<?php
declare(strict_types=1);

use PHPUnit\Framework\TestCase;

/**
 * Integration test: WPDO_Post_Migration core methods (v2.9.3).
 *
 * Verifies diagnose(), backfill_group(), cutover() against real MariaDB,
 * mirroring the user-side WPDO_Migration_Orchestrator's contract but using
 * a new independent class so the user orchestrator's 1105 lines stay frozen.
 *
 * Requires real MariaDB (WPDO_TEST_DB_PASS env var must be set).
 */
class PostMigrationTest extends TestCase {

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

	// ── Fixture lifecycle ─────────────────────────────────────────────────────

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

		// Load post entity chain.
		if ( ! interface_exists( 'WPDO_Entity_Adapter_Interface' ) ) {
			require_once WPDO_PLUGIN_DIR . 'includes/adapters/interface-entity-adapter.php';
		}
		if ( ! class_exists( 'WPDO_Entity_Registry' ) ) {
			require_once WPDO_PLUGIN_DIR . 'includes/engine/class-tmdo-entity-registry.php';
		}
		if ( ! class_exists( 'WPDO_Mode_Manager' ) ) {
			require_once WPDO_PLUGIN_DIR . 'includes/engine/class-tmdo-mode-manager.php';
		}
		if ( ! class_exists( 'WPDO_Schema_Manager' ) ) {
			require_once WPDO_PLUGIN_DIR . 'includes/engine/class-tmdo-schema-manager.php';
		}
		if ( ! class_exists( 'WPDO_Adapter_Post' ) ) {
			require_once WPDO_PLUGIN_DIR . 'includes/adapters/class-tmdo-adapter-post.php';
		}
		if ( ! class_exists( 'WPDO_Post_Fields' ) ) {
			require_once WPDO_PLUGIN_DIR . 'includes/integrations/class-tmdo-post-fields.php';
		}
		if ( ! class_exists( 'WPDO_Post_Migration' ) ) {
			require_once WPDO_PLUGIN_DIR . 'includes/migration/class-tmdo-post-migration.php';
		}

		// wp_posts (minimal — only ID + post_type).
		$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'
		);

		// wp_postmeta — same schema as production WP.
		$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'
		);

		// Flat target for wc_product group (subset of full schema for test).
		$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,
				_price decimal(18,6) DEFAULT NULL,
				_regular_price decimal(18,6) DEFAULT NULL,
				_stock bigint(20) DEFAULT NULL,
				_stock_status varchar(100) DEFAULT NULL,
				_sku varchar(255) 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'
		);

		// Reset Entity Registry + register post adapter + post fields.
		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 . '`' );

		// Reset Mode_Manager + Entity_Registry to avoid polluting later tests.
		$ref   = new ReflectionClass( WPDO_Mode_Manager::class );
		$cache = $ref->getProperty( 'cache' );
		$cache->setAccessible( true );
		$cache->setValue( null, null );
		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 . '`' );
	}

	private function seed_post( int $id, string $post_type ): void {
		global $wpdb;
		$wpdb->insert( self::POSTS, array( 'ID' => $id, 'post_type' => $post_type ) );
	}

	private function seed_meta( int $post_id, string $key, string $value ): void {
		global $wpdb;
		$wpdb->insert( self::POSTMETA, array( 'post_id' => $post_id, 'meta_key' => $key, 'meta_value' => $value ) );
	}

	// ── diagnose() ────────────────────────────────────────────────────────────

	public function test_diagnose_reports_posts_postmeta_ratio(): void {
		// 5 posts, 12 postmeta rows → ratio 2.4
		for ( $i = 1; $i <= 5; $i++ ) {
			$this->seed_post( $i, 'post' );
		}
		for ( $i = 0; $i < 12; $i++ ) {
			$this->seed_meta( ( $i % 5 ) + 1, 'random_key', 'v' );
		}

		$result = WPDO_Post_Migration::diagnose();

