module TestGrading;

   import TestTaking.AnsweredTest;
   import TestTaking.AnsweredSection;
   import TestTaking.AnsweredQuestion;
   import TestTaking.MultipleChoiceAnswer;
   import TestTaking.MatchingAnswer;
   import TestTaking.FreeResponseAnswer;
   import TestTaking.CodeAnswer;

   export GradedTest, GradedSection, GradedQuestion;

   (* OBJECTS *)

   object GradedTest extends AnsweredTest
      components: gs:GradedSection*, grade:integer;
      description: (* This is a complete graded test
         that which contains the student's answers, the assigned score,
         and comments added by the grader. By inheriting AnsweredTest
         a GradedTest already contains the correct answers specified
         by the author of the test/question as well as a the student's
         answers given during testing.
      *);
   end GradedTest;

   object GradedSection extends AnsweredSection
      components: gq:GradedQuestion*, grade:integer;
      description: (* contains the list of GradedQuestions
         forming this section of the AnsweredTest as well as any Section
         attributes inherited from AnsweredSection
      *);
   end AnsweredSection;

   object GradedQuestion extends AnsweredQuestion
      components: MultipleChoiceGraded or MatchingGraded or
         FreeResponseGraded or CodeGraded;
      description: (* Contains a graded question *);
   end AnsweredQuestion;
  
   object MultipleChoiceGraded extends MultipleChoiceAnswer
      components: grade:integer, comment:string;
      description: (* Adds a grade and comment to an answered 
         multiple choice question which includes single answer,
	 multiple answer and true/false questions.
      *);
   end MultipleChoiceGraded;

   object MatchingGraded extends MatchingAnswer
      components: grade:integer, comment:string;
      description: (* Adds a grade and comment to an answered
         matching question.
      *);
   end MatchingGraded;

   object FreeResponseGraded extends FreeResponseAnswer
      components: grade:integer, comment:string;
      description: (* adds a grade and comment to an answered
         free response question which includes essay questions,
	 short answer questions and fill-in-the-blank questions.
      *) ;
   end FreeResponseGraded;

   object CodeGraded extends CodeAnswer
      components: grade:integer, comment:string;
      description: (* adds a grade and comment to an answered
         code question which include both full programming questions
	 and short line fill code questions.
      *);
   end CodeGraded; 
   
   (* OPERATIONS *)

   operation GradeTest
      inputs: AnsweredTest*;
      outputs: GradedTest*;
      description: (* Autogrades a batch of AnsweredTests creating a GradedTest 
         out of each. This means that it will assign a score to every question
	 that does not require manual entry of a score (i.e. - multiple choice
         and matching questions. It will also hightlight keywords in free
	 response questions and execute analysis with output comparison for
	 grading programming questions. 
      *);
   end GradeTest;

   operation AcceptGrade
      inputs: gq:GradedQuestion, gs:GradedSection, gt:GradedTest;
      outputs: gq':GradedQuestion, gs':GradedSection, gt':GradedTest;
      postcondition: forall (gq'':GradedQuestion)
                        (gq'' in gs'.gq) iff ((gq'' = gq') or
			((gq'' != gq) and (gq'' in gs.gq)));
      description: (* Updates a GradedQuestion object with the current
         score and comments.
      *);
   end AcceptGrade;

   operation percentGrade
      inputs: points:AnsweredQuestion.points, percent:integer;
      outputs: score:integer;
      precondition: percent >= 0;
      description: (* Changes the point value awarded for an answer based
         on the percent value entered by the grader.
      *);
   end percentGrade;

end TestGrading;