import 'dart:async';

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

import '../../Utils/image_constant.dart';
import '../../Utils/size_utils.dart';
import '../../theme/app_style.dart';
import '../../widgets/app_bar/appbar_image.dart';
import '../../widgets/app_bar/appbar_title.dart';
import '../../widgets/app_bar/custom_app_bar.dart';
import '../../widgets/custom_button.dart';
import 'attendance_math.dart';
import 'attendance_service.dart';
import 'attendance_storage.dart';

// ---------------------------------------------------------------------------
// Duty punch page: Punch In -> background records one GPS dot every 5 min ->
// Punch Out -> summary (points + km). Sessions stay on the phone (sqflite).
// ---------------------------------------------------------------------------

class PunchScreen extends StatefulWidget {
  const PunchScreen({super.key});

  @override
  State<PunchScreen> createState() => _PunchScreenState();
}

class _PunchScreenState extends State<PunchScreen> {
  bool _punchedIn = false;
  bool _busy = false;
  String? _sessionId;
  String? _punchInTime;
  int _points = 0;
  double _km = 0;
  List<Map<String, dynamic>> _history = [];
  Timer? _clock;

  void _onTaskData(Object data) {
    if (data is Map && mounted) {
      setState(() {
        _points = (data['points'] as num?)?.toInt() ?? _points;
        _km = (data['km'] as num?)?.toDouble() ?? _km;
      });
    }
  }

  @override
  void initState() {
    super.initState();
    FlutterForegroundTask.addTaskDataCallback(_onTaskData);
    _refresh();
    _clock = Timer.periodic(const Duration(seconds: 30), (_) {
      if (mounted && _punchedIn) setState(() {});
    });
  }

  @override
  void dispose() {
    FlutterForegroundTask.removeTaskDataCallback(_onTaskData);
    _clock?.cancel();
    super.dispose();
  }

  Future<void> _refresh() async {
    final bool open = await AttendanceService.isPunchedIn;
    final String? sid = await AttendanceStorage.getActiveSession();
    List<Map<String, dynamic>> history =
        await AttendanceStorage.getRecentSessions(limit: 10);
    int points = 0;
    double km = 0;
    String? punchIn;
    if (open && sid != null) {
      final session = await AttendanceStorage.getSession(sid);
      punchIn = session?['punch_in'] as String?;
      final pts = await AttendanceStorage.getPoints(sid);
      points = pts.length;
      km = _sumKm(pts);
    }
    if (!mounted) return;
    setState(() {
      _punchedIn = open;
      _sessionId = sid;
      _punchInTime = punchIn;
      _points = points;
      _km = km;
      _history = history;
    });
  }

  double _sumKm(List<Map<String, dynamic>> pts) {
    double meters = 0;
    for (int i = 1; i < pts.length; i++) {
      meters += haversineMeters(
        (pts[i - 1]['lat'] as num).toDouble(),
        (pts[i - 1]['lng'] as num).toDouble(),
        (pts[i]['lat'] as num).toDouble(),
        (pts[i]['lng'] as num).toDouble(),
      );
    }
    return meters / 1000.0;
  }

  Future<void> _onPunchIn() async {
    setState(() => _busy = true);
    try {
      final PermissionResult perm =
          await AttendanceService.ensurePermissions();
      if (!perm.ok) {
        _msg(perm.message, true);
        return;
      }
      if (perm.message != ' granted') _msg(perm.message, false);
      await AttendanceService.punchIn();
      if (mounted) {
        await AttendanceService.maybeAskBatteryExemption(context);
      }
      await _refresh();
      _msg('Punched in - tracking every 5 min', false);
    } catch (e) {
      _msg('Punch in failed: $e', true);
    } finally {
      if (mounted) setState(() => _busy = false);
    }
  }

