// GCG.MeinCantor - Die Schulplattform für Cantorianer.
// Copyright (C) 2021-2022 Georg-Cantor-Gymnasium Halle (Saale)

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.

// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

import 'dart:convert';
import 'dart:io';

import 'package:meincantor/cache_manager.dart';
import 'package:flutter_cache_manager/flutter_cache_manager.dart';
import 'package:http/http.dart' as http;
import 'package:flutter/material.dart';
import 'package:intl/intl.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:meincantor/const.dart';
import 'package:meincantor/timetable.dart';
import 'package:meincantor/login.dart';
import 'package:meincantor/main.dart';

Future<http.Response> getArticles() async {
  var uri = Uri.https(szUrl["url"]! as String, "/api/articles");
  final response =
      await http.get(uri, headers: szUrl["headers"]! as Map<String, String>);
  return (response);
}

Future<http.Response> getNews() async {
  var uri = Uri.https(szUrl["url"]! as String, "/api/aktuelles");
  final response =
      await http.get(uri, headers: szUrl["headers"]! as Map<String, String>);
  return (response);
}

Future<http.Response> getToken(
    String user, String password, String otp, String devId) async {
  var uri = Uri.https("mein.cantorgymnasium.de", "/login");
  String body =
      '{"user":"$user", "password": "$password", "otp": "$otp", "devid": "$devId"}';
  final response = await http.post(uri, body: body);
  return (response);
}

Future<String> getUserInfo(
    String user, String password, String otp, String devId) async {
  var uri = Uri.https("mein.cantorgymnasium.de", "/api/userinfo");
  String body =
      '{"user":"$user", "password": "$password", "otp": "$otp", "devid": "$devId"}';
  final response = await http.post(uri, body: body);

  if (response.statusCode == 200) {
    return utf8.decode(response.bodyBytes);
  } else {
    throw Exception('Failed to log in');
  }
}

Future<http.Response> fetchClassTimetable(String ext, String? classNum) async {
  try {
    return (http.Response(await getCachedTimetable(ext, classNum), 200));
  } on HttpExceptionWithStatus catch (e) {
    return http.Response(e.message, e.statusCode);
  } on HttpException catch (e) {
    return http.Response(e.message, 500);
  } on SocketException catch (e) {
    return http.Response(e.message, 404);
  }
}

fetchLessonList() async {
  SharedPreferences prefs = await SharedPreferences.getInstance();
  String classNum;
  if (prefs.getString('class_num') != null) {
    classNum = prefs.getString('class_num')!.replaceAll("/", "_");
  } else {
    classNum = '05_1';
  }
  var apiKey = prefs.getString('api_key');
  var uri = Uri.https("mein.cantorgymnasium.de", "/api/lessons/$classNum");
  var headers = {"x-api-key": "$apiKey"};
  final response =
      await http.get(uri, headers: headers).onError((error, stackTrace) {
    return (http.Response("", 404));
  });
  if (response.statusCode == 200) {
    prefs.setString("lessons", utf8.decode(response.bodyBytes));
  } else {
    prefs.setString("lessons", jsonEncode([]));
  }
}

Widget buildTimetable(Future<http.Response> future, String info) {
  return FutureBuilder<http.Response>(
    future: future,
    builder: (context, snapshot) {
      if (snapshot.hasData) {
        int statusCode = snapshot.data!.statusCode;
        if (statusCode == 200) {
          Widget timetableView = ClassTimetableBuilder.buildView(
                  jsonDecode(snapshot.data!.body), context)
              .view
              .child;
          return timetableView;
        } else if (statusCode == 400) {
          Navigator.push(
              context, MaterialPageRoute(builder: (context) => Login()));
        } else if (statusCode == 500) {
          var chars = Runes('Es konnte kein $info gefunden werden. \u{1F937}');
          List<Widget> cardChildren = [];
          cardChildren.add(ListTile(
            title: Text(String.fromCharCodes(chars),
                style: const TextStyle(color: Palette.primary)),
          ));
          Card card = Card(
              shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.circular(15.0),
              ),
              color: Colors.white,
              child: Column(
                children: cardChildren,
              ));
          return Padding(
              padding: const EdgeInsets.fromLTRB(20, 20, 20, 20),
              child: ListView(
                children: [card],
              ));
        } else if (statusCode == 404) {
          var chars = Runes(
              'Keine Verbindung mit dem MeinCantor-Server möglich. Bitte prüfe deine Internet-Verbindung und deine DNS-Einstellungen oder wende dich an den MeinCantor-Support. \u{1F4e1}');
          List<Widget> cardChildren = [];
          cardChildren.add(ListTile(
            title: Text(String.fromCharCodes(chars),
                style: const TextStyle(color: Palette.primary)),
          ));
          Card card = Card(
              shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.circular(15.0),
              ),
              color: Colors.white,
              child: Column(
                children: cardChildren,
              ));
          return Padding(
              padding: const EdgeInsets.fromLTRB(20, 20, 20, 20),
              child: ListView(
                children: [card],
              ));
        }
        return Center(child: Text('Error $statusCode'));
      } else if (snapshot.hasError) {
        return Text('$snapshot.error');
      } else {
        return const Center(child: CircularProgressIndicator());
      }
    },
  );
}

