import java.io.Reader;
import java.io.Writer;

/**
 * Implementat ion of 
 * interface for specifying per-agent information neccessary to
 * perform formation morphing to morph to a rectangle with a 
 * "comb" topology.  Rect width is specified at construction time.
 * @author     Michael Schuresko
 * @version    %I%, %G%
 * @since      1.0 
 */
public class MorphSpecFourCombs implements IMorphSpec 
{
    int m_nWidth;
    double m_lfDist;

    /**
     * defaults for the first demo
     */
    public MorphSpecFourCombs() {
	m_lfDist = 0.2;
	m_nWidth = 2;
    }

    public MorphSpecFourCombs(int nRectWidth, double lfSpacing) {
	m_lfDist = lfSpacing;
	m_nWidth = nRectWidth;
    }

    public double [] getFinalUv(int nAgentId)
    {
	int nGrp = nAgentId %4;
	nAgentId = (nAgentId +3)/ 4;
	double [] arrLfUv = new double[2];
	if(nAgentId == 0) {
	    arrLfUv[0] = arrLfUv[1] = 0.0;
	} else if(nAgentId == 1) {
	    if(nGrp == 0) {
		arrLfUv[0] = 0.0;
		arrLfUv[1] = m_lfDist;
	    } else if(nGrp == 1) {
		arrLfUv[0] = m_lfDist;
		arrLfUv[1] = 0.0;
	    } else if(nGrp == 2) {
		arrLfUv[0] = 0.0;
		arrLfUv[1] = -m_lfDist;
	    } else if(nGrp == 3) {
		arrLfUv[0] = -m_lfDist;
		arrLfUv[1] = 0.0;
	    } 
	} else if(nAgentId % m_nWidth == 1) {
	    arrLfUv[0] = 0.0;
	    arrLfUv[1] = m_lfDist;
	}
	else {
	    arrLfUv[0] = -m_lfDist;
	    arrLfUv[1] = 0.0;
	}
	return arrLfUv;
    }

    int getGrpOff(int nGrp) {
	return nGrp*(
		     (m_nWidth+m_nWidth+1)*m_nWidth
		     );
    }

    public int getNumChildren(int nAgentId)
    {
	if(nAgentId == 0) {
	    return 4;
	}
	nAgentId = (nAgentId +3)/ 4;
	if(nAgentId % m_nWidth == 0 && nAgentId/m_nWidth < m_nWidth-1) {
	    return 2;
	}
	return 1;
    }

    public int getTopoLastVisit(int nAgentId)
    {
	int nGrp = nAgentId %4;
	nAgentId = (nAgentId +3)/ 4;
	if(nAgentId == 0) {
	    return (m_nWidth+m_nWidth-1)*(nAgentId/m_nWidth)+
		m_nWidth-1+2*m_nWidth*(m_nWidth-nAgentId/m_nWidth)+
		getGrpOff(3);
	}
	if(nAgentId % m_nWidth == 0) {
	    return (m_nWidth+m_nWidth-1)*(nAgentId/m_nWidth)+
		m_nWidth-1+2*m_nWidth*(m_nWidth-nAgentId/m_nWidth)+
		getGrpOff(nGrp);
	} 
	else {
	    return (m_nWidth+m_nWidth-1)*(nAgentId/m_nWidth)+
		m_nWidth+m_nWidth-(nAgentId % m_nWidth)-1+
		getGrpOff(nGrp);
	}
    }
    
    public int getTopoFirstVisit(int nAgentId)
    {
	int nGrp = nAgentId %4;
	nAgentId = (nAgentId+3) / 4;
	return (m_nWidth+m_nWidth-1)*(nAgentId/m_nWidth)+
	    (nAgentId % m_nWidth)+getGrpOff(nGrp);
    }

    public int getTopoDepth(int nAgentId)
    {
	// int nGrp = nAgentId %4;
	nAgentId = (nAgentId+3) / 4;
	return (nAgentId/m_nWidth) + (nAgentId%m_nWidth);
    }
    
    public int getMaxDepth() { return 2*m_nWidth; }
    
    /**
     * Make this more then a stub later
     */
    public void dump(Writer writeTo) {}
    /**
     * Make this more then a stub later
     */
    public void load(Reader readFrom) {}    
}