# All files / framework/migrations MigrationManager.ts

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     /**
     * MigrationManager - Schema Migration and Data Transformation System
     *
     * This class handles:
     * - Schema version management across distributed databases
     * - Automatic data migration and transformation
     * - Rollback capabilities for failed migrations
     * - Conflict resolution during migration
     * - Migration validation and integrity checks
     * - Cross-shard migration coordination
     */

    import { FieldConfig } from '../types/models';

    export interface Migration {
      id: string;
      version: string;
      name: string;
      description: string;
      targetModels: string[];
      up: MigrationOperation[];
      down: MigrationOperation[];
      dependencies?: string[]; // Migration IDs that must run before this one
      validators?: MigrationValidator[];
      createdAt: number;
      author?: string;
      tags?: string[];
    }

    export interface MigrationOperation {
      type:
        | 'add_field'
        | 'remove_field'
        | 'modify_field'
        | 'rename_field'
        | 'add_index'
        | 'remove_index'
        | 'transform_data'
        | 'custom';
      modelName: string;
      fieldName?: string;
      newFieldName?: string;
      fieldConfig?: FieldConfig;
      indexConfig?: any;
      transformer?: (data: any) => any;
      customOperation?: (context: MigrationContext) => Promise<void>;
      rollbackOperation?: (context: MigrationContext) => Promise<void>;
      options?: {
        batchSize?: number;
        parallel?: boolean;
        skipValidation?: boolean;
      };
    }

    export interface MigrationValidator {
      name: string;
      description: string;
      validate: (context: MigrationContext) => Promise<ValidationResult>;
    }

    export interface MigrationContext {
      migration: Migration;
      modelName: string;
      databaseManager: any;
      shardManager: any;
      currentData?: any[];
      operation: MigrationOperation;
      progress: MigrationProgress;
      logger: MigrationLogger;
    }

    export interface MigrationProgress {
      migrationId: string;
      status: 'pending' | 'running' | 'completed' | 'failed' | 'rolled_back';
      startedAt?: number;
      completedAt?: number;
      totalRecords: number;
      processedRecords: number;
      errorCount: number;
      warnings: string[];
      errors: string[];
      currentOperation?: string;
      estimatedTimeRemaining?: number;
    }

    export interface MigrationResult {
      migrationId: string;
      success: boolean;
      duration: number;
      recordsProcessed: number;
      recordsModified: number;
      warnings: string[];
      errors: string[];
      rollbackAvailable: boolean;
    }

    export interface MigrationLogger {
      info: (message: string, meta?: any) => void;
      warn: (message: string, meta?: any) => void;
      error: (message: string, meta?: any) => void;
      debug: (message: string, meta?: any) => void;
    }

    export interface ValidationResult {
      valid: boolean;
      errors: string[];
      warnings: string[];
    }

    export class MigrationManager {
      private databaseManager: any;
      private shardManager: any;
      private migrations: Map<string, Migration> = new Map();
      private migrationHistory: Map<string, MigrationResult[]> = new Map();
      private activeMigrations: Map<string, MigrationProgress> = new Map();
      private migrationOrder: string[] = [];
      private logger: MigrationLogger;

      constructor(databaseManager: any, shardManager: any, logger?: MigrationLogger) {
        this.databaseManager = databaseManager;
        this.shardManager = shardManager;
        this.logger = logger || this.createDefaultLogger();
      }

      // Register a new migration
      registerMigration(migration: Migration): void {
        // Validate migration structure
        this.validateMigrationStructure(migration);

        // Check for version conflicts
        const existingMigration = Array.from(this.migrations.values()).find(
          (m) => m.version === migration.version,
        );

        if (existingMigration && existingMigration.id !== migration.id) {
          throw new Error(`Migration version ${migration.version} already exists with different ID`);
        }

        this.migrations.set(migration.id, migration);
        this.updateMigrationOrder();

        this.logger.info(`Registered migration: ${migration.name} (${migration.version})`, {
          migrationId: migration.id,
          targetModels: migration.targetModels,
        });
      }

      // Get all registered migrations
      getMigrations(): Migration[] {
        return Array.from(this.migrations.values()).sort((a, b) =>
          this.compareVersions(a.version, b.version),
        );
      }

      // Get migration by ID
      getMigration(migrationId: string): Migration | null {
        return this.migrations.get(migrationId) || null;
      }

