package class5_3_StreamDecorator_start;

import java.io.FilterWriter;
import java.io.IOException;
import java.io.Writer;

public class ScrambleWriter extends FilterWriter {

    private boolean isNextByteEven = true;
    private int evenByte = 0;

    public ScrambleWriter(Writer out) {
        super(out);
    }

    @Override
    public void write(String str, int off, int len) throws IOException {
        for(int i = off; i<len; i++) {
            write(str.charAt(i));
        }
    }

    @Override
    public void write(int c) throws IOException {
        if(isNextByteEven) {
            evenByte = c;
        } else {
            super.write(c); // The bug: I had c on this line instead of encrypted.
            super.write(evenByte);
        }
        isNextByteEven = !isNextByteEven;
    }
}