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

import '../../core/providers/activity_provider.dart';
import '../../core/providers/mood_provider.dart';
import '../../shared/widgets/activity_grid.dart';
import '../../shared/widgets/mood_selector.dart';
import 'widgets/activities_chip.dart';
import 'widgets/answer_chip.dart';
import 'widgets/step_scale.dart';

// ── Emoji / label data ────────────────────────────────────────────────────────

const _moodEmojis = ['😞', '😔', '😐', '🙂', '😄'];
const _moodLabels = ['Awful', 'Bad', 'Okay', 'Good', 'Great'];

const _energyEmojis = ['💤', '🥱', '⚡', '🔥', '🚀'];
const _energyLabels = ['Very low', 'Low', 'OK', 'High', 'Very high'];

const _positivityEmojis = ['🌧', '☁️', '🌤', '☀️', '🌈'];
const _positivityLabels = ['Very neg', 'Negative', 'Neutral', 'Positive', 'Very pos'];

const _selfWorthEmojis = ['💔', '😕', '😐', '💪', '⭐'];
const _selfWorthLabels = ['Very low', 'Low', 'Moderate', 'High', 'Very high'];

const _scaleColors = [
  Color(0xFFE57373),
  Color(0xFFFFB74D),
  Color(0xFFFFD54F),
  Color(0xFF81C784),
  Color(0xFF4DB6AC),
];

// ── Step enum ─────────────────────────────────────────────────────────────────

enum _Step { mood, sleep, energy, positivity, selfWorth, activities }

// ── Screen ────────────────────────────────────────────────────────────────────

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

  @override
  ConsumerState<LogMoodScreen> createState() => _LogMoodScreenState();
}

class _LogMoodScreenState extends ConsumerState<LogMoodScreen> {
  // answers
  int? _mood;
  int _sleepHours = 7;
  int _sleepMinutesVal = 30; // 0/5/10…55
  int? _energy;
  int? _positivity;
  int? _selfWorth;

  // navigation state
  int _stepIndex = 0;
  bool _inReview = false;
  bool _editingFromReview = false;

  // sleep scroll controllers
  late final FixedExtentScrollController _hoursCtrl;
  late final FixedExtentScrollController _minsCtrl;

  // computed step list (set once isFirstToday is known)
  List<_Step>? _steps;

  @override
  void initState() {
    super.initState();
    _hoursCtrl = FixedExtentScrollController(initialItem: _sleepHours);
    _minsCtrl =
        FixedExtentScrollController(initialItem: _sleepMinutesVal ~/ 5);
  }

  @override
  void dispose() {
    _hoursCtrl.dispose();
    _minsCtrl.dispose();
    super.dispose();
  }

  // ── Helpers ─────────────────────────────────────────────────────────────────

  List<_Step> _buildStepList(bool isFirstToday) {
    return [
      _Step.mood,
      if (isFirstToday) _Step.sleep,
      _Step.energy,
      _Step.positivity,
      _Step.selfWorth,
      _Step.activities,
    ];
  }

  _Step get _currentStep => _steps![_stepIndex];

  String _sleepLabel() {
    final mm = _sleepMinutesVal.toString().padLeft(2, '0');
    return '$_sleepHours:$mm';
  }

  int _sleepTotalMinutes() => _sleepHours * 60 + _sleepMinutesVal;

  Color _colorFor(int level) => _scaleColors[level - 1];

  // ── Navigation ───────────────────────────────────────────────────────────────

  void _advance() {
    if (_editingFromReview) {
      setState(() {
        _editingFromReview = false;
        _inReview = true;
        _stepIndex = _steps!.length; // back to review index
      });
      return;
    }
    final next = _stepIndex + 1;
    if (next >= _steps!.length) {
      setState(() {
        _inReview = true;
        _stepIndex = _steps!.length;
      });
    } else {
      setState(() => _stepIndex = next);
    }
  }

  void _editStepFromReview(int idx) {
    setState(() {
      _editingFromReview = true;
      _stepIndex = idx;
      _inReview = false;
    });
  }

