import { useState } from 'react';
import { Link } from 'react-router-dom';
import { nip19 } from 'nostr-tools';
import { Avatar, AvatarFallback, AvatarImage } from '@/components/ui/avatar';
import { Button } from '@/components/ui/button';
import { useCurrentUser } from '@/hooks/useCurrentUser';
import { useAuthor } from '@/hooks/useAuthor';
import {
  useApproveJoinRequest,
  useDismissJoinRequest,
  useEndorseJoinRequest,
} from '@/hooks/useCrewInvites';
import { useToast } from '@/hooks/useToast';
import { genUserName } from '@/lib/genUserName';
import { parseAddrCoord, type CrewEndorsement, type CrewJoinRequest, type SkateCrew } from '@/lib/types';
import { UserPlus, Check, X, Loader2, Hand, ThumbsUp, Clock } from 'lucide-react';
import { cn } from '@/lib/utils';

function npubSafe(pubkey: string): string {
  try {
    return nip19.npubEncode(pubkey);
  } catch {
    return pubkey;
  }
}

/** Tiny avatar for an endorsing admin (used in the vouch strip). */
function EndorserAvatar({ pubkey }: { pubkey: string }) {
  const author = useAuthor(pubkey);
  const name = author.data?.metadata?.name ?? genUserName(pubkey);
  return (
    <Avatar className="h-5 w-5 ring-2 ring-gray-900">
      <AvatarImage src={author.data?.metadata?.picture} alt={name} />
      <AvatarFallback className="text-[8px]">{name.slice(0, 2).toUpperCase()}</AvatarFallback>
    </Avatar>
  );
}

/** Readable "Vouched by Rider, Mia +1" line for the endorsement strip. */
function EndorserNames({ pubkeys }: { pubkeys: string[] }) {
  const first = useAuthor(pubkeys[0]);
  const firstName = first.data?.metadata?.name ?? genUserName(pubkeys[0]);
  const extra = pubkeys.length - 1;
  return (
    <span className="font-bold text-emerald-300">
      {firstName}
      {extra > 0 && <span className="font-normal text-emerald-400/70"> +{extra} more</span>}
    </span>
  );
}

/**
 * A single incoming join-request card for a crew's founder / admins.
 *
 * Trust model: only the founder authors the crew event, so only they can *add*
 * a member. Admins therefore **endorse** ("vouch for") a request; the founder
 * sees those endorsements as social proof and ratifies with one click. This
 * closes the admin/founder asymmetry without breaking who-can-edit-the-roster.
 */
export function JoinRequestCard({
  request,
  crew,
  endorsements = [],
  onResolved,
  compact,
}: {
  request: CrewJoinRequest;
  crew: SkateCrew;
  endorsements?: CrewEndorsement[];
  onResolved?: () => void;
  compact?: boolean;
}) {
  const { user } = useCurrentUser();
  const requester = useAuthor(request.requester);
  const requesterName = requester.data?.metadata?.name ?? genUserName(request.requester);
  const requesterPic = requester.data?.metadata?.picture;
  const { toast } = useToast();
  const { mutateAsync: approve, isPending: approving } = useApproveJoinRequest();
  const { mutateAsync: dismiss, isPending: dismissing } = useDismissJoinRequest();
  const { mutateAsync: endorse, isPending: endorsing } = useEndorseJoinRequest();
  const [done, setDone] = useState<'approved' | 'dismissed' | 'endorsed' | null>(null);

  const coord = parseAddrCoord(request.crewCoord);
  const crewHref = coord ? `/crew/${coord.pubkey}/${coord.identifier}` : '/crews';
  const meLc = user?.pubkey.toLowerCase();
  const isFounder = !!meLc && meLc === crew.pubkey.toLowerCase();
  const isAdmin = !!meLc && crew.admins.some((a) => a.toLowerCase() === meLc);

  const endorserPubkeys = endorsements.map((e) => e.endorser);
  const iEndorsed = !!meLc && endorserPubkeys.some((p) => p.toLowerCase() === meLc);
  const hasEndorsements = endorserPubkeys.length > 0;

  const handleApprove = async () => {
    try {
      await approve({ request, crew });
      setDone('approved');
      toast({
        title: `Added ${requesterName} to ${crew.name} 🛹`,
        description: "They'll confirm from their side to appear as a member.",
      });
      onResolved?.();
    } catch (err) {
      toast({
        title: 'Could not add member',
        description: err instanceof Error ? err.message : 'Please try again.',
        variant: 'destructive',
      });
    }
  };

  const handleEndorse = async () => {
    try {
      await endorse({ request, crew });
      setDone('endorsed');
      toast({
        title: `You vouched for ${requesterName} 🤝`,
        description: `The founder of ${crew.name} will see your endorsement and can add them.`,
      });
      onResolved?.();
    } catch (err) {
      toast({
        title: 'Could not endorse',
        description: err instanceof Error ? err.message : 'Please try again.',
        variant: 'destructive',
      });
    }
  };

