'use client';

import React, { useState, useEffect } from 'react';
import { 
    Coins, 
    Copy, 
    CheckCircle2, 
    ExternalLink, 
    RefreshCw, 
    AlertCircle,
    QrCode
} from 'lucide-react';

interface CryptoCheckoutProps {
    amount: number;
    currency: string;
    txId: string;
    onSuccess: (txHash: string) => void;
}

export default function CryptoCheckout({ amount, currency, txId, onSuccess }: CryptoCheckoutProps) {
    const [selectedCoin, setSelectedCoin] = useState('SOL');
    const [depositAddress, setDepositAddress] = useState<string>('');
    const [isVerifying, setIsVerifying] = useState(false);
    const [copied, setCopied] = useState(false);
    const [status, setStatus] = useState<'waiting' | 'verifying' | 'success' | 'error'>('waiting');
    const [cryptoAmount, setCryptoAmount] = useState<string>('Hesaplanıyor...');

    useEffect(() => {
        async function fetchExchangeRate() {
            if (currency === 'TL' || currency === 'TRY') {
                try {
                    const symbol = selectedCoin === 'SOL' ? 'SOLTRY' : 'USDTTRY';
                    const res = await fetch(`https://api.binance.com/api/v3/ticker/price?symbol=${symbol}`);
                    const data = await res.json();
                    const rate = parseFloat(data.price);
                    setCryptoAmount((amount / rate).toFixed(selectedCoin === 'SOL' ? 4 : 2));
                } catch (error) {
                    // Fallback rate if API fails
                    setCryptoAmount((amount / 5500).toFixed(selectedCoin === 'SOL' ? 4 : 2)); 
                }
            } else {
                // If already USD or USDT, 1:1 ratio
                setCryptoAmount(amount.toFixed(2));
            }
        }
        fetchExchangeRate();
    }, [amount, currency]);

    useEffect(() => {
        // Use a real valid Solana test wallet so Phantom doesn't say "Invalid Address"
        setDepositAddress('5pLH1tqZhx8p8WpZ18yr28N42KXB3FXVPzZ9ceCtpBVe');
    }, [selectedCoin]);

    const handleCopy = () => {
        navigator.clipboard.writeText(depositAddress);
        setCopied(true);
        setTimeout(() => setCopied(false), 2000);
    };

    const verifyPayment = async () => {
        setIsVerifying(true);
        setStatus('verifying');
        
        try {
            const response = await fetch('/api/crypto-sweep', {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({
                    txId: txId,
                    merchantAddress: '5pLH1tqZhx8p8WpZ18yr28N42KXB3FXVPzZ9ceCtpBVe' // A placeholder valid Solana Devnet Wallet
                })
            });
            const data = await response.json();

            if (data.success) {
                setStatus('success');
                onSuccess(data.hashes.merchant);
            } else {
                setStatus('error');
            }
        } catch (err) {
            setStatus('error');
        } finally {
            setIsVerifying(false);
        }
    };

    return (
        <div className="bg-white p-8 lg:p-12 rounded-[40px] border border-gray-100 shadow-sm space-y-8 animate-in fade-in zoom-in duration-500 w-full max-w-lg">
            <div className="flex items-center justify-between">
                <div className="flex items-center gap-3">
                    <div className="p-3 bg-orange-50 rounded-2xl text-orange-600">
                        <Coins size={24} />
                    </div>
                    <div>
                        <h3 className="text-xl font-black text-gray-900 uppercase tracking-tight">Kripto Ödeme</h3>
                        <p className="text-[10px] text-gray-400 font-black uppercase tracking-widest">On-Chain Güvenli Transfer</p>
                    </div>
                </div>
                <div className="text-right">
                    <p className="text-2xl font-black text-gray-900">{cryptoAmount} <span className="text-xs text-gray-400">{selectedCoin}</span></p>
                    <p className="text-[10px] text-gray-400 font-bold uppercase">Ağ: Solana (Devnet)</p>
                </div>
            </div>

            {status === 'success' ? (
                <div className="py-10 text-center space-y-6">
                    <div className="w-20 h-20 bg-emerald-50 rounded-[32px] flex items-center justify-center text-emerald-500 mx-auto animate-bounce">
                        <CheckCircle2 size={40} />
                    </div>
                    <div className="space-y-2">
                        <h2 className="text-2xl font-black text-gray-900 uppercase tracking-tight">Ödeme Onaylandı!</h2>
                        <p className="text-gray-400 font-bold uppercase tracking-widest text-[10px]">İşleminiz başarıyla blokzincirine kaydedildi.</p>
                    </div>
                </div>
            ) : (
                <>
                    {/* QR Code Placeholder */}
                    <div className="bg-gray-50 aspect-square rounded-[32px] flex flex-col items-center justify-center border border-gray-100 relative group cursor-pointer">
                        <QrCode size={180} className="text-gray-200 group-hover:text-gray-400 transition-colors" />
                        <div className="absolute inset-0 flex items-center justify-center opacity-0 group-hover:opacity-100 transition-opacity">
                            <span className="bg-white px-4 py-2 rounded-xl text-[10px] font-black uppercase shadow-lg border border-gray-100">Büyüt</span>
                        </div>
                    </div>

                    <div className="space-y-4">
                        <div className="space-y-2">
                            <label className="text-[10px] font-black text-gray-400 uppercase tracking-widest pl-1">Cüzdan Adresi</label>
                            <div className="flex items-center gap-2">
                                <div className="flex-1 bg-gray-50 p-4 rounded-2xl border border-gray-100 font-mono text-[10px] text-gray-600 break-all leading-tight">
                                    {depositAddress}
                                </div>
                                <button 
                                    onClick={handleCopy}
                                    className="p-4 bg-gray-900 text-white rounded-2xl hover:bg-black transition-all shadow-lg shadow-gray-200 active:scale-95"
                                >
                                    {copied ? <CheckCircle2 size={18} /> : <Copy size={18} />}
                                </button>
                            </div>
                        </div>

                        <div className="p-6 bg-blue-50/50 rounded-3xl border border-blue-100 space-y-2">
                            <div className="flex items-center gap-2 text-blue-600">
                                <AlertCircle size={14} />
                                <span className="text-[9px] font-black uppercase tracking-widest">Önemli Uyarı</span>
                            </div>
                            <p className="text-[10px] text-blue-800 leading-relaxed font-medium">
                                Lütfen sadece test amaçlı <b>Solana (Devnet)</b> ağı üzerinden test SOL'ü gönderimi yapın. Gerçek ağ veya USDT bu ortamda kabul edilmez.
                            </p>
                        </div>
                    </div>

                    <button
                        onClick={verifyPayment}
                        disabled={isVerifying}
                        className="w-full py-5 bg-gray-900 text-white rounded-2xl font-black text-xs uppercase tracking-[0.2em] hover:bg-black transition-all shadow-xl shadow-gray-200 flex items-center justify-center gap-3 disabled:opacity-50"
                    >
                        {isVerifying ? (
                            <>
                                <RefreshCw size={18} className="animate-spin" />
                                Doğrulanıyor...
                            </>
                        ) : (
                            'Ödemeyi Doğrula'
                        )}
                    </button>

                    <div className="flex justify-center gap-6">
                        <div className="flex items-center gap-2 text-gray-400 hover:text-gray-600 cursor-pointer transition-colors group">
                            <ExternalLink size={14} />
                            <span className="text-[9px] font-black uppercase tracking-widest group-hover:underline">Explorer'da Gör</span>
                        </div>
                    </div>
                </>
            )}
        </div>
    );
}