MongoDB Backup and Recovery Strategies: Advanced Disaster Recovery and Data Protection for Mission-Critical Applications

-- Traditional PostgreSQL backup management - manual processes with limited automation capabilities

-- Basic backup tracking table with minimal functionality
CREATE TABLE backup_jobs (
    backup_id SERIAL PRIMARY KEY,
    backup_name VARCHAR(255) NOT NULL,
    backup_type VARCHAR(100) NOT NULL, -- full, incremental, differential
    database_name VARCHAR(100) NOT NULL,

    -- Backup execution tracking
    backup_start_time TIMESTAMP NOT NULL,
    backup_end_time TIMESTAMP,
    backup_status VARCHAR(50) DEFAULT 'running',

    -- Basic size and performance metrics (limited visibility)
    backup_size_bytes BIGINT,
    backup_duration_seconds INTEGER,
    backup_compression_ratio DECIMAL(5,2),

    -- File location tracking (manual)
    backup_file_path TEXT,
    backup_storage_location VARCHAR(200),
    backup_retention_days INTEGER DEFAULT 30,

    -- Basic validation (very limited)
    backup_checksum VARCHAR(64),
    backup_verification_status VARCHAR(50),
    backup_verification_time TIMESTAMP,

    -- Error tracking
    backup_error_message TEXT,
    backup_warning_count INTEGER DEFAULT 0,

    -- Metadata
    created_by VARCHAR(100) DEFAULT current_user,
    backup_method VARCHAR(100) DEFAULT 'pg_dump'
);

-- Simple backup scheduling table (no real automation)
CREATE TABLE backup_schedules (
    schedule_id SERIAL PRIMARY KEY,
    schedule_name VARCHAR(255) NOT NULL,
    database_name VARCHAR(100) NOT NULL,
    backup_type VARCHAR(100) NOT NULL,

    -- Basic scheduling (cron-like but manual)
    schedule_frequency VARCHAR(50), -- daily, weekly, monthly
    schedule_time TIME,
    schedule_days VARCHAR(20), -- comma-separated day numbers

    -- Basic configuration
    retention_days INTEGER DEFAULT 30,
    backup_location VARCHAR(200),
    compression_enabled BOOLEAN DEFAULT true,

    -- Status tracking
    schedule_enabled BOOLEAN DEFAULT true,
    last_backup_time TIMESTAMP,
    last_backup_status VARCHAR(50),
    next_backup_time TIMESTAMP,

    -- Error tracking
    consecutive_failures INTEGER DEFAULT 0,
    last_error_message TEXT,

    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

-- Manual backup execution function (very basic functionality)
CREATE OR REPLACE FUNCTION execute_backup(
    database_name_param VARCHAR(100),
    backup_type_param VARCHAR(100) DEFAULT 'full'
) RETURNS TABLE (
    backup_id INTEGER,
    backup_status VARCHAR(50),
    backup_duration_seconds INTEGER,
    backup_size_mb INTEGER,
    backup_file_path TEXT,
    error_message TEXT
) AS $$
DECLARE
    new_backup_id INTEGER;
    backup_start TIMESTAMP;
    backup_end TIMESTAMP;
    backup_command TEXT;
    backup_filename TEXT;
    backup_directory TEXT := '/backup/postgresql/';
    command_result INTEGER;
    backup_size BIGINT;
    final_status VARCHAR(50) := 'completed';
    error_msg TEXT := '';
BEGIN
    backup_start := clock_timestamp();

    -- Generate backup filename
    backup_filename := database_name_param || '_' || 
                      backup_type_param || '_' || 
                      TO_CHAR(backup_start, 'YYYY-MM-DD_HH24-MI-SS') || '.sql';

    -- Create backup job record
    INSERT INTO backup_jobs (
        backup_name, backup_type, database_name, 
        backup_start_time, backup_file_path, backup_method
    )
    VALUES (
        backup_filename, backup_type_param, database_name_param,
        backup_start, backup_directory || backup_filename, 'pg_dump'
    )
    RETURNING backup_jobs.backup_id INTO new_backup_id;

    BEGIN
        -- Execute backup command (this is a simulation - real implementation would call external command)
        -- In reality: pg_dump -h localhost -U postgres -d database_name -f backup_file

        -- Simulate backup process with basic validation
        IF database_name_param NOT IN (SELECT datname FROM pg_database) THEN
            RAISE EXCEPTION 'Database % does not exist', database_name_param;
        END IF;

        -- Simulate backup time based on type
        CASE backup_type_param
            WHEN 'full' THEN PERFORM pg_sleep(2.0);  -- Simulate 2 seconds for full backup
            WHEN 'incremental' THEN PERFORM pg_sleep(0.5);  -- Simulate 0.5 seconds for incremental
            ELSE PERFORM pg_sleep(1.0);
        END CASE;

        -- Simulate backup size calculation (very basic)
        SELECT pg_database_size(database_name_param) INTO backup_size;

        -- Basic compression simulation
        backup_size := backup_size * 0.3;  -- Assume 70% compression

    EXCEPTION WHEN OTHERS THEN
        final_status := 'failed';
        error_msg := SQLERRM;
        backup_size := 0;
    END;

    backup_end := clock_timestamp();

