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

import '../../core/theme/app_colors.dart';
import '../profile/profile_provider.dart';
import '../profile/profile_service.dart';

const int _totalSteps = 6;

const List<Color> _stepAccentColors = [
  Color(0xFF5856D6), // Goal — iOS purple
  Color(0xFF007AFF), // Gender — iOS blue
  Color(0xFFFF9500), // DOB — iOS orange
  Color(0xFF34C759), // Height + Weight — iOS green
  Color(0xFFFF2D55), // Activity — iOS pink
  Color(0xFFFF6B00), // Calories — deep orange
];

const List<IconData> _stepIcons = [
  Icons.emoji_events_outlined,
  Icons.person_outline,
  Icons.cake_outlined,
  Icons.monitor_weight_outlined,
  Icons.directions_run,
  Icons.local_fire_department,
];

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

  @override
  ConsumerState<OnboardingScreen> createState() => _OnboardingScreenState();
}

class _OnboardingScreenState extends ConsumerState<OnboardingScreen> {
  final _pageController = PageController();
  int _currentStep = 0;

  // Collected data — new order: goal first
  String? _goal;
  String? _gender;
  DateTime? _selectedDob;
  final _heightController = TextEditingController();
  final _weightController = TextEditingController();
  String? _activity;
  int _dailyCalories = 2000;

  bool _saving = false;

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

  // Mifflin-St Jeor formula — mirrors backend calories.go
  int _calculateCalories() {
    final heightValue = int.tryParse(_heightController.text);
    final weightValue = double.tryParse(_weightController.text);
    if (heightValue == null ||
        weightValue == null ||
        _selectedDob == null ||
        _gender == null ||
        _activity == null ||
        _goal == null) {
      return 2000;
    }

    final now = DateTime.now();
    int age = now.year - _selectedDob!.year;
    if (now.month < _selectedDob!.month ||
        (now.month == _selectedDob!.month && now.day < _selectedDob!.day)) {
      age--;
    }

    final double bmr = _gender == 'male'
        ? 10 * weightValue + 6.25 * heightValue - 5 * age + 5
        : 10 * weightValue + 6.25 * heightValue - 5 * age - 161;

    const activityMultipliers = {
      'low': 1.375,
      'moderate': 1.55,
      'high': 1.725,
    };
    const goalAdjustments = {
      'lose': -500.0,
      'maintain': 0.0,
      'gain': 300.0,
    };

    final tdee = bmr * (activityMultipliers[_activity] ?? 1.55);
    final adjusted = tdee + (goalAdjustments[_goal] ?? 0);
    return adjusted.round().clamp(1000, 5000);
  }

  bool _canAdvance() {
    switch (_currentStep) {
      case 0: // Goal
        return _goal != null;
      case 1: // Gender
        return _gender != null;
      case 2: // DOB
        return _selectedDob != null;
      case 3: // Height + Weight
        final heightValue = int.tryParse(_heightController.text);
        final weightValue = double.tryParse(_weightController.text);
        return heightValue != null &&
            heightValue >= 100 &&
            heightValue <= 250 &&
            weightValue != null &&
            weightValue >= 30 &&
            weightValue <= 300;
      case 4: // Activity
        return _activity != null;
      case 5: // Calories
        return true;
      default:
        return false;
    }
  }

  void _nextStep() {
    if (!_canAdvance()) return;

    // Entering calorie review — pre-calculate based on collected data
    if (_currentStep == 4) {
      setState(() => _dailyCalories = _calculateCalories());
    }

    if (_currentStep < _totalSteps - 1) {
      _pageController.nextPage(
        duration: const Duration(milliseconds: 300),
        curve: Curves.easeInOut,
      );
    } else {
      _finish();
    }
  }

  void _prevStep() {
    if (_currentStep > 0) {
      _pageController.previousPage(
        duration: const Duration(milliseconds: 300),
        curve: Curves.easeInOut,
      );
    }
  }