      // Get pending migrations for a model or all models
      getPendingMigrations(modelName?: string): Migration[] {
        const allMigrations = this.getMigrations();
        const appliedMigrations = this.getAppliedMigrations(modelName);
        const appliedIds = new Set(appliedMigrations.map((m) => m.migrationId));

        return allMigrations.filter((migration) => {
          if (!appliedIds.has(migration.id)) {
            return modelName ? migration.targetModels.includes(modelName) : true;
          }
          return false;
        });
      }

      // Run a specific migration
      async runMigration(
        migrationId: string,
        options: {
          dryRun?: boolean;
          batchSize?: number;
          parallelShards?: boolean;
          skipValidation?: boolean;
        } = {},
      ): Promise<MigrationResult> {
        const migration = this.migrations.get(migrationId);
        if (!migration) {
          throw new Error(`Migration ${migrationId} not found`);
        }

        // Check if migration is already running
        if (this.activeMigrations.has(migrationId)) {
          throw new Error(`Migration ${migrationId} is already running`);
        }

        // Check dependencies
        await this.validateDependencies(migration);

        const startTime = Date.now();
        const progress: MigrationProgress = {
          migrationId,
          status: 'running',
          startedAt: startTime,
          totalRecords: 0,
          processedRecords: 0,
          errorCount: 0,
          warnings: [],
          errors: [],
        };

        this.activeMigrations.set(migrationId, progress);

        try {
          this.logger.info(`Starting migration: ${migration.name}`, {
            migrationId,
            dryRun: options.dryRun,
            options,
          });

          if (options.dryRun) {
            return await this.performDryRun(migration, options);
          }

          // Pre-migration validation
          if (!options.skipValidation) {
            await this.runPreMigrationValidation(migration);
          }

          // Execute migration operations
          const result = await this.executeMigration(migration, options, progress);

          // Post-migration validation
          if (!options.skipValidation) {
            await this.runPostMigrationValidation(migration);
          }

          // Record successful migration
          progress.status = 'completed';
          progress.completedAt = Date.now();

          await this.recordMigrationResult(result);

          this.logger.info(`Migration completed: ${migration.name}`, {
            migrationId,
            duration: result.duration,
            recordsProcessed: result.recordsProcessed,
          });

          return result;
        } catch (error: any) {
          progress.status = 'failed';
          progress.errors.push(error.message);

          this.logger.error(`Migration failed: ${migration.name}`, {
            migrationId,
            error: error.message,
            stack: error.stack,
          });

          // Attempt rollback if possible
          const rollbackResult = await this.attemptRollback(migration, progress);

          const result: MigrationResult = {
            migrationId,
            success: false,
            duration: Date.now() - startTime,
            recordsProcessed: progress.processedRecords,
            recordsModified: 0,
            warnings: progress.warnings,
            errors: progress.errors,
            rollbackAvailable: rollbackResult.success,
          };

          await this.recordMigrationResult(result);
          throw error;
        } finally {
          this.activeMigrations.delete(migrationId);
        }
      }

      // Run all pending migrations
      async runPendingMigrations(
        options: {
          modelName?: string;
          dryRun?: boolean;
          stopOnError?: boolean;
          batchSize?: number;
        } = {},
      ): Promise<MigrationResult[]> {
        const pendingMigrations = this.getPendingMigrations(options.modelName);
        const results: MigrationResult[] = [];

        this.logger.info(`Running ${pendingMigrations.length} pending migrations`, {
          modelName: options.modelName,
          dryRun: options.dryRun,
        });

        for (const migration of pendingMigrations) {
          try {
            const result = await this.runMigration(migration.id, {
              dryRun: options.dryRun,
              batchSize: options.batchSize,
            });
            results.push(result);

            if (!result.success && options.stopOnError) {
              this.logger.warn('Stopping migration run due to error', {
                failedMigration: migration.id,
                stopOnError: options.stopOnError,
              });
              break;
            }
          } catch (error) {
            if (options.stopOnError) {
              throw error;
            }
            this.logger.error(`Skipping failed migration: ${migration.id}`, { error });
          }
        }

        return results;
      }

      // Rollback a migration
      async rollbackMigration(migrationId: string): Promise<MigrationResult> {
        const migration = this.migrations.get(migrationId);
        if (!migration) {
          throw new Error(`Migration ${migrationId} not found`);
        }

        const appliedMigrations = this.getAppliedMigrations();
        const isApplied = appliedMigrations.some((m) => m.migrationId === migrationId && m.success);

