feat: add content handler registry

src/Content/ContentHandlerInterface.php

@@ -0,0 +1,20 @@
+<?php
+/**
+ * Content package handler boundary.
+ *
+ * @package WPContentSync
+ */
+
+namespace WPContentSync\Content;
+
+use WPContentSync\Sync\SyncContext;
+use WPContentSync\Sync\SyncResult;
+
+interface ContentHandlerInterface {
+	public function bucket(): string;
+
+	/**
+	 * @param array<int, array<string, mixed>> $records Package records for this handler bucket.
+	 */
+	public function importRecords( array $records, SyncContext $context ): SyncResult;
+}

src/Content/ContentHandlerRegistry.php

@@ -0,0 +1,54 @@
+<?php
+/**
+ * Ordered content handler registry.
+ *
+ * @package WPContentSync
+ */
+
+namespace WPContentSync\Content;
+
+final class ContentHandlerRegistry {
+	private const PACKAGE_ORDER = array(
+		'custom_post_types',
+		'terms',
+		'posts',
+		'media',
+	);
+
+	/** @var array<string, ContentHandlerInterface> */
+	private array $handlers = array();
+
+	/**
+	 * @param array<int, ContentHandlerInterface> $handlers Content handlers.
+	 */
+	public function __construct( array $handlers ) {
+		foreach ( $handlers as $handler ) {
+			$this->register( $handler );
+		}
+	}
+
+	private function register( ContentHandlerInterface $handler ): void {
+		$bucket = $handler->bucket();
+
+		if ( isset( $this->handlers[ $bucket ] ) ) {
+			throw new \InvalidArgumentException( sprintf( 'Handler bucket "%s" is already registered.', $bucket ) );
+		}
+
+		$this->handlers[ $bucket ] = $handler;
+	}
+
+	/**
+	 * @return array<int, ContentHandlerInterface>
+	 */
+	public function ordered(): array {
+		$ordered = array();
+
+		foreach ( self::PACKAGE_ORDER as $bucket ) {
+			if ( isset( $this->handlers[ $bucket ] ) ) {
+				$ordered[] = $this->handlers[ $bucket ];
+			}
+		}
+
+		return $ordered;
+	}
+}

src/Content/ContentImportException.php

@@ -0,0 +1,36 @@
+<?php
+/**
+ * Typed content import failure.
+ *
+ * @package WPContentSync
+ */
+
+namespace WPContentSync\Content;
+
+final class ContentImportException extends \RuntimeException {
+	private string $bucket;
+
+	/** @var array<string, mixed> */
+	private array $record;
+
+	/**
+	 * @param array<string, mixed> $record Content record that failed.
+	 */
+	public function __construct( string $bucket, array $record, string $message, ?\Throwable $previous = null ) {
+		parent::__construct( $message, 0, $previous );
+
+		$this->bucket = $bucket;
+		$this->record = $record;
+	}
+
+	public function bucket(): string {
+		return $this->bucket;
+	}
+
+	/**
+	 * @return array<string, mixed>
+	 */
+	public function record(): array {
+		return $this->record;
+	}
+}

tests/Unit/Content/ContentHandlerRegistryTest.php

@@ -0,0 +1,54 @@
+<?php
+/**
+ * Tests for content handler registry.
+ *
+ * @package WPContentSync
+ */
+
+namespace WPContentSync\Tests\Unit\Content;
+
+use PHPUnit\Framework\TestCase;
+use WPContentSync\Content\ContentHandlerInterface;
+use WPContentSync\Content\ContentHandlerRegistry;
+use WPContentSync\Sync\SyncContext;
+use WPContentSync\Sync\SyncResult;
+
+class ContentHandlerRegistryTest extends TestCase {
+	public function test_it_returns_handlers_in_package_order(): void {
+		$posts = $this->handler( 'posts' );
+		$terms = $this->handler( 'terms' );
+		$media = $this->handler( 'media' );
+
+		$registry = new ContentHandlerRegistry( array( $media, $posts, $terms ) );
+
+		self::assertSame( array( $terms, $posts, $media ), $registry->ordered() );
+	}
+
+	public function test_it_rejects_duplicate_buckets(): void {
+		$this->expectException( \InvalidArgumentException::class );
+		$this->expectExceptionMessage( 'Handler bucket "posts" is already registered.' );
+
+		new ContentHandlerRegistry( array( $this->handler( 'posts' ), $this->handler( 'posts' ) ) );
+	}
+
+	private function handler( string $bucket ): ContentHandlerInterface {
+		return new class( $bucket ) implements ContentHandlerInterface {
+			private string $bucket;
+
+			public function __construct( string $bucket ) {
+				$this->bucket = $bucket;
+			}
+
+			public function bucket(): string {
+				return $this->bucket;
+			}
+
+			/**
+			 * @param array<int, array<string, mixed>> $records Package records.
+			 */
+			public function importRecords( array $records, SyncContext $context ): SyncResult {
+				return SyncResult::success( array( 'skipped' => count( $records ) ) );
+			}
+		};
+	}
+}