refactor(policy): auto-discover file appliers from provider registry

Signed-off-by: Vitor Mattos <1079143+vitormattos@users.noreply.github.com>

Author: vitormattos

lib/Service/Policy/FilePolicyApplier.php

@@ -11,74 +11,124 @@
 use OCA\Libresign\Db\File as FileEntity;
 use OCA\Libresign\Service\FileService;
 use OCA\Libresign\Service\Policy\Provider\DocMdp\FilePolicy\DocMdpFilePolicyApplier;
+use OCA\Libresign\Service\Policy\Provider\FilePolicy\Contract\IFilePolicyApplier;
 use OCA\Libresign\Service\Policy\Provider\Footer\FilePolicy\FooterFilePolicyApplier;
+use OCA\Libresign\Service\Policy\Provider\PolicyProviders;
 use OCA\Libresign\Service\Policy\Provider\Signature\FilePolicy\SignatureFlowFilePolicyApplier;
 use OCP\IL10N;
 
 class FilePolicyApplier {
-	private readonly SignatureFlowFilePolicyApplier $signatureFlowApplier;
-	private readonly DocMdpFilePolicyApplier $docMdpApplier;
-	private readonly FooterFilePolicyApplier $footerApplier;
+	/** @var list<IFilePolicyApplier> */
+	private readonly array $appliers;
 
 	public function __construct(
 		private readonly PolicyService $policyService,
 		private readonly FileService $fileService,
 		private readonly IL10N $l10n,
 	) {
-		$this->signatureFlowApplier = new SignatureFlowFilePolicyApplier($this->policyService, $this->fileService, $this->l10n);
-		$this->docMdpApplier = new DocMdpFilePolicyApplier($this->policyService, $this->fileService);
-		$this->footerApplier = new FooterFilePolicyApplier($this->policyService, $this->fileService, $this->l10n);
+		$this->appliers = $this->discoverAppliers();
 	}
 
 	/**
 	 * Apply all policies to a freshly built FileEntity before the first insert.
 	 */
 	public function applyAll(FileEntity $file, array $data): void {
-		$this->applySignatureFlow($file, $data);
-		$this->applyDocMdpLevel($file, $data);
-		$this->applyFooterPolicy($file, $data);
+		foreach ($this->appliers as $applier) {
+			$applier->apply($file, $data);
+		}
 	}
 
 	/**
 	 * Re-evaluate and persist signature_flow + docmdp on an existing file.
 	 * Use this when updating a file located by UUID.
 	 */
 	public function syncCoreFlowPolicies(FileEntity $file, array $data): void {
-		$this->syncSignatureFlow($file, $data);
-		$this->syncDocMdpLevel($file, $data);
+		foreach ($this->appliers as $applier) {
+			if ($applier->supportsCoreFlowSync()) {
+				$applier->sync($file, $data);
+			}
+		}
 	}
 
 	/**
 	 * Re-evaluate and persist all three policies on an existing file.
 	 * Use this when updating a file located by node ID.
 	 */
 	public function syncAllPolicies(FileEntity $file, array $data): void {
-		$this->syncSignatureFlow($file, $data);
-		$this->syncDocMdpLevel($file, $data);
-		$this->syncFooterPolicy($file, $data);
+		foreach ($this->appliers as $applier) {
+			$applier->sync($file, $data);
+		}
 	}
 
 	private function applySignatureFlow(FileEntity $file, array $data): void {
-		$this->signatureFlowApplier->apply($file, $data);
+		$this->getApplierByClass(SignatureFlowFilePolicyApplier::class)->apply($file, $data);
 	}
 
 	private function syncSignatureFlow(FileEntity $file, array $data): void {
-		$this->signatureFlowApplier->sync($file, $data);
+		$this->getApplierByClass(SignatureFlowFilePolicyApplier::class)->sync($file, $data);
 	}
 
 	private function applyDocMdpLevel(FileEntity $file, array $data): void {
-		$this->docMdpApplier->apply($file, $data);
+		$this->getApplierByClass(DocMdpFilePolicyApplier::class)->apply($file, $data);
 	}
 
 	private function syncDocMdpLevel(FileEntity $file, array $data): void {
-		$this->docMdpApplier->sync($file, $data);
+		$this->getApplierByClass(DocMdpFilePolicyApplier::class)->sync($file, $data);
 	}
 
 	private function applyFooterPolicy(FileEntity $file, array $data): void {
-		$this->footerApplier->apply($file, $data);
+		$this->getApplierByClass(FooterFilePolicyApplier::class)->apply($file, $data);
 	}
 
 	private function syncFooterPolicy(FileEntity $file, array $data): void {
-		$this->footerApplier->sync($file, $data);
+		$this->getApplierByClass(FooterFilePolicyApplier::class)->sync($file, $data);
+	}
+
+	/** @return list<IFilePolicyApplier> */
+	private function discoverAppliers(): array {
+		$appliers = [];
+
+		foreach (PolicyProviders::BY_KEY as $providerClass) {
+			$applierClass = $this->buildFileApplierClassFromProvider($providerClass);
+			if ($applierClass === null || !class_exists($applierClass)) {
+				continue;
+			}
+
+			$instance = new $applierClass($this->policyService, $this->fileService, $this->l10n);
+			if (!$instance instanceof IFilePolicyApplier) {
+				continue;
+			}
+
+			$appliers[] = $instance;
+		}
+
+		return $appliers;
+	}
+
+	/** @param class-string $providerClass */
+	private function buildFileApplierClassFromProvider(string $providerClass): ?string {
+		$lastSeparator = strrpos($providerClass, '\\');
+		if ($lastSeparator === false) {
+			return null;
+		}
+
+		$namespace = substr($providerClass, 0, $lastSeparator);
+		$shortName = substr($providerClass, $lastSeparator + 1);
+		$baseName = str_ends_with($shortName, 'Policy')
+			? substr($shortName, 0, -strlen('Policy'))
+			: $shortName;
+
+		return $namespace . '\\FilePolicy\\' . $baseName . 'FilePolicyApplier';
+	}
+
+	/** @param class-string<IFilePolicyApplier> $class */
+	private function getApplierByClass(string $class): IFilePolicyApplier {
+		foreach ($this->appliers as $applier) {
+			if ($applier instanceof $class) {
+				return $applier;
+			}
+		}
+
+		throw new \RuntimeException(sprintf('File policy applier "%s" not registered.', $class));
 	}
 }