import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../controllers/session_controller.dart';
import '../services/api_client.dart';

class RegisterScreen extends StatefulWidget {
  const RegisterScreen({super.key});
  @override
  State<RegisterScreen> createState() => _RegisterScreenState();
}

class _RegisterScreenState extends State<RegisterScreen> {
  final _form = GlobalKey<FormState>();
  final _name = TextEditingController();
  final _organizationCode = TextEditingController();
  final _username = TextEditingController();
  final _email = TextEditingController();
  final _phone = TextEditingController();
  final _password = TextEditingController();
  bool _busy = false;

  @override
  void dispose() {
    for (final value in [
      _organizationCode,
      _name,
      _username,
      _email,
      _phone,
      _password,
    ]) {
      value.dispose();
    }
    super.dispose();
  }

  Future<void> _submit() async {
    if (!_form.currentState!.validate()) return;
    setState(() => _busy = true);
    try {
      final message = await context.read<SessionController>().register({
        'organizationCode': _organizationCode.text.trim().toUpperCase(),
        'name': _name.text.trim(),
        'username': _username.text.trim().toLowerCase(),
        'email': _email.text.trim().toLowerCase(),
        'phone': _phone.text.trim().isEmpty
            ? 'wd${DateTime.now().microsecondsSinceEpoch}'
            : _phone.text.trim(),
        'age': 18,
        'gender': 'Prefer not to say',
        'password': _password.text,
      });
      if (mounted) {
        final messenger = ScaffoldMessenger.of(context);
        Navigator.of(context).popUntil((route) => route.isFirst);
        messenger.showSnackBar(SnackBar(content: Text(message)));
      }
    } catch (error) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text(context.read<ApiClient>().messageFrom(error))),
        );
      }
    } finally {
      if (mounted) setState(() => _busy = false);
    }
  }

  String? _required(String? value) =>
      (value?.trim().isEmpty ?? true) ? 'Required' : null;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Join the digital family')),
      body: SafeArea(
        child: SingleChildScrollView(
          padding: const EdgeInsets.all(20),
          child: Center(
            child: ConstrainedBox(
              constraints: const BoxConstraints(maxWidth: 520),
              child: Form(
                key: _form,
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.stretch,
                  children: [
                    const Text(
                      'Create your private workspace',
                      style: TextStyle(
                        fontSize: 25,
                        fontWeight: FontWeight.w800,
                      ),
                    ),
                    const SizedBox(height: 8),
                    const Text(
                      'We create your personal Google Drive folder automatically.',
                    ),
                    const SizedBox(height: 24),
                    TextFormField(
                      controller: _organizationCode,
                      textCapitalization: TextCapitalization.characters,
                      decoration: const InputDecoration(
                        labelText: 'Organization code',
                        prefixIcon: Icon(Icons.business_outlined),
                      ),
                      validator: (value) => (value?.trim().length ?? 0) < 4
                          ? 'Enter your organization code'
                          : null,
                    ),
                    const SizedBox(height: 12),
                    TextFormField(
                      controller: _name,
                      textCapitalization: TextCapitalization.words,
                      decoration: const InputDecoration(labelText: 'Full name'),
                      validator: _required,
                    ),
                    const SizedBox(height: 12),
                    TextFormField(
                      controller: _username,
                      autocorrect: false,
                      decoration: const InputDecoration(
                        labelText: 'Username',
                        helperText:
                            'Letters, numbers, dot, dash, or underscore',
                      ),
                      validator: (value) =>
                          RegExp(
                            r'^[a-zA-Z0-9._-]{3,30}$',
                          ).hasMatch(value?.trim() ?? '')
                          ? null
                          : 'Enter a valid username',
                    ),
                    const SizedBox(height: 12),
                    TextFormField(
                      controller: _email,
                      keyboardType: TextInputType.emailAddress,
                      decoration: const InputDecoration(
                        labelText: 'Email address',
                      ),
                      validator: (value) =>
                          RegExp(r'^.+@.+\..+$').hasMatch(value?.trim() ?? '')
                          ? null
                          : 'Enter a valid email',
                    ),
                    const SizedBox(height: 12),
                    TextFormField(
                      controller: _phone,
                      keyboardType: TextInputType.phone,
                      decoration: const InputDecoration(
                        labelText: 'Phone number (optional)',
                      ),
                      validator: (value) {
                        final phone = value?.trim() ?? '';
                        return phone.isEmpty || phone.length >= 7
                            ? null
                            : 'Enter at least 7 characters or leave it blank';
                      },
                    ),
                    const SizedBox(height: 12),
                    TextFormField(
                      controller: _password,
                      obscureText: true,
                      decoration: const InputDecoration(
                        labelText: 'Password',
                        helperText: 'At least 8 characters',
                      ),
                      validator: (value) => (value?.length ?? 0) >= 8
                          ? null
                          : 'Use at least 8 characters',
                    ),
                    const SizedBox(height: 24),
                    FilledButton(
                      onPressed: _busy ? null : _submit,
                      child: _busy
                          ? const SizedBox.square(
                              dimension: 22,
                              child: CircularProgressIndicator(
                                strokeWidth: 2,
                                color: Colors.white,
                              ),
                            )
                          : const Text('Create Metatron-Drive'),
                    ),
                  ],
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }
}