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

import 'package:timetrack/features/entries/domain/entries_provider.dart';
import 'package:timetrack/features/entries/domain/time_entry.dart';
import 'package:timetrack/features/entries/presentation/widgets/date_range_filter.dart';
import 'package:timetrack/features/entries/presentation/widgets/day_header.dart';
import 'package:timetrack/features/entries/presentation/widgets/entry_form_sheet.dart';
import 'package:timetrack/features/entries/presentation/widgets/entry_list_tile.dart';
import 'package:timetrack/features/projects/domain/project.dart';
import 'package:timetrack/features/projects/domain/projects_provider.dart';

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

  @override
  ConsumerState<EntriesScreen> createState() => _EntriesScreenState();
}

class _EntriesScreenState extends ConsumerState<EntriesScreen> {
  DateRangeFilter _filter = DateRangeFilter.thisWeek;

  @override
  Widget build(BuildContext context) {
    final (from, to) = dateRangeBounds(_filter);
    final entriesAsync = ref.watch(
      entriesByDateRangeProvider(rangeFrom: from, rangeTo: to),
    );
    final projectsAsync = ref.watch(allProjectsProvider);

    return Scaffold(
      appBar: AppBar(
        title: const Text('Entries'),
        actions: [
          IconButton(
            icon: const Icon(Icons.add),
            tooltip: 'Add entry',
            onPressed: () => EntryFormSheet.show(context),
          ),
        ],
      ),
      body: Column(
        children: [
          DateRangeFilterChips(
            selected: _filter,
            onChanged: (f) => setState(() => _filter = f),
          ),
          Expanded(
            child: entriesAsync.when(
              data: (entries) => projectsAsync.when(
                data: (projects) => _buildList(entries, projects),
                loading: () => const Center(child: CircularProgressIndicator()),
                error: (e, _) => Center(child: Text('Error: $e')),
              ),
              loading: () => const Center(child: CircularProgressIndicator()),
              error: (e, _) => Center(child: Text('Error: $e')),
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildList(List<TimeEntry> entries, List<Project> projects) {
    if (entries.isEmpty) {
      return const Center(
        key: Key('entries_empty'),
        child: Text('No entries yet.'),
      );
    }

    final projectMap = {for (final p in projects) p.id: p};

    // Group by date
    final grouped = <DateTime, List<TimeEntry>>{};
    for (final entry in entries) {
      final day = DateTime(
        entry.startTime.year,
        entry.startTime.month,
        entry.startTime.day,
      );
      grouped.putIfAbsent(day, () => []).add(entry);
    }

    final sortedDays = grouped.keys.toList()
      ..sort((a, b) => b.compareTo(a));

    return ListView.builder(
      itemCount: sortedDays.length,
      itemBuilder: (context, index) {
        final day = sortedDays[index];
        final dayEntries = grouped[day]!;
        final totalSeconds = dayEntries.fold<int>(
          0,
          (sum, e) => sum + (e.durationSeconds ?? 0),
        );

        return Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            DayHeader(
              date: day,
              totalDuration: Duration(seconds: totalSeconds),
            ),
            ...dayEntries.map((entry) {
              final project = projectMap[entry.projectId];
              return EntryListTile(
                key: Key('entry_tile_${entry.id}'),
                entry: entry,
                projectName: project?.name ?? '—',
                projectColor: project?.colorValue ?? 0xFF888888,
                onTap: () => EntryFormSheet.show(context, existing: entry),
                onDelete: () => _deleteWithUndo(entry),
              );
            }),
          ],
        );
      },
    );
  }

  void _deleteWithUndo(TimeEntry entry) {
    ref.read(entriesNotifierProvider.notifier).delete(entry.id);
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(
        content: const Text('Entry deleted'),
        action: SnackBarAction(
          label: 'Undo',
          onPressed: () =>
              ref.read(entriesNotifierProvider.notifier).create(entry),
        ),
      ),
    );
  }
}