  // ── Save ─────────────────────────────────────────────────────────────────────

  Future<void> _save() async {
    final selectedActivities = ref.read(selectedActivitiesProvider);
    await ref.read(moodEntryNotifierProvider.notifier).addEntry(
          moodLevel: _mood ?? 3,
          activityIds: selectedActivities.toList(),
          sleepMinutes:
              _steps!.contains(_Step.sleep) ? _sleepTotalMinutes() : null,
          energyLevel: _energy,
          positivityLevel: _positivity,
          selfWorthLevel: _selfWorth,
        );
    if (!mounted) return;
    ref.read(selectedActivitiesProvider.notifier).clear();
    ref.invalidate(isFirstEntryTodayProvider);
    setState(() {
      _mood = null;
      _sleepHours = 7;
      _sleepMinutesVal = 30;
      _energy = null;
      _positivity = null;
      _selfWorth = null;
      _stepIndex = 0;
      _inReview = false;
      _editingFromReview = false;
      _steps = null;
    });
    // reset scroll controllers
    _hoursCtrl.jumpToItem(7);
    _minsCtrl.jumpToItem(6); // 30 / 5 = 6
    ScaffoldMessenger.of(context).showSnackBar(
      const SnackBar(content: Text('Mood logged!')),
    );
  }

  // ── Answer chip row ──────────────────────────────────────────────────────────

  Widget _buildChipRow() {
    final steps = _steps;
    if (steps == null) return const SizedBox.shrink();

    final chips = <Widget>[];

    for (int i = 0; i < steps.length; i++) {
      final step = steps[i];
      final answered = _stepIndex > i || _inReview;
      final isLiveSleep =
          step == _Step.sleep && _stepIndex == i && !_inReview;

      if (!answered && !isLiveSleep) continue;

      Widget chip;
      final tappable = _inReview ? () => _editStepFromReview(i) : null;

      switch (step) {
        case _Step.mood:
          if (_mood == null) continue;
          chip = AnswerChip(
            label: _moodEmojis[_mood! - 1],
            backgroundColor: _colorFor(_mood!),
            onTap: tappable,
          );
        case _Step.sleep:
          chip = AnswerChip(
            label: _sleepLabel(),
            backgroundColor: const Color(0xFF42A5F5),
            onTap: tappable,
          );
        case _Step.energy:
          if (_energy == null) continue;
          chip = AnswerChip(
            label: _energyEmojis[_energy! - 1],
            backgroundColor: _colorFor(_energy!),
            onTap: tappable,
          );
        case _Step.positivity:
          if (_positivity == null) continue;
          chip = AnswerChip(
            label: _positivityEmojis[_positivity! - 1],
            backgroundColor: _colorFor(_positivity!),
            onTap: tappable,
          );
        case _Step.selfWorth:
          if (_selfWorth == null) continue;
          chip = AnswerChip(
            label: _selfWorthEmojis[_selfWorth! - 1],
            backgroundColor: _colorFor(_selfWorth!),
            onTap: tappable,
          );
        case _Step.activities:
          chip = ActivitiesChip(
            backgroundColor: const Color(0xFF78909C),
            onTap: tappable,
          );
      }

      chips.add(
        Padding(
          padding: const EdgeInsets.only(right: 8),
          child: chip,
        ),
      );
    }

    if (chips.isEmpty) return const SizedBox(height: 60);

    return SizedBox(
      height: 60,
      child: ListView(
        scrollDirection: Axis.horizontal,
        padding: const EdgeInsets.symmetric(horizontal: 24),
        children: chips,
      ),
    );
  }

  // ── Step builders ─────────────────────────────────────────────────────────────

