package net.sourceforge.fenixedu.domain.curriculum;

import net.sourceforge.fenixedu.domain.GradeScale;
import net.sourceforge.fenixedu.domain.exceptions.DomainException;

import org.apache.commons.lang.StringUtils;

class Grade implements IGrade {
    private Object gradeValue;

    private GradeType gradeType;

    public Grade(int grade) {
	initNumeric(grade);
    }

    public Grade(String grade) {
	if (grade == null || grade.equals("") || grade.equals(GradeScale.NA)) {
	    this.gradeValue = GradeScale.NA;
	    this.gradeType = GradeType.GRADENA;
	} else if (StringUtils.isNumeric(grade)) {
	    Integer numericGrade = Integer.parseInt((String) grade);
	    initNumeric(numericGrade);
	} else if (grade.equals(GradeScale.AP)) {
	    this.gradeValue = grade;
	    this.gradeType = GradeType.GRADEAP;
	} else {
	    this.gradeValue = GradeScale.RE;
	    this.gradeType = GradeType.GRADERE;
	}
    }

    protected void initNumeric(int grade) {
	this.gradeValue = grade;

	if (grade <= 5) {
	    this.gradeType = GradeType.GRADEFIVE;
	} else {
	    this.gradeType = GradeType.GRADETWENTY;
	}
    }

    public Object getGradeValue() {
	return gradeValue;
    }

    public GradeType getGradeType() {
	return gradeType;
    }

    // very important: don't change this
    public int compareTo(IGrade o) {
	if (this.getGradeType() == o.getGradeType()) {
	    if (this.getGradeType() == GradeType.GRADEFIVE || this.getGradeType() == GradeType.GRADETWENTY) {
		Integer grade1 = (Integer) this.getGradeValue();
		Integer grade2 = (Integer) o.getGradeValue();
		return grade1.compareTo(grade2);
	    } else {
		return 0;
	    }
	}
	if (this.getGradeType() == GradeType.GRADENA || this.getGradeType() == GradeType.GRADERE) {
	    return 1;
	}
	if (o.getGradeType() == GradeType.GRADENA || o.getGradeType() == GradeType.GRADERE) {
	    return -1;
	}

	throw new DomainException("error.grade.different.grade.types");
    }

}

public class GradeFactory {
    private static GradeFactory instance = new GradeFactory();

    private IGrade[] flyWeight;

    private GradeFactory() {
	flyWeight = new IGrade[24];

	flyWeight[21] = new Grade(GradeScale.RE);
	flyWeight[22] = new Grade(GradeScale.NA);
	flyWeight[23] = new Grade(GradeScale.AP);

	for (int i = 0; i < 21; i++) {
	    flyWeight[i] = new Grade(i);
	}
    }

    public IGrade getGrade(String key) {
	return flyWeight[getGradePosition(key)];
    }

    public IGrade getGrade(int key) {
	return flyWeight[key];
    }

    private int getGradePosition(String key) {
	if (key == null || key.equals("") || key.equals(GradeScale.NA)) {
	    return 22;
	}

	if (key.equals(GradeScale.RE)) {
	    return 21;
	}

	if (key.equals(GradeScale.AP)) {
	    return 23;
	}

	return Integer.parseInt(key);
    }

    public static GradeFactory getInstance() {
	return instance;
    }
}