<?php
namespace Aisentic\Database;

defined( 'ABSPATH' ) || exit;

/**
 * MigrationRunner class.
 *
 * Responsible for running and rolling back all migration files.
 */
class Migration_Runner {
	/**
	 * Run all pending migration files to apply the database schema changes.
	 *
	 * This method loads all PHP files inside the migrations directory,
	 * instantiates named migration classes, sorts them by serial number,
	 * and only runs those that haven't been applied yet.
	 *
	 * @return void
	 */
	public static function migrate() {
		Migration_Table_Manager::ensure_table_exists();

		$migration_files = glob( Aisentic()->plugin_directory . '/migrations/*.php' );

		if ( ! is_array( $migration_files ) ) {
			return;
		}

		$migrations = [];

		foreach ( $migration_files as $file ) {
			$class_name = pathinfo( $file, PATHINFO_FILENAME );

			if ( Migration_Table_Manager::is_migrated( $class_name ) ) {
				continue;
			}

			require_once $file;

			if ( ! class_exists( $class_name ) ) {
				continue;
			}

			$migration = new $class_name();

			if ( $migration instanceof Migration ) {
				$migrations[] = [
					'name'     => $class_name,
					'instance' => $migration,
				];
			}
		}

		usort(
			$migrations,
			function ( $a, $b ) {
				return $a['instance']->get_serial() - $b['instance']->get_serial();
			}
		);

		$batch = Migration_Table_Manager::get_latest_batch() + 1;

		foreach ( $migrations as $entry ) {
			$entry['instance']->up();
			Migration_Table_Manager::mark_as_migrated( $entry['name'], $batch );
		}
	}

	/**
	 * Rollback the latest batch of migrations.
	 *
	 * This method loads migrations from the latest batch in reverse order,
	 * calls their down() method, and removes them from the tracking table.
	 *
	 * @return void
	 */
	public static function rollback() {
		Migration_Table_Manager::ensure_table_exists();

		$migrations = Migration_Table_Manager::get_latest_batch_migrations();

		if ( empty( $migrations ) ) {
			return;
		}

		$migrations_dir = Aisentic()->plugin_directory . '/migrations/';

		foreach ( $migrations as $record ) {
			$file = $migrations_dir . $record->migration . '.php';

			if ( ! file_exists( $file ) ) {
				continue;
			}

			require_once $file;

			$class_name = $record->migration;

			if ( ! class_exists( $class_name ) ) {
				continue;
			}

			$migration = new $class_name();

			if ( $migration instanceof Migration ) {
				$migration->down();
			}

			Migration_Table_Manager::remove_migration( $record->migration );
		}
	}
}