<?php
declare(strict_types=1);

use PHPUnit\Framework\TestCase;

/**
 * Integration test: WPDO_Post_Migration::backfill_group_json() (v2.10.4).
 *
 * Validates row-by-row backfill for groups containing json-typed fields
 * (attachment._wp_attachment_metadata, nav_menu_item._menu_item_classes,
 * etc.) — these can't go through the bulk SQL pivot in backfill_group()
 * because the values need PHP-level safe_unserialize → json_encode.
 *
 * Method is a thin wrapper over WPDO_Entity_Migration_Engine::migrate_group()
 * which is already entity-agnostic; this test confirms the dispatch and
 * sanity-checks output for post entity.
 */
class PostBackfillJsonTest extends TestCase {

	private const POSTS    = 'wp_itest_posts';
	private const POSTMETA = 'wp_itest_postmeta';
	private const FLAT     = 'wp_itest_wpdo_post_attachment';

	public static function setUpBeforeClass(): void {
		global $wpdb;

		if ( ! interface_exists( 'WPDO_Entity_Adapter_Interface' ) ) {
			require_once WPDO_PLUGIN_DIR . 'includes/adapters/interface-entity-adapter.php';
		}
		foreach ( array(
			'includes/engine/class-tmdo-entity-registry.php',
			'includes/engine/class-tmdo-mode-manager.php',
			'includes/engine/class-tmdo-schema-manager.php',
			'includes/engine/class-tmdo-type-caster.php',
			'includes/engine/class-tmdo-entity-migration-engine.php',
			'includes/adapters/class-tmdo-adapter-post.php',
			'includes/integrations/class-tmdo-post-fields.php',
			'includes/migration/class-tmdo-post-migration.php',
		) as $rel ) {
			$file = WPDO_PLUGIN_DIR . $rel;
			if ( file_exists( $file ) ) {
				require_once $file;
			}
		}

		$wpdb->query( 'DROP TABLE IF EXISTS `' . self::POSTS . '`' );
		$wpdb->query(
			'CREATE TABLE `' . self::POSTS . '` (
				ID bigint(20) unsigned NOT NULL AUTO_INCREMENT,
				post_type varchar(20) NOT NULL DEFAULT \'post\',
				PRIMARY KEY (ID),
				KEY post_type (post_type)
			) DEFAULT CHARACTER SET utf8mb4'
		);

		$wpdb->query( 'DROP TABLE IF EXISTS `' . self::POSTMETA . '`' );
		$wpdb->query(
			'CREATE TABLE `' . self::POSTMETA . '` (
				meta_id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
				post_id bigint(20) unsigned NOT NULL DEFAULT 0,
				meta_key varchar(255) DEFAULT NULL,
				meta_value longtext,
				PRIMARY KEY (meta_id),
				KEY post_id (post_id),
				KEY meta_key (meta_key(191))
			) DEFAULT CHARACTER SET utf8mb4'
		);

		$wpdb->query( 'DROP TABLE IF EXISTS `' . self::FLAT . '`' );
		$wpdb->query(
			'CREATE TABLE `' . self::FLAT . '` (
				id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
				post_id bigint(20) unsigned NOT NULL,
				_wp_attached_file varchar(255) DEFAULT NULL,
				_wp_attachment_metadata longtext DEFAULT NULL,
				_wp_attachment_image_alt longtext DEFAULT NULL,
				_wp_attachment_caption longtext DEFAULT NULL,
				created_at datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
				updated_at datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
				PRIMARY KEY (id),
				UNIQUE KEY uk_post_id (post_id)
			) DEFAULT CHARACTER SET utf8mb4'
		);

		// migration_status table needed by Entity_Migration_Engine
		// (schema mirrors MemberBackfillIntegrationTest fixture).
		$wpdb->query( 'DROP TABLE IF EXISTS `wp_itest_wpdo_migration_status`' );
		$wpdb->query(
			'CREATE TABLE `wp_itest_wpdo_migration_status` (
				id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
				entity_type varchar(50) NOT NULL,
				group_name varchar(50) NOT NULL,
				last_id bigint(20) unsigned NOT NULL DEFAULT 0,
				total_migrated bigint(20) unsigned NOT NULL DEFAULT 0,
				status varchar(20) NOT NULL DEFAULT \'pending\',
				started_at datetime DEFAULT NULL,
				completed_at datetime DEFAULT NULL,
				PRIMARY KEY (id),
				UNIQUE KEY entity_group (entity_type, group_name)
			) DEFAULT CHARACTER SET utf8mb4'
		);

