import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../../providers/database_provider.dart';
import '../dashboard/dashboard_screen.dart';
import 'onboarding_state.dart';
import 'steps/child_step.dart';
import 'steps/pin_step.dart';
import 'steps/rules_step.dart';
import 'steps/welcome_step.dart';

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

  @override
  ConsumerState<OnboardingFlow> createState() => _OnboardingFlowState();
}

class _OnboardingFlowState extends ConsumerState<OnboardingFlow> {
  final _pageController = PageController();
  bool _isSaving = false;

  @override
  void dispose() {
    _pageController.dispose();
    super.dispose();
  }

  void _goTo(int page) {
    _pageController.animateToPage(
      page,
      duration: const Duration(milliseconds: 300),
      curve: Curves.easeInOut,
    );
  }

  Future<void> _finish() async {
    final draft = ref.read(onboardingDraftProvider);
    if (draft.childName.trim().isEmpty) {
      _showError('Indiquez le prénom de l\'enfant.');
      _goTo(1);
      return;
    }
    if (draft.pin.length < 4) {
      _showError('Le PIN doit contenir au moins 4 chiffres.');
      _goTo(2);
      return;
    }
    if (draft.pin != draft.pinConfirm) {
      _showError('Les deux PIN ne correspondent pas.');
      _goTo(2);
      return;
    }

    setState(() => _isSaving = true);
    try {
      final repo = ref.read(onboardingRepositoryProvider);
      await repo.finish(
        childName: draft.childName,
        color: draft.color,
        pin: draft.pin,
        importDefaultRules: draft.importDefaultRules,
      );
      ref.invalidate(onboardingCompleteProvider);
      ref.invalidate(childrenProvider);

      if (!mounted) return;
      Navigator.of(context).pushReplacement(
        MaterialPageRoute<void>(builder: (_) => const DashboardScreen()),
      );
    } catch (e) {
      _showError('Erreur lors de l\'enregistrement. Réessayez.');
    } finally {
      if (mounted) setState(() => _isSaving = false);
    }
  }

  void _showError(String message) {
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text(message), backgroundColor: Colors.red.shade700),
    );
  }

  @override
  Widget build(BuildContext context) {
    return PageView(
      controller: _pageController,
      physics: const NeverScrollableScrollPhysics(),
      onPageChanged: (_) {},
      children: [
        WelcomeStep(onNext: () => _goTo(1)),
        ChildStep(
          step: 2,
          onBack: () => _goTo(0),
          onNext: () {
            final name = ref.read(onboardingDraftProvider).childName.trim();
            if (name.isEmpty) {
              _showError('Indiquez le prénom de l\'enfant.');
              return;
            }
            _goTo(2);
          },
        ),
        PinStep(
          step: 3,
          onBack: () => _goTo(1),
          onNext: () {
            final draft = ref.read(onboardingDraftProvider);
            if (draft.pin.length < 4) {
              _showError('Le PIN doit contenir au moins 4 chiffres.');
              return;
            }
            if (draft.pin != draft.pinConfirm) {
              _showError('Les deux PIN ne correspondent pas.');
              return;
            }
            _goTo(3);
          },
        ),
        RulesStep(
          step: 4,
          isSaving: _isSaving,
          onBack: () => _goTo(2),
          onFinish: _finish,
        ),
      ],
    );
  }
}