    -- Update backup job record
    UPDATE backup_jobs 
    SET 
        backup_end_time = backup_end,
        backup_status = final_status,
        backup_size_bytes = backup_size,
        backup_duration_seconds = EXTRACT(SECONDS FROM backup_end - backup_start)::INTEGER,
        backup_compression_ratio = CASE WHEN backup_size > 0 THEN 70.0 ELSE 0 END,
        backup_error_message = CASE WHEN final_status = 'failed' THEN error_msg ELSE NULL END
    WHERE backup_jobs.backup_id = new_backup_id;

    -- Return results
    RETURN QUERY SELECT 
        new_backup_id,
        final_status,
        EXTRACT(SECONDS FROM backup_end - backup_start)::INTEGER,
        (backup_size / 1024 / 1024)::INTEGER,
        backup_directory || backup_filename,
        CASE WHEN final_status = 'failed' THEN error_msg ELSE NULL END;

END;
$$ LANGUAGE plpgsql;

-- Execute a backup (basic functionality)
SELECT * FROM execute_backup('production_db', 'full');

-- Basic backup verification function (very limited)
CREATE OR REPLACE FUNCTION verify_backup(backup_id_param INTEGER)
RETURNS TABLE (
    backup_id INTEGER,
    verification_status VARCHAR(50),
    verification_duration_seconds INTEGER,
    file_exists BOOLEAN,
    file_size_mb INTEGER,
    checksum_valid BOOLEAN,
    error_message TEXT
) AS $$
DECLARE
    backup_record RECORD;
    verification_start TIMESTAMP;
    verification_end TIMESTAMP;
    file_size BIGINT;
    verification_error TEXT := '';
    verification_result VARCHAR(50) := 'valid';
BEGIN
    verification_start := clock_timestamp();

    -- Get backup record
    SELECT * INTO backup_record
    FROM backup_jobs
    WHERE backup_jobs.backup_id = backup_id_param;

    IF NOT FOUND THEN
        RETURN QUERY SELECT 
            backup_id_param,
            'not_found'::VARCHAR(50),
            0,
            false,
            0,
            false,
            'Backup record not found'::TEXT;
        RETURN;
    END IF;

    BEGIN
        -- Simulate file verification (in reality would check actual file)
        -- Check if backup was successful
        IF backup_record.backup_status != 'completed' THEN
            verification_result := 'invalid';
            verification_error := 'Original backup failed';
        END IF;

        -- Simulate file size check
        file_size := backup_record.backup_size_bytes;

        -- Basic integrity simulation
        IF file_size = 0 OR backup_record.backup_duration_seconds = 0 THEN
            verification_result := 'invalid';
            verification_error := 'Backup file appears to be empty or corrupted';
        END IF;

        -- Simulate verification time
        PERFORM pg_sleep(0.1);

    EXCEPTION WHEN OTHERS THEN
        verification_result := 'error';
        verification_error := SQLERRM;
    END;

    verification_end := clock_timestamp();

    -- Update backup record with verification results
    UPDATE backup_jobs
    SET 
        backup_verification_status = verification_result,
        backup_verification_time = verification_end
    WHERE backup_jobs.backup_id = backup_id_param;

    -- Return verification results
    RETURN QUERY SELECT 
        backup_id_param,
        verification_result,
        EXTRACT(SECONDS FROM verification_end - verification_start)::INTEGER,
        CASE WHEN file_size > 0 THEN true ELSE false END,
        (file_size / 1024 / 1024)::INTEGER,
        CASE WHEN verification_result = 'valid' THEN true ELSE false END,
        CASE WHEN verification_result != 'valid' THEN verification_error ELSE NULL END;

END;
$$ LANGUAGE plpgsql;

-- Recovery function (very basic and manual)
CREATE OR REPLACE FUNCTION restore_backup(
    backup_id_param INTEGER,
    target_database_name VARCHAR(100)
) RETURNS TABLE (
    restore_success BOOLEAN,
    restore_duration_seconds INTEGER,
    restored_size_mb INTEGER,
    error_message TEXT
) AS $$
DECLARE
    backup_record RECORD;
    restore_start TIMESTAMP;
    restore_end TIMESTAMP;
    restore_error TEXT := '';
    restore_result BOOLEAN := true;
BEGIN
    restore_start := clock_timestamp();

    -- Get backup information
    SELECT * INTO backup_record
    FROM backup_jobs
    WHERE backup_id = backup_id_param
    AND backup_status = 'completed';

    IF NOT FOUND THEN
        RETURN QUERY SELECT 
            false,
            0,
            0,
            'Valid backup not found for restore operation'::TEXT;
        RETURN;
    END IF;

    BEGIN
        -- Simulate restore process (in reality would execute psql command)
        -- psql -h localhost -U postgres -d target_database -f backup_file

        -- Basic validation
        IF target_database_name IS NULL OR LENGTH(target_database_name) = 0 THEN
            RAISE EXCEPTION 'Target database name is required';
        END IF;

        -- Simulate restore time proportional to backup size
        PERFORM pg_sleep(LEAST(backup_record.backup_duration_seconds * 1.5, 10.0));

    EXCEPTION WHEN OTHERS THEN
        restore_result := false;
        restore_error := SQLERRM;
    END;

    restore_end := clock_timestamp();

    -- Return restore results
    RETURN QUERY SELECT 
        restore_result,
        EXTRACT(SECONDS FROM restore_end - restore_start)::INTEGER,
        (backup_record.backup_size_bytes / 1024 / 1024)::INTEGER,
        CASE WHEN NOT restore_result THEN restore_error ELSE NULL END;

END;
$$ LANGUAGE plpgsql;

