'use client';

import { useEffect, useState, useRef } from 'react';
import { useParams } from 'next/navigation';
import {
  FileText,
  Download,
  Loader2,
  XCircle,
  Package,
  Ship,
  Clock,
  AlertCircle,
  ArrowRight,
} from 'lucide-react';

interface Document {
  id: string;
  type: string;
  fileName: string;
  mimeType: string;
  size: number;
  downloadUrl: string;
}

interface BookingSummary {
  id: string;
  carrierName: string;
  origin: string;
  destination: string;
  routeDescription: string;
  volumeCBM: number;
  weightKG: number;
  palletCount: number;
  price: number;
  currency: string;
  transitDays: number;
  containerType: string;
  acceptedAt: string;
}

interface CarrierDocumentsData {
  booking: BookingSummary;
  documents: Document[];
}

const documentTypeLabels: Record<string, string> = {
  BILL_OF_LADING: 'Connaissement',
  PACKING_LIST: 'Liste de colisage',
  COMMERCIAL_INVOICE: 'Facture commerciale',
  CERTIFICATE_OF_ORIGIN: "Certificat d'origine",
  OTHER: 'Autre document',
};

const formatFileSize = (bytes: number): string => {
  if (bytes < 1024) return `${bytes} B`;
  if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`;
  return `${(bytes / (1024 * 1024)).toFixed(1)} MB`;
};

const getFileIcon = (mimeType: string) => {
  if (mimeType.includes('pdf')) return '📄';
  if (mimeType.includes('image')) return '🖼️';
  if (mimeType.includes('spreadsheet') || mimeType.includes('excel')) return '📊';
  if (mimeType.includes('word') || mimeType.includes('document')) return '📝';
  return '📎';
};

export default function CarrierDocumentsPage() {
  const params = useParams();
  const token = params.token as string;

  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [data, setData] = useState<CarrierDocumentsData | null>(null);
  const [downloading, setDownloading] = useState<string | null>(null);

  const hasCalledApi = useRef(false);

  const fetchDocuments = async () => {
    if (!token) {
      setError('Lien invalide');
      setLoading(false);
      return;
    }

    try {
      const apiUrl = process.env.NEXT_PUBLIC_API_URL || 'http://localhost:4000';
      const response = await fetch(`${apiUrl}/api/v1/csv-booking-actions/documents/${token}`, {
        method: 'GET',
        headers: {
          'Content-Type': 'application/json',
        },
      });

      if (!response.ok) {
        let errorData;
        try {
          errorData = await response.json();
        } catch {
          errorData = { message: `Erreur HTTP ${response.status}` };
        }

        const errorMessage = errorData.message || 'Erreur lors du chargement des documents';

        if (errorMessage.includes('pas encore été acceptée') || errorMessage.includes('not accepted')) {
          throw new Error('Cette réservation n\'a pas encore été acceptée. Les documents seront disponibles après l\'acceptation.');
        } else if (errorMessage.includes('introuvable') || errorMessage.includes('not found')) {
          throw new Error('Réservation introuvable. Vérifiez que le lien est correct.');
        }

        throw new Error(errorMessage);
      }

      const responseData = await response.json();
      setData(responseData);
      setLoading(false);
    } catch (err) {
      console.error('Error fetching documents:', err);
      setError(err instanceof Error ? err.message : 'Erreur lors du chargement');
      setLoading(false);
    }
  };

  useEffect(() => {
    if (hasCalledApi.current) return;
    hasCalledApi.current = true;
    fetchDocuments();
  }, [token]);

  const handleDownload = async (doc: Document) => {
    setDownloading(doc.id);

    try {
      // The downloadUrl is already a signed URL, open it directly
      window.open(doc.downloadUrl, '_blank');
    } catch (err) {
      console.error('Error downloading document:', err);
      alert('Erreur lors du téléchargement. Veuillez réessayer.');
    } finally {
      // Small delay to show loading state
      setTimeout(() => setDownloading(null), 500);
    }
  };

  const handleRefresh = () => {
    setLoading(true);
    setError(null);
    hasCalledApi.current = false;
    fetchDocuments();
  };

  if (loading) {
    return (
      <div className="min-h-screen flex items-center justify-center bg-gradient-to-br from-blue-50 to-sky-50">
        <div className="bg-white p-8 rounded-xl shadow-lg max-w-md w-full text-center">
          <Loader2 className="w-16 h-16 text-sky-600 mx-auto mb-4 animate-spin" />
          <h1 className="text-2xl font-bold text-gray-900 mb-2">
            Chargement des documents...
          </h1>
          <p className="text-gray-600">Veuillez patienter</p>
        </div>
      </div>
    );
  }

  if (error) {
    return (
      <div className="min-h-screen flex items-center justify-center bg-gradient-to-br from-red-50 to-orange-50">
        <div className="bg-white p-8 rounded-xl shadow-lg max-w-md w-full text-center">
          <XCircle className="w-16 h-16 text-red-500 mx-auto mb-4" />
          <h1 className="text-2xl font-bold text-gray-900 mb-4">Erreur</h1>
          <p className="text-gray-600 mb-6">{error}</p>
          <button
            onClick={handleRefresh}
            className="w-full px-4 py-3 bg-gray-800 text-white rounded-lg hover:bg-gray-900 font-medium transition-colors"
          >
            Réessayer
          </button>
        </div>
      </div>
    );
  }

  if (!data) return null;

  const { booking, documents } = data;

  return (
    <div className="min-h-screen bg-gradient-to-br from-blue-50 via-sky-50 to-cyan-50">
      {/* Header */}
      <header className="bg-white shadow-sm border-b">
        <div className="max-w-4xl mx-auto px-4 py-4 flex items-center justify-between">
          <div className="flex items-center gap-3">
            <Ship className="w-8 h-8 text-sky-600" />
            <span className="text-xl font-bold text-gray-900">Xpeditis</span>
          </div>
          <button
            onClick={handleRefresh}
            className="text-sm text-sky-600 hover:text-sky-700 font-medium"
          >
            Actualiser
          </button>
        </div>
      </header>

