package class5_3_StreamDecorator_inClass;

import java.io.*;

/**
 * The StarInserter is a FilterWriter that wraps
 * any Writer, printing a '*' before every character that it is
 * requested to print (except newlines)
 */
public class StarInserter extends FilterWriter {
    /**
     * Wrap out with this FilterWriter
     * @param out The writer to be wrapped.
     */
    public StarInserter(Writer out) {
        super(out);
    }

    /**
     * Where the fun happens.
     * If the character is NOT a new line, we print it, but also print a star.
     *
     * All FilterWriters are required to implement this method to guarantee correctness.
     * @param c The character to be "enhanced"
     * @throws IOException
     */
    @Override
    public void write(int c) throws IOException {
        if(c!='\r'&&c!='\n') {
            super.write('*');
        }
        super.write(c);
    }

    /**
     * All FilterWriters are required to implement this method to
     * guarantee correctness.
     * @param cbuf char array to be written to the underlying stream
     * @param off first char from cbuf to be written
     * @param len number of chars to be written
     * @throws IOException if the underlying stream does
     */
    @Override
    public void write(char[] cbuf, int off, int len) throws IOException {
        throw new UnsupportedEncodingException("Just hoping our client never calls this!");
    }

    /**
     * All FilterWriters are required to implement this method to
     * guarantee correctness.
     * @param str String to be written to the underlying stream
     * @param off first char from str to be written
     * @param len number of chars to be written
     * @throws IOException if the underlying stream does
]     */
    @Override
    public void write(String str, int off, int len) throws IOException {
        for(int i = off; i<len; i++) {
            write(str.charAt(i));
        }
    }
}