        if (!isApplied) {
          throw new Error(`Migration ${migrationId} has not been applied`);
        }

        const startTime = Date.now();
        const progress: MigrationProgress = {
          migrationId,
          status: 'running',
          startedAt: startTime,
          totalRecords: 0,
          processedRecords: 0,
          errorCount: 0,
          warnings: [],
          errors: [],
        };

        try {
          this.logger.info(`Starting rollback: ${migration.name}`, { migrationId });

          const result = await this.executeRollback(migration, progress);

          result.rollbackAvailable = false;
          await this.recordMigrationResult(result);

          this.logger.info(`Rollback completed: ${migration.name}`, {
            migrationId,
            duration: result.duration,
          });

          return result;
        } catch (error: any) {
          this.logger.error(`Rollback failed: ${migration.name}`, {
            migrationId,
            error: error.message,
          });
          throw error;
        }
      }

      // Execute migration operations
      private async executeMigration(
        migration: Migration,
        options: any,
        progress: MigrationProgress,
      ): Promise<MigrationResult> {
        const startTime = Date.now();
        let totalProcessed = 0;
        let totalModified = 0;

        for (const modelName of migration.targetModels) {
          for (const operation of migration.up) {
            if (operation.modelName !== modelName) continue;

            progress.currentOperation = `${operation.type} on ${operation.modelName}.${operation.fieldName || 'N/A'}`;

            this.logger.debug(`Executing operation: ${progress.currentOperation}`, {
              migrationId: migration.id,
              operation: operation.type,
            });

            const context: MigrationContext = {
              migration,
              modelName,
              databaseManager: this.databaseManager,
              shardManager: this.shardManager,
              operation,
              progress,
              logger: this.logger,
            };

            const operationResult = await this.executeOperation(context, options);
            totalProcessed += operationResult.processed;
            totalModified += operationResult.modified;
            progress.processedRecords = totalProcessed;
          }
        }

        return {
          migrationId: migration.id,
          success: true,
          duration: Date.now() - startTime,
          recordsProcessed: totalProcessed,
          recordsModified: totalModified,
          warnings: progress.warnings,
          errors: progress.errors,
          rollbackAvailable: migration.down.length > 0,
        };
      }

      // Execute a single migration operation
      private async executeOperation(
        context: MigrationContext,
        options: any,
      ): Promise<{ processed: number; modified: number }> {
        const { operation } = context;

        switch (operation.type) {
          case 'add_field':
            return await this.executeAddField(context, options);

          case 'remove_field':
            return await this.executeRemoveField(context, options);

          case 'modify_field':
            return await this.executeModifyField(context, options);

          case 'rename_field':
            return await this.executeRenameField(context, options);

          case 'transform_data':
            return await this.executeDataTransformation(context, options);

          case 'custom':
            return await this.executeCustomOperation(context, options);

          default:
            throw new Error(`Unsupported operation type: ${operation.type}`);
        }
      }

      // Execute add field operation
      private async executeAddField(
        context: MigrationContext,
        options: any,
      ): Promise<{ processed: number; modified: number }> {
        const { operation } = context;

        if (!operation.fieldName || !operation.fieldConfig) {
          throw new Error('Add field operation requires fieldName and fieldConfig');
        }

        // Update model metadata (in a real implementation, this would update the model registry)
        this.logger.info(`Adding field ${operation.fieldName} to ${operation.modelName}`, {
          fieldConfig: operation.fieldConfig,
        });

        // Get all records for this model
        const records = await this.getAllRecordsForModel(operation.modelName);
        let modified = 0;

        // Add default value to existing records
        const batchSize = options.batchSize || 100;
        for (let i = 0; i < records.length; i += batchSize) {
          const batch = records.slice(i, i + batchSize);

          for (const record of batch) {
            if (!(operation.fieldName in record)) {
              record[operation.fieldName] = operation.fieldConfig.default || null;
              await this.updateRecord(operation.modelName, record);
              modified++;
            }
          }

          context.progress.processedRecords += batch.length;
        }

        return { processed: records.length, modified };
      }

      // Execute remove field operation
      private async executeRemoveField(
        context: MigrationContext,
        options: any,
      ): Promise<{ processed: number; modified: number }> {
        const { operation } = context;

        if (!operation.fieldName) {
          throw new Error('Remove field operation requires fieldName');
        }

        this.logger.info(`Removing field ${operation.fieldName} from ${operation.modelName}`);

        const records = await this.getAllRecordsForModel(operation.modelName);
        let modified = 0;