-- Basic backup monitoring and cleanup
WITH backup_status_summary AS (
    SELECT 
        DATE_TRUNC('day', backup_start_time) as backup_date,
        database_name,
        backup_type,
        COUNT(*) as total_backups,
        COUNT(*) FILTER (WHERE backup_status = 'completed') as successful_backups,
        COUNT(*) FILTER (WHERE backup_status = 'failed') as failed_backups,
        SUM(backup_size_bytes) as total_backup_size_bytes,
        AVG(backup_duration_seconds) as avg_backup_duration,
        MIN(backup_start_time) as first_backup,
        MAX(backup_start_time) as last_backup

    FROM backup_jobs
    WHERE backup_start_time >= CURRENT_DATE - INTERVAL '7 days'
    GROUP BY DATE_TRUNC('day', backup_start_time), database_name, backup_type
)
SELECT 
    backup_date,
    database_name,
    backup_type,
    total_backups,
    successful_backups,
    failed_backups,

    -- Success rate
    CASE 
        WHEN total_backups > 0 THEN
            ROUND((successful_backups::DECIMAL / total_backups) * 100, 1)
        ELSE 0
    END as success_rate_percent,

    -- Size and performance metrics
    ROUND((total_backup_size_bytes / 1024.0 / 1024.0), 1) as total_size_mb,
    ROUND(avg_backup_duration::NUMERIC, 1) as avg_duration_seconds,

    -- Backup frequency analysis
    EXTRACT(HOURS FROM (last_backup - first_backup))::INTEGER as backup_window_hours,

    -- Health assessment
    CASE 
        WHEN failed_backups > 0 THEN 'issues'
        WHEN successful_backups = 0 THEN 'no_backups'
        ELSE 'healthy'
    END as backup_health,

    -- Recommendations
    CASE 
        WHEN failed_backups > total_backups * 0.2 THEN 'investigate_failures'
        WHEN avg_backup_duration > 3600 THEN 'optimize_performance'
        WHEN total_backup_size_bytes > 100 * 1024 * 1024 * 1024 THEN 'consider_compression'
        ELSE 'monitor'
    END as recommendation

FROM backup_status_summary
ORDER BY backup_date DESC, database_name, backup_type;

-- Cleanup old backups (manual process)
WITH old_backups AS (
    SELECT backup_id, backup_file_path, backup_size_bytes
    FROM backup_jobs
    WHERE backup_start_time < CURRENT_DATE - INTERVAL '90 days'
    AND backup_status = 'completed'
),
cleanup_summary AS (
    DELETE FROM backup_jobs
    WHERE backup_id IN (SELECT backup_id FROM old_backups)
    RETURNING backup_id, backup_size_bytes
)
SELECT 
    COUNT(*) as backups_cleaned,
    SUM(backup_size_bytes) as total_space_freed_bytes,
    ROUND(SUM(backup_size_bytes) / 1024.0 / 1024.0 / 1024.0, 2) as space_freed_gb
FROM cleanup_summary;

-- Problems with traditional backup approaches:
-- 1. Manual backup execution with no automation or scheduling
-- 2. Limited backup verification and integrity checking
-- 3. No point-in-time recovery capabilities
-- 4. Basic error handling with no automatic retry mechanisms
-- 5. No incremental backup support or optimization
-- 6. Manual cleanup and retention management
-- 7. Limited monitoring and alerting capabilities
-- 8. No support for distributed backup strategies
-- 9. Complex recovery procedures requiring manual intervention
-- 10. No integration with cloud storage or disaster recovery systems

// MongoDB Advanced Backup and Recovery - comprehensive data protection with automated disaster recovery
const { MongoClient, GridFSBucket } = require('mongodb');
const { spawn } = require('child_process');
const fs = require('fs').promises;
const path = require('path');
const { createHash } = require('crypto');
const { EventEmitter } = require('events');

// Comprehensive MongoDB Backup and Recovery Manager
class AdvancedBackupRecoveryManager extends EventEmitter {
  constructor(connectionString, backupConfig = {}) {
    super();
    this.connectionString = connectionString;
    this.client = null;
    this.db = null;

    // Advanced backup and recovery configuration
    this.config = {
      // Backup strategy configuration
      enableAutomatedBackups: backupConfig.enableAutomatedBackups !== false,
      enableIncrementalBackups: backupConfig.enableIncrementalBackups || false,
      enablePointInTimeRecovery: backupConfig.enablePointInTimeRecovery || false,
      enableCompression: backupConfig.enableCompression !== false,

      // Backup scheduling
      fullBackupSchedule: backupConfig.fullBackupSchedule || '0 2 * * *', // Daily at 2 AM
      incrementalBackupSchedule: backupConfig.incrementalBackupSchedule || '0 */6 * * *', // Every 6 hours

      // Storage configuration
      backupStoragePath: backupConfig.backupStoragePath || './backups',
      maxBackupSize: backupConfig.maxBackupSize || 10 * 1024 * 1024 * 1024, // 10GB
      compressionLevel: backupConfig.compressionLevel || 6,

      // Retention policies
      dailyBackupRetention: backupConfig.dailyBackupRetention || 30, // 30 days
      weeklyBackupRetention: backupConfig.weeklyBackupRetention || 12, // 12 weeks
      monthlyBackupRetention: backupConfig.monthlyBackupRetention || 12, // 12 months

      // Backup validation
      enableBackupVerification: backupConfig.enableBackupVerification !== false,
      verificationSampleSize: backupConfig.verificationSampleSize || 1000,
      enableChecksumValidation: backupConfig.enableChecksumValidation !== false,