      <main className="max-w-4xl mx-auto px-4 py-8">
        {/* Booking Summary Card */}
        <div className="bg-white rounded-xl shadow-md overflow-hidden mb-6">
          <div className="bg-gradient-to-r from-sky-600 to-cyan-600 px-6 py-4">
            <div className="flex items-center justify-center gap-4 text-white">
              <span className="text-2xl font-bold">{booking.origin}</span>
              <ArrowRight className="w-6 h-6" />
              <span className="text-2xl font-bold">{booking.destination}</span>
            </div>
          </div>

          <div className="p-6">
            <div className="grid grid-cols-2 md:grid-cols-4 gap-4">
              <div className="text-center p-3 bg-gray-50 rounded-lg">
                <Package className="w-5 h-5 text-gray-500 mx-auto mb-1" />
                <p className="text-xs text-gray-500">Volume</p>
                <p className="font-semibold text-gray-900">{booking.volumeCBM} CBM</p>
              </div>
              <div className="text-center p-3 bg-gray-50 rounded-lg">
                <Package className="w-5 h-5 text-gray-500 mx-auto mb-1" />
                <p className="text-xs text-gray-500">Poids</p>
                <p className="font-semibold text-gray-900">{booking.weightKG} kg</p>
              </div>
              <div className="text-center p-3 bg-gray-50 rounded-lg">
                <Clock className="w-5 h-5 text-gray-500 mx-auto mb-1" />
                <p className="text-xs text-gray-500">Transit</p>
                <p className="font-semibold text-gray-900">{booking.transitDays} jours</p>
              </div>
              <div className="text-center p-3 bg-gray-50 rounded-lg">
                <Ship className="w-5 h-5 text-gray-500 mx-auto mb-1" />
                <p className="text-xs text-gray-500">Type</p>
                <p className="font-semibold text-gray-900">{booking.containerType}</p>
              </div>
            </div>

            <div className="mt-4 pt-4 border-t border-gray-100 flex items-center justify-between text-sm">
              <span className="text-gray-500">
                Transporteur: <span className="text-gray-900 font-medium">{booking.carrierName}</span>
              </span>
              <span className="text-gray-500">
                Ref: <span className="font-mono text-gray-900">{booking.id.substring(0, 8).toUpperCase()}</span>
              </span>
            </div>
          </div>
        </div>

        {/* Documents Section */}
        <div className="bg-white rounded-xl shadow-md overflow-hidden">
          <div className="px-6 py-4 border-b border-gray-100">
            <h2 className="text-lg font-semibold text-gray-900 flex items-center gap-2">
              <FileText className="w-5 h-5 text-sky-600" />
              Documents ({documents.length})
            </h2>
          </div>

          {documents.length === 0 ? (
            <div className="p-8 text-center">
              <AlertCircle className="w-12 h-12 text-gray-400 mx-auto mb-3" />
              <p className="text-gray-600">Aucun document disponible pour le moment.</p>
              <p className="text-gray-500 text-sm mt-1">Les documents apparaîtront ici une fois ajoutés.</p>
            </div>
          ) : (
            <div className="divide-y divide-gray-100">
              {documents.map((doc) => (
                <div
                  key={doc.id}
                  className="px-6 py-4 flex items-center justify-between hover:bg-gray-50 transition-colors"
                >
                  <div className="flex items-center gap-4">
                    <span className="text-2xl">{getFileIcon(doc.mimeType)}</span>
                    <div>
                      <p className="font-medium text-gray-900">{doc.fileName}</p>
                      <div className="flex items-center gap-2 mt-1">
                        <span className="text-xs px-2 py-0.5 bg-sky-100 text-sky-700 rounded-full">
                          {documentTypeLabels[doc.type] || doc.type}
                        </span>
                        <span className="text-xs text-gray-500">
                          {formatFileSize(doc.size)}
                        </span>
                      </div>
                    </div>
                  </div>

                  <button
                    onClick={() => handleDownload(doc)}
                    disabled={downloading === doc.id}
                    className="flex items-center gap-2 px-4 py-2 bg-sky-600 text-white rounded-lg hover:bg-sky-700 disabled:opacity-50 disabled:cursor-not-allowed transition-colors font-medium"
                  >
                    {downloading === doc.id ? (
                      <>
                        <Loader2 className="w-4 h-4 animate-spin" />
                        <span>...</span>
                      </>
                    ) : (
                      <>
                        <Download className="w-4 h-4" />
                        <span>Télécharger</span>
                      </>
                    )}
                  </button>
                </div>
              ))}
            </div>
          )}
        </div>

        {/* Info */}
        <p className="mt-6 text-center text-sm text-gray-500">
          Cette page affiche toujours les documents les plus récents de la réservation.
        </p>
      </main>

      {/* Footer */}
      <footer className="mt-auto py-6 text-center text-sm text-gray-500">
        <p>© {new Date().getFullYear()} Xpeditis - Plateforme de fret maritime</p>
      </footer>
    </div>
  );
}