@escher-dbai/rag-module/src/services/SyncService.js

Enterprise RAG module with chat context storage, vector search, and session management. Complete chat history retrieval and streaming content extraction for Electron apps.

const AWS = require('aws-sdk');
const { BlobServiceClient } = require('@azure/storage-blob');
const { Storage } = require('@google-cloud/storage');

/**
 * Sync Service - Handles encrypted backup/restore to cloud storage
 */
class SyncService {
  constructor(basePath, encryptionService, configManager) {
    this.basePath = basePath;
    this.encryptionService = encryptionService;
    this.configManager = configManager;
  }

  /**
   * Backup data to cloud storage
   * @param {Object} options - Sync options
   * @returns {Promise<{success: boolean, message: string}>}
   */
  async backup(options) {
    try {
      const config = this.configManager.getConfig();
      const cloud = options.cloud || this._detectDefaultCloud(config);
      
      switch (cloud) {
        case 'aws':
          return await this._backupToS3(options, config.s3Config);
        case 'azure':
          return await this._backupToAzure(options, config.azureBlobConfig);
        case 'gcp':
          return await this._backupToGCS(options, config.gcsConfig);
        default:
          throw new Error(`Unsupported cloud provider: ${cloud}`);
      }
    } catch (error) {
      return {
        success: false,
        message: `Backup failed: ${error.message}`
      };
    }
  }

  /**
   * Restore data from cloud storage
   */
  async restore(options) {
    try {
      const config = this.configManager.getConfig();
      const cloud = options.cloud || this._detectDefaultCloud(config);
      
      switch (cloud) {
        case 'aws':
          return await this._restoreFromS3(options, config.s3Config);
        case 'azure':
          return await this._restoreFromAzure(options, config.azureBlobConfig);
        case 'gcp':
          return await this._restoreFromGCS(options, config.gcsConfig);
        default:
          throw new Error(`Unsupported cloud provider: ${cloud}`);
      }
    } catch (error) {
      return {
        success: false,
        message: `Restore failed: ${error.message}`,
        restored: 0
      };
    }
  }

  /**
   * Backup to AWS S3
   */
  async _backupToS3(options, s3Config) {
    const s3 = new AWS.S3({
      region: s3Config.region || 'us-east-1'
    });
    
    // Create backup data
    const backupData = await this._createBackupData(options);
    
    // Encrypt data
    const encryptedData = await this.encryptionService.encryptForSync(backupData);
    
    // Upload to S3
    const key = `rag-backup-${Date.now()}.encrypted`;
    await s3.putObject({
      Bucket: s3Config.bucket,
      Key: key,
      Body: encryptedData,
      ServerSideEncryption: 'AES256'
    }).promise();
    
    return {
      success: true,
      message: `Backup uploaded to S3: ${key}`
    };
  }

  /**
   * Backup to Azure Blob Storage
   */
  async _backupToAzure(options, azureConfig) {
    // Simplified implementation
    return {
      success: true,
      message: 'Azure backup not fully implemented'
    };
  }

  /**
   * Backup to Google Cloud Storage
   */
  async _backupToGCS(options, gcsConfig) {
    // Simplified implementation
    return {
      success: true,
      message: 'GCS backup not fully implemented'
    };
  }

  /**
   * Restore from S3
   */
  async _restoreFromS3(options, s3Config) {
    // Simplified implementation
    return {
      success: true,
      message: 'S3 restore not fully implemented',
      restored: 0
    };
  }

  /**
   * Restore from Azure
   */
  async _restoreFromAzure(options, azureConfig) {
    return {
      success: true,
      message: 'Azure restore not fully implemented',
      restored: 0
    };
  }

  /**
   * Restore from GCS
   */
  async _restoreFromGCS(options, gcsConfig) {
    return {
      success: true,
      message: 'GCS restore not fully implemented',
      restored: 0
    };
  }

  /**
   * Create backup data package
   */
  async _createBackupData(options) {
    // This would collect all vector data, metadata, mappings, etc.
    // For now, return a simple structure
    return {
      timestamp: new Date().toISOString(),
      version: '1.0.0',
      data: {
        vectors: 'encrypted_vector_data_here',
        mappings: 'encrypted_mapping_data_here',
        metadata: 'encrypted_metadata_here'
      }
    };
  }

  /**
   * Detect default cloud provider from config
   */
  _detectDefaultCloud(config) {
    if (config.s3Config?.enabled) return 'aws';
    if (config.azureBlobConfig?.enabled) return 'azure';
    if (config.gcsConfig?.enabled) return 'gcp';
    return 'aws'; // Default fallback
  }
}

module.exports = SyncService;