  const handleDismiss = async () => {
    try {
      await dismiss({ request });
      setDone('dismissed');
      onResolved?.();
    } catch {
      toast({ title: 'Could not dismiss', variant: 'destructive' });
    }
  };

  if (done) {
    return (
      <div className="flex items-center gap-2 rounded-xl border border-white/10 bg-white/[0.03] px-3 py-2.5 text-sm text-gray-400">
        {done === 'approved' ? (
          <>
            <Check className="h-4 w-4 text-emerald-400" />
            Added <span className="font-bold text-white">{requesterName}</span> to {crew.name}
          </>
        ) : done === 'endorsed' ? (
          <>
            <ThumbsUp className="h-4 w-4 text-emerald-400" />
            You vouched for <span className="font-bold text-white">{requesterName}</span> — founder will confirm
          </>
        ) : (
          <>
            <X className="h-4 w-4 text-gray-500" />
            Dismissed request from {requesterName}
          </>
        )}
      </div>
    );
  }

  const busy = approving || dismissing || endorsing;

  return (
    <div
      className={cn(
        'rounded-xl border border-emerald-500/25 bg-gradient-to-br from-emerald-500/[0.08] to-transparent p-3',
        compact && 'p-2.5',
      )}
    >
      <div className="flex items-start gap-3">
        <div className="flex h-9 w-9 flex-shrink-0 items-center justify-center rounded-xl bg-emerald-500/15">
          <Hand className="h-4 w-4 text-emerald-400" />
        </div>
        <div className="min-w-0 flex-1">
          <p className="text-sm leading-snug text-gray-200">
            <Link
              to={`/${npubSafe(request.requester)}`}
              className="inline-flex items-center gap-1 font-bold text-white hover:text-emerald-300"
            >
              <Avatar className="h-4 w-4">
                <AvatarImage src={requesterPic} alt={requesterName} />
                <AvatarFallback className="text-[8px]">{requesterName.slice(0, 2).toUpperCase()}</AvatarFallback>
              </Avatar>
              {requesterName}
            </Link>{' '}
            wants to join{' '}
            <Link to={crewHref} className="font-black text-emerald-300 hover:underline">
              {crew.name}
            </Link>
          </p>
          {request.note && (
            <p className="mt-1 rounded-lg bg-black/30 px-2.5 py-1.5 text-xs italic text-gray-400 break-words [overflow-wrap:anywhere]">
              “{request.note}”
            </p>
          )}

          {/* Vouch strip — admins' endorsements as social proof for the founder. */}
          {hasEndorsements && (
            <div className="mt-2 flex items-center gap-2 rounded-lg border border-emerald-500/20 bg-emerald-500/[0.06] px-2.5 py-1.5">
              <div className="flex -space-x-1.5">
                {endorserPubkeys.slice(0, 3).map((pk) => (
                  <EndorserAvatar key={pk} pubkey={pk} />
                ))}
              </div>
              <p className="min-w-0 flex-1 truncate text-[11px] text-emerald-200/90">
                Vouched by <EndorserNames pubkeys={endorserPubkeys} />
              </p>
            </div>
          )}

          <div className="mt-2.5 flex items-center gap-2">
            {isFounder ? (
              <Button
                size="sm"
                onClick={handleApprove}
                disabled={busy}
                className="h-8 flex-1 gap-1.5 bg-emerald-500 font-bold text-black hover:bg-emerald-600"
              >
                {approving ? <Loader2 className="h-3.5 w-3.5 animate-spin" /> : <UserPlus className="h-3.5 w-3.5" />}
                {hasEndorsements ? 'Approve & add' : 'Add to crew'}
              </Button>
            ) : isAdmin ? (
              iEndorsed ? (
                <span className="flex flex-1 items-center gap-1.5 text-xs font-bold text-emerald-400/90">
                  <Clock className="h-3.5 w-3.5" /> Vouched — waiting on the founder
                </span>
              ) : (
                <Button
                  size="sm"
                  onClick={handleEndorse}
                  disabled={busy}
                  className="h-8 flex-1 gap-1.5 bg-emerald-500 font-bold text-black hover:bg-emerald-600"
                >
                  {endorsing ? <Loader2 className="h-3.5 w-3.5 animate-spin" /> : <ThumbsUp className="h-3.5 w-3.5" />}
                  Vouch for them
                </Button>
              )
            ) : (
              <span className="flex-1 text-xs text-gray-500">Crew leadership only.</span>
            )}
            <Button
              size="sm"
              variant="outline"
              onClick={handleDismiss}
              disabled={busy}
              className="h-8 gap-1.5 border-white/15 text-gray-400 hover:bg-white/10 hover:text-white"
            >
              {dismissing ? <Loader2 className="h-3.5 w-3.5 animate-spin" /> : <X className="h-3.5 w-3.5" />}
              Dismiss
            </Button>
          </div>

          {/* Micro-help so the admin path isn't a mystery. */}
          {isAdmin && !iEndorsed && (
            <p className="mt-1.5 text-[11px] leading-snug text-gray-500">
              Admins can’t add members directly — vouching tells the founder you back this rider.
            </p>
          )}
        </div>
      </div>
    </div>
  );
}