import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:provider/provider.dart';
import 'package:qpay/screens/onboarding/onboarding_controller.dart';
import 'package:qpay/screens/onboarding/phone/phone_controller.dart';
import 'package:qpay/screens/onboarding/widgets/onboarding_layout.dart';
import 'package:skeletonizer/skeletonizer.dart';

class PhoneScreen extends StatefulWidget {
  const PhoneScreen({super.key});

  @override
  State<PhoneScreen> createState() => _PhoneScreenState();
}

class _PhoneScreenState extends State<PhoneScreen> {
  late PhoneController phoneController;
  late OnboardingController onboardingController;
  final _formKey = GlobalKey<FormState>();
  final TextEditingController _phoneController = TextEditingController();
  final TextEditingController _emailController = TextEditingController();
  final TextEditingController _passwordController = TextEditingController();
  final TextEditingController _confirmPasswordController =
      TextEditingController();
  final TextEditingController _fullNameController = TextEditingController();

  String selectedCountryCode = '+263'; // Default to ZW
  bool _obscurePassword = true;
  bool _obscureConfirmPassword = true;

  // Common country codes with flags and names
  final List<Map<String, String>> countryCodes = [
    {'code': '+263', 'name': 'ZW', 'flag': '🇿🇼'},
    {'code': '+27', 'name': 'ZA', 'flag': '🇿🇦'},
    {'code': '+1', 'name': 'US', 'flag': '🇺🇸'},
    {'code': '+44', 'name': 'UK', 'flag': '🇬🇧'},
    {'code': '+61', 'name': 'AU', 'flag': '🇦🇺'},
    {'code': '+91', 'name': 'IN', 'flag': '🇮🇳'},
    {'code': '+86', 'name': 'CN', 'flag': '🇨🇳'},
    {'code': '+81', 'name': 'JP', 'flag': '🇯🇵'},
    {'code': '+49', 'name': 'DE', 'flag': '🇩🇪'},
    {'code': '+33', 'name': 'FR', 'flag': '🇫🇷'},
    {'code': '+39', 'name': 'IT', 'flag': '🇮🇹'},
    {'code': '+34', 'name': 'ES', 'flag': '🇪🇸'},
    {'code': '+7', 'name': 'RU', 'flag': '🇷🇺'},
    {'code': '+55', 'name': 'BR', 'flag': '🇧🇷'},
    {'code': '+52', 'name': 'MX', 'flag': '🇲🇽'},
    {'code': '+971', 'name': 'AE', 'flag': '🇦🇪'},
    {'code': '+966', 'name': 'SA', 'flag': '🇸🇦'},
    {'code': '+234', 'name': 'NG', 'flag': '🇳🇬'},
    {'code': '+254', 'name': 'KE', 'flag': '🇰🇪'},
    {'code': '+233', 'name': 'GH', 'flag': '🇬🇭'},
    {'code': '+256', 'name': 'UG', 'flag': '🇺🇬'},
  ];

  @override
  void initState() {
    super.initState();
    phoneController = PhoneController(context);
    onboardingController = Provider.of<OnboardingController>(
      context,
      listen: false,
    );
    // Pre-fill the email field if it has already been captured.
    final existingEmail = onboardingController.model.email;
    if (existingEmail != null && existingEmail.isNotEmpty) {
      _emailController.text = existingEmail;
    }
    // Pre-fill the password field if it has already been captured.
    final existingPassword = onboardingController.model.password;
    if (existingPassword != null && existingPassword.isNotEmpty) {
      _passwordController.text = existingPassword;
      _confirmPasswordController.text = existingPassword;
    }
    // Pre-fill the full name from firstName + lastName if previously captured.
    final firstName = onboardingController.model.firstName;
    final lastName = onboardingController.model.lastName;
    final combined = [
      if (firstName != null && firstName.isNotEmpty) firstName,
      if (lastName != null && lastName.isNotEmpty) lastName,
    ].join(' ');
    if (combined.isNotEmpty) {
      _fullNameController.text = combined;
    }
  }

