import 'dart:async';

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/projects/domain/project.dart';
import 'package:timetrack/features/timer/domain/timer_notifier.dart';
import 'package:timetrack/features/timer/domain/timer_state.dart';
import 'package:timetrack/features/timer/presentation/widgets/quick_access_grid.dart';
import 'package:timetrack/features/timer/presentation/widgets/project_picker_chip.dart';
import 'package:timetrack/features/timer/presentation/widgets/timer_controls.dart';
import 'package:timetrack/features/timer/presentation/widgets/timer_display.dart';
import 'package:timetrack/features/timer/presentation/widgets/today_summary_card.dart';

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

  @override
  ConsumerState<TimerScreen> createState() => _TimerScreenState();
}

class _TimerScreenState extends ConsumerState<TimerScreen> {
  Project? _selectedProject;
  final _noteController = TextEditingController();
  Timer? _ticker;

  @override
  void dispose() {
    _ticker?.cancel();
    _noteController.dispose();
    super.dispose();
  }

  void _startTicker() {
    _ticker?.cancel();
    _ticker = Timer.periodic(const Duration(seconds: 1), (_) {
      if (mounted) setState(() {});
    });
  }

  void _stopTicker() {
    _ticker?.cancel();
    _ticker = null;
  }

  @override
  Widget build(BuildContext context) {
    final timerState = ref.watch(timerNotifierProvider);
    final isRunning = timerState is TimerRunning;

    // Start or stop the local ticker based on running state
    if (isRunning && _ticker == null) {
      WidgetsBinding.instance.addPostFrameCallback((_) => _startTicker());
    } else if (!isRunning && _ticker != null) {
      _stopTicker();
    }

    // Sync selected project from running state
    if (isRunning && _selectedProject?.id != timerState.project.id) {
      WidgetsBinding.instance.addPostFrameCallback((_) {
        if (mounted) setState(() => _selectedProject = timerState.project);
      });
    }

    final elapsed = isRunning
        ? DateTime.now().difference(timerState.startTime)
        : Duration.zero;

    return Scaffold(
      appBar: AppBar(title: const Text('Timer')),
      body: SingleChildScrollView(
        padding: const EdgeInsets.symmetric(vertical: 16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.center,
          children: [
            const SizedBox(height: 24),
            const QuickAccessGrid(),
            const SizedBox(height: 16),
            ProjectPickerChip(
              project: isRunning ? timerState.project : _selectedProject,
              enabled: !isRunning,
              onChanged: (p) => setState(() => _selectedProject = p),
            ),
            const SizedBox(height: 40),
            TimerDisplay(elapsed: elapsed),
            const SizedBox(height: 40),
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: 32),
              child: TextField(
                controller: _noteController,
                decoration: const InputDecoration(
                  hintText: 'Add a note…',
                  border: OutlineInputBorder(),
                  prefixIcon: Icon(Icons.notes_outlined),
                ),
                maxLines: 1,
                onChanged: isRunning
                    ? (val) =>
                        ref.read(timerNotifierProvider.notifier).updateNote(val)
                    : null,
              ),
            ),
            const SizedBox(height: 40),
            TimerControls(
              state: timerState,
              selectedProject: _selectedProject,
            ),
            const SizedBox(height: 32),
            const TodaySummaryCard(),
            const SizedBox(height: 16),
            const _RecentEntriesList(),
          ],
        ),
      ),
    );
  }
}

class _RecentEntriesList extends ConsumerWidget {
  const _RecentEntriesList();

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final now = DateTime.now();
    final todayStart = DateTime(now.year, now.month, now.day);
    final todayEnd = todayStart.add(const Duration(days: 1));

    final entriesAsync = ref.watch(
      entriesByDateRangeProvider(rangeFrom: todayStart, rangeTo: todayEnd),
    );

    return entriesAsync.when(
      data: (entries) {
        final completed =
            entries.where((e) => e.endTime != null).take(5).toList();
        if (completed.isEmpty) return const SizedBox.shrink();

        return Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
              child: Text(
                'Recent today',
                style: Theme.of(context).textTheme.labelLarge?.copyWith(
                      color: Theme.of(context).colorScheme.onSurfaceVariant,
                    ),
              ),
            ),
            ...completed.map(
              (entry) => ListTile(
                dense: true,
                leading: const Icon(Icons.access_time, size: 18),
                title: Text(entry.note ?? '—'),
                trailing: Text(
                  _fmt(Duration(seconds: entry.durationSeconds ?? 0)),
                  style: Theme.of(context).textTheme.bodySmall,
                ),
              ),
            ),
          ],
        );
      },
      loading: () => const SizedBox.shrink(),
      error: (e, st) => const SizedBox.shrink(),
    );
  }

  String _fmt(Duration d) {
    final h = d.inHours;
    final m = d.inMinutes % 60;
    final s = d.inSeconds % 60;
    if (h > 0) return '${h}h ${m}m';
    if (m > 0) return '${m}m ${s}s';
    return '${s}s';
  }
}