/** StudentSolution entity managed by EBean. */
@Entity
@Table(name = Tables.STUDENTSOLUTIONS)
public class StudentSolution extends Model implements Comparable<StudentSolution> {
/** Internal ID. */
@Id @Constraints.Required @Formats.NonEmpty public String id;
/** Timestamp when record was created. */
@Constraints.Required public Long tsCreated = TimeUtils.now();
/** Solver batch number. */
@Constraints.Required public int batchNumber;
/** The student who owns this solution. */
@Constraints.Required @ManyToOne public Student student;
/** The number of courses the student prefers (at the time of the request). */
@Constraints.Required public int numCoursesPreferred;
/**
* True if this record was not explicitly requested by the student. That is, if the record was
* generated as the result of _other_ student(s) submitting requests.
*/
@Constraints.Required public boolean derived;
/** The courses that the solver recommends for this student, based on entered preferences. */
@Constraints.Required @ManyToMany public List<Course> recommendedCourses = new ArrayList<>();
// -- Queries
private static final Model.Finder<String, StudentSolution> FIND =
new Model.Finder<>(String.class, StudentSolution.class);
/**
* Returns all available student solutions.
*
* @return all student solutions
*/
public static List<StudentSolution> findAll() {
return FIND.all();
}
/**
* Returns the student solution with the given ID.
*
* @param id solution ID
* @return the solution
*/
public static StudentSolution findById(String id) {
return FIND.fetch(Fields.RECOMMENDED_COURSES)
.fetch(Fields.STUDENT)
.where()
.eq(Fields.ID, id)
.findUnique();
}
/**
* Returns the set of solutions for a given student.
*
* @param student student
* @return solutions for that student
*/
public static List<StudentSolution> findByStudent(Student student) {
return FIND.fetch(Fields.RECOMMENDED_COURSES)
.fetch(Fields.STUDENT)
.where()
.eq(Fields.STUDENT, student)
.findList();
}
/**
* Returns the solution for a given student and batch number.
*
* @param student student
* @param batch batch number
* @return matching solution for that student, if any
*/
public static StudentSolution findByStudent(Student student, int batch) {
return FIND.fetch(Fields.RECOMMENDED_COURSES)
.fetch(Fields.STUDENT)
.where()
.eq(Fields.STUDENT, student)
.eq(Fields.BATCH_NUMBER, batch)
.findUnique();
}
// --
/**
* Return the record created timestamp as a display string.
*
* @return created timestamp
*/
public String created() {
return TimeUtils.toDisplayString(tsCreated);
}
/**
* Returns true if the specified solution has the same student, number of courses preferred and
* recommended courses list, as this solution.
*
* @param other solution to compare against
* @return true if these solutions are equivalent, false otherwise
*/
public boolean sameSolution(StudentSolution other) {
if (other == null) return false;
return student.equals(other.student)
&& numCoursesPreferred == other.numCoursesPreferred
&& recommendedCourses.equals(other.recommendedCourses);
}
/**
* Comparable implemented to return solutions in reverse chronological order.
*
* @param o other to compare to
* @return positive, zero, negative as this is bigger, same, smaller than other
*/
@Override
public int compareTo(StudentSolution o) {
Long me = tsCreated;
Long you = o.tsCreated;
return me.compareTo(you);
}
}
/**
* Return the record created timestamp as a display string.
*
* @return created timestamp
*/
public String created() {
return TimeUtils.toDisplayString(tsCreated);
}