import { useEffect, useState } from 'react';
import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogDescription } from '@/components/ui/dialog';
import { Button } from '@/components/ui/button';
import { Check, Copy, Share2, Loader2 } from 'lucide-react';
import { useToast } from '@/hooks/useToast';
import { useTranslation } from '@/contexts/language';
import { generateQRCode } from '@/lib/wallet/qrCodeGenerator';

interface ShareProfileDialogProps {
  open: boolean;
  onOpenChange: (open: boolean) => void;
  /** The npub (or nprofile) to build the shareable URL from. */
  npub: string;
  /** Display name, used in the share sheet + QR caption. */
  displayName: string;
  /** Optional path (e.g. `/coach/<pubkey>/<d>`) appended to the canonical origin
   *  instead of the default `/<npub>` — for sharing a specific Lab profile. */
  path?: string;
}

/**
 * Share a skater's profile IRL or online. Skateboarding is a physical, local
 * community — a QR you can flash at a spot (or slap on a sticker) is worth more
 * than a raw npub. Falls back gracefully to copy-link when the native share
 * sheet isn't available.
 */
export function ShareProfileDialog({ open, onOpenChange, npub, displayName, path }: ShareProfileDialogProps) {
  const { t } = useTranslation();
  const { toast } = useToast();
  const [qr, setQr] = useState<string | null>(null);
  const [copied, setCopied] = useState(false);

  // Always anchor to the canonical public site so shared links/QRs point to the
  // real domain — never the preview/sandbox iframe host that window.location
  // would give us inside the editor.
  const CANONICAL_ORIGIN = 'https://skate-spots.org';
  const shareUrl = `${CANONICAL_ORIGIN}${path ?? `/${npub}`}`;

  useEffect(() => {
    if (!open) return;
    let active = true;
    setQr(null);
    // qrcode must be imported lazily (see generateQRCode) — a top-level import
    // crashes on its canvas dependency at module load.
    generateQRCode(shareUrl)
      .then((url) => { if (active) setQr(url); })
      .catch((err) => {
        console.error('[ShareProfileDialog] QR generation failed:', err);
        if (active) setQr(null);
      });
    return () => { active = false; };
  }, [open, shareUrl]);

  const handleCopy = async () => {
    try {
      await navigator.clipboard.writeText(shareUrl);
      setCopied(true);
      setTimeout(() => setCopied(false), 2000);
    } catch {
      toast({ title: t('walletUi.share.copyFailed'), description: t('walletUi.share.copyFailedDesc'), variant: 'destructive' });
    }
  };

  const canNativeShare = typeof navigator !== 'undefined' && !!navigator.share;

  const handleNativeShare = async () => {
    try {
      await navigator.share({
        title: `${displayName} on SkateSpots`,
        text: `Check out ${displayName} on SkateSpots 🛹`,
        url: shareUrl,
      });
    } catch {
      // user cancelled or unsupported — no-op
    }
  };

  return (
    <Dialog open={open} onOpenChange={onOpenChange}>
      <DialogContent className="w-[calc(100vw-2rem)] max-w-sm overflow-hidden bg-black border-white/10">
        <DialogHeader className="min-w-0">
          <DialogTitle className="flex items-center gap-2 uppercase font-black">
            <Share2 className="h-5 w-5 text-[#ff0040] flex-shrink-0" />
            {t('walletUi.share.title')}
          </DialogTitle>
          <DialogDescription className="text-gray-400">
            {t('walletUi.share.desc', { name: displayName })}
          </DialogDescription>
        </DialogHeader>

        {/* QR */}
        <div className="flex flex-col items-center gap-4 py-2 min-w-0 w-full">
          <div className="rounded-2xl bg-white p-3 shadow-lg">
            {qr ? (
              <img src={qr} alt={t('walletUi.share.qrAlt')} className="w-48 h-48 sm:w-52 sm:h-52" />
            ) : (
              <div className="w-48 h-48 sm:w-52 sm:h-52 flex items-center justify-center">
                <Loader2 className="h-6 w-6 animate-spin text-gray-400" />
              </div>
            )}
          </div>

          {/* URL + copy */}
          <button
            onClick={handleCopy}
            className="group w-full max-w-full flex items-center gap-2 rounded-xl border border-white/10 bg-white/5 px-3 py-2.5 hover:border-[#ff0040]/40 transition-colors"
          >
            <span className="flex-1 min-w-0 text-left text-sm text-gray-300 truncate font-mono">
              {shareUrl.replace(/^https?:\/\//, '')}
            </span>
            {copied ? (
              <Check className="h-4 w-4 text-[#ccff00] flex-shrink-0" />
            ) : (
              <Copy className="h-4 w-4 text-gray-500 group-hover:text-white flex-shrink-0" />
            )}
          </button>

          <div className="grid grid-cols-1 gap-2 w-full">
            <Button onClick={handleCopy} variant="outline" className="w-full border-white/15 font-bold">
              {copied ? <><Check className="h-4 w-4 mr-2 text-[#ccff00]" />{t('common.copied')}</> : <><Copy className="h-4 w-4 mr-2" />{t('walletUi.share.copyLink')}</>}
            </Button>
            {canNativeShare && (
              <Button onClick={handleNativeShare} className="w-full bg-[#ff0040] hover:bg-[#ff0040]/90 font-black uppercase">
                <Share2 className="h-4 w-4 mr-2" />
                {t('walletUi.share.shareEllipsis')}
              </Button>
            )}
          </div>
        </div>
      </DialogContent>
    </Dialog>
  );
}