/*
 * Created on 13/Nov/2004
 *
 */
package net.sourceforge.fenixedu.applicationTier.Servico.student;

import pt.ist.fenixWebFramework.services.Service;

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

import java.util.Iterator;
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.InvalidArgumentsServiceException;
import net.sourceforge.fenixedu.applicationTier.Servico.exceptions.InvalidChangeServiceException;
import net.sourceforge.fenixedu.applicationTier.Servico.exceptions.InvalidSituationServiceException;
import net.sourceforge.fenixedu.applicationTier.Servico.exceptions.InvalidStudentNumberServiceException;
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 joaosa and rmalo
 * 
 */

public class UnEnrollGroupShift extends FenixService {

    @Checked("RolePredicates.STUDENT_PREDICATE")
    @Service
    public static Boolean run(Integer studentGroupCode, Integer groupPropertiesCode, String username)
	    throws FenixServiceException {
	Grouping groupProperties = rootDomainObject.readGroupingByOID(groupPropertiesCode);

	if (groupProperties == null) {
	    throw new ExistingServiceException();
	}

	StudentGroup studentGroup = rootDomainObject.readStudentGroupByOID(studentGroupCode);

	if (studentGroup == null)
	    throw new InvalidArgumentsServiceException();

	if (!(studentGroup.getShift() != null && groupProperties.getShiftType() == null) || studentGroup.getShift() == null) {
	    throw new InvalidStudentNumberServiceException();
	}

	Registration registration = Registration.readByUsername(username);

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

	if (!strategy.checkStudentInGrouping(groupProperties, username)) {
	    throw new NotAuthorizedException();
	}

	if (!checkStudentInStudentGroup(registration, studentGroup)) {
	    throw new InvalidSituationServiceException();
	}

	Shift shift = null;
	boolean result = strategy.checkNumberOfGroups(groupProperties, shift);
	if (!result) {
	    throw new InvalidChangeServiceException();
	}
	studentGroup.setShift(shift);

	return true;
    }

    private static boolean checkStudentInStudentGroup(Registration registration, StudentGroup studentGroup) {
	boolean found = false;

	List studentGroupAttends = studentGroup.getAttends();
	Attends attend = null;
	Iterator iterStudentGroupAttends = studentGroupAttends.iterator();
	while (iterStudentGroupAttends.hasNext() && !found) {
	    attend = ((Attends) iterStudentGroupAttends.next());
	    if (attend.getRegistration().equals(registration)) {
		found = true;
	    }
	}
	return found;
    }

}