  @override
  void dispose() {
    _phoneController.dispose();
    _emailController.dispose();
    _passwordController.dispose();
    _confirmPasswordController.dispose();
    _fullNameController.dispose();
    super.dispose();
  }

  /// Splits a full name into a [firstName] and [lastName] using a single
  /// space as the delimiter.
  ///
  /// Examples:
  ///   "John"                 -> firstName: "John",          lastName: ""
  ///   "John Doe"             -> firstName: "John",          lastName: "Doe"
  ///   "John Michael Doe"     -> firstName: "John",          lastName: "Michael Doe"
  ///   "  John   Doe  "       -> firstName: "John",          lastName: "Doe"
  ({String firstName, String lastName}) splitFullName(String fullName) {
    final trimmed = fullName.trim();
    if (trimmed.isEmpty) {
      return (firstName: '', lastName: '');
    }
    final parts = trimmed.split(RegExp(r'\s+'));
    if (parts.length == 1) {
      return (firstName: parts.first, lastName: '');
    }
    return (firstName: parts.first, lastName: parts.sublist(1).join(' '));
  }

  Future<void> _onSubmit() async {
    if (!(_formKey.currentState?.validate() ?? false)) return;

    final fullPhoneNumber = _phoneController.text;
    final email = _emailController.text.trim();
    final password = _passwordController.text;
    final nameParts = splitFullName(_fullNameController.text);

    phoneController.updatePhone(fullPhoneNumber);
    onboardingController.updateEmail(email);
    onboardingController.updatePassword(password);
    onboardingController.updateFirstName(nameParts.firstName);
    onboardingController.updateLastName(nameParts.lastName);

    await phoneController.register();
    if (phoneController.model.status != 'failed') {
      if (!mounted) return;
      context.go('/onboarding/verify');
    }
  }

  @override
  Widget build(BuildContext context) {
    return ListenableBuilder(
      listenable: phoneController,
      builder: (context, child) {
        return OnboardingLayout(
          showBackButton: true,
          trailingLabel: 'Sign in',
          trailingRoute: '/onboarding/login',
          trailingIcon: Icons.login_rounded,
          bottomLinkLabel: 'Continue as guest?',
          bottomLinkRoute: '/',
          child: OnboardingCard(
            child: Form(
              key: _formKey,
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: [
                  const OnboardingHero(
                    icon: Icons.person_add_alt_1_rounded,
                    title: 'Create your account',
                    subtitle:
                        'It only takes a minute — we\'ll send a verification code to confirm your details.',
                  ),
                  const SizedBox(height: 28),
                  OnboardingTextField(
                    controller: _fullNameController,
                    hintText: 'Full name',
                    prefixIcon: Icons.person_outline,
                    textCapitalization: TextCapitalization.words,
                    validator: (value) {
                      if (value == null || value.trim().isEmpty) {
                        return 'Please enter your full name';
                      }
                      if (value.trim().length < 2) {
                        return 'Name is too short';
                      }
                      return null;
                    },
                  ),
                  const SizedBox(height: 14),
                  _buildPhoneField(),
                  const SizedBox(height: 14),
                  OnboardingTextField(
                    controller: _emailController,
                    hintText: 'Email address',
                    prefixIcon: Icons.email_outlined,
                    keyboardType: TextInputType.emailAddress,
                    validator: (value) {
                      if (value == null || value.trim().isEmpty) {
                        return 'Please enter your email address';
                      }
                      final emailRegex = RegExp(r'^[\w\.\-+]+@[\w\.\-]+\.\w+$');
                      if (!emailRegex.hasMatch(value.trim())) {
                        return 'Please enter a valid email address';
                      }
                      return null;
                    },
                  ),
                  const SizedBox(height: 14),
                  OnboardingTextField(
                    controller: _passwordController,
                    hintText: 'Create a password',
                    prefixIcon: Icons.lock_outline,
                    obscureText: _obscurePassword,
                    enableSuggestions: false,
                    autocorrect: false,
                    suffixIcon: IconButton(
                      icon: Icon(
                        _obscurePassword
                            ? Icons.visibility_rounded
                            : Icons.visibility_off_rounded,
                      ),
                      tooltip: _obscurePassword
                          ? 'Show password'
                          : 'Hide password',
                      onPressed: () {
                        setState(() {
                          _obscurePassword = !_obscurePassword;
                        });
                      },
                    ),
                    validator: (value) {
                      if (value == null || value.isEmpty) {
                        return 'Please enter a password';
                      }
                      if (value.length < 8) {
                        return 'Password must be at least 8 characters';
                      }
                      if (value.length > 128) {
                        return 'Password is too long';
                      }
                      return null;
                    },
                  ),
                  const SizedBox(height: 14),
                  OnboardingTextField(
                    controller: _confirmPasswordController,
                    hintText: 'Confirm your password',
                    prefixIcon: Icons.lock_outline,
                    obscureText: _obscureConfirmPassword,
                    enableSuggestions: false,
                    autocorrect: false,
                    suffixIcon: IconButton(
                      icon: Icon(
                        _obscureConfirmPassword
                            ? Icons.visibility_rounded
                            : Icons.visibility_off_rounded,
                      ),
                      tooltip: _obscureConfirmPassword
                          ? 'Show password'
                          : 'Hide password',
                      onPressed: () {
                        setState(() {
                          _obscureConfirmPassword = !_obscureConfirmPassword;
                        });
                      },
                    ),
                    validator: (value) {
                      if (value == null || value.isEmpty) {
                        return 'Please confirm your password';
                      }
                      if (value != _passwordController.text) {
                        return 'Passwords do not match';
                      }
                      return null;
                    },
                  ),
                  const SizedBox(height: 28),
                  Skeletonizer(
                    enabled: phoneController.model.isLoading,
                    child: OnboardingPrimaryButton(
                      label: 'Send verification code',
                      icon: Icons.arrow_forward_rounded,
                      onPressed: _onSubmit,
                    ),
                  ),
                ],
              ),
            ),
          ),
        );
      },
    );
  }

