package course;

import users.*;
import java.util.Collection;
import java.util.List;

/**
* This course divides the students and graders in a particular course
* into various sections. 
* This class pertains to the Administration requirements document, section 2.8, as it
* allows organization of students and graders into various sections of various courses. 
*/
public abstract class Section
{
	Course course;
	Collection<Student> students;
	Collection<Grader> graders;

	public Section(Course c)
	{

	}


	/**
	* Adds a student to this section
	pre:
		// student s must not be in the collection of students
	(!students.contains(s));
	post:
		// student s must be in the list
		// the collection of students must be one greater
	(students'.contains(s)) && (students'.size() == students.size()+1);
	*/
	public abstract void addStudent(Student s);

	/**
	* Adds a grader to this section
	pre:
		// grader g must not be in the collection of graders
	(!graders.contains(g));
	post:
		// grader g must be in the list
		// the collection of graders must be one greater
	(graders'.contains(g)) && (graders'.size() == graders.size()+1);
	*/
	public abstract void addGrader(Grader g);

	/**
	* Removes a student from this section
	pre:
		// student s must be in the collection of students
	(students.contains(s));
	post:
		// student s must not be in the list
		// the collection of students must be one smaller
	(!students'.contains(s)) && (students'.size() == students.size()-1);
	*/
	public abstract void removeStudent(Student s);

	/**
	* Removes a grader from this section
	pre:
		// grader s must be in the collection of graders
	(graders.contains(g));
	post:
		// grader s must not be in the list
		// the collection of graders must be one smaller
	(!graders'.contains(g)) && (graders'.size() == graders.size()-1);
	*/
	public abstract void removeGrader(Grader g);

	public abstract Collection<Student> getStudents();

	public abstract Collection<Grader> getGraders();
}