import { useState } from 'react';
import { Link } from 'react-router-dom';
import { nip19 } from 'nostr-tools';
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { Avatar, AvatarImage, AvatarFallback } from '@/components/ui/avatar';
import { useCurrentUser } from '@/hooks/useCurrentUser';
import { useAuthor } from '@/hooks/useAuthor';
import { useToast } from '@/hooks/useToast';
import {
  useTraderRecommendations,
  useMyRecommendation,
  useRecommendationActions,
} from '@/hooks/useTraderRecommendations';
import { genUserName } from '@/lib/genUserName';
import { ShieldCheck, Loader2 } from 'lucide-react';

function Recommender({ pubkey }: { pubkey: string }) {
  const author = useAuthor(pubkey);
  const name = author.data?.metadata?.name ?? genUserName(pubkey);
  return (
    <Link to={`/${nip19.npubEncode(pubkey)}`} className="flex items-center gap-2">
      <Avatar className="h-6 w-6 border border-white/10">
        <AvatarImage src={author.data?.metadata?.picture} alt={name} />
        <AvatarFallback className="bg-gray-800 text-[10px] text-gray-400">
          {name.slice(0, 2).toUpperCase()}
        </AvatarFallback>
      </Avatar>
      <span className="truncate text-xs text-gray-300 hover:text-white">{name}</span>
    </Link>
  );
}

/**
 * Trusted-trader recommendations for a profile (kind 31873). Shows who vouches
 * for this trader, and lets a logged-in viewer add their own recommendation.
 */
export function TradeRecommendationsCard({ pubkey, className }: { pubkey: string; className?: string }) {
  const { user } = useCurrentUser();
  const { data: recs, isLoading } = useTraderRecommendations(pubkey);
  const { data: mine } = useMyRecommendation(pubkey);
  const { recommend } = useRecommendationActions();
  const { toast } = useToast();
  const [busy, setBusy] = useState(false);

  const isSelf = user?.pubkey === pubkey;
  const count = recs?.length ?? 0;

  // Nothing to show: no recommendations and the viewer can't add one.
  if (!isLoading && count === 0 && (!user || isSelf)) return null;

  const handleRecommend = async () => {
    setBusy(true);
    try {
      await recommend(pubkey);
      toast({ title: 'Recommendation published', description: 'Thanks for vouching.' });
    } catch (e) {
      toast({
        title: 'Could not recommend',
        description: e instanceof Error ? e.message : 'Something went wrong.',
        variant: 'destructive',
      });
    } finally {
      setBusy(false);
    }
  };

  return (
    <Card className={`bg-black/90 border-2 border-[#ff6600]/25 ${className ?? ''}`}>
      <CardHeader className="pb-3">
        <CardTitle className="flex items-center gap-2 text-lg text-[#ff6600]">
          <ShieldCheck className="h-5 w-5" />
          Trusted trader
        </CardTitle>
      </CardHeader>
      <CardContent className="space-y-3">
        <p className="text-sm text-gray-300">
          {count > 0 ? (
            <>
              Recommended by <span className="font-bold text-white">{count}</span> skater
              {count === 1 ? '' : 's'}.
            </>
          ) : (
            'No recommendations yet.'
          )}
        </p>

        {count > 0 && (
          <div className="flex flex-wrap gap-x-4 gap-y-2">
            {recs!.slice(0, 8).map((r) => (
              <Recommender key={r.id} pubkey={r.recommender} />
            ))}
          </div>
        )}

        {user && !isSelf && (
          mine ? (
            <p className="text-xs text-[#ccff00]">You recommend this trader ✓</p>
          ) : (
            <Button
              size="sm"
              onClick={handleRecommend}
              disabled={busy}
              className="w-full gap-2 bg-[#ff6600] font-bold text-black hover:bg-[#ff6600]/90"
            >
              {busy ? <Loader2 className="h-4 w-4 animate-spin" /> : <ShieldCheck className="h-4 w-4" />}
              Recommend as trusted trader
            </Button>
          )
        )}
      </CardContent>
    </Card>
  );
}