/**
 * KYC Integration Service
 * Integrates with Veriff for document verification and liveness checks
 */

export interface VeriffConfig {
  apiKey: string;
  apiUrl: string;
  webhookSecret: string;
}

export interface VeriffSession {
  sessionId: string;
  verificationUrl: string;
  status: 'pending' | 'approved' | 'rejected' | 'expired';
}

export interface VeriffVerificationResult {
  sessionId: string;
  status: 'approved' | 'rejected' | 'pending';
  documentVerification: {
    passed: boolean;
    documentType: string;
    documentNumber: string;
    issuingCountry: string;
    expiryDate?: string;
  };
  livenessCheck: {
    passed: boolean;
    livenessScore: number;
    faceMatch: boolean;
  };
  riskScore: number;
  flags: string[];
}

/**
 * Veriff KYC Provider
 */
export class VeriffKYCProvider {
  // @ts-expect-error - Config will be used when implementing Veriff API integration
  private _config: VeriffConfig;
  
  constructor(config: VeriffConfig) {
    this._config = config;
  }

  /**
   * Create verification session
   */
  async createSession(applicationId: string, _applicantData: {
    email: string;
    givenName: string;
    familyName: string;
    dateOfBirth?: string;
    nationality?: string;
  }): Promise<VeriffSession> {
    // TODO: Implement Veriff API integration
    // const response = await fetch(`${this.config.apiUrl}/sessions`, {
    //   method: 'POST',
    //   headers: {
    //     'Authorization': `Bearer ${this.config.apiKey}`,
    //     'Content-Type': 'application/json',
    //   },
    //   body: JSON.stringify({
    //     verification: {
    //       callback: `https://api.dsb.example/kyc/callback`,
    //       person: {
    //         firstName: applicantData.givenName,
    //         lastName: applicantData.familyName,
    //         dateOfBirth: applicantData.dateOfBirth,
    //       },
    //     },
    //   }),
    // });
    // return await response.json();

    // Placeholder implementation
    return {
      sessionId: `session-${applicationId}`,
      verificationUrl: `https://veriff.com/session/${applicationId}`,
      status: 'pending',
    };
  }

  /**
   * Verify webhook signature
   */
  verifyWebhookSignature(_payload: string, _signature: string): boolean {
    // TODO: Implement Veriff webhook signature verification
    // const crypto = require('crypto');
    // const expectedSignature = crypto
    //   .createHmac('sha256', this.config.webhookSecret)
    //   .update(payload)
    //   .digest('hex');
    // return crypto.timingSafeEqual(Buffer.from(signature), Buffer.from(expectedSignature));

    return true; // Placeholder
  }

  /**
   * Process webhook callback
   */
  async processWebhook(_payload: unknown): Promise<VeriffVerificationResult> {
    // TODO: Implement Veriff webhook processing
    // const data = payload as VeriffWebhookPayload;
    // return {
    //   sessionId: data.verification.id,
    //   status: data.verification.status,
    //   documentVerification: { ... },
    //   livenessCheck: { ... },
    //   riskScore: data.verification.riskScore,
    //   flags: data.verification.flags,
    // };

    // Placeholder implementation
    return {
      sessionId: 'session-id',
      status: 'approved',
      documentVerification: {
        passed: true,
        documentType: 'passport',
        documentNumber: '123456789',
        issuingCountry: 'USA',
      },
      livenessCheck: {
        passed: true,
        livenessScore: 0.95,
        faceMatch: true,
      },
      riskScore: 0.2,
      flags: [],
    };
  }
}

