import React, { useState } from 'react';
import { Button } from '../../ui/button';
import { Input } from '../../ui/input';
import { Smartphone, QrCode, ArrowLeft, Copy, Download, AlertTriangle } from 'lucide-react';
import { useToast } from '../../../context/ToastContext';

interface TwoFactorSetupProps {
  onBack: () => void;
  onComplete: () => void;
}

export const TwoFactorSetup: React.FC<TwoFactorSetupProps> = ({ onBack, onComplete }) => {
  const { addToast } = useToast();
  const [step, setStep] = useState(1);
  const [method, setMethod] = useState<'totp' | 'sms'>('totp');
  const [verificationCode, setVerificationCode] = useState('');
  const [backupCodes] = useState(Array.from({length: 10}, () => Math.random().toString(36).substr(2, 8).toUpperCase()));

  const handleVerify = () => {
    if (verificationCode.length < 6) {
      addToast('Invalid code', 'error');
      return;
    }
    setStep(3);
    addToast('2FA Verified Successfully', 'success');
  };

  const copyCodes = () => {
    navigator.clipboard.writeText(backupCodes.join('\n'));
    addToast('Backup codes copied to clipboard');
  };

  const downloadCodes = () => {
    const element = document.createElement("a");
    const file = new Blob([backupCodes.join('\n')], {type: 'text/plain'});
    element.href = URL.createObjectURL(file);
    element.download = "veza-backup-codes.txt";
    document.body.appendChild(element);
    element.click();
    addToast('Backup codes downloaded');
  };

  return (
    <div className="animate-fadeIn max-w-2xl mx-auto">
      <div className="mb-6 flex items-center gap-4">
        <button onClick={onBack} className="p-2 hover:bg-white/5 rounded-full text-gray-400 hover:text-white transition-colors">
          <ArrowLeft className="w-5 h-5" />
        </button>
        <div>
          <h2 className="text-2xl font-bold text-white">Enable Two-Factor Authentication</h2>
          <p className="text-gray-400 text-sm">Protect your account with an extra layer of security.</p>
        </div>
      </div>

      {/* STEP 1: CHOOSE METHOD */}
      {step === 1 && (
        <div className="grid gap-4">
          <div 
            onClick={() => { setMethod('totp'); setStep(2); }}
            className="p-6 border border-kodo-steel rounded-xl bg-kodo-ink hover:bg-white/5 cursor-pointer transition-all hover:border-kodo-cyan group"
          >
            <div className="flex items-center gap-4 mb-2">
              <div className="w-12 h-12 rounded-full bg-kodo-cyan/10 flex items-center justify-center group-hover:bg-kodo-cyan/20">
                <QrCode className="w-6 h-6 text-kodo-cyan" />
              </div>
              <div>
                <h3 className="text-lg font-bold text-white group-hover:text-kodo-cyan">Authenticator App</h3>
                <p className="text-sm text-gray-400">Use Google Authenticator, Authy, or 1Password. (Recommended)</p>
              </div>
            </div>
          </div>

          <div 
            onClick={() => { setMethod('sms'); setStep(2); }}
            className="p-6 border border-kodo-steel rounded-xl bg-kodo-ink hover:bg-white/5 cursor-pointer transition-all hover:border-kodo-gold group"
          >
            <div className="flex items-center gap-4 mb-2">
              <div className="w-12 h-12 rounded-full bg-kodo-gold/10 flex items-center justify-center group-hover:bg-kodo-gold/20">
                <Smartphone className="w-6 h-6 text-kodo-gold" />
              </div>
              <div>
                <h3 className="text-lg font-bold text-white group-hover:text-kodo-gold">SMS / Text Message</h3>
                <p className="text-sm text-gray-400">Receive a code via text message to your phone.</p>
              </div>
            </div>
          </div>
        </div>
      )}

