import { useState, useEffect } from 'react';
import { useAuth } from '../context/AuthContext';
import { Link } from 'react-router-dom';
import { User, Mail, Lock, ArrowRight, Loader, CheckCircle, Eye, EyeOff, XCircle, Check, Wallet } from 'lucide-react';

const Register = () => {
    const [formData, setFormData] = useState({ username: '', email: '', password: '', confirmPassword: '' });
    const [showPassword, setShowPassword] = useState(false);
    const [showConfirmPassword, setShowConfirmPassword] = useState(false);
    const [isPasswordFocused, setIsPasswordFocused] = useState(false);
    const { register } = useAuth();
    const [isSubmitting, setIsSubmitting] = useState(false);
    const [error, setError] = useState('');

    const [passwordCriteria, setPasswordCriteria] = useState({ length: false, upper: false, lower: false, number: false, special: false });
    const [passwordsMatch, setPasswordsMatch] = useState(true);
    const [allValid, setAllValid] = useState(false);

    useEffect(() => {
        const { password, confirmPassword } = formData;
        const criteria = {
            length: password.length >= 8,
            upper: /[A-Z]/.test(password),
            lower: /[a-z]/.test(password),
            number: /[0-9]/.test(password),
            special: /[^A-Za-z0-9]/.test(password),
        };
        setPasswordCriteria(criteria);
        setPasswordsMatch(password === confirmPassword || confirmPassword === '');
        setAllValid(Object.values(criteria).every(Boolean) && password === confirmPassword && password !== '');
    }, [formData.password, formData.confirmPassword]);

    const handleSubmit = async (e) => {
        e.preventDefault();
        if (isSubmitting) return;
        if (!allValid) { setError('Please ensure all requirements are met and passwords match.'); return; }
        setIsSubmitting(true);
        setError('');
        try {
            await register(formData.username, formData.email, formData.password);
        } catch (err) {
            setError(err.response?.data?.username?.[0] || 'Registration failed. Please try again.');
            setIsSubmitting(false);
        }
    };

    const RequirementItem = ({ met, text }) => (
        <div style={{ display: 'flex', alignItems: 'center', gap: '0.4rem', fontSize: '0.78rem', color: met ? '#34d399' : 'var(--text-muted)', transition: 'color 0.2s', marginBottom: '0.2rem' }}>
            {met ? <Check size={12} color="#34d399" /> : <div style={{ width: 12, height: 12, borderRadius: '50%', border: '1px solid currentColor', flexShrink: 0 }} />}
            {text}
        </div>
    );

    return (
        <div className="home-container" style={{ display: 'flex', justifyContent: 'center', alignItems: 'center', minHeight: '100vh', padding: '2rem 1rem' }}>
            <div className="bg-blobs">
                <div className="blob blob-2 animate-blob" />
                <div className="blob blob-3 animate-blob animation-delay-2000" />
                <div className="blob blob-1 animate-blob animation-delay-4000" />
            </div>
            <div className="grid-overlay" />

            <div className="glass-pro animate-slide-up" style={{
                padding: '2.25rem',
                width: '100%',
                maxWidth: '400px',
                borderRadius: '20px',
                position: 'relative',
                overflow: 'hidden',
                border: '1px solid rgba(139,92,246,0.2)',
                boxShadow: '0 30px 80px rgba(0,0,0,0.6), 0 0 60px rgba(139,92,246,0.08)',
                margin: '1rem',
            }}>
                {/* Decorative orb */}
                <div style={{
                    position: 'absolute', top: '-60px', left: '-60px',
                    width: '200px', height: '200px',
                    background: 'radial-gradient(circle, rgba(139,92,246,0.12) 0%, transparent 70%)',
                    pointerEvents: 'none',
                }} />

                {/* Header */}
                <div style={{ textAlign: 'center', marginBottom: '1.75rem' }}>
                    <div className="brand-icon" style={{ width: '48px', height: '48px', margin: '0 auto 1.25rem', borderRadius: '14px', background: 'linear-gradient(135deg, #8b5cf6, #ec4899)', justifyContent: 'center', alignItems: 'center', display: 'flex', boxShadow: '0 4px 14px rgba(139,92,246,0.4)' }}>
                        <Wallet size={24} />
                    </div>
                    <h2 style={{ fontSize: '1.75rem', marginBottom: '0.4rem', letterSpacing: '-0.02em', background: 'linear-gradient(135deg, #c084fc, #f472b6)', WebkitBackgroundClip: 'text', backgroundClip: 'text', color: 'transparent' }}>
                        Create Account
                    </h2>
                    <p style={{ color: 'var(--text-muted)', fontSize: '0.88rem' }}>Join FinMK and take control of your wealth</p>
                </div>

                {/* Error */}
                {error && (
                    <div className="animate-slide-up" style={{
                        backgroundColor: 'rgba(244,63,94,0.08)',
                        border: '1px solid rgba(244,63,94,0.2)',
                        color: '#fb7185',
                        padding: '0.65rem 0.875rem',
                        borderRadius: '10px',
                        marginBottom: '1.25rem',
                        display: 'flex',
                        alignItems: 'center',
                        gap: '0.5rem',
                        fontSize: '0.875rem'
                    }}>
                        <span>⚠</span> {error}
                    </div>
                )}

