// CIM Identity Service
// Shared KYC/AML standards enforcement
// Cross-certification of sovereign identities
// HSM-signed CBDC wallet identity management
// Identity mapping registry

import prisma from '@/shared/database/prisma';
import { v4 as uuidv4 } from 'uuid';
import { createHash } from 'crypto';


export interface CimIdentityMappingRequest {
  sourceSovereignBankId: string;
  targetSovereignBankId: string;
  sourceIdentityId: string;
  targetIdentityId: string;
  identityType: string;
  certificationLevel: string;
}

export interface CrossCertificationResult {
  mappingId: string;
  crossCertificationHash: string;
  status: string;
}

export class CimIdentityService {
  /**
   * Map cross-sovereign identity
   */
  async mapIdentity(
    request: CimIdentityMappingRequest
  ): Promise<CrossCertificationResult> {
    const mappingId = `CIM-MAP-${uuidv4()}`;

    // Generate cross-certification hash
    const crossCertHash = this.generateCrossCertificationHash(
      request.sourceIdentityId,
      request.targetIdentityId,
      request.identityType
    );

    // Create identity mapping
    const mapping = await prisma.cim_identity_mappings.create({
      data: {
        id: uuidv4(),
        mappingId,
        sourceSovereignBankId: request.sourceSovereignBankId,
        targetSovereignBankId: request.targetSovereignBankId,
        sourceIdentityId: request.sourceIdentityId,
        targetIdentityId: request.targetIdentityId,
        identityType: request.identityType,
        certificationLevel: request.certificationLevel,
        crossCertificationHash: crossCertHash,
        status: 'active',
        createdAt: new Date(),
        updatedAt: new Date(),
      },
    });

    return {
      mappingId: mapping.mappingId,
      crossCertificationHash: mapping.crossCertificationHash || '',
      status: mapping.status,
    };
  }

  /**
   * Generate cross-certification hash
   */
  private generateCrossCertificationHash(
    sourceIdentityId: string,
    targetIdentityId: string,
    identityType: string
  ): string {
    const combined = `${sourceIdentityId}:${targetIdentityId}:${identityType}`;
    return createHash('sha3-256').update(combined).digest('hex');
  }

  /**
   * Verify cross-sovereign identity
   */
  async verifyCrossSovereignIdentity(
    sourceSovereignBankId: string,
    identityId: string,
    identityType: string
  ): Promise<boolean> {
    const mapping = await prisma.cim_identity_mappings.findFirst({
      where: {
        sourceSovereignBankId,
        sourceIdentityId: identityId,
        identityType,
        status: 'active',
      },
    });

    return !!mapping;
  }

  /**
   * Get identity mappings for a sovereign bank
   */
  async getIdentityMappings(
    sovereignBankId: string,
    identityType?: string
  ) {
    return await prisma.cim_identity_mappings.findMany({
      where: {
        OR: [
          { sourceSovereignBankId: sovereignBankId },
          { targetSovereignBankId: sovereignBankId },
        ],
        ...(identityType && { identityType }),
        status: 'active',
      },
    });
  }

  /**
   * Enforce shared KYC/AML standards
   */
  async enforceKycAmlStandards(
    sovereignBankId: string,
    identityType: string
  ): Promise<boolean> {
    // Get minimum standards
    const minimumStandards = this.getMinimumStandards(identityType);

    // Verify against standards
    const mappings = await this.getIdentityMappings(sovereignBankId, identityType);

    // Check if all mappings meet minimum standards
    for (const mapping of mappings) {
      if (!this.meetsStandards(mapping.certificationLevel, minimumStandards)) {
        return false;
      }
    }

    return true;
  }

  /**
   * Get minimum KYC/AML standards
   */
  private getMinimumStandards(identityType: string): string[] {
    const standards: Record<string, string[]> = {
      kyc: ['basic', 'enhanced'],
      aml: ['enhanced', 'sovereign'],
      cbdc_wallet: ['basic', 'enhanced', 'sovereign'],
    };

    return standards[identityType] || ['basic'];
  }

  /**
   * Check if certification level meets standards
   */
  private meetsStandards(
    certificationLevel: string,
    minimumStandards: string[]
  ): boolean {
    const levels: Record<string, number> = {
      basic: 1,
      enhanced: 2,
      sovereign: 3,
    };

    const certificationValue = levels[certificationLevel] || 0;
    const minValue = Math.min(
      ...minimumStandards.map((s) => levels[s] || 0)
    );

    return certificationValue >= minValue;
  }

  /**
   * Get HSM-signed CBDC wallet identity
   */
  async getCbdcWalletIdentity(walletId: string): Promise<string | null> {
    // In production, this would retrieve from HSM
    // For now, generate a signature reference
    const wallet = await prisma.cbdc_wallets.findUnique({
      where: { walletId },
    });

    if (!wallet) {
      return null;
    }

    // Generate HSM identity reference
    const identityData = {
      walletId: wallet.walletId,
      sovereignBankId: wallet.sovereignBankId,
      walletType: wallet.walletType,
    };

    return createHash('sha3-256')
      .update(JSON.stringify(identityData))
      .digest('hex');
  }

  /**
   * Revoke identity mapping
   */
  async revokeIdentityMapping(mappingId: string): Promise<void> {
    await prisma.cim_identity_mappings.update({
      where: { mappingId },
      data: {
        status: 'revoked',
      },
    });
  }
}

export const cimIdentityService = new CimIdentityService();