		$this->assertSame( 5, $result['posts'] );
		$this->assertSame( 12, $result['postmeta'] );
		$this->assertSame( 2.4, $result['ratio'] );
	}

	public function test_diagnose_reports_eav_rows_per_managed_group(): void {
		$this->seed_post( 1, 'product' );
		$this->seed_meta( 1, '_price', '99.99' );
		$this->seed_meta( 1, '_stock', '5' );
		$this->seed_meta( 1, 'unrelated_key', 'x' );  // not in any group

		$result = WPDO_Post_Migration::diagnose();

		$this->assertArrayHasKey( 'groups', $result );
		$this->assertArrayHasKey( 'wc_product', $result['groups'] );
		$this->assertSame(
			2,
			$result['groups']['wc_product']['eav_rows'],
			'wc_product group has 2 EAV rows: _price + _stock (unrelated_key excluded).'
		);
	}

	public function test_diagnose_reports_zero_eav_for_unused_group(): void {
		$this->seed_post( 1, 'post' );
		$this->seed_meta( 1, 'random_key', 'v' );

		$result = WPDO_Post_Migration::diagnose();

		// nav_menu_item group has no postmeta seeded.
		$this->assertSame( 0, $result['groups']['nav_menu_item']['eav_rows'] );
	}

	public function test_diagnose_reports_post_mode(): void {
		$result = WPDO_Post_Migration::diagnose();

		$this->assertArrayHasKey( 'mode', $result );
		// Default post mode is 'disabled' per Mode_Manager defaults().
		$this->assertSame( 'disabled', $result['mode'] );
	}

	// ── backfill_group() — bulk SQL pivot ─────────────────────────────────────

	public function test_backfill_group_pivots_wc_product_keys(): void {
		$this->seed_post( 1, 'product' );
		$this->seed_meta( 1, '_price', '99.99' );
		$this->seed_meta( 1, '_regular_price', '120.00' );
		$this->seed_meta( 1, '_stock', '5' );
		$this->seed_meta( 1, '_stock_status', 'instock' );
		$this->seed_meta( 1, '_sku', 'SKU-001' );

		$this->seed_post( 2, 'product' );
		$this->seed_meta( 2, '_price', '49.50' );
		$this->seed_meta( 2, '_stock_status', 'outofstock' );

		$result = WPDO_Post_Migration::backfill_group( 'wc_product' );

		$this->assertSame( 2, $result['migrated'], 'Two posts produce two flat rows.' );

		global $wpdb;
		$row1 = $wpdb->get_row( 'SELECT _price, _stock, _sku FROM `' . self::FLAT . '` WHERE post_id = 1', ARRAY_A );
		$this->assertSame( '99.990000', $row1['_price'], 'Price decimal stored with full precision.' );
		$this->assertSame( '5', $row1['_stock'] );
		$this->assertSame( 'SKU-001', $row1['_sku'] );

		$row2 = $wpdb->get_row( 'SELECT _price, _stock_status, _sku FROM `' . self::FLAT . '` WHERE post_id = 2', ARRAY_A );
		$this->assertSame( '49.500000', $row2['_price'] );
		$this->assertSame( 'outofstock', $row2['_stock_status'] );
		$this->assertNull( $row2['_sku'], 'Unset key remains NULL in flat row.' );
	}

	public function test_backfill_group_is_idempotent(): void {
		$this->seed_post( 1, 'product' );
		$this->seed_meta( 1, '_price', '50.00' );

		WPDO_Post_Migration::backfill_group( 'wc_product' );
		$result_second = WPDO_Post_Migration::backfill_group( 'wc_product' );

		$this->assertSame( 1, $result_second['migrated'], 'Re-running backfill is idempotent (UPSERT).' );

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

	public function test_backfill_group_skips_posts_of_wrong_type(): void {
		// _price on a non-product post should NOT migrate to wc_product flat.
		$this->seed_post( 99, 'post' );
		$this->seed_meta( 99, '_price', '100.00' );

		$result = WPDO_Post_Migration::backfill_group( 'wc_product' );

		$this->assertSame( 0, $result['migrated'], 'Posts of wrong type are excluded by post_type filter.' );
	}

	public function test_backfill_group_rejects_invalid_group(): void {
		$this->expectException( InvalidArgumentException::class );
		WPDO_Post_Migration::backfill_group( 'bogus_group' );
	}
}