JuLearn/lib/learn.dart

import 'dart:math';

import 'package:flutter/material.dart';
import 'package:ju_learn/main.dart';

class QuizPage extends StatefulWidget {
  Vault v;
  Function saveState;
  QuizPage(this.v, this.saveState, {super.key});

  @override
  // ignore: no_logic_in_create_state, library_private_types_in_public_api
  _QuizPageState createState() => _QuizPageState(v, saveState);
}

class _QuizPageState extends State<QuizPage> {
  int runSeed = Random().nextInt(0xffffff);
  int run = 0;
  Question _currentQuestion = Question("Dummy", ["Dummy aws"], 0, "dummy");
  int askState = -1;
  Vault v;
  Function saveState;
  _QuizPageState(this.v, this.saveState) {
    _currentQuestion.drawer = 0x0fffffff;
    v.softReset();
    _nextQuestion();
  }

  void _checkAnswer(int selectedIndex) {
    if (selectedIndex == _currentQuestion.correct) {
      _currentQuestion.drawer++;
    } else {
      _currentQuestion.drawer = 0;
    }
    _currentQuestion.lastInRun = run;
    saveState();
    setState(() {
      askState = selectedIndex;
    });
  }

  void _nextQuestion() {
    Question lowestQ = _currentQuestion;
    for (var a in v.questions) {
      if (a == _currentQuestion) continue;
      int i = a.drawer - lowestQ.drawer;
      if (i > 1) {
        continue;
      }
      if (i < -1) {
        lowestQ = a;
        continue;
      }
      if ((run - a.lastInRun - 10).abs() -
              (run - lowestQ.lastInRun - 10).abs() <
          0) {
        lowestQ = a;
      }
    }
    if (mounted) {
      setState(() {
        _currentQuestion = lowestQ;
        askState = -1;
      });
    } else {
      _currentQuestion = lowestQ;
    }
    run++;
  }

  /*void _showResultDialog() {
    showDialog(
      context: context,
      builder: (BuildContext context) {
        return AlertDialog(
          title: const Text('Quiz Completed'),
          content: Text('Your score: $_score / ${v.questions.length}'),
          actions: [
            TextButton(
              child: const Text('Restart'),
              onPressed: () {
                setState(() {
                  _currentQuestionIndex = 0;
                  _score = 0;
                });
                Navigator.of(context).pop();
              },
            ),
          ],
        );
      },
    );
  }*/

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Learning: ${v.name}'),
      ),
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Text(
              _currentQuestion.quest,
              style: const TextStyle(
                fontSize: 20.0,
                fontWeight: FontWeight.bold,
              ),
            ),
            const SizedBox(height: 20.0),
            ...() {
              var l = _currentQuestion.answers.map(
                (option) {
                  return Container(
                      margin: const EdgeInsets.symmetric(vertical: 8.0),
                      child: FilledButton(
                          onPressed: () => askState == -1
                              ? _checkAnswer(
                                  _currentQuestion.answers.indexOf(option),
                                )
                              : _nextQuestion(),
                          style: FilledButton.styleFrom(
                            padding: const EdgeInsets.all(16.0),
                            backgroundColor: askState == -1
                                ? null
                                : (_currentQuestion.correct ==
                                        _currentQuestion.answers.indexOf(option)
                                    ? Colors.green
                                    : Colors.red),
                          ),
                          child: Text(option)));
                },
              ).toList();
              l.shuffle(Random(run + runSeed));
              return l;
            }(),
            if (askState != -1)
              Text(
                _currentQuestion.explanation,
                style: const TextStyle(
                  fontSize: 15.0,
                  fontWeight: FontWeight.bold,
                ),
              )
          ],
        ),
      ),
      floatingActionButton: askState != -1
          ? FloatingActionButton.extended(
              onPressed: _nextQuestion,
              icon: const Icon(Icons.chevron_right),
              label: const Text("Next"))
          : null,
    );
  }
}