/*
 * INFO0062 - Object-oriented programming
 * Special session (16/05/2019)
 *
 * Example of solution for the 1st question of the written examination from May 2018.
 *
 * Keep in mind that it is not the only possible solution. There are ways to write some parts of
 * the code in another manner that is still as valid as what is presented here.
 *
 * @author: J.-F. Grailet
 */


public class LineSegment implements Cloneable, Serializable
{
    private Point3D p1, p2;

    // Remark: int[] p1, int[] p2 also accepted
    public LineSegment(int x1, int y1, int z1, int x2, int y2, int z2)
    {
        p1 = new Point3D(x1, y1, z1);
        p2 = new Point3D(x2, y2, z2);
    }

    // Remark: providing the 3 values dx, dy and dz as an array is accepted too
    public synchronized void translate(int dx, int dy, int dz)
    {
        p1.translate(dx, dy, dz);
        p2.translate(dx, dy, dz);
    }

    public synchronized LineSegment[] split() throws ZeroSegmentException
    {
        int m_x, m_y, m_z;
        m_x = (p1.getX() + p2.getX()) / 2;
        m_y = (p1.getY() + p2.getY()) / 2;
        m_z = (p1.getZ() + p2.getZ()) / 2;

        Point3D middle = new Point3D(m_x, m_y, m_z);
        if(middle.equals(p1) || middle.equals(p2))
            throw new ZeroSegmentException();

        LineSegment[] res = new LineSegment[2];
        res[0] = new LineSegment(p1.getX(), p1.getY(), p1.getZ(), m_x, m_y, m_z);
        res[1] = new LineSegment(m_x, m_y, m_z, p2.getX(), p2.getY(), p2.getZ());
        return res;
    }

    public boolean equals(Object o)
    {
        if(!(o instanceof LineSegment))
            return false;

        LineSegment l2 = (LineSegment) o;
        if((p1.equals(l2.p1) && p2.equals(l2.p2)) || (p1.equals(l2.p2) && p2.equals(l2.p1)))
            return true;
        return false;
    }

    public int hashCode()
    {
        return p1.hashCode() + p2.hashCode();
    }

    public Object clone()
    {
        LineSegment clone = null;
        try
        {
            clone = (LineSegment) super.clone();
            clone.p1 = (Point3D) p1.clone();
            clone.p2 = (Point3D) p2.clone();
        }
        catch(CloneNotSupportedException e)
        {
            throw new InternalError("Unable to clone LineSegment object.");
        }
        return clone;
    }

    // Not asked, just for display in the Main class
    public String toString()
    {
        return p1 + " -> " + p2;
    }
}