// ZK Verification Service
// Zero-knowledge verification for VR/AR asset exchanges
// Supplement B: MetaverseDubai Integration Framework

import prisma from '@/shared/database/prisma';
import { logger } from '@/infrastructure/monitoring/logger';
import { createHash } from 'crypto';


export interface ZkVerificationRequest {
  metaverseNodeId: string;
  computeNodeId: string;
  assetId: string;
  transactionId: string;
  proofData: Record<string, unknown>;
}

export interface ZkVerificationResult {
  verified: boolean;
  proofHash: string;
  verificationTime: number; // milliseconds
}

export class ZkVerificationService {
  /**
   * Verify VR/AR asset exchange using zero-knowledge proofs
   */
  async verifyAssetExchange(
    request: ZkVerificationRequest
  ): Promise<ZkVerificationResult> {
    const startTime = Date.now();
    logger.info('ZK Verification: Verifying asset exchange', { request });

    // Get compute node
    const computeNode = await prisma.metaverseComputeNode.findUnique({
      where: { nodeId: request.computeNodeId },
    });

    if (!computeNode) {
      throw new Error(`Compute node not found: ${request.computeNodeId}`);
    }

    // Verify ZK verification is enabled
    if (!computeNode.zkVerificationEnabled) {
      throw new Error('ZK verification not enabled on this compute node');
    }

    // Get asset
    const asset = await prisma.metaverseAsset.findUnique({
      where: { assetId: request.assetId },
    });

    if (!asset) {
      throw new Error(`Asset not found: ${request.assetId}`);
    }

    // Generate proof hash
    const proofHash = this.generateProofHash({
      assetId: request.assetId,
      transactionId: request.transactionId,
      proofData: request.proofData,
      timestamp: new Date().toISOString(),
    });

    // In a full implementation, this would:
    // 1. Generate zero-knowledge proof
    // 2. Verify proof on ZKN (Zero-Knowledge Node)
    // 3. Validate asset ownership
    // 4. Verify transaction integrity

    // For now, we'll simulate verification
    const verified = true;
    const verificationTime = Date.now() - startTime;

    logger.info('ZK Verification: Asset exchange verified', {
      assetId: request.assetId,
      verified,
      verificationTime,
    });

    return {
      verified,
      proofHash,
      verificationTime,
    };
  }

  /**
   * Generate proof hash
   */
  private generateProofHash(data: Record<string, unknown>): string {
    const hash = createHash('sha256');
    hash.update(JSON.stringify(data));
    return hash.digest('hex');
  }
}

export const zkVerificationService = new ZkVerificationService();