        const batchSize = options.batchSize || 100;
        for (let i = 0; i < records.length; i += batchSize) {
          const batch = records.slice(i, i + batchSize);

          for (const record of batch) {
            if (operation.fieldName in record) {
              delete record[operation.fieldName];
              await this.updateRecord(operation.modelName, record);
              modified++;
            }
          }

          context.progress.processedRecords += batch.length;
        }

        return { processed: records.length, modified };
      }

      // Execute modify field operation
      private async executeModifyField(
        context: MigrationContext,
        options: any,
      ): Promise<{ processed: number; modified: number }> {
        const { operation } = context;

        if (!operation.fieldName || !operation.fieldConfig) {
          throw new Error('Modify field operation requires fieldName and fieldConfig');
        }

        this.logger.info(`Modifying field ${operation.fieldName} in ${operation.modelName}`, {
          newConfig: operation.fieldConfig,
        });

        const records = await this.getAllRecordsForModel(operation.modelName);
        let modified = 0;

        const batchSize = options.batchSize || 100;
        for (let i = 0; i < records.length; i += batchSize) {
          const batch = records.slice(i, i + batchSize);

          for (const record of batch) {
            if (operation.fieldName in record) {
              // Apply type conversion if needed
              const oldValue = record[operation.fieldName];
              const newValue = this.convertFieldValue(oldValue, operation.fieldConfig);

              if (newValue !== oldValue) {
                record[operation.fieldName] = newValue;
                await this.updateRecord(operation.modelName, record);
                modified++;
              }
            }
          }

          context.progress.processedRecords += batch.length;
        }

        return { processed: records.length, modified };
      }

      // Execute rename field operation
      private async executeRenameField(
        context: MigrationContext,
        options: any,
      ): Promise<{ processed: number; modified: number }> {
        const { operation } = context;

        if (!operation.fieldName || !operation.newFieldName) {
          throw new Error('Rename field operation requires fieldName and newFieldName');
        }

        this.logger.info(
          `Renaming field ${operation.fieldName} to ${operation.newFieldName} in ${operation.modelName}`,
        );

        const records = await this.getAllRecordsForModel(operation.modelName);
        let modified = 0;

        const batchSize = options.batchSize || 100;
        for (let i = 0; i < records.length; i += batchSize) {
          const batch = records.slice(i, i + batchSize);

          for (const record of batch) {
            if (operation.fieldName in record) {
              record[operation.newFieldName] = record[operation.fieldName];
              delete record[operation.fieldName];
              await this.updateRecord(operation.modelName, record);
              modified++;
            }
          }

          context.progress.processedRecords += batch.length;
        }

        return { processed: records.length, modified };
      }

      // Execute data transformation operation
      private async executeDataTransformation(
        context: MigrationContext,
        options: any,
      ): Promise<{ processed: number; modified: number }> {
        const { operation } = context;

        if (!operation.transformer) {
          throw new Error('Transform data operation requires transformer function');
        }

        this.logger.info(`Transforming data for ${operation.modelName}`);

        const records = await this.getAllRecordsForModel(operation.modelName);
        let modified = 0;

        const batchSize = options.batchSize || 100;
        for (let i = 0; i < records.length; i += batchSize) {
          const batch = records.slice(i, i + batchSize);

          for (const record of batch) {
            try {
              const originalRecord = JSON.stringify(record);
              const transformedRecord = await operation.transformer(record);

              if (JSON.stringify(transformedRecord) !== originalRecord) {
                Object.assign(record, transformedRecord);
                await this.updateRecord(operation.modelName, record);
                modified++;
              }
            } catch (error: any) {
              context.progress.errors.push(`Transform error for record ${record.id}: ${error.message}`);
              context.progress.errorCount++;
            }
          }

          context.progress.processedRecords += batch.length;
        }

        return { processed: records.length, modified };
      }

      // Execute custom operation
      private async executeCustomOperation(
        context: MigrationContext,
        _options: any,
      ): Promise<{ processed: number; modified: number }> {
        const { operation } = context;

        if (!operation.customOperation) {
          throw new Error('Custom operation requires customOperation function');
        }

        this.logger.info(`Executing custom operation for ${operation.modelName}`);

        try {
          await operation.customOperation(context);
          return { processed: 1, modified: 1 }; // Custom operations handle their own counting
        } catch (error: any) {
          context.progress.errors.push(`Custom operation error: ${error.message}`);
          throw error;
        }
      }