      // Recovery configuration
      enableParallelRecovery: backupConfig.enableParallelRecovery || false,
      maxRecoveryThreads: backupConfig.maxRecoveryThreads || 4,
      recoveryBatchSize: backupConfig.recoveryBatchSize || 1000,

      // Monitoring and alerting
      enableBackupMonitoring: backupConfig.enableBackupMonitoring !== false,
      enableRecoveryTesting: backupConfig.enableRecoveryTesting || false,
      alertThresholds: {
        backupFailureCount: backupConfig.backupFailureThreshold || 3,
        backupDurationMinutes: backupConfig.backupDurationThreshold || 120,
        backupSizeVariation: backupConfig.backupSizeVariationThreshold || 50
      },

      // Disaster recovery
      enableReplication: backupConfig.enableReplication || false,
      replicationTargets: backupConfig.replicationTargets || [],
      enableCloudSync: backupConfig.enableCloudSync || false,
      cloudSyncConfig: backupConfig.cloudSyncConfig || {}
    };

    // Backup and recovery state management
    this.backupJobs = new Map();
    this.scheduledBackups = new Map();
    this.recoveryOperations = new Map();
    this.backupMetrics = {
      totalBackups: 0,
      successfulBackups: 0,
      failedBackups: 0,
      totalDataBackedUp: 0,
      averageBackupDuration: 0
    };

    // Backup history and metadata
    this.backupHistory = [];
    this.recoveryHistory = [];

    this.initializeBackupSystem();
  }

  async initializeBackupSystem() {
    console.log('Initializing advanced backup and recovery system...');

    try {
      // Connect to MongoDB
      this.client = new MongoClient(this.connectionString);
      await this.client.connect();
      this.db = this.client.db();

      // Setup backup infrastructure
      await this.setupBackupInfrastructure();

      // Initialize automated backup scheduling
      if (this.config.enableAutomatedBackups) {
        await this.setupAutomatedBackups();
      }

      // Setup backup monitoring
      if (this.config.enableBackupMonitoring) {
        await this.setupBackupMonitoring();
      }

      // Initialize point-in-time recovery if enabled
      if (this.config.enablePointInTimeRecovery) {
        await this.setupPointInTimeRecovery();
      }

      console.log('Advanced backup and recovery system initialized successfully');

    } catch (error) {
      console.error('Error initializing backup system:', error);
      throw error;
    }
  }

  async setupBackupInfrastructure() {
    console.log('Setting up backup infrastructure...');

    try {
      // Create backup storage directory
      await fs.mkdir(this.config.backupStoragePath, { recursive: true });

      // Create subdirectories for different backup types
      const backupDirs = ['full', 'incremental', 'logs', 'metadata', 'recovery-points'];
      for (const dir of backupDirs) {
        await fs.mkdir(path.join(this.config.backupStoragePath, dir), { recursive: true });
      }

      // Setup backup metadata collections
      const collections = {
        backupJobs: this.db.collection('backup_jobs'),
        backupMetadata: this.db.collection('backup_metadata'),
        recoveryOperations: this.db.collection('recovery_operations'),
        backupSchedules: this.db.collection('backup_schedules')
      };

      // Create indexes for backup operations
      await collections.backupJobs.createIndex(
        { startTime: -1, status: 1 },
        { background: true }
      );

      await collections.backupMetadata.createIndex(
        { backupId: 1, backupType: 1, timestamp: -1 },
        { background: true }
      );

      await collections.recoveryOperations.createIndex(
        { recoveryId: 1, startTime: -1 },
        { background: true }
      );

      this.collections = collections;

    } catch (error) {
      console.error('Error setting up backup infrastructure:', error);
      throw error;
    }
  }

  async createFullBackup(backupOptions = {}) {
    console.log('Starting full database backup...');

    const backupId = this.generateBackupId('full');
    const startTime = new Date();

    try {
      // Create backup job record
      const backupJob = {
        backupId: backupId,
        backupType: 'full',
        startTime: startTime,
        status: 'running',

        // Backup configuration
        options: {
          compression: this.config.enableCompression,
          compressionLevel: this.config.compressionLevel,
          includeIndexes: backupOptions.includeIndexes !== false,
          includeSystemCollections: backupOptions.includeSystemCollections || false,
          oplogCapture: this.config.enablePointInTimeRecovery
        },

        // Progress tracking
        progress: {
          collectionsProcessed: 0,
          totalCollections: 0,
          documentsProcessed: 0,
          totalDocuments: 0,
          bytesProcessed: 0,
          estimatedTotalBytes: 0
        },

        // Performance metrics
        performance: {
          throughputMBps: 0,
          compressionRatio: 0,
          parallelStreams: 1
        }
      };

      await this.collections.backupJobs.insertOne(backupJob);
      this.backupJobs.set(backupId, backupJob);

      // Get database statistics for progress tracking
      const dbStats = await this.db.stats();
      backupJob.progress.estimatedTotalBytes = dbStats.dataSize;

      // Get collection list and metadata
      const collections = await this.db.listCollections().toArray();
      backupJob.progress.totalCollections = collections.length;

      // Calculate total document count across collections
      let totalDocuments = 0;
      for (const collectionInfo of collections) {
        if (collectionInfo.type === 'collection') {
          const collection = this.db.collection(collectionInfo.name);
          const count = await collection.estimatedDocumentCount();
          totalDocuments += count;
        }
      }
      backupJob.progress.totalDocuments = totalDocuments;

