public override bool ValidateInput(LabConfigurationExerciseEntry exercise, object input)
{
if (!(exercise is LabConfigurationMultipleChoiceExerciseEntry multipleChoiceExercise))
{
throw new ArgumentException("Invalid exercise type", nameof(exercise));
}
if (!(input is IEnumerable <int> selectedOptions))
{
throw new ArgumentException("Invalid input type", nameof(input));
}
var selectedIds = selectedOptions
.OrderBy(id => id)
.ToArray();
// Extract correct options
var correctIds = multipleChoiceExercise.Options
.Select((option, index) => (option, index))
.Where(opt => opt !.option.Correct) // IDE says this may be null, which is wrong
.Select(opt => opt.index)
.OrderBy(id => id)
.ToArray();
// Compare
if (multipleChoiceExercise.RequireAll)
{
return(selectedIds.SequenceEqual(correctIds));
}
return(selectedIds.Any() && selectedIds.All(id => correctIds.Contains(id)));
}
public override bool Update(LabConfigurationExerciseEntry exercise)
{
if (!(exercise is LabConfigurationStringExerciseEntry stringExercise))
{
throw new ArgumentException("Invalid exercise type", nameof(exercise));
}
// Is the expected solution still valid?
if (stringExercise.AllowAnySolution)
{
// We allow any solution, so no need to store a name
if (SolutionName != null)
{
// Drop previous solution name
SolutionName = null;
return(true);
}
}
else
{
// Check whether the exercise requires a specific, existing solution
if (SolutionName == null || stringExercise.ValidSolutions.All(s => s.Name != SolutionName))
{
// Pick a random solution
var random = stringExercise.ValidSolutions[RandomNumberGenerator.GetInt32(stringExercise.ValidSolutions.Length)];
SolutionName = random.Name;
return(true);
}
}
return(false);
}
public override string FormatDescriptionString(LabConfigurationExerciseEntry exercise)
{
if (exercise.DescriptionFormat == null)
{
return("");
}
return(string.Format(exercise.DescriptionFormat, SolutionName));
}
public override bool Update(LabConfigurationExerciseEntry exercise)
{
if (!(exercise is LabConfigurationScriptExerciseEntry))
{
throw new ArgumentException("Invalid exercise type", nameof(exercise));
}
// No changes required
return(false);
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
JObject jsonObject = JObject.Load(reader);
var exerciseType = jsonObject[nameof(LabConfigurationExerciseEntry.Type)]?.ToObject <LabConfigurationExerciseEntryType>();
LabConfigurationExerciseEntry exercise = exerciseType switch
{
LabConfigurationExerciseEntryType.String => new LabConfigurationStringExerciseEntry(),
LabConfigurationExerciseEntryType.MultipleChoice => new LabConfigurationMultipleChoiceExerciseEntry(),
LabConfigurationExerciseEntryType.Script => new LabConfigurationScriptExerciseEntry(),
_ => throw new JsonSerializationException("Unknown exercise type")
};
serializer.Populate(jsonObject.CreateReader(), exercise);
return(exercise);
}
public override bool ValidateInput(LabConfigurationExerciseEntry exercise, object input)
{
if (!(exercise is LabConfigurationStringExerciseEntry stringExercise))
{
throw new ArgumentException("Invalid exercise type", nameof(exercise));
}
if (!(input is string inputStr))
{
throw new ArgumentException("Invalid input type", nameof(input));
}
if (stringExercise.UseRegex)
{
// Match any solution
if (stringExercise.AllowAnySolution)
{
return(stringExercise.ValidSolutions.Any(s => Regex.IsMatch(inputStr, s.Value)));
}
// Match specific solution
var pattern = stringExercise.ValidSolutions.FirstOrDefault(s => s.Name == SolutionName)?.Value;
if (pattern == null)
{
return(false);
}
return(Regex.IsMatch(inputStr, pattern));
}
// Compare against any solution
if (stringExercise.AllowAnySolution)
{
return(stringExercise.ValidSolutions.Any(s => s.Value == inputStr));
}
// Compare against specific solutions
return(stringExercise.ValidSolutions.FirstOrDefault(s => s.Name == SolutionName)?.Value == inputStr);
}
/// <summary> /// Returns a description string for the given exercise, with placeholders replaced by values from this state. /// </summary> /// <param name="exercise">Exercise data.</param> /// <returns></returns> public abstract string FormatDescriptionString(LabConfigurationExerciseEntry exercise);
/// <summary> /// Returns whether the given input is a valid solution. /// </summary> /// <param name="exercise">Exercise data.</param> /// <param name="input">Input.</param> /// <returns></returns> public abstract bool ValidateInput(LabConfigurationExerciseEntry exercise, object input);
/// <summary> /// Checks whether the internal state is still consistent with the given exercise data, and updates it if necessary. /// The return value indicates whether the state has been updated. /// </summary> /// <param name="exercise">Exercise data.</param> public abstract bool Update(LabConfigurationExerciseEntry exercise);
public override string FormatDescriptionString(LabConfigurationExerciseEntry exercise)
{
return(exercise.DescriptionFormat ?? "");
}
public override bool Update(LabConfigurationExerciseEntry exercise)
{
return(true);
}
public override bool ValidateInput(LabConfigurationExerciseEntry exercise, object input)
{
// Input validation is left to state service
throw new NotSupportedException("Script exercises must be checked using the Docker service.");
}
