package Info;
import Grades.*;

/**
 * Represents a user class.
 */
public abstract class UserClass{
	/**
	 * Contains the basic information for this user class.
	 */
	public BasicInfo basicInfo;

	/**
	 * The roster of students in the user class.
	 */	
	public Roster roster;	

	/**
	 * The gradebook of the user class.
	 */
	public GradeBook gradeBook;


 /**
  * changeInfo adds information to this.basicInfo, replacing any
  * previously entered information.
  */
 public abstract void changeInfo(BasicInfo newInfo);


 /**
  * addStudent updates the class roster with the new student.
  */

  /*@
    requires
        //
        // There must be a class roster.
        //
        (roster != null)

	&&

	//
	// Student must at least have a first name.
	//
	(newStudent.firstName != null) && (newStudent.firstName.length() > 0); 
	
    ensures
	//
	// If the preconditions are met, the class will be updated with the new student.
	//
        (\forall Student aStudent;
            (roster.students.contains(aStudent)) <==>
                aStudent.equals(newStudent) || \old(roster.students).contains(aStudent));
  @*/
 public abstract void addStudent(Student newStudent);

	/**
	 * Deletes the given Student from the given Roster.
	 */
	/*@
	  requires
	     //
	     // The passed Student to be deleted is a Student in the input Roster.
	     //
	     ((\exists Student aStudent ;
	     	roster.students.contains(aStudent) ;
			aStudent.equals(toRemove)));

	  ensures
	    //
	    // If preconditions are met, a user class is in the output classes if and only
	    // if it is not the existing class to be deleted or it is in the input classes.
	    //
	    (\forall Student aStudent ;
            (roster.students.contains(aStudent)) <==>
                !aStudent.equals(toRemove) && \old(roster.students).contains(aStudent));
	@*/
 public abstract void removeStudent(Student toRemove);
}