package polling;

import java.util.*;

/**
 * A Question has a string and a collection of responses from 
 * other students. It is used to keep a record of what students 
 * have said
 */
public class Question<K>{
   /**
    * Response is used to keep track of what a specific student said
    * to a cetain question.
    */
   class Response {
      /**
       * Username of the student
       */
      User student;
      /**
       * An answer in generic form. It can be an integer or a string
       * depending on the question asked.
       */
      K answer;
   }
   /**
    * Question holds the specified question that the instructor
    * is asking
    */
   String question;
   /**
    * Holds each student and their answers to the specified question.
    */
   Collection<Response> responses; 

   /**
    * The ask command creates a new question for the instructor to ask
    * their students.
    */
   /*@
     //ensures
    */
   public void ask(){
      new Question<K>();
   }
   /**
    * Respond will be used by the student to answer the free 
    * response questions or multiple choice.
    * @param std a user (mostly a student user)
    * @param ans an answer to the question in generic form as
    * an integer or string
    */
   /*@
     requires
     //
     // User be a valid user and that answer be a string or integer
     //
     std != null;
     ensures
     //
     // An answer is saved in the question by a particular user
     //
     \result.answer == ans;
    @*/
   public Response respond(User std,K ans){
      Response resp = new Response();
      resp.student = std;
      resp.answer = ans;
      return resp;
   }
}
/**
 * A FreeResponse Question is used to seperate the two different 
 * types of questions that will be asked. It holds two strings: 
 * the question and the user's response.
 */
class FreeresponseQuestion extends Question<String> {

}
/**
 * A MultipleChoice Question is used to seperate the two 
 * different types of questions that will be asked. It holds the 
 * correct answer for the multiple choice, a collection of 
 * strings that contain the choices.
 */
class MultipleChoiceQuestion extends Question<Integer> {
   /**
    * the correct answer number in the collection (counted like an array)
    */
   int correctAnswer;    
   /**
    * A collection of chioces that hold both the correct answer 
    * and one or more incorrect answers.
    */
   Collection<String> choices;
}
/**
 * User is the student. It contains relevent information.
 */
class User { /*yet to decide format*/ }