'use client';

import { useMutation, useQuery } from '@tanstack/react-query';
import Link from 'next/link';
import { useRouter } from 'next/navigation';
import { Icons } from '@/components/icons';
import { Button } from '@/components/ui/button';
import { NotificationCard, type NotificationAction } from '@/components/ui/notification-card';
import { Popover, PopoverContent, PopoverTrigger } from '@/components/ui/popover';
import { ScrollArea } from '@/components/ui/scroll-area';
import { Separator } from '@/components/ui/separator';
import {
  markAllNotificationsReadMutation,
  markNotificationReadMutation
} from '../api/mutations';
import { notificationsQueryOptions } from '../api/queries';

const MAX_VISIBLE = 5;

function buildNotificationActions(linkUrl: string | null): NotificationAction[] {
  if (!linkUrl) {
    return [];
  }

  return [{ id: `open:${linkUrl}`, label: 'Open', type: 'redirect', style: 'primary' }];
}

export function NotificationCenter() {
  const router = useRouter();
  const notificationsQuery = useQuery(notificationsQueryOptions({ page: 1, limit: MAX_VISIBLE }));
  const markRead = useMutation(markNotificationReadMutation);
  const markAllRead = useMutation(markAllNotificationsReadMutation);

  const notifications = notificationsQuery.data?.items ?? [];
  const unreadCount = notificationsQuery.data?.unreadCount ?? 0;

  return (
    <Popover>
      <PopoverTrigger asChild>
        <Button variant='ghost' size='icon' className='relative h-8 w-8'>
          <Icons.notification className='h-4 w-4' />
          {unreadCount > 0 && (
            <span className='bg-destructive text-destructive-foreground absolute -top-0.5 -right-0.5 flex h-4 min-w-4 items-center justify-center rounded-full px-1 text-[10px] font-medium'>
              {unreadCount > 9 ? '9+' : unreadCount}
            </span>
          )}
          <span className='sr-only'>Notifications</span>
        </Button>
      </PopoverTrigger>
      <PopoverContent align='end' className='w-[calc(100vw-2rem)] p-0 sm:w-[380px]' sideOffset={8}>
        <div className='flex items-center justify-between px-4 py-3'>
          <Link href='/dashboard/notifications' className='group flex items-center gap-1'>
            <h4 className='text-sm font-semibold group-hover:underline'>Notifications</h4>
            <Icons.chevronRight className='text-muted-foreground h-3.5 w-3.5 transition-transform group-hover:translate-x-0.5' />
          </Link>
          <div className='flex items-center gap-2'>
            {unreadCount > 0 && (
              <span className='bg-muted text-muted-foreground rounded-full px-2 py-0.5 text-xs'>
                {unreadCount} new
              </span>
            )}
            {unreadCount > 0 && (
              <Button
                variant='ghost'
                size='sm'
                className='text-muted-foreground h-auto px-2 py-1 text-xs'
                disabled={markAllRead.isPending}
                onClick={() => markAllRead.mutate()}
              >
                Mark all as read
              </Button>
            )}
          </div>
        </div>
        <Separator />
        <ScrollArea className='h-[400px]'>
          {notificationsQuery.isError ? (
            <div className='flex flex-col items-center justify-center py-12 text-center'>
              <Icons.alertCircle className='text-muted-foreground/40 mb-2 h-8 w-8' />
              <p className='text-muted-foreground text-sm'>Unable to load notifications</p>
            </div>
          ) : notificationsQuery.isLoading ? (
            <div className='flex flex-col gap-2 p-2'>
              {Array.from({ length: 3 }).map((_, index) => (
                <div key={index} className='bg-muted h-24 animate-pulse rounded-2xl' />
              ))}
            </div>
          ) : notifications.length === 0 ? (
            <div className='flex flex-col items-center justify-center py-12'>
              <Icons.notification className='text-muted-foreground/40 mb-2 h-8 w-8' />
              <p className='text-muted-foreground text-sm'>No notifications yet</p>
            </div>
          ) : (
            <div className='flex flex-col gap-1 p-2'>
              {notifications.map((notification) => (
                <NotificationCard
                  key={notification.id}
                  id={notification.id}
                  title={notification.title}
                  body={notification.body}
                  status={notification.status}
                  createdAt={notification.createdAt}
                  actions={buildNotificationActions(notification.linkUrl)}
                  onMarkAsRead={(id) => markRead.mutate(id)}
                  onAction={async (notificationId, actionId) => {
                    if (actionId.startsWith('open:')) {
                      await markRead.mutateAsync(notificationId);
                      router.push(actionId.replace('open:', ''));
                    }
                  }}
                />
              ))}
            </div>
          )}
        </ScrollArea>
      </PopoverContent>
    </Popover>
  );
}