Widget buildTodayClassTimetableLesson(int count) {
  return FutureBuilder<http.Response>(
    future: fetchClassTimetable(
        "/${DateFormat("yyyyMMdd").format(DateTime.now())}", null),
    builder: (context, snapshot) {
      if (snapshot.hasData) {
        int statusCode = snapshot.data!.statusCode;
        if (statusCode == 200) {
          List<Widget> lessons = LessonsListBuilder.buildList(
                  jsonDecode(snapshot.data!.body),
                  count: count)
              .lessons;
          if (lessons.isNotEmpty) {
            return Column(children: lessons);
          } else {
            var chars = Runes(
                'Keine Stunden mehr gefunden. Sieht so aus als hättest du Schluss für heute \u{1F389}');
            List<Widget> cardChildren = [];
            cardChildren.add(ListTile(
                title: Text(String.fromCharCodes(chars),
                    style: const TextStyle(color: Palette.primary))));
            Card card = Card(
                shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.circular(15.0),
                ),
                color: Colors.white,
                child: Column(
                  children: cardChildren,
                ));
            return Column(children: [card]);
          }
        } else if (statusCode == 400) {
          Future.delayed(Duration.zero, () {
            Navigator.push(
              context,
              MaterialPageRoute(builder: (context) => Login()),
            );
          });
        } else if (statusCode == 500) {
          var chars = Runes(
              'Es konnte kein Vertretungsplan für heute gefunden werden. \u{1F937}');
          List<Widget> cardChildren = [];
          cardChildren.add(ListTile(
              title: Text(String.fromCharCodes(chars),
                  style: const TextStyle(color: Palette.primary))));
          Card card = Card(
              shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.circular(15.0),
              ),
              color: Colors.white,
              child: Column(
                children: cardChildren,
              ));
          return card;
        } else if (statusCode == 404) {
          var chars = Runes(
              'Keine Verbindung mit dem MeinCantor-Server möglich. Bitte prüfe deine Internet-Verbindung und deine DNS-Einstellungen oder wende dich an den MeinCantor-Support. \u{1F4e1}');
          List<Widget> cardChildren = [];
          cardChildren.add(ListTile(
            title: Text(String.fromCharCodes(chars),
                style: const TextStyle(color: Palette.primary)),
          ));
          Card card = Card(
              shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.circular(15.0),
              ),
              color: Colors.white,
              child: Column(
                children: cardChildren,
              ));
          return Column(
            children: [card],
          );
        }
        return Center(child: Text('Error $statusCode'));
      } else if (snapshot.hasError) {
        return Text('$snapshot.error');
      } else {
        return const Center(child: CircularProgressIndicator());
      }
    },
  );
}

Future<http.Response> fetchClassesList() async {
  SharedPreferences prefs = await SharedPreferences.getInstance();
  var apiKey = prefs.getString('api_key');
  var uri = Uri.https("mein.cantorgymnasium.de", "/api/classes");
  var headers = {"x-api-key": "$apiKey"};
  final response = http.get(uri, headers: headers).onError((error, stackTrace) {
    return (http.Response("", 404));
  });
  return response;
}

Widget buildClassesChooser() {
  return FutureBuilder<http.Response>(
    future: fetchClassesList(),
    builder: (context, snapshot) {
      if (snapshot.hasData) {
        int statusCode = snapshot.data!.statusCode;
        if (statusCode == 200) {
          List<String> items = [];
          jsonDecode(utf8.decode(snapshot.data!.bodyBytes)).forEach((value) {
            items.add(value.toString());
          });
          return ClassesChooser(items: items);
        } else if (statusCode == 400) {
          Navigator.push(
              context, MaterialPageRoute(builder: (context) => Login()));
        } else if (statusCode == 500) {
          return const Padding(
            padding: EdgeInsets.fromLTRB(10, 10, 10, 10),
            child: Center(
                child: Text(
                    "Serverfehler. Bitte wende dich an den MeinCantor-Support.")),
          );
        } else if (statusCode == 404) {
          return const Padding(
            padding: EdgeInsets.fromLTRB(10, 10, 10, 10),
            child: Center(
                child: Text(
                    "Keine Verbindung mit dem MeinCantor-Server möglich. Bitte prüfe deine Internetverbindung und deine DNS-Einstellungen oder wende dich an den MeinCantor-Support")),
          );
        }
        return Text('$statusCode');
      } else if (snapshot.hasError) {
        return Text('$snapshot.error');
      } else {
        return const Center(child: CircularProgressIndicator());
      }
    },
  );
}

class ClassesChooser extends StatefulWidget {
  final List<String> items;
  const ClassesChooser({Key? key, required this.items}) : super(key: key);

  @override
  State<ClassesChooser> createState() => _ClassesChooserState(items);
}

class _ClassesChooserState extends State<ClassesChooser> {
  final List<String> items;
  String? dropdownValue;
  _ClassesChooserState(this.items);

  @override
  void initState() {
    super.initState();
    _read(); // read in initState
  }

  _read() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    setState(() {
      dropdownValue = prefs.getString("class_num"); // get the value
    });
  }

  @override
  Widget build(BuildContext context) {
    return DropdownButtonFormField<String>(
      value: dropdownValue,
      decoration: const InputDecoration(
        icon: Icon(Icons.people_outline),
        border: OutlineInputBorder(),
        labelText: 'Klasse (05/1, 07/3, 10/2...)',
      ),
      onChanged: (String? newValue) async {
        SharedPreferences prefs = await SharedPreferences.getInstance();
        String classNum = newValue!;
        prefs.setString('class_num', classNum);
        prefs.remove("lessons");
        prefs.remove("todayTImetable");
        prefs.remove("tomorrowTimetable");
        setState(() {
          dropdownValue = newValue;
        });
      },
      items: items.map<DropdownMenuItem<String>>((String value) {
        return DropdownMenuItem<String>(
          value: value,
          child: Text(value),
        );
      }).toList(),
    );
  }
}