      {/* STEP 2: CONFIGURE & VERIFY */}
      {step === 2 && method === 'totp' && (
        <div className="space-y-8 bg-kodo-ink p-8 rounded-xl border border-kodo-steel">
          <div className="text-center">
            <div className="bg-white p-4 inline-block rounded-xl mb-4">
              {/* Mock QR */}
              <div className="w-48 h-48 bg-gray-900 flex items-center justify-center relative overflow-hidden">
                 <QrCode className="w-full h-full text-black opacity-20 absolute" />
                 <span className="relative font-bold text-black text-xs">MOCK QR CODE</span>
                 <div className="absolute inset-0 border-4 border-black/10"></div>
                 {/* Decorative pixel pattern simulated */}
                 <div className="absolute top-2 left-2 w-10 h-10 bg-black"></div>
                 <div className="absolute top-2 right-2 w-10 h-10 bg-black"></div>
                 <div className="absolute bottom-2 left-2 w-10 h-10 bg-black"></div>
              </div>
            </div>
            <p className="text-sm text-gray-300 mb-2">Scan this QR code with your authenticator app.</p>
            <p className="text-xs text-gray-500 font-mono bg-black/30 py-1 px-2 rounded inline-block cursor-pointer hover:text-white" onClick={() => { navigator.clipboard.writeText("VEZA-SECRET-KEY-123"); addToast("Key copied"); }}>
              KEY: VEZA-SECRET-KEY-123
            </p>
          </div>

          <div className="border-t border-kodo-steel pt-6">
            <h4 className="font-bold text-white mb-4">Verify Configuration</h4>
            <div className="flex gap-3">
              <Input 
                placeholder="Enter 6-digit code" 
                value={verificationCode} 
                onChange={(e) => setVerificationCode(e.target.value.replace(/\D/g,'').slice(0,6))}
                className="font-mono text-center tracking-widest text-lg"
              />
              <Button variant="primary" onClick={handleVerify} disabled={verificationCode.length !== 6}>
                VERIFY
              </Button>
            </div>
          </div>
        </div>
      )}

      {step === 2 && method === 'sms' && (
        <div className="bg-kodo-ink p-8 rounded-xl border border-kodo-steel text-center">
           <Smartphone className="w-16 h-16 text-kodo-gold mx-auto mb-4" />
           <h3 className="text-xl font-bold text-white mb-2">SMS Setup</h3>
           <p className="text-gray-400 mb-6">Enter your phone number to receive a verification code.</p>
           <div className="flex gap-2 max-w-sm mx-auto">
              <Input placeholder="+1 (555) 000-0000" />
              <Button variant="primary" onClick={() => addToast("Code sent to your phone", "info")}>SEND</Button>
           </div>
           
           <div className="mt-8 border-t border-kodo-steel pt-6 text-left">
              <h4 className="font-bold text-white mb-4">Enter Verification Code</h4>
              <div className="flex gap-3">
                <Input 
                  placeholder="000000" 
                  value={verificationCode} 
                  onChange={(e) => setVerificationCode(e.target.value.replace(/\D/g,'').slice(0,6))}
                  className="font-mono text-center tracking-widest text-lg"
                />
                <Button variant="primary" onClick={handleVerify} disabled={verificationCode.length !== 6}>
                  VERIFY
                </Button>
              </div>
           </div>
        </div>
      )}

      {/* STEP 3: BACKUP CODES */}
      {step === 3 && (
        <div className="space-y-6 bg-kodo-ink p-8 rounded-xl border border-kodo-steel">
          <div className="flex items-center gap-4 text-kodo-lime mb-2">
            <CheckCircle className="w-8 h-8" />
            <h3 className="text-xl font-bold">2FA Enabled Successfully</h3>
          </div>
          
          <div className="bg-kodo-orange/10 border border-kodo-orange/30 p-4 rounded-lg flex gap-3">
            <AlertTriangle className="w-6 h-6 text-kodo-orange flex-shrink-0" />
            <div>
              <h4 className="font-bold text-kodo-orange text-sm mb-1">Save these backup codes</h4>
              <p className="text-xs text-gray-300">If you lose your device, these codes are the only way to access your account. Keep them safe.</p>
            </div>
          </div>

          <div className="grid grid-cols-2 gap-3 bg-black/40 p-4 rounded-lg font-mono text-sm text-gray-300 text-center border border-kodo-steel/50">
            {backupCodes.map(code => (
              <div key={code} className="py-1 tracking-wider">{code}</div>
            ))}
          </div>

          <div className="flex gap-3 pt-2">
            <Button variant="secondary" className="flex-1" icon={<Copy className="w-4 h-4" />} onClick={copyCodes}>Copy All</Button>
            <Button variant="secondary" className="flex-1" icon={<Download className="w-4 h-4" />} onClick={downloadCodes}>Download</Button>
            <Button variant="primary" className="flex-1" onClick={onComplete}>Done</Button>
          </div>
        </div>
      )}
    </div>
  );
};