import { Link } from 'react-router-dom';
import { formatDistanceToNow } from 'date-fns';
import { Heart, Repeat2, Zap, AtSign, MessageCircle, CalendarCheck, Megaphone } from 'lucide-react';
import { Avatar, AvatarFallback, AvatarImage } from '@/components/ui/avatar';
import { useAuthor } from '@/hooks/useAuthor';
import { genUserName } from '@/lib/genUserName';
import { cn } from '@/lib/utils';
import { nip19 } from 'nostr-tools';
import {
  activityVerb,
  type ActivityNotification,
  type ActivityType,
} from '@/hooks/useActivityNotifications';

const TYPE_META: Record<
  ActivityType,
  { icon: typeof Heart; color: string; ring: string }
> = {
  reaction: { icon: Heart, color: 'text-pink-400', ring: 'bg-pink-500/15' },
  repost: { icon: Repeat2, color: 'text-green-400', ring: 'bg-green-500/15' },
  zap: { icon: Zap, color: 'text-yellow-400', ring: 'bg-yellow-500/15' },
  mention: { icon: AtSign, color: 'text-sky-400', ring: 'bg-sky-500/15' },
  reply: { icon: MessageCircle, color: 'text-teal-400', ring: 'bg-teal-500/15' },
  rsvp: { icon: CalendarCheck, color: 'text-emerald-400', ring: 'bg-emerald-500/15' },
  'event-update': { icon: Megaphone, color: 'text-[#ccff00]', ring: 'bg-[#ccff00]/15' },
};

/**
 * A single "social" activity notification (reaction / repost / zap / mention /
 * reply). Links to the actor's profile and — when there's a target event — to
 * that note so the user can jump straight to the context.
 */
export function ActivityNotificationCard({
  notification,
  unread,
  onNavigate,
}: {
  notification: ActivityNotification;
  unread?: boolean;
  onNavigate?: () => void;
}) {
  const author = useAuthor(notification.pubkey);
  const name = author.data?.metadata?.name ?? genUserName(notification.pubkey);
  const pic = author.data?.metadata?.picture;

  const meta = TYPE_META[notification.type];
  const Icon = meta.icon;

  const npub = (() => {
    try {
      return nip19.npubEncode(notification.pubkey);
    } catch {
      return null;
    }
  })();

  const timeAgo = formatDistanceToNow(new Date(notification.createdAt * 1000), {
    addSuffix: true,
  });

  const snippet =
    (notification.type === 'reply' ||
      notification.type === 'mention' ||
      notification.type === 'event-update') &&
    notification.content
      ? notification.content.slice(0, 120)
      : null;

  const body = (
    <div
      className={cn(
        'flex items-start gap-3 rounded-xl border p-3 transition-colors',
        unread
          ? 'border-teal-500/25 bg-teal-500/[0.06]'
          : 'border-white/10 bg-white/[0.02]',
      )}
    >
      {/* Actor avatar with a type badge */}
      <div className="relative flex-shrink-0">
        <Avatar className="h-9 w-9">
          <AvatarImage src={pic} alt={name} />
          <AvatarFallback className="text-[10px]">
            {name.slice(0, 2).toUpperCase()}
          </AvatarFallback>
        </Avatar>
        <span
          className={cn(
            'absolute -bottom-1 -right-1 flex h-5 w-5 items-center justify-center rounded-full ring-2 ring-background',
            meta.ring,
          )}
        >
          <Icon className={cn('h-3 w-3', meta.color)} />
        </span>
      </div>

      <div className="min-w-0 flex-1">
        <p className="text-sm leading-snug text-gray-200">
          <span className="font-bold text-white">{name}</span>{' '}
          <span className="text-gray-400">{activityVerb(notification)}</span>
        </p>
        {snippet && (
          <p className="mt-0.5 line-clamp-2 text-xs text-gray-500">"{snippet}"</p>
        )}
        <p className="mt-0.5 text-[11px] text-gray-600">{timeAgo}</p>
      </div>

      {unread && (
        <span className="mt-1 h-2 w-2 flex-shrink-0 rounded-full bg-teal-400" />
      )}
    </div>
  );

  // Link to the actor's profile (the always-valid in-app destination).
  if (!npub) return body;

  return (
    <Link to={`/${npub}`} onClick={onNavigate} className="block">
      {body}
    </Link>
  );
}