      // Create backup using mongodump
      const backupResult = await this.executeMongoDump(backupId, backupJob);

      // Verify backup integrity
      if (this.config.enableBackupVerification) {
        await this.verifyBackupIntegrity(backupId, backupResult);
      }

      // Calculate backup metrics
      const endTime = new Date();
      const duration = endTime.getTime() - startTime.getTime();
      const backupSizeBytes = backupResult.backupSize;
      const compressionRatio = backupResult.originalSize > 0 ? 
        (backupResult.originalSize - backupSizeBytes) / backupResult.originalSize : 0;

      // Update backup job with results
      const completedJob = {
        ...backupJob,
        endTime: endTime,
        status: 'completed',
        duration: duration,
        backupSize: backupSizeBytes,
        originalSize: backupResult.originalSize,
        compressionRatio: compressionRatio,
        backupPath: backupResult.backupPath,
        checksum: backupResult.checksum,

        // Final performance metrics
        performance: {
          throughputMBps: (backupSizeBytes / 1024 / 1024) / (duration / 1000),
          compressionRatio: compressionRatio,
          parallelStreams: backupResult.parallelStreams || 1
        }
      };

      await this.collections.backupJobs.replaceOne(
        { backupId: backupId },
        completedJob
      );

      // Update backup metrics
      this.updateBackupMetrics(completedJob);

      // Store backup metadata for recovery operations
      await this.storeBackupMetadata(completedJob);

      this.emit('backupCompleted', {
        backupId: backupId,
        backupType: 'full',
        duration: duration,
        backupSize: backupSizeBytes,
        compressionRatio: compressionRatio
      });

      console.log(`Full backup completed: ${backupId} (${Math.round(backupSizeBytes / 1024 / 1024)} MB, ${Math.round(duration / 1000)}s)`);

      return {
        success: true,
        backupId: backupId,
        backupSize: backupSizeBytes,
        duration: duration,
        compressionRatio: compressionRatio,
        backupPath: backupResult.backupPath
      };

    } catch (error) {
      console.error(`Full backup failed for ${backupId}:`, error);

      // Update backup job with error
      await this.collections.backupJobs.updateOne(
        { backupId: backupId },
        {
          $set: {
            status: 'failed',
            endTime: new Date(),
            error: {
              message: error.message,
              stack: error.stack,
              timestamp: new Date()
            }
          }
        }
      );

      this.backupMetrics.failedBackups++;

      this.emit('backupFailed', {
        backupId: backupId,
        backupType: 'full',
        error: error.message
      });

      return {
        success: false,
        backupId: backupId,
        error: error.message
      };
    }
  }

  async executeMongoDump(backupId, backupJob) {
    console.log(`Executing mongodump for backup: ${backupId}`);

    return new Promise((resolve, reject) => {
      const backupPath = path.join(
        this.config.backupStoragePath,
        'full',
        `${backupId}.archive`
      );

      // Build mongodump command arguments
      const mongodumpArgs = [
        '--uri', this.connectionString,
        '--archive=' + backupPath,
        '--gzip'
      ];

      // Add additional options based on configuration
      if (backupJob.options.oplogCapture) {
        mongodumpArgs.push('--oplog');
      }

      if (!backupJob.options.includeSystemCollections) {
        mongodumpArgs.push('--excludeCollection=system.*');
      }

      // Execute mongodump
      const mongodumpProcess = spawn('mongodump', mongodumpArgs);

      let stdoutData = '';
      let stderrData = '';

      mongodumpProcess.stdout.on('data', (data) => {
        stdoutData += data.toString();
        this.parseBackupProgress(backupId, data.toString());
      });

      mongodumpProcess.stderr.on('data', (data) => {
        stderrData += data.toString();
        console.warn('mongodump stderr:', data.toString());
      });

      mongodumpProcess.on('close', async (code) => {
        try {
          if (code === 0) {
            // Get backup file statistics
            const stats = await fs.stat(backupPath);
            const backupSize = stats.size;

            // Calculate checksum for integrity verification
            const checksum = await this.calculateFileChecksum(backupPath);

            resolve({
              backupPath: backupPath,
              backupSize: backupSize,
              originalSize: backupJob.progress.estimatedTotalBytes,
              checksum: checksum,
              stdout: stdoutData,
              parallelStreams: 1
            });
          } else {
            reject(new Error(`mongodump failed with exit code ${code}: ${stderrData}`));
          }
        } catch (error) {
          reject(error);
        }
      });

      mongodumpProcess.on('error', (error) => {
        reject(new Error(`Failed to start mongodump: ${error.message}`));
      });
    });
  }

  parseBackupProgress(backupId, output) {
    // Parse mongodump output to extract progress information
    const backupJob = this.backupJobs.get(backupId);
    if (!backupJob) return;

    // Look for progress indicators in mongodump output
    const progressMatches = output.match(/(\d+)\s+documents?\s+to\s+(\w+)\.(\w+)/g);
    if (progressMatches) {
      for (const match of progressMatches) {
        const [, docCount, dbName, collectionName] = match.match(/(\d+)\s+documents?\s+to\s+(\w+)\.(\w+)/);

        backupJob.progress.documentsProcessed += parseInt(docCount);
        backupJob.progress.collectionsProcessed++;

