package net.sourceforge.fenixedu.domain.student.curriculum;

import static net.sourceforge.fenixedu.domain.studentCurriculum.ISCTEEnrolmentWrapperUtils.getEnrolmentWrappersEctsCredits;
import static net.sourceforge.fenixedu.domain.studentCurriculum.ISCTEEnrolmentWrapperUtils.getEnrolmentWrappersWeight;
import static net.sourceforge.fenixedu.domain.studentCurriculum.ISCTEEnrolmentWrapperUtils.hasEnrolmentWrappers;

import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.Collection;

import net.sourceforge.fenixedu.domain.DegreeCurricularPlan;
import net.sourceforge.fenixedu.domain.ExecutionYear;
import net.sourceforge.fenixedu.domain.studentCurriculum.CurriculumGroup;

public class AverageWeightRule extends AverageWeightRule_Base {

    protected AverageWeightRule() {
	super();
    }

    public AverageWeightRule(final DegreeCurricularPlan degreeCurricularPlan, final ExecutionYear executionYear) {
	this();
	init(degreeCurricularPlan, executionYear);
    }

    @Override
    protected AverageRuleResult createResult(final CurriculumGroup topCurriculumGroup,
	    final Collection<ICurriculumEntry> entries, final int scale, final RoundingMode roundingMode) {
	return new AverageWeightRuleResult(topCurriculumGroup, entries, scale, roundingMode);
    }

    static private class AverageWeightRuleResult extends AverageRuleResult {

	static private final long serialVersionUID = 1L;

	public AverageWeightRuleResult(final CurriculumGroup topCurriculumGroup, final Collection<ICurriculumEntry> entries,
		final int scale, final RoundingMode roundingMode) {

	    for (ICurriculumEntry entry : entries) {
		if (entry.getGrade().isNumeric()) {
		    calculateCurriculumEntryAverage(entry, topCurriculumGroup);
		}
	    }

	    average = (sumOfWeight == BigDecimal.ZERO) ? sumOfWeight : gradeTimesFactor.divide(sumOfWeight, scale, roundingMode);
	}

	private void calculateCurriculumEntryAverage(final ICurriculumEntry entry, final CurriculumGroup topCurriculumGroup) {
	    BigDecimal factor;
	    if (!hasEnrolmentWrappers(entry, topCurriculumGroup)) {
		factor = entry.getWeigthForCurriculum();
		sumOfEcts = sumOfEcts.add(entry.getEctsCreditsForCurriculum());
	    } else {
		factor = getEnrolmentWrappersWeight(entry, topCurriculumGroup);
		sumOfEcts = sumOfEcts.add(getEnrolmentWrappersEctsCredits(entry, topCurriculumGroup));
	    }

	    sumOfWeight = sumOfWeight.add(factor);
	    gradeTimesFactor = gradeTimesFactor.add(entry.getGrade().getNumericValue().multiply(factor));
	}
    }

    @Override
    public boolean isWeightRule() {
	return true;
    }

}