import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';
void main() {
  runApp(const MyApp());
}
class MyApp extends StatelessWidget {
  const MyApp({super.key});
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.blue),
        scaffoldBackgroundColor: Color(0xff292929),
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}
class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});
  final String title;
  @override
  State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
  final controller  = PageController(initialPage: 0);
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: PageView(
        controller: controller,
        children: const[
        DetailPage(headline: "Heute", daysInPast: 0),
        DetailPage(headline: "Gestern", daysInPast: 1),
        DetailPage(headline: "Vorgestern", daysInPast: 2)
        ],
      ) ,
    );
  }
}
class DetailPage extends StatefulWidget {
  const DetailPage({super.key, required this.headline, required this.daysInPast});
  final String headline;
  final int daysInPast;
  @override
  State<DetailPage> createState() => _DetailPageState();
}
class _DetailPageState extends State<DetailPage> {
  @override
  Widget build(BuildContext context) {
    return Padding(
        padding: EdgeInsetsDirectional.fromSTEB(0, 48, 0, 32),
        child: Column(children: [
          Text(widget.headline, style: const TextStyle(fontSize: 48.0, color: Colors.white)),
          TrackingElement(color: const Color(0xFFECC94E), iconData: Icons.directions_run, unit: 'm', max: 5000, daysInPast: widget.daysInPast),
          TrackingElement(color: const Color(0xFF9AFF3B), iconData: Icons.local_drink, unit: "ml" , max: 3000, daysInPast: widget.daysInPast),
          TrackingElement(color: const Color(0xFFEC2D2D), iconData: Icons.fastfood_sharp, unit: "kcal", max: 1680, daysInPast: widget.daysInPast),
        ],)
    );
  }
}
class TrackingElement extends StatefulWidget {
  const TrackingElement({super.key, required this.color, required this.iconData, required this.unit, required this.max, required this.daysInPast});
  final Color color;
  final IconData iconData;
  final String unit;
  final double max ;
  final int daysInPast;
  @override
  _TrackingElementState createState() => _TrackingElementState();
}
class _TrackingElementState extends State<TrackingElement> {
  final Future<SharedPreferences> _prefs = SharedPreferences.getInstance();
  int _counter = 0;
  double _progress = 0;
  var now = DateTime.now();
  String _StorageKey= '';
  Future<void> _incrementCounter() async {
    setState(() {
      _counter += 200;
      _progress = _counter / widget.max;
    });
    (await _prefs).setInt(_StorageKey, _counter);
  }
  @override
  void initState() {
    super.initState();
    _StorageKey = '${now.year} -${now.month}-${now.day - widget.daysInPast}_${widget.unit}';
  }
  @override
  void didChangeDependencies(){
    super.didChangeDependencies();
    _prefs.then((prefs) {
      setState(() {
        _counter = prefs.getInt(_StorageKey) ?? 0;
        _progress = _counter / widget.max;
      });
     });
  }
  @override
  Widget build(BuildContext context) {
    return InkWell(
      onTap: _incrementCounter,
      child: Column(
      children: <Widget>[
        Padding(
            padding: const EdgeInsetsDirectional.fromSTEB(32, 64, 32, 24),
            child: Row(children: <Widget>[
              Icon(widget.iconData, color: Colors.white70, size: 50),
              Text(
                '$_counter / ${widget.max.toInt()} ${widget.unit}',
                style: const TextStyle(color: Colors.white70, fontSize: 32),
              ),
            ],)
        ),
        LinearProgressIndicator(
          value: _progress,
          color: widget.color,
          backgroundColor: const Color(0x40FFFFFF),
          minHeight: 12.0,
        )
      ],
    ),);
  }
}