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 Center(
      child: ConstrainedBox(
        constraints: const BoxConstraints(maxWidth: 620),
        child: Padding(
          padding: const EdgeInsets.all(24),
          child: FrostedCard(
            child: 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),
                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: $error',
                      style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                        color: const Color(0xFFC83030),
                      ),
                    ),
                  ),
                const SizedBox(height: 16),
                Row(
                  children: <Widget>[
                    FilledButton.icon(
                      onPressed: busy ? null : _submit,
                      icon: busy
                          ? const SizedBox(
                              width: 16,
                              height: 16,
                              child: CircularProgressIndicator(
                                strokeWidth: 2,
                                color: Colors.white,
                              ),
                            )
                          : const Icon(Icons.login_rounded),
                      label: const Text('Sign In'),
                    ),
                    const SizedBox(width: 12),
                    Text(
                      AppConfig.useFakeBackend
                          ? 'Fake mode enabled'
                          : 'REST mode (${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,
        );
  }
}