<?php
/**
 * Migration phase: row-by-row backfill for groups with JSON/serialized fields.
 *
 * @package TMDO
 * @since 3.0.1
 */

declare(strict_types=1);


if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Uses TMDO_Entity_Migration_Engine for groups whose fields contain JSON type,
 * which cannot be bulk-pivoted via INSERT … SELECT.
 */
class TMDO_Phase_Backfill_Unserialize extends TMDO_Migration_Phase_Base {

	/**
	 * Returns the phase slug.
	 *
	 * @return string
	 */
	public function name(): string {
		return 'backfill_unserialize';
	}

	/**
	 * Executes the phase.
	 *
	 * @param array $job Job array (by reference).
	 * @return array{status: string}
	 * @throws \RuntimeException On migration engine failure.
	 */
	public function execute( array &$job ): array {
		if ( ! empty( $job['options']['dry_run'] ) ) {
			$this->log( $job, '↪ Backfill unserialize skipped (dry_run)' );
			return array( 'status' => 'ok' );
		}

		$total_rows = 0;

		foreach ( TMDO_Entity_Registry::get_groups_for_type( $this->entity_type ) as $group ) {
			if ( ! $this->group_has_json_field( $group ) ) {
				continue; // Handled in backfill_bulk.
			}

			$result = TMDO_Entity_Migration_Engine::migrate_group(
				$this->entity_type,
				$group,
				array( 'sleep_ms' => 0 )
			);

			if ( ! empty( $result['error'] ) ) {
				throw new \RuntimeException( "Row-by-row backfill {$group} failed: " . $result['error'] );
			}
			if ( ( $result['errors'] ?? 0 ) > 0 && 0 === ( $result['migrated'] ?? 0 ) ) {
				throw new \RuntimeException( "All rows failed during {$group} backfill — see error_log" );
			}

			$total_rows += (int) ( $result['migrated'] ?? 0 );
			$this->log( $job, sprintf( '  • row-by-row %s: %d row(s)', $group, $result['migrated'] ?? 0 ) );
		}

		$this->log( $job, sprintf( 'Row-by-row backfill: %d rows total', $total_rows ) );
		return array( 'status' => 'ok' );
	}
}