  Widget _buildPhoneField() {
    final colorScheme = Theme.of(context).colorScheme;
    return Row(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        // Country code dropdown
        SizedBox(
          width: 110,
          child: Container(
            height: 47,
            decoration: BoxDecoration(
              color: colorScheme.surface,
              border: Border.all(
                color: colorScheme.onSurface.withValues(alpha: 0.12),
              ),
              borderRadius: BorderRadius.circular(14),
            ),
            child: DropdownButtonHideUnderline(
              child: DropdownButton<String>(
                value: selectedCountryCode,
                isExpanded: true,
                icon: const Icon(Icons.arrow_drop_down_rounded),
                padding: const EdgeInsets.symmetric(horizontal: 12),
                borderRadius: BorderRadius.circular(14),
                items: countryCodes.map((country) {
                  return DropdownMenuItem<String>(
                    value: country['code'],
                    child: Row(
                      mainAxisSize: MainAxisSize.min,
                      children: [
                        Text(country['flag']!),
                        const SizedBox(width: 6),
                        Text(
                          country['code']!,
                          style: const TextStyle(
                            fontSize: 15,
                            fontWeight: FontWeight.w500,
                          ),
                        ),
                      ],
                    ),
                  );
                }).toList(),
                onChanged: (String? newValue) {
                  if (newValue != null) {
                    setState(() {
                      selectedCountryCode = newValue;
                    });
                  }
                },
              ),
            ),
          ),
        ),
        const SizedBox(width: 10),
        // Phone number field
        Expanded(
          child: OnboardingTextField(
            controller: _phoneController,
            hintText: 'Phone number',
            prefixIcon: Icons.phone_outlined,
            keyboardType: TextInputType.numberWithOptions(decimal: true),
            validator: (value) {
              if (value == null || value.isEmpty) {
                return 'Please enter a phone number';
              }
              // Remove any non-digit characters for validation
              final digitsOnly = value.replaceAll(RegExp(r'[^\d]'), '');
              if (digitsOnly.length < 7) {
                return 'Phone number must be at least 7 digits';
              }
              if (digitsOnly.length > 15) {
                return 'Phone number is too long';
              }
              return null;
            },
          ),
        ),
      ],
    );
  }
}