  Future<void> _finish() async {
    setState(() => _saving = true);

    final dob = _selectedDob!;
    final dobString =
        '${dob.year.toString().padLeft(4, '0')}-'
        '${dob.month.toString().padLeft(2, '0')}-'
        '${dob.day.toString().padLeft(2, '0')}';

    final profileRequest = UpdateProfileRequest(
      heightCm: int.tryParse(_heightController.text),
      weightKg: double.tryParse(_weightController.text),
      dateOfBirth: dobString,
      gender: _gender,
      goal: _goal,
      activity: _activity,
      dailyCalories: _dailyCalories,
    );

    final success =
        await ref.read(profileProvider.notifier).update(profileRequest);

    if (!mounted) return;
    setState(() => _saving = false);

    if (success) {
      context.go('/home');
    } else {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(
            content: Text('Не удалось сохранить. Попробуйте ещё раз.')),
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    final accentColor = _stepAccentColors[_currentStep];
    return Scaffold(
      backgroundColor: Colors.white,
      body: SafeArea(
        child: Column(
          children: [
            _ProgressHeader(
              currentStep: _currentStep,
              accentColor: accentColor,
              onBack: _currentStep > 0 ? _prevStep : null,
            ),
            Expanded(
              child: PageView(
                controller: _pageController,
                physics: const NeverScrollableScrollPhysics(),
                onPageChanged: (index) =>
                    setState(() => _currentStep = index),
                children: [
                  _StepPage(
                    accentColor: _stepAccentColors[0],
                    icon: _stepIcons[0],
                    child: _GoalStepContent(
                      selected: _goal,
                      accentColor: _stepAccentColors[0],
                      onChanged: (value) => setState(() => _goal = value),
                    ),
                  ),
                  _StepPage(
                    accentColor: _stepAccentColors[1],
                    icon: _stepIcons[1],
                    child: _GenderStepContent(
                      selected: _gender,
                      accentColor: _stepAccentColors[1],
                      onChanged: (value) =>
                          setState(() => _gender = value),
                    ),
                  ),
                  _StepPage(
                    accentColor: _stepAccentColors[2],
                    icon: _stepIcons[2],
                    child: _DobStepContent(
                      selectedDob: _selectedDob,
                      accentColor: _stepAccentColors[2],
                      onChanged: (value) =>
                          setState(() => _selectedDob = value),
                    ),
                  ),
                  _StepPage(
                    accentColor: _stepAccentColors[3],
                    icon: _stepIcons[3],
                    child: _HeightWeightStepContent(
                      heightController: _heightController,
                      weightController: _weightController,
                      accentColor: _stepAccentColors[3],
                      onChanged: () => setState(() {}),
                    ),
                  ),
                  _StepPage(
                    accentColor: _stepAccentColors[4],
                    icon: _stepIcons[4],
                    child: _ActivityStepContent(
                      selected: _activity,
                      accentColor: _stepAccentColors[4],
                      onChanged: (value) =>
                          setState(() => _activity = value),
                    ),
                  ),
                  _StepPage(
                    accentColor: _stepAccentColors[5],
                    icon: _stepIcons[5],
                    child: _CalorieStepContent(
                      calories: _dailyCalories,
                      accentColor: _stepAccentColors[5],
                      onChanged: (value) =>
                          setState(() => _dailyCalories = value),
                    ),
                  ),
                ],
              ),
            ),
            _ContinueButton(
              isLastStep: _currentStep == _totalSteps - 1,
              enabled: _canAdvance() && !_saving,
              saving: _saving,
              accentColor: accentColor,
              onPressed: _nextStep,
            ),
          ],
        ),
      ),
    );
  }
}

// ── Progress header ────────────────────────────────────────────

class _ProgressHeader extends StatelessWidget {
  final int currentStep;
  final Color accentColor;
  final VoidCallback? onBack;

  const _ProgressHeader({
    required this.currentStep,
    required this.accentColor,
    this.onBack,
  });

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.fromLTRB(8, 8, 16, 0),
      child: Row(
        children: [
          SizedBox(
            width: 48,
            child: onBack != null
                ? IconButton(
                    icon: const Icon(Icons.arrow_back),
                    onPressed: onBack,
                  )
                : const SizedBox.shrink(),
          ),
          Expanded(
            child: ClipRRect(
              borderRadius: BorderRadius.circular(4),
              child: LinearProgressIndicator(
                value: (currentStep + 1) / _totalSteps,
                minHeight: 6,
                backgroundColor: AppColors.separator,
                valueColor: AlwaysStoppedAnimation<Color>(accentColor),
              ),
            ),
          ),
          const SizedBox(width: 48),
        ],
      ),
    );
  }
}