  Future<void> _onPunchOut() async {
    setState(() => _busy = true);
    try {
      final Map<String, dynamic> summary = await AttendanceService.punchOut();
      await _refresh();
      if (!mounted) return;
      final double km = (summary['km'] as num).toDouble();
      final int pts = summary['points'] as int;
      showDialog(
        context: context,
        builder: (c) => AlertDialog(
          title: const Text('Duty summary'),
          content: Text(
            'Points recorded: $pts\n'
            'Distance (straight line): ${km.toStringAsFixed(2)} km\n'
            'Road distance: coming in step 4 (free API).',
          ),
          actions: [
            TextButton(
              onPressed: () => Navigator.of(c).pop(),
              child: const Text('OK'),
            ),
          ],
        ),
      );
    } catch (e) {
      _msg('Punch out failed: $e', true);
    } finally {
      if (mounted) setState(() => _busy = false);
    }
  }

  void _msg(String text, bool isError) {
    if (!mounted) return;
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(
        content: Text(text),
        backgroundColor: isError ? Colors.red : Colors.green,
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: CustomAppBar(
        height: getVerticalSize(49),
        leadingWidth: 40,
        leading: AppbarImage(
          height: getSize(24),
          width: getSize(24),
          svgPath: ImageConstant.imgArrowleftBlueGray900,
          margin: getMargin(left: 16, top: 12, bottom: 13),
          onTap: () => Navigator.pop(context),
        ),
        centerTitle: true,
        title: AppbarTitle(text: 'Duty Punch'),
      ),
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            _statusCard(),
            const SizedBox(height: 16),
            CustomButton(
              height: getVerticalSize(50),
              text: _busy
                  ? 'Please wait...'
                  : (_punchedIn ? 'Punch Out' : 'Punch In'),
              margin: getMargin(top: 8, bottom: 5),
              onTap: _busy ? () {} : (_punchedIn ? _onPunchOut : _onPunchIn),
            ),
            const SizedBox(height: 8),
            Text(
              'Keeps recording one location every 5 min, even with the app '
              'minimized. For Xiaomi/Oppo/Vivo/Samsung allow Unrestricted '
              'battery use or tracking may pause.',
              style: AppStyle.txtGilroyMedium16Bluegray900.copyWith(
                fontSize: 12,
              ),
            ),
            const SizedBox(height: 20),
            Text('Recent duties',
                style: AppStyle.txtGilroyMedium16Bluegray900.copyWith(
                  fontWeight: FontWeight.bold,
                )),
            const SizedBox(height: 8),
            ..._history.map(_historyTile),
          ],
        ),
      ),
    );
  }

  Widget _statusCard() {
    final Color dot = _punchedIn ? Colors.green : Colors.grey;
    return Card(
      elevation: 2,
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              children: [
                Container(
                  width: 12,
                  height: 12,
                  decoration:
                      BoxDecoration(color: dot, shape: BoxShape.circle),
                ),
                const SizedBox(width: 8),
                Text(
                  _punchedIn ? 'Punched IN' : 'Punched OUT',
                  style: const TextStyle(
                      fontSize: 18, fontWeight: FontWeight.bold),
                ),
              ],
            ),
            const SizedBox(height: 12),
            Text('Session: ${_sessionId ?? '-'}'),
            if (_punchInTime != null) Text('Since: $_punchInTime'),
            const SizedBox(height: 8),
            Text('Points: $_points',
                style:
                    const TextStyle(fontSize: 16, fontWeight: FontWeight.w600)),
            Text('Distance: ${_km.toStringAsFixed(2)} km',
                style:
                    const TextStyle(fontSize: 16, fontWeight: FontWeight.w600)),
          ],
        ),
      ),
    );
  }

  Widget _historyTile(Map<String, dynamic> s) {
    final String status = (s['status'] ?? '') as String;
    final double km = ((s['total_km_haversine'] ?? 0) as num).toDouble();
    return Card(
      child: ListTile(
        title: Text('${s['punch_in']}',
            style: const TextStyle(fontSize: 12)),
        subtitle: Text(
            'Out: ${s['punch_out'] ?? '-'} • ${km.toStringAsFixed(2)} km',
            style: const TextStyle(fontSize: 11)),
        trailing: Text(status,
            style: TextStyle(
              color: status == 'OPEN' ? Colors.green : Colors.grey,
              fontWeight: FontWeight.bold,
            )),
      ),
    );
  }
}