MultiCloudManager.ts

export enum CloudProvider {
  AWS = 'AWS',
  GCP = 'GCP',
  AZURE = 'AZURE'
}

export interface StorageResponse {
  provider: CloudProvider;
  key: string;
  success: boolean;
}

export class MultiCloudManager {
  private providers: CloudProvider[] = [CloudProvider.AWS, CloudProvider.GCP, CloudProvider.AZURE];
  private activeProviderIndex: number = 0;

  constructor() {
    // Initialization for SDKs would happen here
  }

  /**
   * Uploads data with automatic failover across providers
   */
  public async upload(key: string, data: Buffer): Promise<StorageResponse> {
    let attempts = 0;
    
    while (attempts < this.providers.length) {
      const provider = this.providers[this.activeProviderIndex];
      try {
        await this.performUpload(provider, key, data);
        return { provider, key, success: true };
      } catch (error) {
        console.warn(`Upload failed for ${provider}, failing over...`);
        this.failover();
        attempts++;
      }
    }

    throw new Error('All cloud providers failed to upload data');
  }

  /**
   * Downloads data from the primary provider with fallback
   */
  public async download(key: string, preferredProvider?: CloudProvider): Promise<Buffer> {
    const providerOrder = preferredProvider 
      ? [preferredProvider, ...this.providers.filter(p => p !== preferredProvider)]
      : [this.providers[this.activeProviderIndex], ...this.providers.filter((_, i) => i !== this.activeProviderIndex)];

    for (const provider of providerOrder) {
      try {
        return await this.performDownload(provider, key);
      } catch (error) {
        console.warn(`Download failed for ${provider}, trying next provider...`);
      }
    }

    throw new Error('Data could not be retrieved from any provider');
  }

  private failover(): void {
    this.activeProviderIndex = (this.activeProviderIndex + 1) % this.providers.length;
  }

  private async performUpload(provider: CloudProvider, key: string, data: Buffer): Promise<void> {
    // Mocking the actual SDK calls (s3.putObject, gcs.upload, etc.)
    console.log(`Uploading to ${provider}: ${key}`);
    if (Math.random() < 0.1) throw new Error('Simulated Provider Error');
    return Promise.resolve();
  }

  private async performDownload(provider: CloudProvider, key: string): Promise<Buffer> {
    // Mocking retrieval
    console.log(`Downloading from ${provider}: ${key}`);
    return Buffer.from("mock data");
  }

  public async replicate(key: string, data: Buffer): Promise<CloudProvider[]> {
    const successfulProviders: CloudProvider[] = [];
    for (const provider of this.providers) {
      try {
        await this.performUpload(provider, key, data);
        successfulProviders.push(provider);
      } catch (e) {
        console.error(`Replication to ${provider} failed`);
      }
    }
    return successfulProviders;
  }
}