		WPDO_Entity_Registry::init();
		WPDO_Entity_Registry::register_adapter( 'post', new WPDO_Adapter_Post() );
		WPDO_Post_Fields::register_entity_fields();
	}

	public static function tearDownAfterClass(): void {
		global $wpdb;
		$wpdb->query( 'DROP TABLE IF EXISTS `' . self::POSTS . '`' );
		$wpdb->query( 'DROP TABLE IF EXISTS `' . self::POSTMETA . '`' );
		$wpdb->query( 'DROP TABLE IF EXISTS `' . self::FLAT . '`' );
		$wpdb->query( 'DROP TABLE IF EXISTS `wp_itest_wpdo_migration_status`' );
		WPDO_Entity_Registry::init();
	}

	protected function setUp(): void {
		global $wpdb;
		$wpdb->query( 'TRUNCATE TABLE `' . self::POSTS . '`' );
		$wpdb->query( 'TRUNCATE TABLE `' . self::POSTMETA . '`' );
		$wpdb->query( 'TRUNCATE TABLE `' . self::FLAT . '`' );
		$wpdb->query( 'TRUNCATE TABLE `wp_itest_wpdo_migration_status`' );
		WPDO_Entity_Migration_Engine::reset_checkpoint( 'post', 'attachment' );
	}

	private function seed_attachment( int $post_id, array $metadata, string $alt = '' ): void {
		global $wpdb;
		$wpdb->insert( self::POSTS, array( 'ID' => $post_id, 'post_type' => 'attachment' ) );
		// Real WP serializes _wp_attachment_metadata via PHP serialize().
		$wpdb->insert( self::POSTMETA, array(
			'post_id'    => $post_id,
			'meta_key'   => '_wp_attachment_metadata',
			'meta_value' => serialize( $metadata ),
		) );
		if ( '' !== $alt ) {
			$wpdb->insert( self::POSTMETA, array(
				'post_id'    => $post_id,
				'meta_key'   => '_wp_attachment_image_alt',
				'meta_value' => $alt,
			) );
		}
	}

	// ── backfill_group_json() ────────────────────────────────────────────────

	public function test_unserializes_attachment_metadata_to_json(): void {
		$this->seed_attachment( 1, array(
			'width'  => 800,
			'height' => 600,
			'file'   => '2026/04/test.jpg',
			'sizes'  => array(
				'thumbnail' => array( 'width' => 150, 'height' => 150 ),
			),
		), 'Stress test alt' );

		$result = WPDO_Post_Migration::backfill_group_json( 'attachment' );

		$this->assertGreaterThan( 0, $result['migrated'] ?? 0 );
		$this->assertSame( 0, $result['errors'] ?? -1 );

		global $wpdb;
		$row = $wpdb->get_row(
			'SELECT _wp_attachment_metadata, _wp_attachment_image_alt FROM `' . self::FLAT . '` WHERE post_id = 1',
			ARRAY_A
		);

		$this->assertNotNull( $row );

		// metadata value should now be JSON.
		$decoded = json_decode( (string) $row['_wp_attachment_metadata'], true );
		$this->assertIsArray( $decoded );
		$this->assertSame( 800, $decoded['width'] );
		$this->assertSame( 'thumbnail', array_keys( $decoded['sizes'] )[0] );

		// Non-json field still passes through.
		$this->assertSame( 'Stress test alt', $row['_wp_attachment_image_alt'] );
	}

	public function test_idempotent_re_run(): void {
		$this->seed_attachment( 1, array( 'width' => 100 ) );

		WPDO_Post_Migration::backfill_group_json( 'attachment' );
		// reset checkpoint so the engine reprocesses the same row.
		WPDO_Entity_Migration_Engine::reset_checkpoint( 'post', 'attachment' );
		$result2 = WPDO_Post_Migration::backfill_group_json( 'attachment' );

		$this->assertSame( 0, $result2['errors'] ?? -1 );

		global $wpdb;
		$count = (int) $wpdb->get_var( 'SELECT COUNT(*) FROM `' . self::FLAT . '`' );
		$this->assertSame( 1, $count, 'No duplicate row after re-run.' );
	}

	public function test_handles_already_serialized_string_safely(): void {
		// Attacker-style: write an object signature into _wp_attachment_metadata
		// (this is what safe_unserialize defends against).
		global $wpdb;
		$wpdb->insert( self::POSTS, array( 'ID' => 99, 'post_type' => 'attachment' ) );
		$wpdb->insert( self::POSTMETA, array(
			'post_id'    => 99,
			'meta_key'   => '_wp_attachment_metadata',
			'meta_value' => 'O:8:"stdClass":0:{}',  // Object string — should be NULL'd
		) );

		$result = WPDO_Post_Migration::backfill_group_json( 'attachment' );

		// Engine should NOT throw — safe_unserialize converts object to NULL.
		$this->assertSame( 0, $result['errors'] ?? -1 );
	}

	public function test_handles_empty_postmeta_gracefully(): void {
		$result = WPDO_Post_Migration::backfill_group_json( 'attachment' );

		$this->assertSame( 0, $result['migrated'] ?? -1 );
		$this->assertSame( 0, $result['errors'] ?? -1 );
	}

	public function test_returns_error_for_unknown_group(): void {
		$result = WPDO_Post_Migration::backfill_group_json( 'bogus_group' );

		// Engine returns error_result with 'error' key set.
		$this->assertNotEmpty( $result['error'] ?? null );
	}
}