        // Emit progress update
        this.emit('backupProgress', {
          backupId: backupId,
          progress: {
            collectionsProcessed: backupJob.progress.collectionsProcessed,
            totalCollections: backupJob.progress.totalCollections,
            documentsProcessed: backupJob.progress.documentsProcessed,
            totalDocuments: backupJob.progress.totalDocuments,
            percentComplete: (backupJob.progress.documentsProcessed / backupJob.progress.totalDocuments) * 100
          }
        });
      }
    }
  }

  async calculateFileChecksum(filePath) {
    console.log(`Calculating checksum for: ${filePath}`);

    try {
      const fileBuffer = await fs.readFile(filePath);
      const hash = createHash('sha256');
      hash.update(fileBuffer);
      return hash.digest('hex');

    } catch (error) {
      console.error('Error calculating file checksum:', error);
      throw error;
    }
  }

  async verifyBackupIntegrity(backupId, backupResult) {
    console.log(`Verifying backup integrity: ${backupId}`);

    try {
      const verification = {
        backupId: backupId,
        verificationTime: new Date(),
        checksumVerified: false,
        sampleVerified: false,
        errors: []
      };

      // Verify file checksum
      const currentChecksum = await this.calculateFileChecksum(backupResult.backupPath);
      verification.checksumVerified = currentChecksum === backupResult.checksum;

      if (!verification.checksumVerified) {
        verification.errors.push('Checksum verification failed - file may be corrupted');
      }

      // Perform sample restore verification
      if (this.config.verificationSampleSize > 0) {
        const sampleResult = await this.performSampleRestoreTest(backupId, backupResult);
        verification.sampleVerified = sampleResult.success;

        if (!sampleResult.success) {
          verification.errors.push(`Sample restore failed: ${sampleResult.error}`);
        }
      }

      // Store verification results
      await this.collections.backupMetadata.updateOne(
        { backupId: backupId },
        {
          $set: {
            verification: verification,
            lastVerificationTime: verification.verificationTime
          }
        },
        { upsert: true }
      );

      this.emit('backupVerified', {
        backupId: backupId,
        verification: verification
      });

      return verification;

    } catch (error) {
      console.error(`Backup verification failed for ${backupId}:`, error);
      throw error;
    }
  }

  async performSampleRestoreTest(backupId, backupResult) {
    console.log(`Performing sample restore test for backup: ${backupId}`);

    try {
      // Create temporary database for restore test
      const testDbName = `backup_test_${backupId}_${Date.now()}`;

      // Execute mongorestore on sample data
      const restoreResult = await this.executeSampleRestore(
        backupResult.backupPath,
        testDbName
      );

      // Verify restored data integrity
      const verificationResult = await this.verifySampleData(testDbName);

      // Cleanup test database
      await this.cleanupTestDatabase(testDbName);

      return {
        success: restoreResult.success && verificationResult.success,
        error: restoreResult.error || verificationResult.error,
        restoredDocuments: restoreResult.documentCount,
        verificationDetails: verificationResult
      };

    } catch (error) {
      console.error(`Sample restore test failed for ${backupId}:`, error);
      return {
        success: false,
        error: error.message
      };
    }
  }

  async createIncrementalBackup(baseBackupId, backupOptions = {}) {
    console.log(`Starting incremental backup based on: ${baseBackupId}`);

    const backupId = this.generateBackupId('incremental');
    const startTime = new Date();

    try {
      // Get base backup metadata
      const baseBackup = await this.collections.backupJobs.findOne({ backupId: baseBackupId });
      if (!baseBackup) {
        throw new Error(`Base backup not found: ${baseBackupId}`);
      }

      // Create incremental backup job record
      const backupJob = {
        backupId: backupId,
        backupType: 'incremental',
        baseBackupId: baseBackupId,
        startTime: startTime,
        status: 'running',

        // Incremental backup specific configuration
        options: {
          ...backupOptions,
          fromTimestamp: baseBackup.endTime,
          toTimestamp: startTime,
          oplogOnly: true,
          compression: this.config.enableCompression
        },

        progress: {
          oplogEntriesProcessed: 0,
          totalOplogEntries: 0,
          bytesProcessed: 0
        }
      };

      await this.collections.backupJobs.insertOne(backupJob);
      this.backupJobs.set(backupId, backupJob);

      // Execute incremental backup using oplog
      const backupResult = await this.executeOplogBackup(backupId, backupJob);

      // Update backup job with results
      const endTime = new Date();
      const duration = endTime.getTime() - startTime.getTime();

      const completedJob = {
        ...backupJob,
        endTime: endTime,
        status: 'completed',
        duration: duration,
        backupSize: backupResult.backupSize,
        oplogEntries: backupResult.oplogEntries,
        backupPath: backupResult.backupPath,
        checksum: backupResult.checksum
      };

      await this.collections.backupJobs.replaceOne(
        { backupId: backupId },
        completedJob
      );

      this.updateBackupMetrics(completedJob);
      await this.storeBackupMetadata(completedJob);

      this.emit('backupCompleted', {
        backupId: backupId,
        backupType: 'incremental',
        baseBackupId: baseBackupId,
        duration: duration,
        backupSize: backupResult.backupSize,
        oplogEntries: backupResult.oplogEntries
      });

      console.log(`Incremental backup completed: ${backupId}`);

      return {
        success: true,
        backupId: backupId,
        baseBackupId: baseBackupId,
        backupSize: backupResult.backupSize,
        duration: duration,
        oplogEntries: backupResult.oplogEntries
      };

