import 'dart:async';

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

import '../services/auth_controller.dart';

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

  @override
  State<AuthFlow> createState() => _AuthFlowState();
}

class _AuthFlowState extends State<AuthFlow> {
  final _phone = TextEditingController();
  final _password = TextEditingController();
  bool _staff = false;
  bool _waiting = false;
  Timer? _poll;

  @override
  void dispose() {
    _poll?.cancel();
    _phone.dispose();
    _password.dispose();
    super.dispose();
  }

  Future<void> _staffLogin() async {
    final auth = context.read<AuthController>();
    try {
      await auth.staffLogin(_phone.text.trim(), _password.text);
    } catch (_) {}
  }

  Future<void> _dealerLogin() async {
    final auth = context.read<AuthController>();
    try {
      final started = await auth.startDealerLogin(_phone.text.trim());
      if (!mounted) return;
      setState(() => _waiting = true);
      _poll = Timer.periodic(
        const Duration(seconds: 2),
        (_) => _check(started.requestId, started.secret),
      );
      await _check(started.requestId, started.secret);
    } catch (_) {}
  }

  Future<void> _check(String requestId, String secret) async {
    final auth = context.read<AuthController>();
    try {
      final status = await auth.pollDealerLogin(requestId, secret);
      if (!mounted) return;
      if (status == 'pending') return;
      _poll?.cancel();
      if (status != 'approved') setState(() => _waiting = false);
    } catch (_) {
      if (!mounted) return;
      _poll?.cancel();
      setState(() => _waiting = false);
    }
  }

  void _cancelWait() {
    _poll?.cancel();
    context.read<AuthController>().error = null;
    setState(() => _waiting = false);
  }

  @override
  Widget build(BuildContext context) {
    final auth = context.watch<AuthController>();
    final theme = Theme.of(context);
    return Scaffold(
      body: SafeArea(
        child: Align(
          alignment: Alignment.topCenter,
          child: ConstrainedBox(
            constraints: const BoxConstraints(maxWidth: 440),
            child: ListView(
              padding: const EdgeInsets.fromLTRB(24, 48, 24, 24),
              children: [
                Center(
                  child: ClipRRect(
                    borderRadius: BorderRadius.circular(8),
                    child: Image.asset(
                      'assets/images/senaro_logo.png',
                      width: 300,
                      semanticLabel: 'Senaro',
                    ),
                  ),
                ),
                const SizedBox(height: 20),
                Text(
                  'Dealer Network',
                  textAlign: TextAlign.center,
                  style: theme.textTheme.headlineMedium,
                ),
                const SizedBox(height: 8),
                Text(
                  _waiting
                      ? 'Waiting for a sales rep or super admin to approve ${_phone.text.trim()}.'
                      : _staff
                      ? 'Staff sign in with the phone number and password on the account.'
                      : 'Dealers sign in with the phone number already registered for the dealership.',
                  style: theme.textTheme.bodyLarge,
                ),
                const SizedBox(height: 28),
                if (_waiting)
                  const Center(child: CircularProgressIndicator())
                else ...[
                  SegmentedButton<bool>(
                    segments: const [
                      ButtonSegment(value: false, label: Text('Dealer')),
                      ButtonSegment(value: true, label: Text('Staff')),
                    ],
                    selected: {_staff},
                    onSelectionChanged: auth.busy
                        ? null
                        : (value) => setState(() => _staff = value.first),
                  ),
                  const SizedBox(height: 16),
                  TextField(
                    controller: _phone,
                    keyboardType: TextInputType.phone,
                    inputFormatters: [FilteringTextInputFormatter.digitsOnly],
                    decoration: const InputDecoration(
                      labelText: 'Phone',
                      hintText: '071xxxxxxx',
                    ),
                    onSubmitted: (_) => _staff ? _staffLogin() : _dealerLogin(),
                  ),
                  if (_staff) ...[
                    const SizedBox(height: 12),
                    TextField(
                      controller: _password,
                      obscureText: true,
                      decoration: const InputDecoration(labelText: 'Password'),
                      onSubmitted: (_) => _staffLogin(),
                    ),
                  ],
                ],
                if (auth.error != null) ...[
                  const SizedBox(height: 12),
                  Text(
                    auth.error!,
                    style: TextStyle(color: theme.colorScheme.error),
                  ),
                ],
                const SizedBox(height: 20),
                if (_waiting)
                  TextButton(
                    onPressed: _cancelWait,
                    child: const Text('Cancel'),
                  )
                else
                  FilledButton(
                    onPressed: auth.busy
                        ? null
                        : (_staff ? _staffLogin : _dealerLogin),
                    child: Text(
                      auth.busy
                          ? 'Please wait'
                          : (_staff ? 'Sign in' : 'Request login'),
                    ),
                  ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}