import React, { useState, useEffect } from 'react';
import { Link, useNavigate } from 'react-router-dom';
import { Eye, EyeOff, Mail, Lock, User, MessageCircle } from 'lucide-react';
import { useAuth } from '../../contexts/AuthContext';
import { useTheme } from '../../contexts/ThemeContext';

const Register = () => {
  const [formData, setFormData] = useState({
    username: '',
    email: '',
    password: '',
    displayName: '',
    confirmPassword: ''
  });
  const [showPassword, setShowPassword] = useState(false);
  const [showConfirmPassword, setShowConfirmPassword] = useState(false);
  const [isLoading, setIsLoading] = useState(false);
  const [validationErrors, setValidationErrors] = useState({});
  
  const { register, error, clearError } = useAuth();
  const { theme, toggleTheme } = useTheme();
  const navigate = useNavigate();

  useEffect(() => {
    clearError();
  }, []);

  const validateForm = () => {
    const errors = {};

    if (formData.username.length < 3) {
      errors.username = 'Username must be at least 3 characters';
    }

    if (!formData.email.match(/^\S+@\S+\.\S+$/)) {
      errors.email = 'Please enter a valid email address';
    }

    if (formData.password.length < 6) {
      errors.password = 'Password must be at least 6 characters';
    }

    if (formData.password !== formData.confirmPassword) {
      errors.confirmPassword = 'Passwords do not match';
    }

    if (!formData.displayName.trim()) {
      errors.displayName = 'Display name is required';
    }

    setValidationErrors(errors);
    return Object.keys(errors).length === 0;
  };

  const handleChange = (e) => {
    const { name, value } = e.target;
    setFormData(prev => ({
      ...prev,
      [name]: value
    }));

    // Clear validation error for this field
    if (validationErrors[name]) {
      setValidationErrors(prev => ({
        ...prev,
        [name]: ''
      }));
    }

    if (error) clearError();
  };

  const handleSubmit = async (e) => {
    e.preventDefault();
    
    if (!validateForm()) {
      return;
    }

    setIsLoading(true);

    try {
      const { confirmPassword, ...registerData } = formData;
      await register(registerData);
      navigate('/');
    } catch (error) {
      console.error('Registration error:', error);
    } finally {
      setIsLoading(false);
    }
  };

  return (
    <div className="min-h-screen flex items-center justify-center bg-gray-50 dark:bg-gray-900 py-12 px-4 sm:px-6 lg:px-8">
      <div className="max-w-md w-full space-y-8">
        {/* Header */}
        <div className="text-center">
          <div className="flex items-center justify-center space-x-3 mb-6">
            <MessageCircle className="h-12 w-12 text-primary-500" />
            <div>
              <h1 className="text-3xl font-bold text-gray-900 dark:text-white">YSNRFD</h1>
              <p className="text-sm text-gray-600 dark:text-gray-400">Messenger</p>
            </div>
          </div>
          <h2 className="text-2xl font-bold text-gray-900 dark:text-white">
            Create your account
          </h2>
          <p className="mt-2 text-sm text-gray-600 dark:text-gray-400">
            Or{' '}
            <Link
              to="/login"
              className="font-medium text-primary-500 hover:text-primary-600 transition-colors"
            >
              sign in to existing account
            </Link>
          </p>
        </div>

        {/* Theme Toggle */}
        <div className="flex justify-center">
          <button
            onClick={toggleTheme}
            className="p-2 rounded-lg bg-gray-200 dark:bg-gray-700 text-gray-600 dark:text-gray-300 hover:bg-gray-300 dark:hover:bg-gray-600 transition-colors"
          >
            {theme === 'dark' ? '🌙' : '☀️'}
          </button>
        </div>

        {/* Error Message */}
        {error && (
          <div className="bg-red-50 dark:bg-red-900/20 border border-red-200 dark:border-red-800 rounded-lg p-4">
            <p className="text-sm text-red-600 dark:text-red-400">{error}</p>
          </div>
        )}

        {/* Registration Form */}
        <form className="mt-8 space-y-6" onSubmit={handleSubmit}>
          <div className="space-y-4">
            {/* Username Field */}
            <div>
              <label htmlFor="username" className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-1">
                Username
              </label>
              <div className="relative">
                <div className="absolute inset-y-0 left-0 pl-3 flex items-center pointer-events-none">
                  <User className="h-5 w-5 text-gray-400" />
                </div>
                <input
                  id="username"
                  name="username"
                  type="text"
                  autoComplete="username"
                  required
                  value={formData.username}
                  onChange={handleChange}
                  className={`input-field pl-10 ${validationErrors.username ? 'border-red-500' : ''}`}
                  placeholder="Choose a username"
                />
              </div>
              {validationErrors.username && (
                <p className="mt-1 text-sm text-red-600 dark:text-red-400">{validationErrors.username}</p>
              )}
            </div>

