package net.sourceforge.fenixedu.domain;

import java.math.BigDecimal;

import net.sourceforge.fenixedu.domain.degreeStructure.CompetenceCourseLoad;
import net.sourceforge.fenixedu.domain.exceptions.DomainException;

public class CourseLoad extends CourseLoad_Base {

    public CourseLoad(ExecutionCourse executionCourse, ShiftType type, BigDecimal unitQuantity, BigDecimal totalQuantity) {

	super();

	if (executionCourse != null && type != null && executionCourse.getCourseLoadByShiftType(type) != null) {
	    throw new DomainException("error.CourseLoad.executionCourse.already.contains.type");
	}

	setRootDomainObject(RootDomainObject.getInstance());
	setUnitQuantity(unitQuantity);
	setTotalQuantity(totalQuantity);
	setExecutionCourse(executionCourse);
	setType(type);

	checkQuantities();
    }

    public void edit(BigDecimal unitQuantity, BigDecimal totalQuantity) {
	setUnitQuantity(unitQuantity);
	setTotalQuantity(totalQuantity);

	checkQuantities();
    }

    public void delete() {
	if (!canBeDeleted()) {
	    throw new DomainException("error.CourseLoad.cannot.be.deleted");
	}
	super.setExecutionCourse(null);
	removeRootDomainObject();
	deleteDomainObject();
    }

    @Override
    public void setExecutionCourse(ExecutionCourse executionCourse) {
	if (executionCourse == null) {
	    throw new DomainException("error.CourseLoad.empty.executionCourse");
	}
	super.setExecutionCourse(executionCourse);
    }

    @Override
    public void setType(ShiftType type) {
	if (type == null) {
	    throw new DomainException("error.CourseLoad.empty.type");
	}
	super.setType(type);
    }

    public boolean isEmpty() {
	return getTotalQuantity().signum() == 0;
    }

    private boolean canBeDeleted() {
	return !hasAnyLessonInstances() && !hasAnyShifts();
    }

    public BigDecimal getWeeklyHours() {
	return getTotalQuantity().divide(BigDecimal.valueOf(CompetenceCourseLoad.NUMBER_OF_WEEKS), 2, BigDecimal.ROUND_HALF_UP);
    }

    @Override
    public void setTotalQuantity(BigDecimal totalQuantity) {
	if (totalQuantity == null || totalQuantity.signum() == -1) {
	    throw new DomainException("error.CourseLoad.empty.totalQuantity");
	}
	super.setTotalQuantity(totalQuantity);
    }

    @Override
    public void setUnitQuantity(BigDecimal unitQuantity) {
	if (unitQuantity != null && unitQuantity.signum() == -1) {
	    throw new DomainException("error.CourseLoad.empty.unitQuantity");
	}
	super.setUnitQuantity(unitQuantity);
    }

    @jvstm.cps.ConsistencyPredicate
    protected boolean checkRequiredParameters() {
	return !isEmpty() && isTotalQuantityValid() && getType() != null;
    }

    private void checkQuantities() {
	if (!isTotalQuantityValid()) {
	    throw new DomainException("error.CourseLoad.totalQuantity.less.than.unitQuantity");
	}
    }

    private boolean isTotalQuantityValid() {
	return getUnitQuantity() == null || getTotalQuantity().compareTo(getUnitQuantity()) != -1;
    }
}