/**
 * 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');
  }

  /** Vendor integration: implement IESignatureAdapter (DocuSign, Adobe Sign, etc.). Set E_SIGNATURE_BASE_URL and provider credentials. */
  // const adapter = getESignatureAdapter();
  // const { request_id, signature_url } = await adapter.createEnvelope(document.file_url, request);
  // return { request_id, signature_url };

  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,
    },
  });

  // E-signature provider integration (DocuSign, Adobe Sign, etc.) not yet configured.
  // Set E_SIGNATURE_BASE_URL in env when provider is integrated.
  const baseUrl = process.env.E_SIGNATURE_BASE_URL;
  if (!baseUrl) {
    throw new Error(
      'E-signature not implemented: Set E_SIGNATURE_BASE_URL and integrate DocuSign/Adobe Sign'
    );
  }

  return {
    request_id,
    signature_url: `${baseUrl.replace(/\/$/, '')}/sign/${request_id}`,
  };
}

/**
 * Get signature status
 */
export async function getSignatureStatus(
  request_id: string
): Promise<SignatureStatus> {
  if (!process.env.E_SIGNATURE_BASE_URL) {
    throw new Error('E-signature not implemented: Set E_SIGNATURE_BASE_URL');
  }
  // TODO: Query e-signature provider for status when integrated
  // const envelope = await docusignClient.getEnvelope(request_id);
  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> {
  if (!process.env.E_SIGNATURE_BASE_URL) {
    throw new Error('E-signature not implemented: Set E_SIGNATURE_BASE_URL');
  }
  // TODO: When provider integrated: verify webhook signature, extract document_id,
  // update status, create signed version, notify users
}