  Widget _buildMoodStep() {
    final theme = Theme.of(context);
    return Column(
      children: [
        Text(
          'How are you feeling?',
          style: theme.textTheme.headlineSmall
              ?.copyWith(fontWeight: FontWeight.w600),
          textAlign: TextAlign.center,
        ),
        const SizedBox(height: 48),
        MoodSelector(
          selected: _mood ?? 3,
          emojis: _moodEmojis,
          labels: _moodLabels,
          colors: _scaleColors,
          onChanged: (v) {
            setState(() => _mood = v);
            Future.delayed(const Duration(milliseconds: 250), _advance);
          },
        ),
        const SizedBox(height: 16),
        if (_mood != null)
          AnimatedSwitcher(
            duration: const Duration(milliseconds: 200),
            child: Text(
              _moodLabels[_mood! - 1],
              key: ValueKey(_mood),
              style: theme.textTheme.titleLarge?.copyWith(
                color: _colorFor(_mood!),
                fontWeight: FontWeight.w500,
              ),
            ),
          ),
      ],
    );
  }

  Widget _buildSleepStep() {
    final theme = Theme.of(context);
    const minuteOptions = [0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55];
    return Column(
      children: [
        Text(
          'How long did you sleep?',
          style: theme.textTheme.headlineSmall
              ?.copyWith(fontWeight: FontWeight.w600),
          textAlign: TextAlign.center,
        ),
        const SizedBox(height: 32),
        // live circle
        Container(
          width: 100,
          height: 100,
          decoration: const BoxDecoration(
            color: Color(0xFF42A5F5),
            shape: BoxShape.circle,
          ),
          child: Center(
            child: Text(
              _sleepLabel(),
              style: const TextStyle(
                fontSize: 22,
                fontWeight: FontWeight.w700,
                color: Colors.white,
              ),
            ),
          ),
        ),
        const SizedBox(height: 32),
        Row(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            // Hours wheel
            Column(
              children: [
                Text('Hours', style: theme.textTheme.labelLarge),
                const SizedBox(height: 8),
                SizedBox(
                  width: 80,
                  height: 160,
                  child: ListWheelScrollView.useDelegate(
                    controller: _hoursCtrl,
                    itemExtent: 48,
                    perspective: 0.003,
                    diameterRatio: 1.4,
                    physics: const FixedExtentScrollPhysics(),
                    onSelectedItemChanged: (i) =>
                        setState(() => _sleepHours = i),
                    childDelegate: ListWheelChildBuilderDelegate(
                      childCount: 13, // 0–12
                      builder: (ctx, i) => Center(
                        child: Text(
                          '$i',
                          style: theme.textTheme.titleLarge,
                        ),
                      ),
                    ),
                  ),
                ),
              ],
            ),
            const SizedBox(width: 16),
            Text(':', style: theme.textTheme.headlineMedium),
            const SizedBox(width: 16),
            // Minutes wheel
            Column(
              children: [
                Text('Minutes', style: theme.textTheme.labelLarge),
                const SizedBox(height: 8),
                SizedBox(
                  width: 80,
                  height: 160,
                  child: ListWheelScrollView.useDelegate(
                    controller: _minsCtrl,
                    itemExtent: 48,
                    perspective: 0.003,
                    diameterRatio: 1.4,
                    physics: const FixedExtentScrollPhysics(),
                    onSelectedItemChanged: (i) =>
                        setState(() => _sleepMinutesVal = minuteOptions[i]),
                    childDelegate: ListWheelChildBuilderDelegate(
                      childCount: minuteOptions.length,
                      builder: (ctx, i) => Center(
                        child: Text(
                          minuteOptions[i].toString().padLeft(2, '0'),
                          style: theme.textTheme.titleLarge,
                        ),
                      ),
                    ),
                  ),
                ),
              ],
            ),
          ],
        ),
        const SizedBox(height: 32),
        FilledButton(
          onPressed: _advance,
          child: const Text('Next →'),
        ),
      ],
    );
  }

