rely/lib/features/auth/sign_in_view.dart

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:relationship_saver/core/config/app_config.dart';
import 'package:relationship_saver/core/config/app_theme.dart';
import 'package:relationship_saver/features/auth/session_controller.dart';
import 'package:relationship_saver/features/shared/frosted_card.dart';
import 'package:relationship_saver/integrations/backend/models/backend_models.dart';

class SignInView extends ConsumerStatefulWidget {
  const SignInView({super.key});

  @override
  ConsumerState<SignInView> createState() => _SignInViewState();
}

class _SignInViewState extends ConsumerState<SignInView> {
  SignInMethod _method = SignInMethod.password;
  final TextEditingController _emailController = TextEditingController(
    text: 'demo@example.com',
  );
  final TextEditingController _passwordController = TextEditingController(
    text: 'password123',
  );
  final TextEditingController _idTokenController = TextEditingController();

  @override
  void dispose() {
    _emailController.dispose();
    _passwordController.dispose();
    _idTokenController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final AsyncValue<AuthSession?> session = ref.watch(
      sessionControllerProvider,
    );
    final bool busy = session.isLoading;
    final Object? error = session.asError?.error;

    return LayoutBuilder(
      builder: (BuildContext context, BoxConstraints viewport) {
        return SingleChildScrollView(
          padding: const EdgeInsets.all(16),
          child: ConstrainedBox(
            constraints: BoxConstraints(minHeight: viewport.maxHeight - 32),
            child: Center(
              child: ConstrainedBox(
                constraints: const BoxConstraints(maxWidth: 620),
                child: FrostedCard(
                  child: LayoutBuilder(
                    builder: (BuildContext context, BoxConstraints constraints) {
                      final bool compact = constraints.maxWidth < 480;
                      return Column(
                        mainAxisSize: MainAxisSize.min,
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: <Widget>[
                          Text(
                            'Sign in to continue',
                            style: Theme.of(context).textTheme.headlineMedium,
                          ),
                          const SizedBox(height: 8),
                          Text(
                            'Your local data remains available offline. Backend unlocks sync and signals.',
                            style: Theme.of(context).textTheme.bodyLarge
                                ?.copyWith(color: AppTheme.textSecondary),
                          ),
                          const SizedBox(height: 18),
                          if (compact)
                            DropdownButtonFormField<SignInMethod>(
                              initialValue: _method,
                              items: SignInMethod.values
                                  .map(
                                    (SignInMethod method) =>
                                        DropdownMenuItem<SignInMethod>(
                                          value: method,
                                          child: Text(_labelForMethod(method)),
                                        ),
                                  )
                                  .toList(growable: false),
                              onChanged: busy
                                  ? null
                                  : (SignInMethod? value) {
                                      if (value == null) {
                                        return;
                                      }
                                      setState(() {
                                        _method = value;
                                      });
                                    },
                              decoration: const InputDecoration(
                                labelText: 'Method',
                              ),
                            )
                          else
                            SegmentedButton<SignInMethod>(
                              segments: const <ButtonSegment<SignInMethod>>[
                                ButtonSegment<SignInMethod>(
                                  value: SignInMethod.password,
                                  label: Text('Password'),
                                ),
                                ButtonSegment<SignInMethod>(
                                  value: SignInMethod.emailMagicLink,
                                  label: Text('Magic Link'),
                                ),
                                ButtonSegment<SignInMethod>(
                                  value: SignInMethod.oidc,
                                  label: Text('OIDC'),
                                ),
                              ],
                              selected: <SignInMethod>{_method},
                              onSelectionChanged: busy
                                  ? null
                                  : (Set<SignInMethod> value) {
                                      setState(() {
                                        _method = value.first;
                                      });
                                    },
                            ),
                          const SizedBox(height: 14),
                          if (_method == SignInMethod.password ||
                              _method == SignInMethod.emailMagicLink)
                            TextField(
                              controller: _emailController,
                              keyboardType: TextInputType.emailAddress,
                              enabled: !busy,
                              decoration: const InputDecoration(
                                labelText: 'Email',
                              ),
                            ),
                          if (_method == SignInMethod.password)
                            TextField(
                              controller: _passwordController,
                              obscureText: true,
                              enabled: !busy,
                              decoration: const InputDecoration(
                                labelText: 'Password',
                              ),
                            ),
                          if (_method == SignInMethod.oidc)
                            TextField(
                              controller: _idTokenController,
                              enabled: !busy,
                              decoration: const InputDecoration(
                                labelText: 'ID Token',
                              ),
                            ),
                          if (error != null)
                            Padding(
                              padding: const EdgeInsets.only(top: 10),
                              child: Text(
                                'Sign-in failed: $error',
                                style: Theme.of(context).textTheme.bodyMedium
                                    ?.copyWith(color: const Color(0xFFC83030)),
                              ),
                            ),
                          const SizedBox(height: 16),
                          Wrap(
                            spacing: 12,
                            runSpacing: 8,
                            crossAxisAlignment: WrapCrossAlignment.center,
                            children: <Widget>[
                              FilledButton.icon(
                                onPressed: busy ? null : _submit,
                                icon: busy
                                    ? const SizedBox(
                                        width: 16,
                                        height: 16,
                                        child: CircularProgressIndicator(
                                          strokeWidth: 2,
                                          color: Colors.white,
                                        ),
                                      )
                                    : const Icon(Icons.login_rounded),
                                label: const Text('Sign In'),
                              ),
                              Text(
                                AppConfig.useFakeBackend
                                    ? 'Fake mode enabled'
                                    : 'REST mode (${AppConfig.backendBaseUrl})',
                                style: Theme.of(context).textTheme.bodyMedium
                                    ?.copyWith(color: AppTheme.textSecondary),
                              ),
                            ],
                          ),
                        ],
                      );
                    },
                  ),
                ),
              ),
            ),
          ),
        );
      },
    );
  }

  Future<void> _submit() async {
    final String? email = _emailController.text.trim().isEmpty
        ? null
        : _emailController.text.trim();
    final String? password = _passwordController.text.trim().isEmpty
        ? null
        : _passwordController.text.trim();
    final String? idToken = _idTokenController.text.trim().isEmpty
        ? null
        : _idTokenController.text.trim();

    await ref
        .read(sessionControllerProvider.notifier)
        .signIn(
          method: _method,
          email: email,
          password: password,
          idToken: idToken,
        );
  }

  String _labelForMethod(SignInMethod method) {
    return switch (method) {
      SignInMethod.password => 'Password',
      SignInMethod.emailMagicLink => 'Magic Link',
      SignInMethod.oidc => 'OIDC',
    };
  }
}