Multi-Cloud Design Patterns

class StorageService {
  // Upload file to bucket/container
  async uploadFile(bucketName, key, body, contentType) {}

  // Download file from bucket
  async downloadFile(bucketName, key) {}  // returns Buffer

  // Delete file from bucket
  async deleteFile(bucketName, key) {}

  // List files with optional prefix
  async listFiles(bucketName, prefix = '') {}  
  // returns [{ key, size, lastModified }]

  // Generate temporary access URL (pre-signed)
  async getSignedUrl(bucketName, key, expiresInSeconds = 3600) {}  
  // returns string URL
}

class DatabaseService {
  // Execute SQL query
  async query(sql, params = []) {}  
  // returns { rows: [], rowCount: number }

  // Transaction management
  async beginTransaction() {}
  async commitTransaction(client) {}
  async rollbackTransaction(client) {}

  // Health check
  async ping() {}  
  // returns { status: 'healthy' | 'unhealthy', latencyMs: number }
}

class MonitoringService {
  // Record numeric metric
  async putMetric(namespace, metricName, value, unit = 'Count') {}

  // Log event
  async logEvent(logGroup, message, level = 'INFO') {}

  // Create/update alarm
  async createAlarm(alarmName, metricName, threshold, comparison) {}

  // Get recent metrics
  async getMetrics(namespace, metricName, periodMinutes = 60) {}
  // returns [{ timestamp, value }]
}

const PROVIDER = process.env.CLOUD_PROVIDER || 'aws';

const PROVIDERS = {
  aws: {
    storage:    () => new (require('./providers/aws/aws-storage.service').AwsStorageService)(),
    database:   () => new (require('./providers/aws/aws-database.service').AwsDatabaseService)(),
    monitoring: () => new (require('./providers/aws/aws-monitoring.service').AwsMonitoringService)(),
    auth:       () => new (require('./providers/aws/aws-auth.service').AwsAuthService)(),
  },
  // Add OCI, GCP, Azure implementations as needed
};

function getService(type) {
  const provider = PROVIDERS[PROVIDER];
  if (!provider) {
    throw new Error(`Provider '${PROVIDER}' not implemented. Options: ${Object.keys(PROVIDERS).join(', ')}`);
  }
  return provider[type]();
}

module.exports = {
  getStorageService:    () => getService('storage'),
  getDatabaseService:   () => getService('database'),
  getMonitoringService: () => getService('monitoring'),
  getAuthService:       () => getService('auth'),
};