import 'package:refilc/api/providers/user_provider.dart';
import 'package:refilc/api/providers/database_provider.dart';
import 'package:refilc/helpers/notification_helper.dart';
import 'package:refilc/models/settings.dart';
import 'package:refilc/models/user.dart';
import 'package:refilc_kreta_api/client/api.dart';
import 'package:refilc_kreta_api/client/client.dart';
import 'package:refilc_kreta_api/models/grade.dart';
import 'package:refilc_kreta_api/models/group_average.dart';
import 'package:refilc_kreta_api/providers/grade_provider.i18n.dart';
import 'package:flutter/material.dart';

class GradeProvider with ChangeNotifier {
  // Private
  late List<Grade> _grades;
  late DateTime _lastSeen;
  late String _groups;
  List<GroupAverage> _groupAvg = [];
  late final SettingsProvider _settings;
  late final UserProvider _user;
  late final DatabaseProvider _database;
  late final KretaClient _kreta;

  // Public
  List<Grade> get grades => _grades;
  DateTime get lastSeenDate =>
      _settings.gradeOpeningFun ? _lastSeen : DateTime(3000);
  String get groups => _groups;
  List<GroupAverage> get groupAverages => _groupAvg;

  GradeProvider({
    List<Grade> initialGrades = const [],
    required SettingsProvider settings,
    required UserProvider user,
    required DatabaseProvider database,
    required KretaClient kreta,
  }) {
    _settings = settings;
    _user = user;
    _database = database;
    _kreta = kreta;

    _grades = List.castFrom(initialGrades);
    _lastSeen = DateTime.now();

    if (_grades.isEmpty) restore();
  }

  Future<void> seenAll() async {
    String? userId = _user.id;
    if (userId != null) {
      final userStore = _database.userStore;
      userStore.storeLastSeen(DateTime.now(),
          userId: userId, category: LastSeenCategory.surprisegrade);
      _lastSeen = DateTime.now();
    }
  }

  Future<void> unseenAll() async {
    String? userId = _user.id;
    if (userId != null) {
      final userStore = _database.userStore;
      userStore.storeLastSeen(DateTime(1969),
          userId: userId, category: LastSeenCategory.surprisegrade);
      _lastSeen = DateTime(1969);
    }
  }

  Future<void> restore() async {
    String? userId = _user.id;

    // Load grades from the database
    if (userId != null) {
      final userQuery = _database.userQuery;

      _grades = await userQuery.getGrades(userId: userId);
      await convertBySettings();
      await getGradeStreak();
      _groupAvg = await userQuery.getGroupAverages(userId: userId);
      notifyListeners();
      DateTime lastSeenDB = await userQuery.lastSeen(
          userId: userId, category: LastSeenCategory.surprisegrade);
      if (lastSeenDB.millisecondsSinceEpoch == 0 ||
          lastSeenDB.year == 0 ||
          !_settings.gradeOpeningFun) {
        _lastSeen = DateTime.now();
        await seenAll();
      } else {
        _lastSeen = lastSeenDB;
      }
      notifyListeners();
    }
  }

  // good student mode, renamed subjects
  Future<void> convertBySettings() async {
    Map<String, String> renamedSubjects = _settings.renamedSubjectsEnabled
        ? await _database.userQuery.renamedSubjects(userId: _user.user!.id)
        : {};
    Map<String, String> renamedTeachers = _settings.renamedTeachersEnabled
        ? await _database.userQuery.renamedTeachers(userId: _user.user!.id)
        : {};

