import { useState } from 'react';
import { useNavigate, Link } from 'react-router-dom';
import { useAuthStore } from '../../store/authStore';
import { Blocks, Eye, EyeOff, Mail, User as UserIcon, Lock, Check } from 'lucide-react';
import GoogleButton from './GoogleButton';

export default function RegisterForm() {
  const [email, setEmail] = useState('');
  const [username, setUsername] = useState('');
  const [password, setPassword] = useState('');
  const [confirmPassword, setConfirmPassword] = useState('');
  const [showPassword, setShowPassword] = useState(false);
  const [passwordError, setPasswordError] = useState('');
  const [formError, setFormError] = useState('');
  const { register, loading, error: storeError, clearError } = useAuthStore();
  const navigate = useNavigate();

  const displayError = formError || storeError;

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    setPasswordError('');
    setFormError('');

    if (password !== confirmPassword) {
      setPasswordError('Passwords do not match');
      return;
    }
    if (password.length < 8) {
      setPasswordError('Password must be at least 8 characters');
      return;
    }

    try {
      await register(email, username, password);
      navigate('/dashboard');
    } catch (err: any) {
      setFormError(err.message || 'Registration failed. Please try again.');
    }
  };

  return (
    <div className="min-h-screen flex items-center justify-center bg-surface-950 p-4">
      <div className="w-full max-w-md">
        <div className="text-center mb-8">
          <div className="flex items-center justify-center gap-2 mb-4">
            <Blocks className="w-10 h-10 text-primary-500" />
            <span className="text-3xl font-bold text-white">RealBlocks</span>
          </div>
          <p className="text-surface-400">Create your account</p>
        </div>

        <form onSubmit={handleSubmit} className="card space-y-4">
          {(displayError || passwordError) && (
            <div className="bg-red-500/10 border border-red-500/30 text-red-400 px-4 py-2 rounded-lg text-sm">
              {passwordError || displayError}
            </div>
          )}

          <div>
            <label className="block text-sm text-surface-300 mb-1">Username</label>
            <div className="relative">
              <UserIcon className="absolute left-3 top-1/2 -translate-y-1/2 w-4 h-4 text-surface-400" />
              <input
                type="text"
                value={username}
                onChange={(e) => { setUsername(e.target.value); clearError(); }}
                className="input pl-10"
                placeholder="coolcoder"
                required
                minLength={3}
                maxLength={30}
                pattern="^[a-zA-Z0-9_]+$"
              />
            </div>
          </div>

          <div>
            <label className="block text-sm text-surface-300 mb-1">Email</label>
            <div className="relative">
              <Mail className="absolute left-3 top-1/2 -translate-y-1/2 w-4 h-4 text-surface-400" />
              <input
                type="email"
                value={email}
                onChange={(e) => { setEmail(e.target.value); clearError(); }}
                className="input pl-10"
                placeholder="you@example.com"
                required
              />
            </div>
          </div>

          <div>
            <label className="block text-sm text-surface-300 mb-1">Password</label>
            <div className="relative">
              <Lock className="absolute left-3 top-1/2 -translate-y-1/2 w-4 h-4 text-surface-400" />
              <input
                type={showPassword ? 'text' : 'password'}
                value={password}
                onChange={(e) => { setPassword(e.target.value); clearError(); setPasswordError(''); }}
                className="input pl-10 pr-10"
                placeholder="••••••••"
                required
                minLength={8}
              />
              <button
                type="button"
                onClick={() => setShowPassword(!showPassword)}
                className="absolute right-3 top-1/2 -translate-y-1/2 text-surface-400 hover:text-white"
              >
                {showPassword ? <EyeOff className="w-4 h-4" /> : <Eye className="w-4 h-4" />}
              </button>
            </div>
            <div className="flex gap-2 mt-1 text-xs">
              <span className={`flex items-center gap-1 ${password.length >= 8 ? 'text-green-400' : 'text-surface-400'}`}>
                <Check className="w-3 h-3" /> 8+ chars
              </span>
              <span className={`flex items-center gap-1 ${/[A-Z]/.test(password) ? 'text-green-400' : 'text-surface-400'}`}>
                <Check className="w-3 h-3" /> Uppercase
              </span>
              <span className={`flex items-center gap-1 ${/[0-9]/.test(password) ? 'text-green-400' : 'text-surface-400'}`}>
                <Check className="w-3 h-3" /> Number
              </span>
            </div>
          </div>

          <div>
            <label className="block text-sm text-surface-300 mb-1">Confirm Password</label>
            <div className="relative">
              <Lock className="absolute left-3 top-1/2 -translate-y-1/2 w-4 h-4 text-surface-400" />
              <input
                type={showPassword ? 'text' : 'password'}
                value={confirmPassword}
                onChange={(e) => setConfirmPassword(e.target.value)}
                className="input pl-10"
                placeholder="••••••••"
                required
              />
            </div>
          </div>

          <button type="submit" disabled={loading} className="btn-primary w-full">
            {loading ? 'Creating account...' : 'Create Account'}
          </button>

          <div className="relative">
            <div className="absolute inset-0 flex items-center">
              <div className="w-full border-t border-surface-700" />
            </div>
            <div className="relative flex justify-center text-xs">
              <span className="bg-surface-800 px-2 text-surface-400">or continue with</span>
            </div>
          </div>

          <GoogleButton label="Sign up with Google" />

          <p className="text-center text-sm text-surface-400">
            Already have an account?{' '}
            <Link to="/login" className="text-primary-400 hover:text-primary-300">
              Sign in
            </Link>
          </p>
        </form>
      </div>
    </div>
  );
}