import { useState } from 'react';
import { Undo2, Trash2, ChevronRight, Inbox, Send, X } from 'lucide-react';
import { CachedEmail, cachedEmailApi } from '../../services/api';
import { useMutation, useQueryClient } from '@tanstack/react-query';
import Button from '../ui/Button';
import toast from 'react-hot-toast';

interface TrashEmailListProps {
  emails: CachedEmail[];
  selectedEmailId?: number;
  onSelectEmail: (email: CachedEmail) => void;
  onEmailRestored?: (emailId: number) => void;
  onEmailDeleted?: (emailId: number) => void;
  isLoading?: boolean;
}

export default function TrashEmailList({
  emails,
  selectedEmailId,
  onSelectEmail,
  onEmailRestored,
  onEmailDeleted,
  isLoading,
}: TrashEmailListProps) {
  const [actionConfirmId, setActionConfirmId] = useState<number | null>(null);
  const [actionType, setActionType] = useState<'restore' | 'delete' | null>(null);
  const queryClient = useQueryClient();

  // Absender/Empfänger anzeigen
  const getDisplayName = (email: CachedEmail) => {
    if (email.folder === 'SENT') {
      try {
        const toAddresses = JSON.parse(email.toAddresses);
        if (toAddresses.length > 0) {
          return `An: ${toAddresses[0]}${toAddresses.length > 1 ? ` (+${toAddresses.length - 1})` : ''}`;
        }
      } catch {
        return 'An: (Unbekannt)';
      }
    }
    return email.fromName || email.fromAddress;
  };

  const restoreMutation = useMutation({
    mutationFn: (emailId: number) => cachedEmailApi.restore(emailId),
    onSuccess: (_data, emailId) => {
      queryClient.invalidateQueries({ queryKey: ['emails'] });
      toast.success('E-Mail wiederhergestellt');
      setActionConfirmId(null);
      setActionType(null);
      onEmailRestored?.(emailId);
    },
    onError: (error: Error) => {
      console.error('Restore error:', error);
      toast.error(error.message || 'Fehler beim Wiederherstellen');
      setActionConfirmId(null);
      setActionType(null);
    },
  });

  const deleteMutation = useMutation({
    mutationFn: (emailId: number) => cachedEmailApi.permanentDelete(emailId),
    onSuccess: (_data, emailId) => {
      queryClient.invalidateQueries({ queryKey: ['emails'] });
      toast.success('E-Mail endgültig gelöscht');
      setActionConfirmId(null);
      setActionType(null);
      onEmailDeleted?.(emailId);
    },
    onError: (error: Error) => {
      console.error('Permanent delete error:', error);
      toast.error(error.message || 'Fehler beim endgültigen Löschen');
      setActionConfirmId(null);
      setActionType(null);
    },
  });

  const unassignMutation = useMutation({
    mutationFn: (emailId: number) => cachedEmailApi.unassignFromContract(emailId),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['emails'] });
      toast.success('Vertragszuordnung aufgehoben');
    },
    onError: (error: Error) => {
      console.error('Unassign error:', error);
      toast.error(error.message || 'Fehler beim Aufheben der Zuordnung');
    },
  });

  const handleUnassign = (e: React.MouseEvent, emailId: number) => {
    e.stopPropagation();
    unassignMutation.mutate(emailId);
  };

  const handleRestoreClick = (e: React.MouseEvent, emailId: number) => {
    e.stopPropagation();
    setActionConfirmId(emailId);
    setActionType('restore');
  };

  const handleDeleteClick = (e: React.MouseEvent, emailId: number) => {
    e.stopPropagation();
    setActionConfirmId(emailId);
    setActionType('delete');
  };

  const handleConfirm = (e: React.MouseEvent) => {
    e.stopPropagation();
    if (actionConfirmId && actionType) {
      if (actionType === 'restore') {
        restoreMutation.mutate(actionConfirmId);
      } else {
        deleteMutation.mutate(actionConfirmId);
      }
    }
  };

  const handleCancel = (e: React.MouseEvent) => {
    e.stopPropagation();
    setActionConfirmId(null);
    setActionType(null);
  };

  const formatDate = (dateStr: string) => {
    const date = new Date(dateStr);
    return date.toLocaleDateString('de-DE', { day: '2-digit', month: '2-digit' });
  };

  const formatDeletedAt = (dateStr?: string) => {
    if (!dateStr) return '';
    const date = new Date(dateStr);
    const now = new Date();
    const isToday = date.toDateString() === now.toDateString();
    if (isToday) {
      return `Gelöscht um ${date.toLocaleTimeString('de-DE', { hour: '2-digit', minute: '2-digit' })}`;
    }
    return `Gelöscht am ${date.toLocaleDateString('de-DE', { day: '2-digit', month: '2-digit' })}`;
  };

  if (isLoading) {
    return (
      <div className="flex items-center justify-center h-64">
        <div className="animate-spin rounded-full h-8 w-8 border-b-2 border-red-600"></div>
      </div>
    );
  }