// ── Continue button ────────────────────────────────────────────

class _ContinueButton extends StatelessWidget {
  final bool isLastStep;
  final bool enabled;
  final bool saving;
  final Color accentColor;
  final VoidCallback onPressed;

  const _ContinueButton({
    required this.isLastStep,
    required this.enabled,
    required this.saving,
    required this.accentColor,
    required this.onPressed,
  });

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.fromLTRB(24, 12, 24, 24),
      child: SizedBox(
        width: double.infinity,
        child: FilledButton(
          style: FilledButton.styleFrom(backgroundColor: accentColor),
          onPressed: enabled ? onPressed : null,
          child: saving
              ? const SizedBox(
                  height: 20,
                  width: 20,
                  child: CircularProgressIndicator(
                    strokeWidth: 2,
                    color: Colors.white,
                  ),
                )
              : Text(isLastStep ? 'Готово' : 'Продолжить'),
        ),
      ),
    );
  }
}

// ── Step page: hero + content ──────────────────────────────────

class _StepPage extends StatelessWidget {
  final Color accentColor;
  final IconData icon;
  final Widget child;

  const _StepPage({
    required this.accentColor,
    required this.icon,
    required this.child,
  });

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Expanded(
          flex: 2,
          child: _StepHero(accentColor: accentColor, icon: icon),
        ),
        Expanded(
          flex: 3,
          child: _StepContent(child: child),
        ),
      ],
    );
  }
}

// ── Step hero — colored illustration area ──────────────────────

class _StepHero extends StatelessWidget {
  final Color accentColor;
  final IconData icon;

  const _StepHero({required this.accentColor, required this.icon});

  @override
  Widget build(BuildContext context) {
    return Container(
      width: double.infinity,
      color: accentColor.withValues(alpha: 0.12),
      child: Center(
        child: SizedBox(
          width: 180,
          height: 180,
          child: Stack(
            alignment: Alignment.center,
            children: [
              Container(
                width: 180,
                height: 180,
                decoration: BoxDecoration(
                  shape: BoxShape.circle,
                  color: accentColor.withValues(alpha: 0.12),
                ),
              ),
              Container(
                width: 130,
                height: 130,
                decoration: BoxDecoration(
                  shape: BoxShape.circle,
                  color: accentColor.withValues(alpha: 0.18),
                ),
              ),
              Container(
                width: 90,
                height: 90,
                decoration: BoxDecoration(
                  shape: BoxShape.circle,
                  color: accentColor.withValues(alpha: 0.25),
                ),
              ),
              Icon(icon, size: 48, color: accentColor),
            ],
          ),
        ),
      ),
    );
  }
}

// ── Step content — white card with rounded top corners ─────────

class _StepContent extends StatelessWidget {
  final Widget child;

  const _StepContent({required this.child});

  @override
  Widget build(BuildContext context) {
    return Container(
      width: double.infinity,
      decoration: const BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.vertical(top: Radius.circular(28)),
      ),
      padding: const EdgeInsets.fromLTRB(24, 28, 24, 16),
      child: SingleChildScrollView(child: child),
    );
  }
}

// ── Shared selectable card ──────────────────────────────────────

class _SelectableCard extends StatelessWidget {
  final bool selected;
  final Color accentColor;
  final VoidCallback onTap;
  final Widget child;
  final EdgeInsets? padding;

  const _SelectableCard({
    required this.selected,
    required this.accentColor,
    required this.onTap,
    required this.child,
    this.padding,
  });

  @override
  Widget build(BuildContext context) {
    return InkWell(
      onTap: onTap,
      borderRadius: BorderRadius.circular(16),
      child: AnimatedContainer(
        duration: const Duration(milliseconds: 150),
        padding: padding ??
            const EdgeInsets.symmetric(horizontal: 16, vertical: 16),
        decoration: BoxDecoration(
          borderRadius: BorderRadius.circular(16),
          border: Border.all(
            color: selected ? accentColor : AppColors.separator,
            width: selected ? 2 : 1,
          ),
          color: selected
              ? accentColor.withValues(alpha: 0.08)
              : Colors.transparent,
        ),
        child: child,
      ),
    );
  }
}

