import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../../core/database/app_database.dart';
import '../../core/providers/mood_provider.dart';
import 'widgets/day_entry_card.dart';

const _weekdays = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday'];
const _months = [
  'January', 'February', 'March', 'April', 'May', 'June',
  'July', 'August', 'September', 'October', 'November', 'December',
];

class DayDetailScreen extends ConsumerWidget {
  const DayDetailScreen({super.key, required this.day});

  final DateTime day;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final entriesAsync = ref.watch(moodEntriesForDayProvider(day));

    return Scaffold(
      appBar: AppBar(
        title: Text(_appBarTitle(day)),
        centerTitle: false,
      ),
      body: entriesAsync.when(
        data: (entries) => entries.isEmpty
            ? Center(
                child: Text(
                  'No entries',
                  style: Theme.of(context)
                      .textTheme
                      .bodyMedium
                      ?.copyWith(color: Theme.of(context).colorScheme.outline),
                ),
              )
            : ListView.builder(
                padding: const EdgeInsets.symmetric(vertical: 8),
                itemCount: entries.length,
                itemBuilder: (context, i) => _SwipeToDeleteCard(
                  entry: entries[i],
                  onDelete: () => _deleteWithUndo(context, ref, entries[i]),
                ),
              ),
        loading: () => const Center(child: CircularProgressIndicator()),
        error: (_, __) => const SizedBox.shrink(),
      ),
    );
  }

  void _deleteWithUndo(BuildContext context, WidgetRef ref, MoodEntry entry) {
    ref.read(moodEntryNotifierProvider.notifier).deleteEntry(entry.id);
    ScaffoldMessenger.of(context)
      ..clearSnackBars()
      ..showSnackBar(
        SnackBar(
          content: const Text('Entry deleted'),
          action: SnackBarAction(
            label: 'Undo',
            onPressed: () => ref.read(moodEntryNotifierProvider.notifier).addEntry(
                  moodLevel: entry.moodLevel,
                  note: entry.note,
                  timestamp: entry.timestamp,
                  sleepMinutes: entry.sleepMinutes,
                  energyLevel: entry.energyLevel,
                  positivityLevel: entry.positivityLevel,
                  selfWorthLevel: entry.selfWorthLevel,
                ),
          ),
        ),
      );
  }

  static String _appBarTitle(DateTime day) {
    final now = DateTime.now();
    final today = DateTime(now.year, now.month, now.day);
    final yesterday = today.subtract(const Duration(days: 1));
    if (day == today) return 'Today';
    if (day == yesterday) return 'Yesterday';
    return '${_weekdays[day.weekday - 1]}, ${day.day} ${_months[day.month - 1]}';
  }
}

class _SwipeToDeleteCard extends StatelessWidget {
  const _SwipeToDeleteCard({required this.entry, required this.onDelete});

  final MoodEntry entry;
  final VoidCallback onDelete;

  @override
  Widget build(BuildContext context) {
    final cs = Theme.of(context).colorScheme;
    return Dismissible(
      key: ValueKey(entry.id),
      direction: DismissDirection.endToStart,
      onDismissed: (_) => onDelete(),
      background: Container(
        alignment: Alignment.centerRight,
        padding: const EdgeInsets.only(right: 24),
        margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 4),
        decoration: BoxDecoration(
          color: cs.errorContainer,
          borderRadius: BorderRadius.circular(12),
        ),
        child: Icon(Icons.delete_outline, color: cs.onErrorContainer),
      ),
      child: DayEntryCard(entry: entry),
    );
  }
}