  Widget _buildScaleStep({
    required String title,
    required List<String> emojis,
    required List<String> labels,
    required int? current,
    required ValueChanged<int> onSelected,
  }) {
    final theme = Theme.of(context);
    return Column(
      children: [
        Text(
          title,
          style: theme.textTheme.headlineSmall
              ?.copyWith(fontWeight: FontWeight.w600),
          textAlign: TextAlign.center,
        ),
        const SizedBox(height: 48),
        StepScale(
          emojis: emojis,
          labels: labels,
          colors: _scaleColors,
          selected: current,
          onSelected: (v) {
            onSelected(v);
            Future.delayed(const Duration(milliseconds: 250), _advance);
          },
        ),
        const SizedBox(height: 16),
        if (current != null)
          AnimatedSwitcher(
            duration: const Duration(milliseconds: 200),
            child: Text(
              labels[current - 1],
              key: ValueKey(current),
              style: theme.textTheme.titleLarge?.copyWith(
                color: _colorFor(current),
                fontWeight: FontWeight.w500,
              ),
            ),
          ),
      ],
    );
  }

  Widget _buildActivitiesStep() {
    final theme = Theme.of(context);
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Center(
          child: Text(
            'What have you been doing?',
            style: theme.textTheme.headlineSmall
                ?.copyWith(fontWeight: FontWeight.w600),
            textAlign: TextAlign.center,
          ),
        ),
        const SizedBox(height: 32),
        const ActivityGrid(),
        const SizedBox(height: 32),
        Center(
          child: FilledButton(
            onPressed: _advance,
            child: const Text('Done →'),
          ),
        ),
      ],
    );
  }

  Widget _buildReviewStep() {
    final theme = Theme.of(context);
    final steps = _steps!;

    return Column(
      children: [
        Text(
          'Ready to save?',
          style: theme.textTheme.headlineSmall
              ?.copyWith(fontWeight: FontWeight.w600),
          textAlign: TextAlign.center,
        ),
        const SizedBox(height: 24),
        Wrap(
          spacing: 12,
          runSpacing: 12,
          alignment: WrapAlignment.center,
          children: [
            for (int i = 0; i < steps.length; i++)
              _reviewChipFor(steps[i], i),
          ],
        ),
        const SizedBox(height: 48),
        // Save FAB
        GestureDetector(
          onTap: _save,
          child: Container(
            width: 72,
            height: 72,
            decoration: const BoxDecoration(
              color: Color(0xFF4CAF50),
              shape: BoxShape.circle,
              boxShadow: [
                BoxShadow(
                  color: Color(0x554CAF50),
                  blurRadius: 12,
                  offset: Offset(0, 4),
                )
              ],
            ),
            child: const Icon(Icons.check, color: Colors.white, size: 36),
          ),
        ),
      ],
    );
  }

  Widget _reviewChipFor(_Step step, int idx) {
    switch (step) {
      case _Step.mood:
        return _reviewChipTile(
          label: _mood != null ? _moodLabels[_mood! - 1] : '—',
          emoji: _mood != null ? _moodEmojis[_mood! - 1] : '?',
          color: _mood != null ? _colorFor(_mood!) : Colors.grey,
          onTap: () => _editStepFromReview(idx),
        );
      case _Step.sleep:
        return _reviewChipTile(
          label: 'Sleep',
          emoji: _sleepLabel(),
          color: const Color(0xFF42A5F5),
          onTap: () => _editStepFromReview(idx),
        );
      case _Step.energy:
        return _reviewChipTile(
          label: _energy != null ? _energyLabels[_energy! - 1] : '—',
          emoji: _energy != null ? _energyEmojis[_energy! - 1] : '?',
          color: _energy != null ? _colorFor(_energy!) : Colors.grey,
          onTap: () => _editStepFromReview(idx),
        );
      case _Step.positivity:
        return _reviewChipTile(
          label: _positivity != null ? _positivityLabels[_positivity! - 1] : '—',
          emoji: _positivity != null ? _positivityEmojis[_positivity! - 1] : '?',
          color: _positivity != null ? _colorFor(_positivity!) : Colors.grey,
          onTap: () => _editStepFromReview(idx),
        );
      case _Step.selfWorth:
        return _reviewChipTile(
          label: _selfWorth != null ? _selfWorthLabels[_selfWorth! - 1] : '—',
          emoji: _selfWorth != null ? _selfWorthEmojis[_selfWorth! - 1] : '?',
          color: _selfWorth != null ? _colorFor(_selfWorth!) : Colors.grey,
          onTap: () => _editStepFromReview(idx),
        );
      case _Step.activities:
        return GestureDetector(
          onTap: () => _editStepFromReview(idx),
          child: ActivitiesChip(
            backgroundColor: const Color(0xFF78909C),
            onTap: () => _editStepFromReview(idx),
          ),
        );
    }
  }

