     You can use `php artisan lychee:generate_thumbs placeholder %d` to generate them.';
+	public const INFO_MSG_UNENCODED = 'Info: Found %d placeholder images that have not been encoded.';
+	public const INFO_LINE_UNENCODED = '     You can use `php artisan lychee:encode_placeholders %d` to encode them.';
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function handle(array &$data, \Closure $next): array
+	{
+		if (!Schema::hasTable('configs') || !Schema::hasTable('size_variants')) {
+			// @codeCoverageIgnoreStart
+			return $next($data);
+			// @codeCoverageIgnoreEnd
+		}
+
+		$svHelpers = new SizeVariantDimensionHelpers();
+		if (!$svHelpers->isEnabledByConfiguration(SizeVariantType::PLACEHOLDER)) {
+			return $next($data);
+		}
+
+		$result = DB::query()
+		->selectSub(
+			SizeVariant::query()
+			->selectRaw('COUNT(*)')
+			->where('type', '=', SizeVariantType::PLACEHOLDER),
+			self::NUM_PLACEHOLDER
+		)
+		->selectSub(
+			SizeVariant::query()
+			->selectRaw('COUNT(*)')
+			->where('type', '=', SizeVariantType::ORIGINAL),
+			self::MAX_NUM_PLACEHOLDER
+		)
+		->selectSub(
+			SizeVariant::query()
+			->selectRaw('COUNT(*)')
+			->where('short_path', 'LIKE', '%placeholder/%'),
+			self::NUM_UNENCODED_PLACEHOLDER
+		)
+		->first();
+
+		$num = $result->{self::NUM_UNENCODED_PLACEHOLDER}; // @phpstan-ignore-line
+		if ($num > 0) {
+			$data[] = sprintf(self::INFO_MSG_UNENCODED, $num);
+			$data[] = sprintf(self::INFO_LINE_UNENCODED, $num);
+		}
+
+		$num = $result->{self::MAX_NUM_PLACEHOLDER} - $result->{self::NUM_PLACEHOLDER}; // @phpstan-ignore-line
+		if ($num > 0) {
+			$data[] = sprintf(self::INFO_MSG_MISSING, $num);
+			$data[] = sprintf(self::INFO_LINE_MISSING, $num);
+		}
+
+		return $next($data);
+	}
+}

app/Actions/Photo/Create.php

@@ -167,6 +167,7 @@ private function handleStandalone(InitDTO $initDTO): Photo
 			Shared\Save::class,
 			Standalone\CreateOriginalSizeVariant::class,
 			Standalone\CreateSizeVariants::class,
+			Standalone\EncodePlaceholder::class,
 			Standalone\ReplaceOriginalWithBackup::class,
 			Shared\UploadSizeVariantsToS3::class,
 		];
@@ -253,6 +254,7 @@ private function handlePhotoLivePartner(InitDTO $initDTO): Photo
 			Shared\Save::class,
 			Standalone\CreateOriginalSizeVariant::class,
 			Standalone\CreateSizeVariants::class,
+			Standalone\EncodePlaceholder::class,
 			Standalone\ReplaceOriginalWithBackup::class,
 			Shared\UploadSizeVariantsToS3::class,
 		];

app/Actions/Photo/Pipes/Standalone/EncodePlaceholder.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace App\Actions\Photo\Pipes\Standalone;
+
+use App\Contracts\PhotoCreate\StandalonePipe;
+use App\DTO\PhotoCreate\StandaloneDTO;
+use App\Exceptions\MediaFileOperationException;
+use App\Image\PlaceholderEncoder;
+
+class EncodePlaceholder implements StandalonePipe
+{
+	public function handle(StandaloneDTO $state, \Closure $next): StandaloneDTO
+	{
+		try {
+			$placeholderEncoder = new PlaceholderEncoder();
+			$placeholder = $state->getPhoto()->size_variants->getPlaceholder();
+			if ($placeholder !== null) {
+				$placeholderEncoder->do($placeholder);
+			}
+
+			return $next($state);
+		} catch (\ErrorException $e) {
+			throw new MediaFileOperationException('Failed to encode placeholder to base64', $e);
+		}
+	}
+}

app/Assets/BaseSizeVariantNamingStrategy.php

@@ -17,6 +17,11 @@ abstract class BaseSizeVariantNamingStrategy extends AbstractSizeVariantNamingSt
 	 */
 	public const THUMB_EXTENSION = '.jpeg';
 
+	/**
+	 * The file extension which is always used by placeholder variants.
+	 */
+	public const PLACEHOLDER_EXTENSION = '.webp';
+
 	/**
 	 * Returns the file extension incl. the preceding dot.
 	 *
@@ -32,6 +37,10 @@ protected function generateExtension(SizeVariantType $sizeVariant): string
 			return self::THUMB_EXTENSION;
 		}
 
