// Stablecoin Proof Service
// Zero-knowledge collateral proofs

import prisma from '@/shared/database/prisma';
import { Decimal } from '@prisma/client/runtime/library';
import { createHash } from 'crypto';


export interface ZKProofRequest {
  stablecoinId: string;
  proofType: string; // collateral_proof, reserve_proof
}

export interface ZKProofResult {
  proof: string;
  proofHash: string;
  verified: boolean;
}

export class StablecoinProofService {
  /**
   * Generate zero-knowledge collateral proof
   */
  async generateCollateralProof(
    request: ZKProofRequest
  ): Promise<ZKProofResult> {
    const stablecoin = await prisma.sovereign_stablecoins.findUnique({
      where: { stablecoinId: request.stablecoinId },
      include: {
        stablecoin_collaterals: {
          where: { status: 'active' },
        },
      },
    });

    if (!stablecoin) {
      throw new Error(`Stablecoin not found: ${request.stablecoinId}`);
    }

    // Prepare proof data (in production, would use actual ZK proof library)
    const proofData = {
      stablecoinId: request.stablecoinId,
      totalSupply: stablecoin.totalSupply.toString(),
      totalCollateral: stablecoin.stablecoin_collaterals.reduce(
        (sum, coll) => sum.plus(coll.valuation),
        new Decimal(0)
      ).toString(),
      collateralCount: stablecoin.stablecoin_collaterals.length,
      timestamp: new Date().toISOString(),
    };

    // Generate ZK proof (simplified - in production would use actual ZK library)
    const proof = this.generateZKProof(proofData);
    const proofHash = createHash('sha3-256').update(proof).digest('hex');

    return {
      proof,
      proofHash,
      verified: true,
    };
  }

  /**
   * Verify zero-knowledge proof
   */
  async verifyProof(proof: string, proofHash: string): Promise<boolean> {
    const calculatedHash = createHash('sha3-256').update(proof).digest('hex');
    return calculatedHash === proofHash;
  }

  /**
   * Generate ZK proof (mock implementation)
   */
  private generateZKProof(data: any): string {
    // In production, would use actual ZK proof library (e.g., zk-SNARKs, zk-STARKs)
    // For now, generate a proof hash
    const dataString = JSON.stringify(data);
    const proof = createHash('sha3-256')
      .update(dataString + 'ZK_PROOF_SECRET')
      .digest('hex');
    return `ZK-PROOF-${proof}`;
  }
}

export const stablecoinProofService = new StablecoinProofService();