  Widget _reviewChipTile({
    required String label,
    required String emoji,
    required Color color,
    required VoidCallback onTap,
  }) {
    return GestureDetector(
      onTap: onTap,
      child: Container(
        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
        decoration: BoxDecoration(
          color: color.withValues(alpha: 0.15),
          borderRadius: BorderRadius.circular(30),
          border: Border.all(color: color.withValues(alpha: 0.5), width: 1.5),
        ),
        child: Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            Text(emoji, style: const TextStyle(fontSize: 20)),
            const SizedBox(width: 8),
            Text(
              label,
              style: TextStyle(
                color: color,
                fontWeight: FontWeight.w600,
                fontSize: 14,
              ),
            ),
            const SizedBox(width: 4),
            Icon(Icons.edit, size: 14, color: color.withValues(alpha: 0.7)),
          ],
        ),
      ),
    );
  }

  // ── Build ─────────────────────────────────────────────────────────────────────

  @override
  Widget build(BuildContext context) {
    final firstEntryAsync = ref.watch(isFirstEntryTodayProvider);

    return firstEntryAsync.when(
      loading: () => const Scaffold(
        body: Center(child: CircularProgressIndicator()),
      ),
      error: (e, _) => Scaffold(
        body: Center(child: Text('Error: $e')),
      ),
      data: (isFirstToday) {
        // Build (or reuse) the step list once resolved
        _steps ??= _buildStepList(isFirstToday);

        return Scaffold(
          body: SafeArea(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                const SizedBox(height: 16),
                // ── Answer chip row ──────────────────────────────────
                _buildChipRow(),
                const SizedBox(height: 24),
                // ── Step content ─────────────────────────────────────
                Expanded(
                  child: SingleChildScrollView(
                    padding: const EdgeInsets.symmetric(horizontal: 24),
                    child: _buildCurrentStep(),
                  ),
                ),
              ],
            ),
          ),
        );
      },
    );
  }

  Widget _buildCurrentStep() {
    if (_inReview) return _buildReviewStep();

    final step = _currentStep;
    switch (step) {
      case _Step.mood:
        return _buildMoodStep();
      case _Step.sleep:
        return _buildSleepStep();
      case _Step.energy:
        return _buildScaleStep(
          title: 'How is your energy level?',
          emojis: _energyEmojis,
          labels: _energyLabels,
          current: _energy,
          onSelected: (v) => setState(() => _energy = v),
        );
      case _Step.positivity:
        return _buildScaleStep(
          title: 'How positive do you feel?',
          emojis: _positivityEmojis,
          labels: _positivityLabels,
          current: _positivity,
          onSelected: (v) => setState(() => _positivity = v),
        );
      case _Step.selfWorth:
        return _buildScaleStep(
          title: 'How is your self-worth?',
          emojis: _selfWorthEmojis,
          labels: _selfWorthLabels,
          current: _selfWorth,
          onSelected: (v) => setState(() => _selfWorth = v),
        );
      case _Step.activities:
        return _buildActivitiesStep();
    }
  }
}