package ECC;
import java.util.HashMap;
import java.util.List;
public class Decoder {
public static int PAD = 5;
private HashMap pointTable;
public Decoder(HashMap pointTable) {
this.pointTable = pointTable;
}
public String decode(Matrix A) {
List subKeys = Helpers.getSubKeys();
for (String subKey : subKeys) {
String[] array = subKey.split("\\/");
String transformation = array[0];
int op = Integer.parseInt(array[1]);
int a = Integer.parseInt(array[2]);
int b = Integer.parseInt(array[3]);
int c = Integer.parseInt(array[4]);
int d = Integer.parseInt(array[5]);
if (transformation.equals("R")) {
A.reverseRowTrasformation(a, c, d, op);
A.reverseRowTrasformation(b, c, d, op);
} else {
A.reverseColumnTrasformation(a, c, d, op);
A.reverseColumnTrasformation(b, c, d, op);
}
System.out.println("sub-key : " + subKey);
System.out.println(A);
}
return getPlainText(A);
}
private String getPlainText(Matrix A) {
String plaintText = "";
System.out.println("4) Convert the matrix M to a list of points");
A.toPoints().stream().forEach(System.out::print);
System.out.println("");
for (Point p : A.toPoints()) {
if (pointTable.get(p) != null) {
int asciCode = pointTable.get(p);
plaintText += Character.toString((char) asciCode);
} else {
plaintText += "$";
}
}
return plaintText;
}
}