      // Helper methods for data access
      private async getAllRecordsForModel(modelName: string): Promise<any[]> {
        // In a real implementation, this would query all shards for the model
        // For now, return empty array as placeholder
        this.logger.debug(`Getting all records for model: ${modelName}`);
        return [];
      }

      private async updateRecord(modelName: string, record: any): Promise<void> {
        // In a real implementation, this would update the record in the appropriate database
        this.logger.debug(`Updating record in ${modelName}:`, { id: record.id });
      }

      private convertFieldValue(value: any, fieldConfig: FieldConfig): any {
        // Convert value based on field configuration
        switch (fieldConfig.type) {
          case 'string':
            return value != null ? String(value) : null;
          case 'number':
            return value != null ? Number(value) : null;
          case 'boolean':
            return value != null ? Boolean(value) : null;
          case 'array':
            return Array.isArray(value) ? value : [value];
          default:
            return value;
        }
      }

      // Validation methods
      private validateMigrationStructure(migration: Migration): void {
        if (!migration.id || !migration.version || !migration.name) {
          throw new Error('Migration must have id, version, and name');
        }

        if (!migration.targetModels || migration.targetModels.length === 0) {
          throw new Error('Migration must specify target models');
        }

        if (!migration.up || migration.up.length === 0) {
          throw new Error('Migration must have at least one up operation');
        }

        // Validate operations
        for (const operation of migration.up) {
          this.validateOperation(operation);
        }

        if (migration.down) {
          for (const operation of migration.down) {
            this.validateOperation(operation);
          }
        }
      }

      private validateOperation(operation: MigrationOperation): void {
        const validTypes = [
          'add_field',
          'remove_field',
          'modify_field',
          'rename_field',
          'add_index',
          'remove_index',
          'transform_data',
          'custom',
        ];

        if (!validTypes.includes(operation.type)) {
          throw new Error(`Invalid operation type: ${operation.type}`);
        }

        if (!operation.modelName) {
          throw new Error('Operation must specify modelName');
        }
      }

      private async validateDependencies(migration: Migration): Promise<void> {
        if (!migration.dependencies) return;

        const appliedMigrations = this.getAppliedMigrations();
        const appliedIds = new Set(appliedMigrations.map((m) => m.migrationId));

        for (const dependencyId of migration.dependencies) {
          if (!appliedIds.has(dependencyId)) {
            throw new Error(`Migration dependency not satisfied: ${dependencyId}`);
          }
        }
      }

      private async runPreMigrationValidation(migration: Migration): Promise<void> {
        if (!migration.validators) return;

        for (const validator of migration.validators) {
          this.logger.debug(`Running pre-migration validator: ${validator.name}`);

          const context: MigrationContext = {
            migration,
            modelName: '', // Will be set per model
            databaseManager: this.databaseManager,
            shardManager: this.shardManager,
            operation: migration.up[0], // First operation for context
            progress: this.activeMigrations.get(migration.id)!,
            logger: this.logger,
          };

          const result = await validator.validate(context);
          if (!result.valid) {
            throw new Error(`Pre-migration validation failed: ${result.errors.join(', ')}`);
          }

          if (result.warnings.length > 0) {
            context.progress.warnings.push(...result.warnings);
          }
        }
      }

      private async runPostMigrationValidation(_migration: Migration): Promise<void> {
        // Similar to pre-migration validation but runs after
        this.logger.debug('Running post-migration validation');
      }

      // Rollback operations
      private async executeRollback(
        migration: Migration,
        progress: MigrationProgress,
      ): Promise<MigrationResult> {
        if (!migration.down || migration.down.length === 0) {
          throw new Error('Migration has no rollback operations defined');
        }

        const startTime = Date.now();
        let totalProcessed = 0;
        let totalModified = 0;

