import { useState, useEffect } from 'react';
import { Zap, Copy, Check, ShieldCheck, HelpCircle } from 'lucide-react';
import { Button } from '@/components/ui/button';
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogHeader,
  DialogTitle,
} from '@/components/ui/dialog';
import {
  Tooltip,
  TooltipContent,
  TooltipProvider,
  TooltipTrigger,
} from '@/components/ui/tooltip';
import { useToast } from '@/hooks/useToast';
import { normalizeClinkCode, parseClinkOffer } from '@/lib/clink';
import { cn } from '@/lib/utils';
import { useTranslation } from '@/contexts/language';

interface ClinkPayButtonProps {
  /** The CLINK Offer code (noffer1...) */
  noffer: string;
  /** Display name of the recipient, e.g. the provider or shop name */
  recipientName?: string;
  className?: string;
  /** Button variant — defaults to a subtle outline so it stays secondary */
  variant?: 'default' | 'outline' | 'secondary';
  size?: 'default' | 'sm' | 'lg';
  /**
   * Friendlier button label. Defaults to "Tip in Bitcoin" — CLINK is jargon,
   * so we lead with what it does and explain the tech in the tooltip/dialog.
   */
  label?: string;
}

/**
 * A self-custodial "Pay via CLINK" button.
 *
 * CLINK Offers (noffer1...) are Nostr-native, self-custodial static payment
 * codes (see https://clinkme.dev). This component does NOT transact — it hands
 * the code off to a CLINK-compatible wallet via QR, copy, or a nostr: deep link.
 * It only renders when a valid noffer is present, so it is purely additive and
 * never replaces the existing Lightning Address / zap flow.
 */
export function ClinkPayButton({
  noffer,
  recipientName,
  className,
  variant = 'outline',
  size = 'default',
  label,
}: ClinkPayButtonProps) {
  const { t } = useTranslation();
  const resolvedLabel = label ?? t('marketUi.clink.tip');
  const [open, setOpen] = useState(false);
  const [copied, setCopied] = useState(false);
  const [qrDataUrl, setQrDataUrl] = useState<string | null>(null);
  const { toast } = useToast();

  const offer = parseClinkOffer(noffer);
  const code = offer?.raw ?? normalizeClinkCode(noffer);

  useEffect(() => {
    if (!open || !offer) return;
    let cancelled = false;
    (async () => {
      try {
        const { default: QRCode } = await import('qrcode');
        // Spec: the QR payload is the RAW code — no `nostr:`/URI wrapper.
        const url = await QRCode.toDataURL(code, {
          width: 260,
          margin: 2,
          color: { dark: '#000000', light: '#ffffff' },
        });
        if (!cancelled) setQrDataUrl(url);
      } catch {
        if (!cancelled) setQrDataUrl(null);
      }
    })();
    return () => {
      cancelled = true;
    };
  }, [open, code, offer]);

  // Don't render anything if the code is invalid — keeps the feature opt-in.
  if (!offer) return null;

  const handleCopy = async () => {
    try {
      await navigator.clipboard.writeText(code);
      setCopied(true);
      setTimeout(() => setCopied(false), 2000);
      toast({ title: t('common.copied'), description: t('marketUi.clink.copiedBody') });
    } catch {
      toast({
        title: t('marketUi.clink.copyFailed'),
        description: t('marketUi.clink.copyFailedBody'),
        variant: 'destructive',
      });
    }
  };

  const shortCode = `${code.slice(0, 12)}…${code.slice(-6)}`;

