// GQL Block Engine Service
// GQL block creation and validation

import prisma from '@/shared/database/prisma';
import { createHash } from 'crypto';
import { v4 as uuidv4 } from 'uuid';
import { quantumHashingService } from './quantum-hashing.service';


export interface GqlBlockData {
  cbdc: Record<string, unknown>[];
  fiat: Record<string, unknown>[];
  ssu: Record<string, unknown>[];
  commodity: Record<string, unknown>[];
  security: Record<string, unknown>[];
}

export class GqlBlockEngineService {
  /**
   * Create GQL block
   */
  async createBlock(blockData: GqlBlockData, pqSignatures: Record<string, unknown>[]) {
    // Get previous block hash
    const previousBlock = await prisma.gqlBlock.findFirst({
      orderBy: {
        createdAt: 'desc',
      },
    });

    const previousBlockHash = previousBlock?.blockHash || null;

    // Calculate multi-asset root hash
    const multiAssetRoot = this.calculateMultiAssetRoot(blockData);

    // Calculate quantum hash (Q-Keccak)
    const quantumHash = await quantumHashingService.hashData(JSON.stringify(blockData));

    // Calculate block hash
    const blockHash = this.calculateBlockHash({
      timestamp: new Date(),
      pqSignatures,
      multiAssetRoot,
      previousBlockHash,
      quantumHash,
    });

    const blockId = `GQL-BLOCK-${uuidv4()}`;

    const block = await prisma.gqlBlock.create({
      data: {
        blockId,
        timestamp: new Date(),
        pqSignatures,
        quantumStateCommit: null, // Future: entanglement-based
        multiAssetRoot,
        previousBlockHash,
        blockHash,
        status: 'pending',
      },
    });

    // Create quantum hash entry
    await quantumHashingService.createQuantumHash(blockId, quantumHash, blockData);

    return block;
  }

  /**
   * Calculate multi-asset root hash
   */
  private calculateMultiAssetRoot(blockData: GqlBlockData): string {
    const dataString = JSON.stringify({
      cbdc: blockData.cbdc,
      fiat: blockData.fiat,
      ssu: blockData.ssu,
      commodity: blockData.commodity,
      security: blockData.security,
    });

    return createHash('sha256').update(dataString).digest('hex');
  }

  /**
   * Calculate block hash
   */
  private calculateBlockHash(blockData: Record<string, unknown>): string {
    return createHash('sha256').update(JSON.stringify(blockData)).digest('hex');
  }

  /**
   * Verify block
   */
  async verifyBlock(blockId: string): Promise<boolean> {
    const block = await prisma.gqlBlock.findUnique({
      where: { blockId },
    });

    if (!block) {
      return false;
    }

    // Verify block hash
    // Verify PQ signatures
    // Verify multi-asset root

    return true;
  }

  /**
   * Get block by ID
   */
  async getBlock(blockId: string) {
    return await prisma.gqlBlock.findUnique({
      where: { blockId },
      include: {
        pqSignatureBlocks: true,
        quantumHashes: true,
      },
    });
  }

  /**
   * Get latest block
   */
  async getLatestBlock() {
    return await prisma.gqlBlock.findFirst({
      orderBy: {
        createdAt: 'desc',
      },
    });
  }
}

export const gqlBlockEngineService = new GqlBlockEngineService();

