/**
 * Hook pour générer une preuve de signature avec QR code
 * 
 * Utilisation après signature d'un document:
 * 
 * const { createSignatureProof, isCreating } = useSignatureProof();
 * 
 * const proof = await createSignatureProof({
 *   document_name: "Contrat CDDU - Jean Dupont",
 *   pdf_url: "https://s3.eu-west-3.amazonaws.com/...",
 *   signer_name: "Jean Dupont",
 *   signer_email: "jean.dupont@example.com",
 *   signature_hash: "dafe9a5e258d144190bcf82327ed9dcc...",
 *   contract_id: "uuid",
 *   organization_id: "uuid"
 * });
 * 
 * // proof contient:
 * // - verification_url: URL de vérification publique
 * // - qr_code_data_url: Data URL du QR code
 * // - proof_pdf_blob: Blob du PDF de preuve
 */

import { useState } from "react";
import { generateSignatureProofPDF } from "@/lib/signature-proof-pdf";

interface CreateSignatureProofParams {
  document_name: string;
  pdf_url: string;
  signer_name: string;
  signer_email: string;
  signature_hash: string;
  signature_hex?: string;
  certificate_info?: {
    issuer: string;
    subject: string;
    valid_from: string;
    valid_until: string;
    serial_number: string;
  };
  timestamp?: {
    tsa_url: string;
    timestamp: string;
    hash: string;
  };
  contract_id?: string;
  organization_id: string;
}

interface SignatureProofResult {
  verification_id: string;
  verification_url: string;
  qr_code_data_url: string;
  proof_pdf_url: string;
  proof_pdf_blob: Blob;
}

export function useSignatureProof() {
  const [isCreating, setIsCreating] = useState(false);
  const [error, setError] = useState<string | null>(null);

  const createSignatureProof = async (
    params: CreateSignatureProofParams
  ): Promise<SignatureProofResult | null> => {
    setIsCreating(true);
    setError(null);

    try {
      // Appeler l'API pour créer l'entrée de vérification et générer le QR code
      const response = await fetch("/api/signatures/create-verification", {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: JSON.stringify(params),
      });

      if (!response.ok) {
        throw new Error("Erreur lors de la création de la preuve");
      }

      const data = await response.json();

      // Générer le PDF de preuve avec le QR code
      const proofPdfBlob = await generateSignatureProofPDF({
        document_name: params.document_name,
        signer_name: params.signer_name,
        signer_email: params.signer_email,
        signed_at: new Date().toISOString(),
        signature_hash: params.signature_hash,
        verification_url: data.verification_url,
        qr_code_data_url: data.qr_code_data_url,
        certificate_info: params.certificate_info || {
          issuer: "Odentas Media SAS",
          subject: `CN=${params.signer_name}`,
          valid_from: new Date().toISOString(),
          valid_until: new Date(Date.now() + 365 * 24 * 60 * 60 * 1000).toISOString(),
          serial_number: Math.random().toString(16).substring(2, 18),
        },
      });

      return {
        verification_id: data.verification_id,
        verification_url: data.verification_url,
        qr_code_data_url: data.qr_code_data_url,
        proof_pdf_url: data.proof_pdf_url,
        proof_pdf_blob: proofPdfBlob,
      };
    } catch (err) {
      console.error("Erreur création preuve:", err);
      setError(err instanceof Error ? err.message : "Erreur inconnue");
      return null;
    } finally {
      setIsCreating(false);
    }
  };

  return {
    createSignatureProof,
    isCreating,
    error,
  };
}