+		if ($sizeVariant === SizeVariantType::PLACEHOLDER) {
+			return self::PLACEHOLDER_EXTENSION;
+		}
+
 		if ($this->extension === '') {
 			throw new MissingValueException('extension');
 		}

app/Console/Commands/ImageProcessing/EncodePlaceholders.php

@@ -0,0 +1,63 @@
+<?php
+
+namespace App\Console\Commands\ImageProcessing;
+
+use App\Exceptions\UnexpectedException;
+use App\Image\PlaceholderEncoder;
+use App\Models\SizeVariant;
+use Illuminate\Console\Command;
+use Safe\Exceptions\InfoException;
+use function Safe\set_time_limit;
+
+class EncodePlaceholders extends Command
+{
+	/**
+	 * The name and signature of the console command.
+	 *
+	 * @var string
+	 */
+	protected $signature = 'lychee:encode_placeholders {limit=5 : number of photos to encode placeholders for} {tm=600 : timeout time requirement}';
+
+	/**
+	 * The console command description.
+	 *
+	 * @var string
+	 */
+	protected $description = 'Encode placeholders if size variant exists and image has not been encoded';
+
+	/**
+	 * Execute the console command.
+	 */
+	public function handle(): int
+	{
+		try {
+			$limit = (int) $this->argument('limit');
+			$timeout = (int) $this->argument('tm');
+
+			try {
+				set_time_limit($timeout);
+			} catch (InfoException) {
+				// Silently do nothing, if `set_time_limit` is denied.
+			}
+
+			$placeholders = SizeVariant::query()
+				->where('short_path', 'LIKE', '%placeholder/%')
+				->limit($limit)
+				->get();
+			if (count($placeholders) === 0) {
+				$this->line('No placeholders require encoding.');
+
+				return 0;
+			}
+
+			$placeholderEncoder = new PlaceholderEncoder();
+			foreach ($placeholders as $placeholder) {
+				$placeholderEncoder->do($placeholder);
+			}
+
+			return 0;
+		} catch (\Throwable $e) {
+			throw new UnexpectedException($e);
+		}
+	}
+}

app/Console/Commands/ImageProcessing/GenerateThumbs.php

@@ -20,6 +20,7 @@ class GenerateThumbs extends Command
 	 * @var array<string,SizeVariantType>
 	 */
 	public const SIZE_VARIANTS = [
+		'placeholder' => SizeVariantType::PLACEHOLDER,
 		'thumb' => SizeVariantType::THUMB,
 		'thumb2x' => SizeVariantType::THUMB2X,
 		'small' => SizeVariantType::SMALL,

app/Enum/SizeVariantType.php

@@ -16,6 +16,7 @@ enum SizeVariantType: int
 	case SMALL = 4;
 	case THUMB2X = 5;
 	case THUMB = 6;
+	case PLACEHOLDER = 7;
 
 	/**
 	 * Given a sizeVariantType return the associated name.
@@ -25,6 +26,7 @@ enum SizeVariantType: int
 	public function name(): string
 	{
 		return match ($this) {
+			self::PLACEHOLDER => 'placeholder',
 			self::THUMB => 'thumb',
 			self::THUMB2X => 'thumb2x',
 			self::SMALL => 'small',
@@ -43,6 +45,7 @@ public function name(): string
 	public function localization(): string
 	{
 		return match ($this) {
+			self::PLACEHOLDER => __('lychee.PHOTO_PLACEHOLDER'),
 			self::THUMB => __('lychee.PHOTO_THUMB'),
 			self::THUMB2X => __('lychee.PHOTO_THUMB_HIDPI'),
 			self::SMALL => __('lychee.PHOTO_SMALL'),

app/Http/Resources/Models/SizeVariantsResouce.php

@@ -19,6 +19,7 @@ class SizeVariantsResouce extends Data
 	public ?SizeVariantResource $small;
 	public ?SizeVariantResource $thumb2x;
 	public ?SizeVariantResource $thumb;
+	public ?SizeVariantResource $placeholder;
 
 	public function __construct(Photo $photo)
 	{
@@ -34,6 +35,7 @@ public function __construct(Photo $photo)
 		$small2x = $size_variants?->getSizeVariant(SizeVariantType::SMALL2X);
 		$thumb = $size_variants?->getSizeVariant(SizeVariantType::THUMB);
 		$thumb2x = $size_variants?->getSizeVariant(SizeVariantType::THUMB2X);
+		$placeholder = $size_variants?->getSizeVariant(SizeVariantType::PLACEHOLDER);
 
 		$this->medium = $medium?->toResource();
 		$this->medium2x = $medium2x?->toResource();
@@ -42,5 +44,6 @@ public function __construct(Photo $photo)
 		$this->small2x = $small2x?->toResource();
 		$this->thumb = $thumb?->toResource();
 		$this->thumb2x = $thumb2x?->toResource();
+		$this->placeholder = $placeholder?->toResource();
 	}
 }