feat: Implement abstract `QuestionViewModel`

[apomalyn]

As a developer, I want to standardize the way question view-models behave

Requirements

Implement a abstract class QuestionViewModel extending BaseViewModel, that:

• provide an implementation of
  • onCancelPressed: handle QuizAppBar cancel button
  • onReportPressed: handle report button pressed on the QuestionResult widget
  • _onError: display the QuestionResult of a wrong answer
  • _onSuccess: display the QuestionResult of a wrong answer
  • _determineAskAgain: determine if the question needs to be ask again during the quiz
• provide signature of onSubmitPressed, function that will be called when the answer is submitted for validation
• requires:
  • Question question
  • onAnswered(bool askAgain)

What needs to be done

Implement under practice/questions, a view model QuestionViewModel:

• constructor needs:
  • Question question
  • onAnswered(bool askAgain)
  • GoRouter router
• add the signature onSubmitPressed()
• Implement:
  • _onSuccess({String? explanation, bool skipResultDialog = false}): open a BottomSheetDialog containing QuestionResult for a correct answer, and onContinuePressed: onAnswered(false) if skipResultDialog is false. Otherwise, call directly onAnswered(false)
  • _onError(bool askAgain, {bool isFinished = true, String? explanation, VoidCallback? onContinuePressed}):
  • open a BottomSheetDialog containing QuestionResult for a false answer
  • if isFinished true, onContinuePressed: onAnswered(askAgain), otherwise close the dialog
  • if isFinished is false and onContinuePressed is provided, QuestionResult.onContinuePressed: onContinuePressed
  • _determineAskAgain(KnowledgeUpdate? toUpdate):
  • if toUpdate is null, take toUpdate = question.knowledgeUpdates[0]
  • if toUpdate.grade > 0
    • return true
    • otherwise false
  • onCancelPressed(), open a confirmation dialog to ask confirm exiting the quiz
  • on confirmation, go back to practice home screen
  • onReportPressed(), open the report feature with Bug selected

Dependencies

Child of #160

Depends on:

• 167

• 170