    } catch (error) {
      console.error(`Incremental backup failed for ${backupId}:`, error);

      await this.collections.backupJobs.updateOne(
        { backupId: backupId },
        {
          $set: {
            status: 'failed',
            endTime: new Date(),
            error: {
              message: error.message,
              stack: error.stack,
              timestamp: new Date()
            }
          }
        }
      );

      return {
        success: false,
        backupId: backupId,
        error: error.message
      };
    }
  }

  async restoreFromBackup(backupId, restoreOptions = {}) {
    console.log(`Starting database restore from backup: ${backupId}`);

    const recoveryId = this.generateRecoveryId();
    const startTime = new Date();

    try {
      // Get backup metadata
      const backupJob = await this.collections.backupJobs.findOne({ backupId: backupId });
      if (!backupJob || backupJob.status !== 'completed') {
        throw new Error(`Valid backup not found: ${backupId}`);
      }

      // Create recovery operation record
      const recoveryOperation = {
        recoveryId: recoveryId,
        backupId: backupId,
        backupType: backupJob.backupType,
        startTime: startTime,
        status: 'running',

        // Recovery configuration
        options: {
          targetDatabase: restoreOptions.targetDatabase || this.db.databaseName,
          dropBeforeRestore: restoreOptions.dropBeforeRestore || false,
          restoreIndexes: restoreOptions.restoreIndexes !== false,
          parallelRecovery: this.config.enableParallelRecovery,
          batchSize: this.config.recoveryBatchSize
        },

        progress: {
          collectionsRestored: 0,
          totalCollections: 0,
          documentsRestored: 0,
          totalDocuments: 0,
          bytesRestored: 0
        }
      };

      await this.collections.recoveryOperations.insertOne(recoveryOperation);
      this.recoveryOperations.set(recoveryId, recoveryOperation);

      // Execute restore process
      const restoreResult = await this.executeRestore(recoveryId, backupJob, recoveryOperation);

      // Verify restore integrity
      if (this.config.enableBackupVerification) {
        await this.verifyRestoreIntegrity(recoveryId, restoreResult);
      }

      // Update recovery operation with results
      const endTime = new Date();
      const duration = endTime.getTime() - startTime.getTime();

      const completedRecovery = {
        ...recoveryOperation,
        endTime: endTime,
        status: 'completed',
        duration: duration,
        restoredSize: restoreResult.restoredSize,
        documentsRestored: restoreResult.documentsRestored,
        collectionsRestored: restoreResult.collectionsRestored
      };

      await this.collections.recoveryOperations.replaceOne(
        { recoveryId: recoveryId },
        completedRecovery
      );

      this.recoveryHistory.push(completedRecovery);

      this.emit('restoreCompleted', {
        recoveryId: recoveryId,
        backupId: backupId,
        duration: duration,
        restoredSize: restoreResult.restoredSize,
        documentsRestored: restoreResult.documentsRestored
      });

      console.log(`Database restore completed: ${recoveryId}`);

      return {
        success: true,
        recoveryId: recoveryId,
        backupId: backupId,
        duration: duration,
        restoredSize: restoreResult.restoredSize,
        documentsRestored: restoreResult.documentsRestored,
        collectionsRestored: restoreResult.collectionsRestored
      };

    } catch (error) {
      console.error(`Database restore failed for ${recoveryId}:`, error);

      await this.collections.recoveryOperations.updateOne(
        { recoveryId: recoveryId },
        {
          $set: {
            status: 'failed',
            endTime: new Date(),
            error: {
              message: error.message,
              stack: error.stack,
              timestamp: new Date()
            }
          }
        }
      );

      return {
        success: false,
        recoveryId: recoveryId,
        backupId: backupId,
        error: error.message
      };
    }
  }

  async getBackupStatus(backupId = null) {
    console.log(`Getting backup status${backupId ? ' for: ' + backupId : ' (all backups)'}`);

    try {
      let query = {};
      if (backupId) {
        query.backupId = backupId;
      }

      const backups = await this.collections.backupJobs
        .find(query)
        .sort({ startTime: -1 })
        .limit(backupId ? 1 : 50)
        .toArray();

      const backupStatuses = backups.map(backup => ({
        backupId: backup.backupId,
        backupType: backup.backupType,
        status: backup.status,
        startTime: backup.startTime,
        endTime: backup.endTime,
        duration: backup.duration,
        backupSize: backup.backupSize,
        compressionRatio: backup.compressionRatio,
        documentsProcessed: backup.progress?.documentsProcessed || 0,
        collectionsProcessed: backup.progress?.collectionsProcessed || 0,
        error: backup.error?.message || null,

        // Additional metadata
        baseBackupId: backup.baseBackupId || null,
        checksum: backup.checksum || null,
        backupPath: backup.backupPath || null,

        // Performance metrics
        throughputMBps: backup.performance?.throughputMBps || 0,

        // Health indicators
        healthStatus: this.assessBackupHealth(backup),
        lastVerificationTime: backup.verification?.verificationTime || null,
        verificationStatus: backup.verification?.checksumVerified ? 'verified' : 'pending'
      }));

      return {
        success: true,
        backups: backupStatuses,
        totalBackups: backups.length,

        // System-wide metrics
        systemMetrics: {
          totalBackups: this.backupMetrics.totalBackups,
          successfulBackups: this.backupMetrics.successfulBackups,
          failedBackups: this.backupMetrics.failedBackups,
          averageBackupDuration: this.backupMetrics.averageBackupDuration,
          totalDataBackedUp: this.backupMetrics.totalDataBackedUp
        }
      };

