/**
 * E-Signature Service
 * Handles electronic signature integration
 */

import { getDocumentById, createDocumentVersion } from '@the-order/database';
import { createDocumentAuditLog } from '@the-order/database';

export interface SignatureRequest {
  document_id: string;
  signers: Array<{
    email: string;
    name: string;
    role?: string;
    order?: number;
  }>;
  message?: string;
  expires_in_days?: number;
}

export interface SignatureStatus {
  request_id: string;
  status: 'pending' | 'signed' | 'declined' | 'expired';
  signers: Array<{
    email: string;
    status: 'pending' | 'signed' | 'declined';
    signed_at?: Date;
  }>;
  completed_at?: Date;
}

/**
 * Create signature request
 * Note: This is a placeholder - actual implementation would integrate with
 * DocuSign, Adobe Sign, or another e-signature provider
 */
export async function createSignatureRequest(
  request: SignatureRequest,
  user_id: string
): Promise<{ request_id: string; signature_url: string }> {
  const document = await getDocumentById(request.document_id);
  if (!document) {
    throw new Error('Document not found');
  }

  // TODO: Integrate with e-signature provider
  // Example with DocuSign:
  // const envelope = await docusignClient.createEnvelope({
  //   document: document.file_url,
  //   signers: request.signers,
  //   message: request.message,
  // });

  const request_id = `sig_${Date.now()}`;

  await createDocumentAuditLog({
    document_id: request.document_id,
    action: 'signature_requested',
    performed_by: user_id,
    details: {
      request_id,
      signers: request.signers,
    },
  });

  // In a real implementation, you would:
  // 1. Create envelope with e-signature provider
  // 2. Store request_id and envelope_id in database
  // 3. Return signature URL for first signer

  return {
    request_id,
    signature_url: `https://sign.example.com/sign/${request_id}`, // Placeholder
  };
}

/**
 * Get signature status
 */
export async function getSignatureStatus(
  request_id: string
): Promise<SignatureStatus> {
  // TODO: Query e-signature provider for status
  // const envelope = await docusignClient.getEnvelope(request_id);

  // Placeholder response
  return {
    request_id,
    status: 'pending',
    signers: [],
  };
}

/**
 * Handle signature webhook
 * This would be called by the e-signature provider when a document is signed
 */
export async function handleSignatureWebhook(
  webhook_data: any
): Promise<void> {
  // TODO: Process webhook from e-signature provider
  // 1. Verify webhook signature
  // 2. Extract document_id and signer info
  // 3. Update signature status
  // 4. Create new document version with signed copy
  // 5. Notify relevant users
}

