feat: introduce CLI commands with integration test infrastructure

includes/Application/Bootstrapper.php

@@ -0,0 +1,201 @@
+<?php
+/**
+ * Plugin bootstrapper.
+ *
+ * @package Automattic\Syndication\Application
+ */
+
+declare( strict_types=1 );
+
+namespace Automattic\Syndication\Application;
+
+use Automattic\Syndication\Application\Services\PullService;
+use Automattic\Syndication\Application\Services\PushService;
+use Automattic\Syndication\Domain\Contracts\TransportFactoryInterface;
+use Automattic\Syndication\Infrastructure\DI\Container;
+use Automattic\Syndication\Infrastructure\WordPress\HookManager;
+
+/**
+ * Main plugin bootstrapper.
+ *
+ * Wires up the DI container and registers WordPress hooks for the
+ * new DDD-based architecture. This class serves as the entry point
+ * for the refactored syndication functionality.
+ */
+final class Bootstrapper {
+
+	/**
+	 * Singleton instance.
+	 *
+	 * @var self|null
+	 */
+	private static ?self $instance = null;
+
+	/**
+	 * DI container.
+	 *
+	 * @var Container
+	 */
+	private readonly Container $container;
+
+	/**
+	 * Hook manager.
+	 *
+	 * @var HookManager
+	 */
+	private readonly HookManager $hooks;
+
+	/**
+	 * Hook registrar.
+	 *
+	 * @var HookRegistrar
+	 */
+	private readonly HookRegistrar $hook_registrar;
+
+	/**
+	 * Whether the bootstrapper has been initialised.
+	 *
+	 * @var bool
+	 */
+	private bool $initialised = false;
+
+	/**
+	 * Private constructor - use init() to get instance.
+	 *
+	 * @param Container $container DI container.
+	 */
+	private function __construct( Container $container ) {
+		$this->container      = $container;
+		$this->hooks          = $container->get( HookManager::class );
+		$this->hook_registrar = new HookRegistrar( $container, $this->hooks );
+	}
+
+	/**
+	 * Initialise the bootstrapper.
+	 *
+	 * @param Container|null $container Optional container for testing.
+	 * @return self The singleton instance.
+	 */
+	public static function init( ?Container $container = null ): self {
+		if ( null === self::$instance ) {
+			self::$instance = new self( $container ?? new Container() );
+		}
+
+		if ( ! self::$instance->initialised ) {
+			self::$instance->register_services();
+			self::$instance->register_hooks();
+			self::$instance->initialised = true;
+		}
+
+		return self::$instance;
+	}
+
+	/**
+	 * Get the singleton instance.
+	 *
+	 * @return self|null The instance or null if not initialised.
+	 */
+	public static function get_instance(): ?self {
+		return self::$instance;
+	}
+
+	/**
+	 * Reset the singleton instance (for testing).
+	 */
+	public static function reset(): void {
+		self::$instance = null;
+	}
+
+	/**
+	 * Get the DI container.
+	 *
+	 * @return Container The container.
+	 */
+	public function container(): Container {
+		return $this->container;
+	}
+
+	/**
+	 * Get the hook manager.
+	 *
+	 * @return HookManager The hook manager.
+	 */
+	public function hooks(): HookManager {
+		return $this->hooks;
+	}
+
+	/**
+	 * Register additional services in the container.
+	 */
+	private function register_services(): void {
+		// Register PushService.
+		$this->container->register(
+			PushService::class,
+			function ( Container $container ): PushService {
+				$factory = $container->get( TransportFactoryInterface::class );
+				\assert( $factory instanceof TransportFactoryInterface );
+				return new PushService( $factory );
+			}
+		);
+
+		// Register PullService.
+		$this->container->register(
+			PullService::class,
+			function ( Container $container ): PullService {
+				$factory = $container->get( TransportFactoryInterface::class );
+				\assert( $factory instanceof TransportFactoryInterface );
+				return new PullService( $factory );
+			}
+		);
+	}
+
+	/**
+	 * Register WordPress hooks.
+	 *
+	 * Note: These hooks run in parallel with the legacy hooks during
+	 * migration. Once verified, the legacy code can be removed.
+	 */
+	private function register_hooks(): void {
+		// Register hook to provide DI container to legacy code.
+		$this->hooks->add_action(
+			'syn_get_container',
+			function (): Container {
+				return $this->container;
+			}
+		);
+
+		// Register all hooks via the HookRegistrar.
+		$this->hook_registrar->register();
+	}
+
+	/**
+	 * Get the hook registrar.
+	 *
+	 * @return HookRegistrar The hook registrar.
+	 */
+	public function hook_registrar(): HookRegistrar {
+		return $this->hook_registrar;
+	}
+
+	/**
+	 * Get the push service.
+	 *
+	 * @return PushService The push service.
+	 */
+	public function push_service(): PushService {
+		$service = $this->container->get( PushService::class );
+		\assert( $service instanceof PushService );
+		return $service;
+	}
+
+	/**
+	 * Get the pull service.
+	 *
+	 * @return PullService The pull service.
+	 */
+	public function pull_service(): PullService {
+		$service = $this->container->get( PullService::class );
+		\assert( $service instanceof PullService );
+		return $service;
+	}
+}

