/**
 * Notification Panel Component
 *
 * Sidebar panel that displays all notifications with detailed view
 */

'use client';

import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
import { useState } from 'react';
import { useRouter } from 'next/navigation';
import {
  listNotifications,
  markNotificationAsRead,
  markAllNotificationsAsRead,
  deleteNotification
} from '@/lib/api';
import type { NotificationResponse } from '@/types/api';
import { X, Trash2, CheckCheck, Filter } from 'lucide-react';

interface NotificationPanelProps {
  isOpen: boolean;
  onClose: () => void;
}

export default function NotificationPanel({ isOpen, onClose }: NotificationPanelProps) {
  const [selectedFilter, setSelectedFilter] = useState<'all' | 'unread' | 'read'>('all');
  const [currentPage, setCurrentPage] = useState(1);
  const queryClient = useQueryClient();
  const router = useRouter();

  // Fetch notifications with pagination
  const { data, isLoading } = useQuery({
    queryKey: ['notifications', 'panel', selectedFilter, currentPage],
    queryFn: () =>
      listNotifications({
        page: currentPage,
        limit: 20,
        isRead: selectedFilter === 'all' ? undefined : selectedFilter === 'read',
      }),
    enabled: isOpen,
  });

  const notifications = data?.notifications || [];
  const total = data?.total || 0;
  const totalPages = Math.ceil(total / 20);

  // Mark single notification as read
  const markAsReadMutation = useMutation({
    mutationFn: markNotificationAsRead,
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['notifications'] });
    },
  });

  // Mark all as read
  const markAllAsReadMutation = useMutation({
    mutationFn: markAllNotificationsAsRead,
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['notifications'] });
    },
  });

  // Delete notification
  const deleteNotificationMutation = useMutation({
    mutationFn: deleteNotification,
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['notifications'] });
    },
  });

  const handleNotificationClick = (notification: NotificationResponse) => {
    if (!notification.read) {
      markAsReadMutation.mutate(notification.id);
    }

    // Navigate to actionUrl if available
    if (notification.actionUrl) {
      onClose();
      router.push(notification.actionUrl);
    }
  };

  const handleDelete = (e: React.MouseEvent, notificationId: string) => {
    e.stopPropagation();
    if (confirm('Are you sure you want to delete this notification?')) {
      deleteNotificationMutation.mutate(notificationId);
    }
  };

  const getPriorityColor = (priority: string) => {
    const colors = {
      urgent: 'border-l-4 border-red-500 bg-red-50',
      high: 'border-l-4 border-orange-500 bg-orange-50',
      medium: 'border-l-4 border-yellow-500 bg-yellow-50',
      low: 'border-l-4 border-blue-500 bg-blue-50',
    };
    return colors[priority as keyof typeof colors] || 'border-l-4 border-gray-300';
  };

  const getNotificationIcon = (type: string) => {
    const icons: Record<string, string> = {
      booking_created: '📦',
      booking_updated: '🔄',
      booking_cancelled: '❌',
      booking_confirmed: '✅',
      csv_booking_accepted: '✅',
      csv_booking_rejected: '❌',
      csv_booking_request_sent: '📧',
      rate_quote_expiring: '⏰',
      document_uploaded: '📄',
      system_announcement: '📢',
      user_invited: '👤',
      organization_update: '🏢',
    };
    return icons[type.toLowerCase()] || '🔔';
  };

  const formatTime = (dateString: string) => {
    const date = new Date(dateString);
    const now = new Date();
    const diffMs = now.getTime() - date.getTime();
    const diffMins = Math.floor(diffMs / 60000);
    const diffHours = Math.floor(diffMs / 3600000);
    const diffDays = Math.floor(diffMs / 86400000);

    if (diffMins < 1) return 'Just now';
    if (diffMins < 60) return `${diffMins}m ago`;
    if (diffHours < 24) return `${diffHours}h ago`;
    if (diffDays < 7) return `${diffDays}d ago`;
    return date.toLocaleDateString('en-US', {
      month: 'short',
      day: 'numeric',
      year: date.getFullYear() !== now.getFullYear() ? 'numeric' : undefined,
    });
  };

  if (!isOpen) return null;

  return (
    <>
      {/* Backdrop */}
      <div
        className="fixed inset-0 bg-black/30 z-40 transition-opacity"
        onClick={onClose}
      />

      {/* Panel */}
      <div className="fixed right-0 top-0 bottom-0 w-full max-w-2xl bg-white shadow-2xl z-50 flex flex-col animate-slide-in-right">
        {/* Header */}
        <div className="flex items-center justify-between px-6 py-4 border-b bg-white">
          <div>
            <h2 className="text-xl font-bold text-gray-900">Notifications</h2>
            <p className="text-sm text-gray-600 mt-1">
              {total} notification{total !== 1 ? 's' : ''} total
            </p>
          </div>
          <button
            onClick={onClose}
            className="p-2 hover:bg-gray-100 rounded-lg transition-colors text-gray-600"
            aria-label="Close panel"
          >
            <X className="w-6 h-6" />
          </button>
        </div>

