import { BaseMigration } from './base-migration.ts';
import { MigrationV1ToV2 } from './migration-v1-to-v2.ts';
import { MigrationV3ToV4 } from './migration-v3-to-v4.ts';
import { logger } from '../logger.ts';

/**
 * Migration runner
 *
 * Discovers all available migrations, sorts them by order,
 * and runs applicable migrations in sequence.
 */
export class MigrationRunner {
  private migrations: BaseMigration[];

  constructor() {
    // Register all migrations here
    this.migrations = [
      new MigrationV1ToV2(),
      new MigrationV3ToV4(),
      // Add future migrations here (v4→v5, v5→v6, etc.)
    ];

    // Sort by order to ensure they run in sequence
    this.migrations.sort((a, b) => a.order - b.order);
  }

  /**
   * Run all applicable migrations on the config
   *
   * @param config - Raw configuration object to migrate
   * @returns Migrated configuration and whether migrations ran
   */
  async run(config: any): Promise<{ config: any; migrated: boolean }> {
    let currentConfig = config;
    let anyMigrationsRan = false;

    logger.dim('Checking for required config migrations...');

    for (const migration of this.migrations) {
      const shouldRun = await migration.shouldRun(currentConfig);

      if (shouldRun) {
        logger.info(`Running ${migration.getName()}...`);
        currentConfig = await migration.migrate(currentConfig);
        anyMigrationsRan = true;
      }
    }

    if (anyMigrationsRan) {
      logger.success('Configuration migrations complete');
    } else {
      logger.dim('No migrations needed');
    }

    return {
      config: currentConfig,
      migrated: anyMigrationsRan,
    };
  }

  /**
   * Get all registered migrations
   *
   * @returns Array of all migrations sorted by order
   */
  getMigrations(): BaseMigration[] {
    return [...this.migrations];
  }
}