// ── Step 1: Goal ───────────────────────────────────────────────

class _GoalStepContent extends StatelessWidget {
  final String? selected;
  final Color accentColor;
  final ValueChanged<String?> onChanged;

  const _GoalStepContent({
    required this.selected,
    required this.accentColor,
    required this.onChanged,
  });

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text('Ваша цель', style: theme.textTheme.headlineSmall),
        const SizedBox(height: 4),
        Text(
          'Что вы хотите достичь?',
          style: theme.textTheme.bodyMedium
              ?.copyWith(color: AppColors.textSecondary),
        ),
        const SizedBox(height: 20),
        _GoalCard(
          icon: Icons.trending_down,
          label: 'Похудеть',
          selected: selected == 'lose',
          accentColor: accentColor,
          onTap: () => onChanged('lose'),
        ),
        const SizedBox(height: 12),
        _GoalCard(
          icon: Icons.balance,
          label: 'Поддержать вес',
          selected: selected == 'maintain',
          accentColor: accentColor,
          onTap: () => onChanged('maintain'),
        ),
        const SizedBox(height: 12),
        _GoalCard(
          icon: Icons.trending_up,
          label: 'Набрать массу',
          selected: selected == 'gain',
          accentColor: accentColor,
          onTap: () => onChanged('gain'),
        ),
      ],
    );
  }
}

class _GoalCard extends StatelessWidget {
  final IconData icon;
  final String label;
  final bool selected;
  final Color accentColor;
  final VoidCallback onTap;

  const _GoalCard({
    required this.icon,
    required this.label,
    required this.selected,
    required this.accentColor,
    required this.onTap,
  });

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return _SelectableCard(
      selected: selected,
      accentColor: accentColor,
      onTap: onTap,
      child: Row(
        children: [
          Icon(
            icon,
            size: 28,
            color: selected ? accentColor : AppColors.textSecondary,
          ),
          const SizedBox(width: 16),
          Expanded(
            child: Text(
              label,
              style: theme.textTheme.bodyLarge?.copyWith(
                color: selected ? accentColor : AppColors.textPrimary,
                fontWeight:
                    selected ? FontWeight.w600 : FontWeight.normal,
              ),
            ),
          ),
          Icon(
            Icons.arrow_forward_ios,
            size: 16,
            color: selected ? accentColor : AppColors.textSecondary,
          ),
        ],
      ),
    );
  }
}

// ── Step 2: Gender ─────────────────────────────────────────────

class _GenderStepContent extends StatelessWidget {
  final String? selected;
  final Color accentColor;
  final ValueChanged<String?> onChanged;

  const _GenderStepContent({
    required this.selected,
    required this.accentColor,
    required this.onChanged,
  });

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text('Ваш пол', style: theme.textTheme.headlineSmall),
        const SizedBox(height: 4),
        Text(
          'Учитывается при расчёте BMR',
          style: theme.textTheme.bodyMedium
              ?.copyWith(color: AppColors.textSecondary),
        ),
        const SizedBox(height: 20),
        Row(
          children: [
            Expanded(
              child: _GenderCard(
                label: 'Мужской',
                icon: Icons.person_outline,
                selected: selected == 'male',
                accentColor: accentColor,
                onTap: () => onChanged('male'),
              ),
            ),
            const SizedBox(width: 12),
            Expanded(
              child: _GenderCard(
                label: 'Женский',
                icon: Icons.person_2_outlined,
                selected: selected == 'female',
                accentColor: accentColor,
                onTap: () => onChanged('female'),
              ),
            ),
          ],
        ),
      ],
    );
  }
}

class _GenderCard extends StatelessWidget {
  final String label;
  final IconData icon;
  final bool selected;
  final Color accentColor;
  final VoidCallback onTap;

  const _GenderCard({
    required this.label,
    required this.icon,
    required this.selected,
    required this.accentColor,
    required this.onTap,
  });