includes/Application/Contracts/PullServiceInterface.php

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+<?php
+/**
+ * Pull service interface.
+ *
+ * @package Automattic\Syndication\Application\Contracts
+ */
+
+declare( strict_types=1 );
+
+namespace Automattic\Syndication\Application\Contracts;
+
+use Automattic\Syndication\Application\DTO\PullResult;
+
+/**
+ * Interface for pull syndication service.
+ */
+interface PullServiceInterface {
+
+	/**
+	 * Set whether to update existing posts.
+	 *
+	 * @param bool $update Whether to update.
+	 * @return self
+	 */
+	public function set_update_existing( bool $update ): self;
+
+	/**
+	 * Pull content from multiple sites.
+	 *
+	 * @param int[] $site_ids Array of site post IDs.
+	 * @return PullResult[] Array of results keyed by site ID.
+	 */
+	public function pull_from_sites( array $site_ids ): array;
+
+	/**
+	 * Pull content from a single site.
+	 *
+	 * @param int $site_id The site post ID.
+	 * @return PullResult The pull result.
+	 */
+	public function pull_from_site( int $site_id ): PullResult;
+}

includes/Application/Contracts/PushServiceInterface.php

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+<?php
+/**
+ * Push service interface.
+ *
+ * @package Automattic\Syndication\Application\Contracts
+ */
+
+declare( strict_types=1 );
+
+namespace Automattic\Syndication\Application\Contracts;
+
+use Automattic\Syndication\Application\DTO\PushResult;
+
+/**
+ * Interface for push syndication service.
+ */
+interface PushServiceInterface {
+
+	/**
+	 * Push a post to multiple sites.
+	 *
+	 * @param int   $post_id  The local post ID.
+	 * @param int[] $site_ids Array of site post IDs to push to.
+	 * @return PushResult[] Array of results keyed by site ID.
+	 */
+	public function push_to_sites( int $post_id, array $site_ids ): array;
+
+	/**
+	 * Push a post to a single site.
+	 *
+	 * @param int                       $post_id      The local post ID.
+	 * @param int                       $site_id      The site post ID.
+	 * @param array<string, mixed>|null $slave_states Optional slave states array (modified by reference).
+	 * @return PushResult The push result.
+	 */
+	public function push_to_site( int $post_id, int $site_id, ?array &$slave_states = null ): PushResult;
+
+	/**
+	 * Delete a post from a site.
+	 *
+	 * @param int $post_id The local post ID.
+	 * @param int $site_id The site post ID.
+	 * @return PushResult The delete result.
+	 */
+	public function delete_from_site( int $post_id, int $site_id ): PushResult;
+}