        // Execute rollback operations in reverse order
        for (const modelName of migration.targetModels) {
          for (const operation of migration.down.reverse()) {
            if (operation.modelName !== modelName) continue;

            const context: MigrationContext = {
              migration,
              modelName,
              databaseManager: this.databaseManager,
              shardManager: this.shardManager,
              operation,
              progress,
              logger: this.logger,
            };

            const operationResult = await this.executeOperation(context, {});
            totalProcessed += operationResult.processed;
            totalModified += operationResult.modified;
          }
        }

        return {
          migrationId: migration.id,
          success: true,
          duration: Date.now() - startTime,
          recordsProcessed: totalProcessed,
          recordsModified: totalModified,
          warnings: progress.warnings,
          errors: progress.errors,
          rollbackAvailable: false,
        };
      }

      private async attemptRollback(
        migration: Migration,
        progress: MigrationProgress,
      ): Promise<{ success: boolean }> {
        try {
          if (migration.down && migration.down.length > 0) {
            await this.executeRollback(migration, progress);
            progress.status = 'rolled_back';
            return { success: true };
          }
        } catch (error: any) {
          this.logger.error(`Rollback failed for migration ${migration.id}`, { error });
        }

        return { success: false };
      }

      // Dry run functionality
      private async performDryRun(migration: Migration, _options: any): Promise<MigrationResult> {
        this.logger.info(`Performing dry run for migration: ${migration.name}`);

        const startTime = Date.now();
        let estimatedRecords = 0;

        // Estimate the number of records that would be affected
        for (const modelName of migration.targetModels) {
          const modelRecords = await this.countRecordsForModel(modelName);
          estimatedRecords += modelRecords;
        }

        // Simulate operations without actually modifying data
        for (const operation of migration.up) {
          this.logger.debug(`Dry run operation: ${operation.type} on ${operation.modelName}`);
        }

        return {
          migrationId: migration.id,
          success: true,
          duration: Date.now() - startTime,
          recordsProcessed: estimatedRecords,
          recordsModified: estimatedRecords, // Estimate
          warnings: ['This was a dry run - no data was actually modified'],
          errors: [],
          rollbackAvailable: migration.down.length > 0,
        };
      }

      private async countRecordsForModel(_modelName: string): Promise<number> {
        // In a real implementation, this would count records across all shards
        return 0;
      }

      // Migration history and state management
      private getAppliedMigrations(_modelName?: string): MigrationResult[] {
        const allResults: MigrationResult[] = [];

        for (const results of this.migrationHistory.values()) {
          allResults.push(...results.filter((r) => r.success));
        }

        return allResults;
      }

      private async recordMigrationResult(result: MigrationResult): Promise<void> {
        if (!this.migrationHistory.has(result.migrationId)) {
          this.migrationHistory.set(result.migrationId, []);
        }

        this.migrationHistory.get(result.migrationId)!.push(result);

        // In a real implementation, this would persist to database
        this.logger.debug('Recorded migration result', { result });
      }

      // Version comparison
      private compareVersions(version1: string, version2: string): number {
        const v1Parts = version1.split('.').map(Number);
        const v2Parts = version2.split('.').map(Number);

        for (let i = 0; i < Math.max(v1Parts.length, v2Parts.length); i++) {
          const v1Part = v1Parts[i] || 0;
          const v2Part = v2Parts[i] || 0;

          if (v1Part < v2Part) return -1;
          if (v1Part > v2Part) return 1;
        }

        return 0;
      }

      private updateMigrationOrder(): void {
        const migrations = Array.from(this.migrations.values());
        this.migrationOrder = migrations
          .sort((a, b) => this.compareVersions(a.version, b.version))
          .map((m) => m.id);
      }

      // Utility methods
      private createDefaultLogger(): MigrationLogger {
        return {
          info: (message: string, meta?: any) => console.log(`[MIGRATION INFO] ${message}`, meta || ''),
          warn: (message: string, meta?: any) =>
            console.warn(`[MIGRATION WARN] ${message}`, meta || ''),
          error: (message: string, meta?: any) =>
            console.error(`[MIGRATION ERROR] ${message}`, meta || ''),
          debug: (message: string, meta?: any) =>
            console.log(`[MIGRATION DEBUG] ${message}`, meta || ''),
        };
      }

      // Status and monitoring
      getMigrationProgress(migrationId: string): MigrationProgress | null {
        return this.activeMigrations.get(migrationId) || null;
      }

      getActiveMigrations(): MigrationProgress[] {
        return Array.from(this.activeMigrations.values());
      }

      getMigrationHistory(migrationId?: string): MigrationResult[] {
        if (migrationId) {
          return this.migrationHistory.get(migrationId) || [];
        }

        const allResults: MigrationResult[] = [];
        for (const results of this.migrationHistory.values()) {
          allResults.push(...results);
        }

        return allResults.sort((a, b) => b.duration - a.duration);
      }

      // Cleanup and maintenance
      async cleanup(): Promise<void> {
        this.logger.info('Cleaning up migration manager');
        this.activeMigrations.clear();
      }
    }