    } catch (error) {
      console.error('Error getting backup status:', error);
      return {
        success: false,
        error: error.message
      };
    }
  }

  assessBackupHealth(backup) {
    if (backup.status === 'failed') return 'unhealthy';
    if (backup.status === 'running') return 'in_progress';
    if (backup.status !== 'completed') return 'unknown';

    // Check verification status
    if (backup.verification && !backup.verification.checksumVerified) {
      return 'verification_failed';
    }

    // Check backup age
    const ageHours = (Date.now() - backup.startTime.getTime()) / (1000 * 60 * 60);
    if (ageHours > 24 * 7) return 'stale'; // Older than 1 week

    return 'healthy';
  }

  updateBackupMetrics(backupJob) {
    this.backupMetrics.totalBackups++;

    if (backupJob.status === 'completed') {
      this.backupMetrics.successfulBackups++;
      this.backupMetrics.totalDataBackedUp += backupJob.backupSize || 0;

      // Update average duration
      const currentAvg = this.backupMetrics.averageBackupDuration;
      const totalSuccessful = this.backupMetrics.successfulBackups;
      this.backupMetrics.averageBackupDuration = 
        ((currentAvg * (totalSuccessful - 1)) + (backupJob.duration || 0)) / totalSuccessful;
    } else if (backupJob.status === 'failed') {
      this.backupMetrics.failedBackups++;
    }
  }

  async storeBackupMetadata(backupJob) {
    const metadata = {
      backupId: backupJob.backupId,
      backupType: backupJob.backupType,
      timestamp: backupJob.startTime,
      backupSize: backupJob.backupSize,
      backupPath: backupJob.backupPath,
      checksum: backupJob.checksum,
      compressionRatio: backupJob.compressionRatio,
      baseBackupId: backupJob.baseBackupId || null,

      // Retention information
      retentionPolicy: this.determineRetentionPolicy(backupJob),
      expirationDate: this.calculateExpirationDate(backupJob),

      // Recovery information
      recoveryMetadata: {
        documentsCount: backupJob.progress?.documentsProcessed || 0,
        collectionsCount: backupJob.progress?.collectionsProcessed || 0,
        indexesIncluded: backupJob.options?.includeIndexes !== false,
        oplogIncluded: backupJob.options?.oplogCapture === true
      }
    };

    await this.collections.backupMetadata.replaceOne(
      { backupId: backupJob.backupId },
      metadata,
      { upsert: true }
    );
  }

  determineRetentionPolicy(backupJob) {
    const dayOfWeek = backupJob.startTime.getDay();
    const dayOfMonth = backupJob.startTime.getDate();

    if (dayOfMonth === 1) return 'monthly';
    if (dayOfWeek === 0) return 'weekly'; // Sunday
    return 'daily';
  }

  calculateExpirationDate(backupJob) {
    const retentionPolicy = this.determineRetentionPolicy(backupJob);
    const startTime = backupJob.startTime;

    switch (retentionPolicy) {
      case 'monthly':
        return new Date(startTime.getTime() + (this.config.monthlyBackupRetention * 30 * 24 * 60 * 60 * 1000));
      case 'weekly':
        return new Date(startTime.getTime() + (this.config.weeklyBackupRetention * 7 * 24 * 60 * 60 * 1000));
      default:
        return new Date(startTime.getTime() + (this.config.dailyBackupRetention * 24 * 60 * 60 * 1000));
    }
  }

  generateBackupId(type) {
    const timestamp = new Date().toISOString().replace(/[:.]/g, '-');
    return `backup_${type}_${timestamp}_${Math.random().toString(36).substr(2, 9)}`;
  }

  generateRecoveryId() {
    const timestamp = new Date().toISOString().replace(/[:.]/g, '-');
    return `recovery_${timestamp}_${Math.random().toString(36).substr(2, 9)}`;
  }

  async shutdown() {
    console.log('Shutting down backup and recovery manager...');

    try {
      // Stop all scheduled backups
      for (const [scheduleId, schedule] of this.scheduledBackups.entries()) {
        clearInterval(schedule.interval);
      }

      // Wait for active backup jobs to complete
      for (const [backupId, backupJob] of this.backupJobs.entries()) {
        if (backupJob.status === 'running') {
          console.log(`Waiting for backup to complete: ${backupId}`);
          // In a real implementation, we would wait for or gracefully cancel the backup
        }
      }

      // Close MongoDB connection
      if (this.client) {
        await this.client.close();
      }

      console.log('Backup and recovery manager shutdown complete');

    } catch (error) {
      console.error('Error during shutdown:', error);
    }
  }

  // Additional methods would include implementations for:
  // - setupAutomatedBackups()
  // - setupBackupMonitoring() 
  // - setupPointInTimeRecovery()
  // - executeOplogBackup()
  // - executeRestore()
  // - executeSampleRestore()
  // - verifySampleData()
  // - cleanupTestDatabase()
  // - verifyRestoreIntegrity()
}

// Benefits of MongoDB Advanced Backup and Recovery:
// - Automated backup scheduling with flexible retention policies
// - Comprehensive backup verification and integrity checking
// - Point-in-time recovery capabilities with oplog integration
// - Incremental backup support for efficient storage utilization
// - Advanced compression and optimization for large databases
// - Parallel backup and recovery operations for improved performance
// - Comprehensive monitoring and alerting for backup operations
// - Disaster recovery capabilities with replication and cloud sync
// - SQL-compatible backup management through QueryLeaf integration
// - Production-ready backup automation with minimal configuration

module.exports = {
  AdvancedBackupRecoveryManager
};