// ZK-CBDC Verification Service
// Smart contract verification: if zkBP && zkCP && zkIP: execute_CBDC_transfer()

import { v4 as uuidv4 } from 'uuid';
import prisma from '@/shared/database/prisma';
import { logger } from '@/infrastructure/monitoring/logger';
import { zkBalanceProofService } from './zk-balance-proof.service';
import { zkComplianceProofService } from './zk-compliance-proof.service';
import { zkIdentityProofService } from './zk-identity-proof.service';


export interface ZkVerificationRequest {
  walletId: string;
  transactionAmount: string;
  destinationWalletId: string;
  currencyCode: string;
  contractId?: string;
}

export interface ZkVerificationResult {
  verificationId: string;
  zkbpResult: boolean;
  zkcpResult: boolean;
  zkipResult: boolean;
  overallResult: boolean;
  canExecute: boolean;
}

export class ZkVerificationService {
  /**
   * Verify all ZK proofs for CBDC transfer
   * if zkBP && zkCP && zkIP: execute_CBDC_transfer()
   */
  async verifyCbdcTransfer(request: ZkVerificationRequest): Promise<ZkVerificationResult> {
    const verificationId = `ZK-VERIFY-${uuidv4()}`;

    try {
      // Generate and verify ZK-Balance Proof
      const zkbpProof = await zkBalanceProofService.generateBalanceProof({
        walletId: request.walletId,
        requiredAmount: request.transactionAmount,
        currencyCode: request.currencyCode,
      });
      const zkbpResult = await zkBalanceProofService.verifyBalanceProof(zkbpProof.proofId);

      // Generate and verify ZK-Compliance Proof
      const zkcpProof = await zkComplianceProofService.generateComplianceProof({
        walletId: request.walletId,
        transactionAmount: request.transactionAmount,
        destinationWalletId: request.destinationWalletId,
        currencyCode: request.currencyCode,
      });
      const zkcpResult = await zkComplianceProofService.verifyComplianceProof(zkcpProof.proofId);

      // Generate and verify ZK-Identity Proof
      const zkipProof = await zkIdentityProofService.generateIdentityProof({
        walletId: request.walletId,
        identityClaim: 'wallet belongs to verified entity',
      });
      const zkipResult = await zkIdentityProofService.verifyIdentityProof(zkipProof.proofId);

      // Overall result: all proofs must be valid
      const overallResult = zkbpResult && zkcpResult && zkipResult;

      // Create verification record
      await prisma.zk_verifications.create({
        data: {
          id: uuidv4(),
          verificationId,
          proofId: zkbpProof.proofId, // Reference to one of the proofs
          contractId: request.contractId || null,
          verificationType: 'combined',
          zkbpResult,
          zkcpResult,
          zkipResult,
          overallResult,
          status: overallResult ? 'verified' : 'rejected',
          verifiedAt: overallResult ? new Date() : null,
          createdAt: new Date(),
          updatedAt: new Date(),
        },
      });

      logger.info('ZK-CBDC: Verification completed', {
        verificationId,
        zkbpResult,
        zkcpResult,
        zkipResult,
        overallResult,
      });

      return {
        verificationId,
        zkbpResult,
        zkcpResult,
        zkipResult,
        overallResult,
        canExecute: overallResult,
      };
    } catch (error) {
      logger.error('ZK-CBDC: Verification failed', { error, request });

      // Create failed verification record
      await prisma.zk_verifications.create({
        data: {
          id: uuidv4(),
          verificationId,
          proofId: '',
          contractId: request.contractId || null,
          verificationType: 'combined',
          zkbpResult: false,
          zkcpResult: false,
          zkipResult: false,
          overallResult: false,
          status: 'rejected',
          createdAt: new Date(),
          updatedAt: new Date(),
        },
      });

      return {
        verificationId,
        zkbpResult: false,
        zkcpResult: false,
        zkipResult: false,
        overallResult: false,
        canExecute: false,
      };
    }
  }

  /**
   * Execute CBDC transfer if verification passes
   */
  async executeCbdcTransferIfVerified(
    verificationId: string,
    transferRequest: {
      sourceWalletId: string;
      destinationWalletId: string;
      amount: string;
      currencyCode: string;
    }
  ): Promise<{ executed: boolean; transactionId?: string }> {
    const verification = await prisma.zk_verifications.findUnique({
      where: { verificationId },
    });

    if (!verification || !verification.overallResult) {
      logger.warn('ZK-CBDC: Transfer not executed - verification failed', { verificationId });
      return { executed: false };
    }

    // Execute transfer (in production, would call CBDC transaction service)
    try {
      // Simplified transfer execution
      const transactionId = `CBDC-TX-${Date.now()}`;

      logger.info('ZK-CBDC: Executing CBDC transfer', {
        verificationId,
        transactionId,
        transferRequest,
      });

      // In production, would actually execute the transfer
      return {
        executed: true,
        transactionId,
      };
    } catch (error) {
      logger.error('ZK-CBDC: Transfer execution failed', { error, verificationId });
      return { executed: false };
    }
  }
}

export const zkVerificationService = new ZkVerificationService();

