/*
 * Created on 28/Ago/2003
 *
 */
package net.sourceforge.fenixedu.applicationTier.Servico.student;

import pt.ist.fenixWebFramework.services.Service;

import pt.ist.fenixWebFramework.security.accessControl.Checked;

import java.util.List;

import net.sourceforge.fenixedu.applicationTier.FenixService;
import net.sourceforge.fenixedu.applicationTier.Servico.exceptions.FenixServiceException;
import net.sourceforge.fenixedu.applicationTier.Servico.exceptions.InvalidArgumentsServiceException;
import net.sourceforge.fenixedu.applicationTier.Servico.exceptions.InvalidSituationServiceException;
import net.sourceforge.fenixedu.applicationTier.Servico.exceptions.InvalidStudentNumberServiceException;
import net.sourceforge.fenixedu.applicationTier.Servico.exceptions.NoChangeMadeServiceException;
import net.sourceforge.fenixedu.applicationTier.Servico.exceptions.NonExistingServiceException;
import net.sourceforge.fenixedu.applicationTier.Servico.exceptions.NonValidChangeServiceException;
import net.sourceforge.fenixedu.applicationTier.Servico.exceptions.NotAuthorizedException;
import net.sourceforge.fenixedu.applicationTier.strategy.groupEnrolment.strategys.GroupEnrolmentStrategyFactory;
import net.sourceforge.fenixedu.applicationTier.strategy.groupEnrolment.strategys.IGroupEnrolmentStrategy;
import net.sourceforge.fenixedu.applicationTier.strategy.groupEnrolment.strategys.IGroupEnrolmentStrategyFactory;
import net.sourceforge.fenixedu.domain.Attends;
import net.sourceforge.fenixedu.domain.Grouping;
import net.sourceforge.fenixedu.domain.Shift;
import net.sourceforge.fenixedu.domain.StudentGroup;
import net.sourceforge.fenixedu.domain.student.Registration;

/**
 * @author asnr and scpo
 * 
 */
public class GroupEnrolment extends FenixService {

    @Checked("RolePredicates.STUDENT_PREDICATE")
    @Service
    public static Boolean run(Integer groupingID, Integer shiftID, Integer groupNumber, List studentUsernames,
	    String studentUsername) throws FenixServiceException {
	final Grouping grouping = rootDomainObject.readGroupingByOID(groupingID);
	if (grouping == null) {
	    throw new NonExistingServiceException();
	}

	final Registration userStudent = Registration.readByUsername(studentUsername);

	final IGroupEnrolmentStrategyFactory enrolmentGroupPolicyStrategyFactory = GroupEnrolmentStrategyFactory.getInstance();
	final IGroupEnrolmentStrategy strategy = enrolmentGroupPolicyStrategyFactory.getGroupEnrolmentStrategyInstance(grouping);

	if (grouping.getStudentAttend(studentUsername) == null) {
	    throw new NoChangeMadeServiceException();
	}
	Shift shift = null;
	if (shiftID != null) {
	    shift = rootDomainObject.readShiftByOID(shiftID);
	}
	Integer result = strategy.enrolmentPolicyNewGroup(grouping, studentUsernames.size() + 1, shift);

	if (result.equals(Integer.valueOf(-1))) {
	    throw new InvalidArgumentsServiceException();
	}
	if (result.equals(Integer.valueOf(-2))) {
	    throw new NonValidChangeServiceException();
	}
	if (result.equals(Integer.valueOf(-3))) {
	    throw new NotAuthorizedException();
	}

	final Attends userAttend = grouping.getStudentAttend(userStudent);
	if (userAttend == null) {
	    throw new InvalidStudentNumberServiceException();
	}
	if (strategy.checkAlreadyEnroled(grouping, studentUsername)) {
	    throw new InvalidSituationServiceException();
	}

	StudentGroup newStudentGroup = grouping.readStudentGroupBy(groupNumber);
	if (newStudentGroup != null) {
	    throw new FenixServiceException();
	}

	if (!strategy.checkStudentsUserNamesInGrouping(studentUsernames, grouping)) {
	    throw new InvalidStudentNumberServiceException();
	}
	checkStudentUsernamesAlreadyEnroledInStudentGroup(strategy, studentUsernames, grouping);

	newStudentGroup = new StudentGroup(groupNumber, grouping, shift);
	for (final String studentUsernameIter : (List<String>) studentUsernames) {
	    Attends attend = grouping.getStudentAttend(studentUsernameIter);
	    attend.addStudentGroups(newStudentGroup);
	}
	userAttend.addStudentGroups(newStudentGroup);
	grouping.addStudentGroups(newStudentGroup);

	return true;
    }

    private static void checkStudentUsernamesAlreadyEnroledInStudentGroup(final IGroupEnrolmentStrategy strategy,
	    final List<String> studentUsernames, final Grouping grouping) throws FenixServiceException {

	for (final String studentUsername : studentUsernames) {
	    if (strategy.checkAlreadyEnroled(grouping, studentUsername)) {
		throw new InvalidSituationServiceException();
	    }
	}
    }
}