package Assignments;
import Visual.*;
import Grades.*;
import Info.*;
import Prediction.*;
import Reports.*;
import java.util.Collection;

/**
 * AssignmentsView represents the "Assignments Tab" in the grader project.
 */
abstract public class AssignmentsView{

	/**
	 * A collection of all the assignments created by the instructor to date.
	 */
	Collection<Assignment> assignments;

	/**
	 * A collection of top level categories, which each contain subcategories.
	 */
	Collection<Category> categories;

	/**
	 * Represents which column (name, points, etc.) is currently being sorted.
	 */
	int sortedColumn;

	/**
	 * Adds an assignment to the assignments collection.
	 */
	/*@
	requires
	  //assignment is not already present in assignments.
	  ! assignments.contains(assignment);
	ensures
	  //assignment is now present in assignments.
	  assignments.contains(assignment);
	@*/
	abstract void addAssignment(Assignment assignment);

	/**
	 * Removes and assignment from the assignments collection.
	 */
	/*@
	requires
	  //assignment is present in assignments.
	  assignments.contains(assignment);
	ensures
	  //assignment is now not present in assignments.
	  ! assignments.contains(assignment);
	@*/
	abstract void removeAssignment(Assignment assignment);

	/**
	 * Switches out the old assignment with the new one.
	 */
	/*@
	requires
	  //oldA is present in assignments.
	  assignments.contains(oldA)
	  &&
	  //newA is different from oldA.
	  ! newA.equals(oldA);
	ensures
	  //If oldA was present in assignments, oldA is no longer present in assignments and newA is now present in assignments.
	  \old(assignments).contains(oldA) ==> (!assignments.contains(oldA) && assignments.contains(newA));
	@*/
	abstract void changeAssignment(Assignment oldA, Assignment newA);

	/**
	 * Sorts the assignment list by a certain column.
	 */
	abstract void sort(int column, boolean ascending);
}