            {/* Display Name Field */}
            <div>
              <label htmlFor="displayName" className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-1">
                Display Name
              </label>
              <input
                id="displayName"
                name="displayName"
                type="text"
                autoComplete="name"
                required
                value={formData.displayName}
                onChange={handleChange}
                className={`input-field ${validationErrors.displayName ? 'border-red-500' : ''}`}
                placeholder="Enter your display name"
              />
              {validationErrors.displayName && (
                <p className="mt-1 text-sm text-red-600 dark:text-red-400">{validationErrors.displayName}</p>
              )}
            </div>

            {/* Email Field */}
            <div>
              <label htmlFor="email" className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-1">
                Email Address
              </label>
              <div className="relative">
                <div className="absolute inset-y-0 left-0 pl-3 flex items-center pointer-events-none">
                  <Mail className="h-5 w-5 text-gray-400" />
                </div>
                <input
                  id="email"
                  name="email"
                  type="email"
                  autoComplete="email"
                  required
                  value={formData.email}
                  onChange={handleChange}
                  className={`input-field pl-10 ${validationErrors.email ? 'border-red-500' : ''}`}
                  placeholder="Enter your email"
                />
              </div>
              {validationErrors.email && (
                <p className="mt-1 text-sm text-red-600 dark:text-red-400">{validationErrors.email}</p>
              )}
            </div>

            {/* Password Field */}
            <div>
              <label htmlFor="password" className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-1">
                Password
              </label>
              <div className="relative">
                <div className="absolute inset-y-0 left-0 pl-3 flex items-center pointer-events-none">
                  <Lock className="h-5 w-5 text-gray-400" />
                </div>
                <input
                  id="password"
                  name="password"
                  type={showPassword ? 'text' : 'password'}
                  autoComplete="new-password"
                  required
                  value={formData.password}
                  onChange={handleChange}
                  className={`input-field pl-10 pr-10 ${validationErrors.password ? 'border-red-500' : ''}`}
                  placeholder="Create a password"
                />
                <button
                  type="button"
                  className="absolute inset-y-0 right-0 pr-3 flex items-center"
                  onClick={() => setShowPassword(!showPassword)}
                >
                  {showPassword ? (
                    <EyeOff className="h-5 w-5 text-gray-400 hover:text-gray-600" />
                  ) : (
                    <Eye className="h-5 w-5 text-gray-400 hover:text-gray-600" />
                  )}
                </button>
              </div>
              {validationErrors.password && (
                <p className="mt-1 text-sm text-red-600 dark:text-red-400">{validationErrors.password}</p>
              )}
            </div>

            {/* Confirm Password Field */}
            <div>
              <label htmlFor="confirmPassword" className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-1">
                Confirm Password
              </label>
              <div className="relative">
                <div className="absolute inset-y-0 left-0 pl-3 flex items-center pointer-events-none">
                  <Lock className="h-5 w-5 text-gray-400" />
                </div>
                <input
                  id="confirmPassword"
                  name="confirmPassword"
                  type={showConfirmPassword ? 'text' : 'password'}
                  autoComplete="new-password"
                  required
                  value={formData.confirmPassword}
                  onChange={handleChange}
                  className={`input-field pl-10 pr-10 ${validationErrors.confirmPassword ? 'border-red-500' : ''}`}
                  placeholder="Confirm your password"
                />
                <button
                  type="button"
                  className="absolute inset-y-0 right-0 pr-3 flex items-center"
                  onClick={() => setShowConfirmPassword(!showConfirmPassword)}
                >
                  {showConfirmPassword ? (
                    <EyeOff className="h-5 w-5 text-gray-400 hover:text-gray-600" />
                  ) : (
                    <Eye className="h-5 w-5 text-gray-400 hover:text-gray-600" />
                  )}
                </button>
              </div>
              {validationErrors.confirmPassword && (
                <p className="mt-1 text-sm text-red-600 dark:text-red-400">{validationErrors.confirmPassword}</p>
              )}
            </div>
          </div>

          {/* Submit Button */}
          <button
            type="submit"
            disabled={isLoading}
            className="w-full btn-primary py-3 px-4 text-base font-medium disabled:opacity-50 disabled:cursor-not-allowed"
          >
            {isLoading ? (
              <div className="flex items-center justify-center">
                <div className="animate-spin rounded-full h-5 w-5 border-b-2 border-white mr-2"></div>
                Creating account...
              </div>
            ) : (
              'Create Account'
            )}
          </button>

          {/* Terms Notice */}
          <div className="text-center">
            <p className="text-xs text-gray-500 dark:text-gray-400">
              By creating an account, you agree to our Terms of Service and Privacy Policy
            </p>
          </div>
        </form>
      </div>
    </div>
  );
};

export default Register;