/// <summary>
/// Validate if the exercise implemented the <see cref="IExerciseDefinition"/> interface correctly.
/// Instantiation, answer cell, get expected solution and answer details are validated.
/// </summary>
/// <param name="exercise">The exercises which is validated.</param>
/// <param name="seed">The seed with which the exercise is validated.</param>
/// <returns>Returns an error or an empty string if the exercise is valid for the given seed.</returns>
public static string GetError(IExerciseDefinition exercise, string seed)
{
//Validate the instantiation
exercise.Instantiate(seed);
//Validate the answer cells
var answerCells = exercise.AnswerCells;
if (answerCells == null || answerCells.Count < 1)
{
return($"{exercise.Name} does not generate any answer cells.");
}
//Validate the exercise values
var values = exercise.GetValues();
//Validate the expected solutions
var solutions = exercise.GetExpectedSolutions();
//Valdaite the answer cells
var answerDetails = exercise.GetAnswerDetails(solutions);
//Validate if the expected solutions are considered correct
foreach (var answerDetail in answerDetails)
{
if (answerDetail.Value != Enum.AnswerCellStatus.Correct)
{
return($"{exercise.Name}: The expected solutions is incorrect at {answerDetail.Key}.");
}
}
//Check if there is a solution for each answer cell
foreach (var answerCell in answerCells)
{
if (answerCell.Value.InputType != InputTypes.Label &&
!solutions.ContainsKey(answerCell.Key))
{
return($"{exercise.Name}: The answer cell {answerCell.Key} is not part of the solution.");
}
}
//Check if there is an answer cell for each solution
foreach (var solution in solutions)
{
if (!answerCells.ContainsKey(solution.Key))
{
return($"{exercise.Name}: The solution {solution.Key} is not part of the answer cells.");
}
}
//No errors detected
return(string.Empty);
}
/// <summary>
/// Validate if the exercise calculates quick enough.
/// </summary>
/// <param name="exercise">The exercises which is validated.</param>
/// <param name="seed">The seed with which the exercise is validated.</param>
/// <returns>Returns an error or an empty string if the exercise is valid for the given seed.</returns>
public static async Task <string> GetError(IExerciseDefinition exercise, string seed)
{
//Validate the instantiation
var task = Task.Run(() => exercise.Instantiate(seed));
if (await Task.WhenAny(task, Task.Delay(MAX_INSTANTIATE)) != task)
{
return($"{exercise.Name} took too long to instantiate for the seed {seed}.");
}
task = Task.Run(() => exercise.GetExpectedSolutions());
if (await Task.WhenAny(task, Task.Delay(MAX_SOLUTION)) != task)
{
return($"{exercise.Name} took too long to calculate the solution.");
}
//No errors detected
return(string.Empty);
}