  if (emails.length === 0) {
    return (
      <div className="flex flex-col items-center justify-center h-64 text-gray-500">
        <Trash2 className="w-12 h-12 mb-2 opacity-50" />
        <p>Papierkorb ist leer</p>
      </div>
    );
  }

  return (
    <div className="divide-y divide-gray-200">
      {emails.map((email) => (
        <div
          key={email.id}
          onClick={() => onSelectEmail(email)}
          className={[
            'flex items-start gap-3 p-3 cursor-pointer transition-colors',
            selectedEmailId === email.id
              ? 'bg-red-100'
              : 'hover:bg-gray-100 bg-gray-50/50'
          ].join(' ')}
          style={{
            borderLeft: selectedEmailId === email.id ? '4px solid #dc2626' : '4px solid transparent'
          }}
        >
          {/* Folder Icon */}
          <div className="flex-shrink-0 mt-1 p-1 -ml-1 text-gray-400" title={email.folder === 'SENT' ? 'Aus Gesendet' : 'Aus Posteingang'}>
            {email.folder === 'SENT' ? (
              <Send className="w-4 h-4" />
            ) : (
              <Inbox className="w-4 h-4" />
            )}
          </div>

          {/* Restore */}
          <button
            onClick={(e) => handleRestoreClick(e, email.id)}
            className="flex-shrink-0 mt-1 p-1 -ml-1 rounded hover:bg-green-100 text-gray-400 hover:text-green-600"
            title="Wiederherstellen"
          >
            <Undo2 className="w-4 h-4" />
          </button>

          {/* Permanent Delete */}
          <button
            onClick={(e) => handleDeleteClick(e, email.id)}
            className="flex-shrink-0 mt-1 p-1 -ml-1 rounded hover:bg-red-100 text-gray-400 hover:text-red-600"
            title="Endgültig löschen"
          >
            <Trash2 className="w-4 h-4" />
          </button>

          {/* Email Content */}
          <div className="flex-1 min-w-0">
            {/* From/To & Date */}
            <div className="flex items-center justify-between gap-2 mb-1">
              <span className="text-sm truncate text-gray-700">
                {getDisplayName(email)}
              </span>
              <span className="text-xs text-gray-500 flex-shrink-0">
                {formatDate(email.receivedAt)}
              </span>
            </div>

            {/* Subject */}
            <div className="text-sm truncate text-gray-600">
              {email.subject || '(Kein Betreff)'}
            </div>

            {/* Deleted At */}
            <div className="text-xs text-red-500 mt-1">
              {formatDeletedAt(email.deletedAt)}
            </div>

            {/* Contract Badge */}
            {email.contract && (
              <div className="mt-1 flex items-center gap-1">
                <span className="inline-flex items-center px-2 py-0.5 rounded text-xs font-medium bg-green-100 text-green-800">
                  {email.contract.contractNumber}
                </span>
                {/* X-Button nur für ursprüngliche INBOX oder manuell zugeordnete gesendete E-Mails */}
                {(email.folder === 'INBOX' || (email.folder === 'SENT' && !email.isAutoAssigned)) && (
                  <button
                    onClick={(e) => handleUnassign(e, email.id)}
                    className="p-0.5 text-gray-400 hover:text-red-600 hover:bg-red-50 rounded"
                    title="Zuordnung aufheben"
                    disabled={unassignMutation.isPending}
                  >
                    <X className="w-3.5 h-3.5" />
                  </button>
                )}
              </div>
            )}
          </div>

          {/* Chevron */}
          <ChevronRight className="w-4 h-4 text-gray-400 flex-shrink-0 mt-2" />
        </div>
      ))}

      {/* Bestätigungs-Modal */}
      {actionConfirmId && actionType && (
        <div className="fixed inset-0 bg-black bg-opacity-50 flex items-center justify-center z-50">
          <div className="bg-white rounded-lg shadow-xl p-6 max-w-md mx-4">
            <h3 className="text-lg font-semibold text-gray-900 mb-2">
              {actionType === 'restore' ? 'E-Mail wiederherstellen?' : 'E-Mail endgültig löschen?'}
            </h3>
            <p className="text-gray-600 mb-4">
              {actionType === 'restore'
                ? 'Die E-Mail wird wieder in den ursprünglichen Ordner verschoben.'
                : 'Die E-Mail wird unwiderruflich gelöscht. Diese Aktion kann nicht rückgängig gemacht werden.'}
            </p>
            <div className="flex justify-end gap-3">
              <Button
                variant="secondary"
                onClick={handleCancel}
                disabled={restoreMutation.isPending || deleteMutation.isPending}
              >
                Abbrechen
              </Button>
              <Button
                variant={actionType === 'restore' ? 'primary' : 'danger'}
                onClick={handleConfirm}
                disabled={restoreMutation.isPending || deleteMutation.isPending}
              >
                {restoreMutation.isPending || deleteMutation.isPending
                  ? 'Wird ausgeführt...'
                  : actionType === 'restore'
                    ? 'Wiederherstellen'
                    : 'Endgültig löschen'}
              </Button>
            </div>
          </div>
        </div>
      )}
    </div>
  );
}