    // v5
    Map<String, String> customRoundings =
        await _database.userQuery.getRoundings(userId: _user.user!.id);

    for (Grade grade in _grades) {
      grade.subject.renamedTo =
          renamedSubjects.isNotEmpty ? renamedSubjects[grade.subject.id] : null;
      grade.teacher.renamedTo =
          renamedTeachers.isNotEmpty ? renamedTeachers[grade.teacher.id] : null;

      grade.value.value = _settings.goodStudent
          ? (grade.value.percentage ? 100 : 5)
          : grade.json!["SzamErtek"] ?? 0;
      grade.value.valueName = _settings.goodStudent
          ? "Jeles".i18n
          : (grade.value.percentage
              ? '${grade.json!["SzovegesErtek"]}'
              : '${grade.json!["SzovegesErtek"]}'
                  .replaceAll(RegExp(r'[(]+[12345]?[)]'), '')
                  .i18n);
      grade.value.shortName = _settings.goodStudent
          ? "Jeles".i18n
          : '${grade.json!["SzovegesErtekelesRovidNev"]}' != "null" &&
                  '${grade.json!["SzovegesErtekelesRovidNev"]}' != "-" &&
                  '${grade.json!["SzovegesErtekelesRovidNev"]}'
                          .replaceAll(RegExp(r'[0123456789]+[%]?'), '') !=
                      ""
              ? '${grade.json!["SzovegesErtekelesRovidNev"]}'.i18n
              : grade.value.valueName;

      // v5
      grade.subject.customRounding = customRoundings.isNotEmpty
          ? double.parse(customRoundings[grade.subject.id] ?? '5.0')
          : null;
    }

    notifyListeners();
  }

  // get current grade streak and set it to the user
  Future<void> getGradeStreak() async {
    User? user = _user.user;
    if (user == null) throw "Cannot get Grade Streak for User null";

    // streak magic
    int gradeStreak = 0;
    List<Grade> grs = _grades;
    grs.sort((a, b) => -a.date.compareTo(b.date));

    for (Grade grade in grs) {
      if (grade.value.value == 5) {
        gradeStreak++;
      } else if (grade.value.value !=0) {
        break;
      }
    }

    user.gradeStreak = gradeStreak;
    notifyListeners();
  }

  // Fetches Grades from the Kreta API then stores them in the database
  Future<void> fetch() async {
    // test cucc
    // unseenAll();

    User? user = _user.user;
    if (user == null) throw "Cannot fetch Grades for User null";
    String iss = user.instituteCode;

    List? gradesJson = await _kreta.getAPI(KretaAPI.grades(iss));
    if (gradesJson == null) throw "Cannot fetch Grades for User ${user.id}";
    List<Grade> grades = gradesJson.map((e) => Grade.fromJson(e)).toList();

    if (grades.isNotEmpty || _grades.isNotEmpty) await store(grades);

    List? groupsJson = await _kreta.getAPI(KretaAPI.groups(iss));
    if (groupsJson == null || groupsJson.isEmpty) {
      throw "Cannot fetch Groups for User ${user.id}";
    }
    _groups = (groupsJson[0]["OktatasNevelesiFeladat"] ?? {})["Uid"] ?? "";

    List? groupAvgJson =
        await _kreta.getAPI(KretaAPI.groupAverages(iss, _groups));
    if (groupAvgJson == null) {
      throw "Cannot fetch Class Averages for User ${user.id}";
    }
    final groupAvgs =
        groupAvgJson.map((e) => GroupAverage.fromJson(e)).toList();
    await storeGroupAvg(groupAvgs);
  }

  // Stores Grades in the database
  Future<void> store(List<Grade> grades) async {
    User? user = _user.user;
    if (user == null) throw "Cannot store Grades for User null";
    String userId = user.id;

    await _database.userStore.storeGrades(grades, userId: userId);
    _grades = grades;
    await convertBySettings();
    await getGradeStreak();
  }

  Future<void> storeGroupAvg(List<GroupAverage> groupAvgs) async {
    _groupAvg = groupAvgs;

    User? user = _user.user;
    if (user == null) throw "Cannot store Grades for User null";
    String userId = user.id;
    await _database.userStore.storeGroupAverages(groupAvgs, userId: userId);
    notifyListeners();
  }
}