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return _SelectableCard(
      selected: selected,
      accentColor: accentColor,
      onTap: onTap,
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 28),
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Icon(
            icon,
            size: 36,
            color: selected ? accentColor : AppColors.textSecondary,
          ),
          const SizedBox(height: 10),
          Text(
            label,
            style: theme.textTheme.bodyLarge?.copyWith(
              color: selected ? accentColor : AppColors.textPrimary,
              fontWeight:
                  selected ? FontWeight.w600 : FontWeight.normal,
            ),
          ),
        ],
      ),
    );
  }
}

// ── Step 3: Date of birth ──────────────────────────────────────

class _DobStepContent extends StatelessWidget {
  final DateTime? selectedDob;
  final Color accentColor;
  final ValueChanged<DateTime?> onChanged;

  const _DobStepContent({
    required this.selectedDob,
    required this.accentColor,
    required this.onChanged,
  });

  Future<void> _pickDate(BuildContext context) async {
    final now = DateTime.now();
    final initialDate =
        selectedDob ?? DateTime(now.year - 25, now.month, now.day);
    final pickedDate = await showDatePicker(
      context: context,
      initialDate: initialDate,
      firstDate: DateTime(now.year - 120),
      lastDate: DateTime(now.year - 10, now.month, now.day),
    );
    if (pickedDate != null) onChanged(pickedDate);
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final displayText = selectedDob != null
        ? '${selectedDob!.day.toString().padLeft(2, '0')}.'
            '${selectedDob!.month.toString().padLeft(2, '0')}.'
            '${selectedDob!.year}'
        : 'Выбрать дату';
    final isSelected = selectedDob != null;

    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text('Дата рождения', style: theme.textTheme.headlineSmall),
        const SizedBox(height: 4),
        Text(
          'Используется для расчёта нормы калорий',
          style: theme.textTheme.bodyMedium
              ?.copyWith(color: AppColors.textSecondary),
        ),
        const SizedBox(height: 20),
        InkWell(
          onTap: () => _pickDate(context),
          borderRadius: BorderRadius.circular(16),
          child: AnimatedContainer(
            duration: const Duration(milliseconds: 150),
            padding: const EdgeInsets.symmetric(
                horizontal: 20, vertical: 22),
            decoration: BoxDecoration(
              borderRadius: BorderRadius.circular(16),
              border: Border.all(
                color:
                    isSelected ? accentColor : AppColors.separator,
                width: isSelected ? 2 : 1,
              ),
              color: isSelected
                  ? accentColor.withValues(alpha: 0.08)
                  : Colors.transparent,
            ),
            child: Row(
              children: [
                Icon(
                  Icons.calendar_today_outlined,
                  color: isSelected
                      ? accentColor
                      : AppColors.textSecondary,
                ),
                const SizedBox(width: 16),
                Text(
                  displayText,
                  style: theme.textTheme.bodyLarge?.copyWith(
                    color: isSelected
                        ? accentColor
                        : AppColors.textSecondary,
                    fontWeight: isSelected
                        ? FontWeight.w600
                        : FontWeight.normal,
                  ),
                ),
              ],
            ),
          ),
        ),
      ],
    );
  }
}

// ── Step 4: Height + Weight ────────────────────────────────────

class _HeightWeightStepContent extends StatelessWidget {
  final TextEditingController heightController;
  final TextEditingController weightController;
  final Color accentColor;
  final VoidCallback onChanged;

  const _HeightWeightStepContent({
    required this.heightController,
    required this.weightController,
    required this.accentColor,
    required this.onChanged,
  });

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text('Рост и вес', style: theme.textTheme.headlineSmall),
        const SizedBox(height: 4),
        Text(
          'Введите ваши параметры',
          style: theme.textTheme.bodyMedium
              ?.copyWith(color: AppColors.textSecondary),
        ),
        const SizedBox(height: 20),
        Row(
          children: [
            Expanded(
              child: _MeasurementTile(
                controller: heightController,
                unit: 'см',
                accentColor: accentColor,
                keyboardType: TextInputType.number,
                inputFormatters: [
                  FilteringTextInputFormatter.digitsOnly,
                ],
                onChanged: (_) => onChanged(),
              ),
            ),
            const SizedBox(width: 16),
            Expanded(
              child: _MeasurementTile(
                controller: weightController,
                unit: 'кг',
                accentColor: accentColor,
                keyboardType: const TextInputType.numberWithOptions(
                    decimal: true),
                inputFormatters: [
                  FilteringTextInputFormatter.allow(
                      RegExp(r'[0-9.]')),
                ],
                onChanged: (_) => onChanged(),
              ),
            ),
          ],
        ),
      ],
    );
  }
}

