/*
 * Created on 24/Ago/2004
 *
 */
package net.sourceforge.fenixedu.applicationTier.Servico.teacher;

import java.util.List;

import net.sourceforge.fenixedu.applicationTier.FenixService;
import net.sourceforge.fenixedu.applicationTier.Servico.exceptions.ExistingServiceException;
import net.sourceforge.fenixedu.applicationTier.Servico.exceptions.FenixServiceException;
import net.sourceforge.fenixedu.applicationTier.Servico.exceptions.InvalidSituationServiceException;
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.StudentGroup;

/**
 * @author joaosa & rmalo
 * 
 */

public class DeleteGroupingMembers extends FenixService {

    public Boolean run(Integer executionCourseCode, Integer groupingCode, List<String> studentUsernames)
	    throws FenixServiceException {

	final Grouping grouping = rootDomainObject.readGroupingByOID(groupingCode);
	if (grouping == null) {
	    throw new ExistingServiceException();
	}

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

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

	for (final String studentUsername : (List<String>) studentUsernames) {
	    Attends attend = grouping.getStudentAttend(studentUsername);
	    removeAttendFromStudentGroups(grouping, attend);
	    grouping.removeAttends(attend);
	}
	return true;
    }

    private void removeAttendFromStudentGroups(final Grouping grouping, Attends attend) {
	if (attend != null) {
	    for (final StudentGroup studentGroup : grouping.getStudentGroups()) {
		studentGroup.removeAttends(attend);
	    }
	}
    }
}