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;
+	}
+}