                <form onSubmit={handleSubmit}>
                    <div className="auth-input-group delay-100 animate-slide-up">
                        <input type="text" className="input-field-pro" placeholder="Username"
                            value={formData.username} onChange={(e) => setFormData({ ...formData, username: e.target.value })} required />
                        <User className="auth-input-icon" size={18} />
                    </div>

                    <div className="auth-input-group delay-200 animate-slide-up">
                        <input type="email" className="input-field-pro" placeholder="Email Address"
                            value={formData.email} onChange={(e) => setFormData({ ...formData, email: e.target.value })} required />
                        <Mail className="auth-input-icon" size={18} />
                    </div>

                    <div className="auth-input-group delay-300 animate-slide-up" style={{ marginBottom: '0.75rem' }}>
                        <input type={showPassword ? 'text' : 'password'} className="input-field-pro" placeholder="Password"
                            value={formData.password}
                            onChange={(e) => setFormData({ ...formData, password: e.target.value })}
                            onFocus={() => setIsPasswordFocused(true)}
                            onBlur={() => setIsPasswordFocused(false)}
                            required style={{ paddingRight: '2.8rem' }} />
                        <Lock className="auth-input-icon" size={18} />
                        <button type="button" onClick={() => setShowPassword(!showPassword)} style={{ position: 'absolute', right: '0.875rem', top: '50%', transform: 'translateY(-50%)', background: 'none', border: 'none', color: 'var(--text-muted)', cursor: 'pointer', padding: 0, display: 'flex' }}>
                            {showPassword ? <EyeOff size={18} /> : <Eye size={18} />}
                        </button>
                    </div>

                    <div className="auth-input-group delay-300 animate-slide-up" style={{ marginBottom: '0.75rem' }}>
                        <input type={showConfirmPassword ? 'text' : 'password'} className="input-field-pro" placeholder="Confirm Password"
                            value={formData.confirmPassword}
                            onChange={(e) => setFormData({ ...formData, confirmPassword: e.target.value })}
                            required style={{ paddingRight: '2.8rem', borderColor: (!passwordsMatch && formData.confirmPassword) ? 'rgba(244,63,94,0.5)' : 'var(--glass-border)' }} />
                        <Lock className="auth-input-icon" size={18} />
                        <button type="button" onClick={() => setShowConfirmPassword(!showConfirmPassword)} style={{ position: 'absolute', right: '0.875rem', top: '50%', transform: 'translateY(-50%)', background: 'none', border: 'none', color: 'var(--text-muted)', cursor: 'pointer', padding: 0, display: 'flex' }}>
                            {showConfirmPassword ? <EyeOff size={18} /> : <Eye size={18} />}
                        </button>
                    </div>

                    {/* Password strength */}
                    {(isPasswordFocused || formData.password.length > 0) && (
                        <div className="animate-slide-up" style={{ background: 'rgba(0,0,0,0.2)', padding: '0.75rem', borderRadius: '10px', marginBottom: '1rem', border: '1px solid var(--glass-border)' }}>
                            <p style={{ fontSize: '0.7rem', color: 'var(--text-muted)', marginBottom: '0.5rem', textTransform: 'uppercase', letterSpacing: '0.08em', fontWeight: 600 }}>Requirements</p>
                            <div style={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: '0.15rem' }}>
                                <RequirementItem met={passwordCriteria.length} text="8+ Characters" />
                                <RequirementItem met={passwordCriteria.upper} text="Uppercase" />
                                <RequirementItem met={passwordCriteria.lower} text="Lowercase" />
                                <RequirementItem met={passwordCriteria.number} text="Number" />
                                <RequirementItem met={passwordCriteria.special} text="Symbol" />
                                <RequirementItem met={passwordsMatch && formData.confirmPassword !== ''} text="Passwords match" />
                            </div>
                        </div>
                    )}

                    <button type="submit" className="btn-primary delay-300 animate-slide-up" disabled={isSubmitting || !allValid} style={{
                        width: '100%', display: 'flex', justifyContent: 'center', alignItems: 'center',
                        gap: '0.5rem', marginTop: '0.25rem', padding: '0.8rem', borderRadius: '10px',
                        background: 'linear-gradient(135deg, #8b5cf6, #ec4899)',
                        boxShadow: allValid ? '0 8px 24px rgba(139,92,246,0.4)' : 'none',
                        opacity: (!allValid && !isSubmitting) ? 0.55 : 1,
                        cursor: (!allValid && !isSubmitting) ? 'not-allowed' : 'pointer',
                        fontSize: '0.95rem',
                    }}>
                        {isSubmitting ? (
                            <><Loader className="spinning" size={18} /> Creating Account...</>
                        ) : (
                            <><CheckCircle size={18} /> Create Account</>
                        )}
                    </button>
                </form>

                <div className="delay-300 animate-slide-up" style={{ marginTop: '1.5rem', textAlign: 'center', borderTop: '1px solid var(--glass-border)', paddingTop: '1.25rem' }}>
                    <p style={{ color: 'var(--text-muted)', fontSize: '0.875rem' }}>
                        Already have an account?{' '}
                        <Link to="/login" style={{ color: '#c084fc', marginLeft: '0.25rem', fontWeight: 600, textDecoration: 'none' }}>
                            Sign in →
                        </Link>
                    </p>
                </div>
            </div>
        </div>
    );
};

export default Register;