  // Pricing comes from the decoded TLV (0 fixed / 1 variable / 2 spontaneous).
  const pricingLabel =
    offer.priceType === 0
      ? offer.priceSats != null
        ? t('marketUi.clink.priceFixed', { amount: offer.priceSats.toLocaleString() })
        : t('marketUi.clink.priceFixedShort')
      : offer.priceType === 1
        ? offer.currency
          ? t('marketUi.clink.priceVariableCurrency', { currency: offer.currency })
          : t('marketUi.clink.priceVariable')
        : t('marketUi.clink.priceSpontaneous');

  return (
    <>
      <div className={cn('flex items-center gap-1.5', className)}>
        <Button
          type="button"
          variant={variant}
          size={size}
          className="flex-1 gap-2 border-indigo-500/40 text-indigo-600 hover:bg-indigo-500/10 hover:text-indigo-700 dark:text-indigo-400 dark:hover:text-indigo-300"
          onClick={() => setOpen(true)}
        >
          <Zap className="h-4 w-4" />
          {resolvedLabel}
        </Button>
        <TooltipProvider delayDuration={150}>
          <Tooltip>
            <TooltipTrigger asChild>
              <button
                type="button"
                onClick={() => setOpen(true)}
                aria-label={t('marketUi.clink.whatIs')}
                className="flex h-7 w-7 shrink-0 items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-indigo-500/10 hover:text-indigo-500"
              >
                <HelpCircle className="h-4 w-4" />
              </button>
            </TooltipTrigger>
            <TooltipContent side="top" className="max-w-[220px] text-xs">
              <p className="font-semibold">{t('marketUi.clink.tooltipTitle')}</p>
              <p className="mt-1 text-muted-foreground">
                {t('marketUi.clink.tooltipBody')}
              </p>
            </TooltipContent>
          </Tooltip>
        </TooltipProvider>
      </div>

      <Dialog open={open} onOpenChange={setOpen}>
        <DialogContent className="sm:max-w-sm">
          <DialogHeader>
            <DialogTitle className="flex items-center gap-2">
              <Zap className="h-5 w-5 text-indigo-500" />
              {resolvedLabel}
            </DialogTitle>
            <DialogDescription>
              {recipientName
                ? t('marketUi.clink.descRecipient', { recipientName })
                : t('marketUi.clink.descGeneric')}
            </DialogDescription>
          </DialogHeader>

          <div className="flex flex-col items-center gap-4 py-2">
            {qrDataUrl ? (
              <div className="rounded-2xl bg-white p-3 shadow-sm ring-1 ring-black/5">
                <img
                  src={qrDataUrl}
                  alt={t('marketUi.clink.qrAlt')}
                  className="h-[220px] w-[220px]"
                />
              </div>
            ) : (
              <div className="flex h-[220px] w-[220px] items-center justify-center rounded-2xl bg-muted">
                <Zap className="h-8 w-8 animate-pulse text-muted-foreground" />
              </div>
            )}

            <div className="flex w-full items-center gap-2 rounded-lg border bg-muted/50 px-3 py-2">
              <code className="flex-1 truncate text-xs text-muted-foreground">
                {shortCode}
              </code>
              <Button
                type="button"
                variant="ghost"
                size="icon"
                className="h-7 w-7 shrink-0"
                onClick={handleCopy}
                aria-label={t('marketUi.clink.copyCode')}
              >
                {copied ? (
                  <Check className="h-4 w-4 text-green-500" />
                ) : (
                  <Copy className="h-4 w-4" />
                )}
              </Button>
            </div>

            <p className="text-xs font-semibold text-indigo-500">{pricingLabel}</p>

            <Button
              type="button"
              className="w-full gap-2 bg-indigo-600 hover:bg-indigo-700"
              onClick={handleCopy}
            >
              {copied ? <Check className="h-4 w-4" /> : <Copy className="h-4 w-4" />}
              {t('marketUi.clink.copyToWallet')}
            </Button>

            <p className="flex items-start gap-1.5 text-center text-xs text-muted-foreground">
              <ShieldCheck className="mt-0.5 h-3.5 w-3.5 shrink-0 text-indigo-500" />
              <span>
                {t('marketUi.clink.footnote')}
              </span>
            </p>
          </div>
        </DialogContent>
      </Dialog>
    </>
  );
}