package Current.basic;
import Current.*;
import java.applet.Applet;
import java.awt.event.*;
import java.awt.*;

/**This class converts between various ways of encoding
   information about the some of the geometric objects.*/



public class Converter {

    public Converter() {}


    /**Here is a palindrome test.  1 means palindrome*/

    public static int palindromeTest(CombinatorialTriangle[] T) {
	int N=T[0].c[0]+1;
	for(int i=1;i<N;++i) {
	    for(int j=0;j<=2;++j) {
	    if(T[i].b[j]+T[N-i].b[j]!=0) return(0);
	    }
	}
	return(1);
    }



    public static int getDigit(String W,int q) {
	String S=new String();
	int m=0;
	int n=W.length();
	int qq=q;
	if(q<0) qq=q+n;
	if(q>=n) qq=q-n;
	S=W.substring(qq,qq+1);  
        if(S.compareTo("1")==0) m=0;
	if(S.compareTo("2")==0) m=1;
	if(S.compareTo("3")==0) m=2;
	return(m);
    }


    public static int lastDigit(String W) {
	return(getDigit(W,W.length()-1));
    }



    public static int[] getTriple(String W,int q) {
	int[] m=new int[3];
	int n=W.length();
	for(int i=-1;i<=1;++i) {
	    m[i+1]=getDigit(W,q+i);
	}
	return(m);
    }


    /**here j is the vertex type. 
       w[0] tells if the vertex is a top or bottom vertex.
       w[1] names the vertex
    */

    public static int[] typeToCoords(CombinatorialTriangle T,int j) {
	int[] w=new int[2];
	int up=1;
	if((T.c[0]==0)&&(j==1)) up=-1;
	if((T.c[0]==1)&&(j==2)) up=-1;
	if((T.c[0]==2)&&(j==0)) up=-1;
	up=up*T.parity;
	if(up==1) w[0]=1;
	if(up==-1) w[0]=2;
	if(up==-1) w[1]=T.c[2];
	if(up==+1) w[1]=T.c[1];
	return(w);
    }


    public static int findType(CombinatorialTriangle T,int up,int m) {
	int test=-T.parity;
	if(up==2) test=-test;
	int j=T.c[0]+test;
	if(j>=3) j=j-3;
	if(j<0) j=j+3;
	return(j);
    }

    public static int spineNumber(VertexPair V,CombinatorialTriangle[] T) {
	int n1=coordsToType(T[V.e1],V.o1);
        int n2=coordsToType(T[V.e2],V.o2);
	if(n1!=n2) return(3-n1-n2);
	if(n1==2) return(1);
	return(2);
    }

    public static int coordsToType(CombinatorialTriangle T,int m0) {
	return((3+T.c[0]+T.parity*(2*m0-3))%3);
    }

}