class _MeasurementTile extends StatefulWidget {
  final TextEditingController controller;
  final String unit;
  final Color accentColor;
  final TextInputType keyboardType;
  final List<TextInputFormatter> inputFormatters;
  final ValueChanged<String> onChanged;

  const _MeasurementTile({
    required this.controller,
    required this.unit,
    required this.accentColor,
    required this.keyboardType,
    required this.inputFormatters,
    required this.onChanged,
  });

  @override
  State<_MeasurementTile> createState() => _MeasurementTileState();
}

class _MeasurementTileState extends State<_MeasurementTile> {
  late final FocusNode _focusNode;
  bool _hasFocus = false;

  @override
  void initState() {
    super.initState();
    _focusNode = FocusNode();
    _focusNode.addListener(
        () => setState(() => _hasFocus = _focusNode.hasFocus));
  }

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

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final hasValue = widget.controller.text.isNotEmpty;
    final isActive = _hasFocus || hasValue;

    return InkWell(
      onTap: () => _focusNode.requestFocus(),
      borderRadius: BorderRadius.circular(16),
      child: AnimatedContainer(
        duration: const Duration(milliseconds: 150),
        padding: const EdgeInsets.symmetric(
            horizontal: 16, vertical: 20),
        decoration: BoxDecoration(
          borderRadius: BorderRadius.circular(16),
          border: Border.all(
            color: isActive
                ? widget.accentColor
                : AppColors.separator,
            width: isActive ? 2 : 1,
          ),
          color: isActive
              ? widget.accentColor.withValues(alpha: 0.06)
              : Colors.transparent,
        ),
        child: Column(
          children: [
            TextField(
              controller: widget.controller,
              focusNode: _focusNode,
              keyboardType: widget.keyboardType,
              inputFormatters: widget.inputFormatters,
              textAlign: TextAlign.center,
              style: theme.textTheme.headlineLarge?.copyWith(
                color: isActive
                    ? widget.accentColor
                    : AppColors.textPrimary,
                fontWeight: FontWeight.w600,
              ),
              decoration: InputDecoration(
                border: InputBorder.none,
                isDense: true,
                contentPadding: EdgeInsets.zero,
                hintText: '–',
                hintStyle: theme.textTheme.headlineLarge?.copyWith(
                  color: AppColors.separator,
                  fontWeight: FontWeight.w300,
                ),
              ),
              onChanged: widget.onChanged,
            ),
            const SizedBox(height: 4),
            Text(
              widget.unit,
              style: theme.textTheme.bodyMedium?.copyWith(
                color: isActive
                    ? widget.accentColor
                    : AppColors.textSecondary,
              ),
            ),
          ],
        ),
      ),
    );
  }
}

// ── Step 5: Activity ───────────────────────────────────────────

class _ActivityStepContent extends StatelessWidget {
  final String? selected;
  final Color accentColor;
  final ValueChanged<String?> onChanged;

  const _ActivityStepContent({
    required this.selected,
    required this.accentColor,
    required this.onChanged,
  });

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text('Уровень активности',
            style: theme.textTheme.headlineSmall),
        const SizedBox(height: 4),
        Text(
          'Насколько активен ваш образ жизни?',
          style: theme.textTheme.bodyMedium
              ?.copyWith(color: AppColors.textSecondary),
        ),
        const SizedBox(height: 20),
        _ActivityCard(
          icon: Icons.directions_walk,
          label: 'Низкая',
          description: 'Сидячая работа, мало движения',
          selected: selected == 'low',
          accentColor: accentColor,
          onTap: () => onChanged('low'),
        ),
        const SizedBox(height: 12),
        _ActivityCard(
          icon: Icons.directions_run,
          label: 'Средняя',
          description: 'Тренировки 3–5 раз в неделю',
          selected: selected == 'moderate',
          accentColor: accentColor,
          onTap: () => onChanged('moderate'),
        ),
        const SizedBox(height: 12),
        _ActivityCard(
          icon: Icons.fitness_center,
          label: 'Высокая',
          description: 'Интенсивные тренировки каждый день',
          selected: selected == 'high',
          accentColor: accentColor,
          onTap: () => onChanged('high'),
        ),
      ],
    );
  }
}