        {/* Filter Bar */}
        <div className="flex items-center justify-between px-6 py-3 border-b bg-gray-50">
          <div className="flex items-center space-x-2">
            <Filter className="w-4 h-4 text-gray-500" />
            <div className="flex space-x-1">
              {(['all', 'unread', 'read'] as const).map((filter) => (
                <button
                  key={filter}
                  onClick={() => {
                    setSelectedFilter(filter);
                    setCurrentPage(1);
                  }}
                  className={`px-3 py-1.5 text-sm font-medium rounded-md transition-colors ${
                    selectedFilter === filter
                      ? 'bg-blue-600 text-white'
                      : 'bg-white text-gray-700 hover:bg-gray-100 border border-gray-300'
                  }`}
                >
                  {filter.charAt(0).toUpperCase() + filter.slice(1)}
                </button>
              ))}
            </div>
          </div>
          {selectedFilter === 'unread' && notifications.length > 0 && (
            <button
              onClick={() => markAllAsReadMutation.mutate()}
              disabled={markAllAsReadMutation.isPending}
              className="flex items-center space-x-1 text-sm text-blue-600 hover:text-blue-800 font-medium disabled:opacity-50"
            >
              <CheckCheck className="w-4 h-4" />
              <span>Mark all as read</span>
            </button>
          )}
        </div>

        {/* Notifications List */}
        <div className="flex-1 overflow-y-auto">
          {isLoading ? (
            <div className="flex items-center justify-center h-64">
              <div className="text-center">
                <div className="animate-spin rounded-full h-12 w-12 border-b-2 border-blue-600 mx-auto mb-4" />
                <p className="text-sm text-gray-500">Loading notifications...</p>
              </div>
            </div>
          ) : notifications.length === 0 ? (
            <div className="flex items-center justify-center h-64">
              <div className="text-center">
                <div className="text-6xl mb-4">🔔</div>
                <h3 className="text-lg font-semibold text-gray-900 mb-2">No notifications</h3>
                <p className="text-sm text-gray-500">
                  {selectedFilter === 'unread'
                    ? "You're all caught up!"
                    : 'No notifications to display'}
                </p>
              </div>
            </div>
          ) : (
            <div className="divide-y">
              {notifications.map((notification: NotificationResponse) => (
                <div
                  key={notification.id}
                  onClick={() => handleNotificationClick(notification)}
                  className={`p-6 hover:bg-gray-50 transition-all cursor-pointer group ${
                    !notification.read ? 'bg-blue-50/50' : ''
                  } ${getPriorityColor(notification.priority || 'low')}`}
                >
                  <div className="flex items-start space-x-4">
                    {/* Icon */}
                    <div className="flex-shrink-0 text-3xl">
                      {getNotificationIcon(notification.type)}
                    </div>

                    {/* Content */}
                    <div className="flex-1 min-w-0">
                      <div className="flex items-start justify-between mb-2">
                        <div className="flex items-center space-x-2">
                          <h3 className="text-base font-semibold text-gray-900">
                            {notification.title}
                          </h3>
                          {!notification.read && (
                            <span className="w-2.5 h-2.5 bg-blue-600 rounded-full" />
                          )}
                        </div>
                        <button
                          onClick={(e) => handleDelete(e, notification.id)}
                          className="opacity-0 group-hover:opacity-100 transition-opacity p-1 hover:bg-red-100 rounded"
                          title="Delete notification"
                        >
                          <Trash2 className="w-4 h-4 text-red-600" />
                        </button>
                      </div>

                      <p className="text-sm text-gray-700 mb-3 leading-relaxed">
                        {notification.message}
                      </p>

                      {/* Metadata */}
                      <div className="flex items-center justify-between">
                        <div className="flex items-center space-x-4 text-xs text-gray-500">
                          <span className="font-medium">
                            {formatTime(notification.createdAt)}
                          </span>
                          <span className="px-2 py-0.5 bg-gray-200 rounded-full text-gray-700 font-medium">
                            {notification.type.replace(/_/g, ' ').toUpperCase()}
                          </span>
                          {notification.priority && (
                            <span
                              className={`px-2 py-0.5 rounded-full font-medium ${
                                notification.priority === 'urgent'
                                  ? 'bg-red-100 text-red-700'
                                  : notification.priority === 'high'
                                  ? 'bg-orange-100 text-orange-700'
                                  : notification.priority === 'medium'
                                  ? 'bg-yellow-100 text-yellow-700'
                                  : 'bg-blue-100 text-blue-700'
                              }`}
                            >
                              {notification.priority.toUpperCase()}
                            </span>
                          )}
                        </div>
                        {notification.actionUrl && (
                          <span className="text-xs text-blue-600 font-medium group-hover:underline">
                            View details →
                          </span>
                        )}
                      </div>
                    </div>
                  </div>
                </div>
              ))}
            </div>
          )}
        </div>

        {/* Pagination */}
        {totalPages > 1 && (
          <div className="flex items-center justify-between px-6 py-4 border-t bg-gray-50">
            <div className="text-sm text-gray-600">
              Page {currentPage} of {totalPages}
            </div>
            <div className="flex space-x-2">
              <button
                onClick={() => setCurrentPage((p) => Math.max(1, p - 1))}
                disabled={currentPage === 1}
                className="px-3 py-1.5 text-sm font-medium bg-white border border-gray-300 rounded-md hover:bg-gray-50 disabled:opacity-50 disabled:cursor-not-allowed"
              >
                Previous
              </button>
              <button
                onClick={() => setCurrentPage((p) => Math.min(totalPages, p + 1))}
                disabled={currentPage === totalPages}
                className="px-3 py-1.5 text-sm font-medium bg-white border border-gray-300 rounded-md hover:bg-gray-50 disabled:opacity-50 disabled:cursor-not-allowed"
              >
                Next
              </button>
            </div>
          </div>
        )}
      </div>

      <style jsx>{`
        @keyframes slide-in-right {
          from {
            transform: translateX(100%);
          }
          to {
            transform: translateX(0);
          }
        }

        .animate-slide-in-right {
          animation: slide-in-right 0.3s ease-out;
        }
      `}</style>
    </>
  );
}