class _ActivityCard extends StatelessWidget {
  final IconData icon;
  final String label;
  final String description;
  final bool selected;
  final Color accentColor;
  final VoidCallback onTap;

  const _ActivityCard({
    required this.icon,
    required this.label,
    required this.description,
    required this.selected,
    required this.accentColor,
    required this.onTap,
  });

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return _SelectableCard(
      selected: selected,
      accentColor: accentColor,
      onTap: onTap,
      child: Row(
        children: [
          Icon(
            icon,
            size: 28,
            color: selected ? accentColor : AppColors.textSecondary,
          ),
          const SizedBox(width: 12),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  label,
                  style: theme.textTheme.bodyLarge?.copyWith(
                    color:
                        selected ? accentColor : AppColors.textPrimary,
                    fontWeight:
                        selected ? FontWeight.w600 : FontWeight.normal,
                  ),
                ),
                const SizedBox(height: 2),
                Text(
                  description,
                  style: theme.textTheme.bodySmall
                      ?.copyWith(color: AppColors.textSecondary),
                ),
              ],
            ),
          ),
          if (selected)
            Icon(Icons.check_circle, color: accentColor),
        ],
      ),
    );
  }
}

// ── Step 6: Calorie review ─────────────────────────────────────

class _CalorieStepContent extends StatelessWidget {
  final int calories;
  final Color accentColor;
  final ValueChanged<int> onChanged;

  const _CalorieStepContent({
    required this.calories,
    required this.accentColor,
    required this.onChanged,
  });

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text('Норма калорий', style: theme.textTheme.headlineSmall),
        const SizedBox(height: 4),
        Text(
          'Рассчитана по формуле Миффлина-Сан Жеора. Вы можете скорректировать значение.',
          style: theme.textTheme.bodyMedium
              ?.copyWith(color: AppColors.textSecondary),
        ),
        const SizedBox(height: 32),
        Row(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            _AdjustButton(
              icon: Icons.remove,
              accentColor: accentColor,
              onPressed:
                  calories > 1000 ? () => onChanged(calories - 50) : null,
            ),
            const SizedBox(width: 24),
            Column(
              children: [
                Text(
                  '$calories',
                  style: theme.textTheme.displaySmall?.copyWith(
                    color: accentColor,
                    fontWeight: FontWeight.w700,
                  ),
                ),
                Text(
                  'ккал / день',
                  style: theme.textTheme.bodyMedium
                      ?.copyWith(color: AppColors.textSecondary),
                ),
              ],
            ),
            const SizedBox(width: 24),
            _AdjustButton(
              icon: Icons.add,
              accentColor: accentColor,
              onPressed:
                  calories < 5000 ? () => onChanged(calories + 50) : null,
            ),
          ],
        ),
        const SizedBox(height: 20),
        Center(
          child: Text(
            'Шаг: 50 ккал',
            style: theme.textTheme.bodySmall
                ?.copyWith(color: AppColors.textSecondary),
          ),
        ),
      ],
    );
  }
}

class _AdjustButton extends StatelessWidget {
  final IconData icon;
  final Color accentColor;
  final VoidCallback? onPressed;

  const _AdjustButton({
    required this.icon,
    required this.accentColor,
    this.onPressed,
  });

  @override
  Widget build(BuildContext context) {
    return IconButton.outlined(
      onPressed: onPressed,
      icon: Icon(
        icon,
        color: onPressed != null ? accentColor : AppColors.separator,
      ),
      iconSize: 28,
      padding: const EdgeInsets.all(12),
      style: IconButton.styleFrom(
        side: BorderSide(
          color:
              onPressed != null ? accentColor : AppColors.separator,
        ),
      ),
    );
  }
}