//Copyright 2006-2007 Regents of the University of California.  May be used 
//under the terms of the revised BSD license.  See LICENSING for details.
package net.nova.crypto;

import java.nio.charset.Charset;
import java.nio.ByteBuffer;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.Writer;

/**
* ASCII I/O.
*/
public final class ASCII {
 private static final Charset charset = Charset.forName("US-ASCII");
 
 private ASCII() {}

 /**
  * Encodes a string in US-ASCII.
  * @param text  The text to encode.
  * @return The ASCII bytes.
  */
 static public byte[] encode(final String text) {
     return charset.encode(text).array();
 }
 
 /**
  * Decodes a US-ASCII string. Each byte not corresponding to a US-ASCII
  * character decodes to the Unicode replacement character U+FFFD.  This
  * method is equivalent to <code>decode(buffer, 0, buffer.length)</code>.
  * @param buffer    the ASCII-encoded string to decode
  * @return The corresponding string
  * @throws java.lang.IndexOutOfBoundsException
  */
 static public String decode(byte[] buffer) {
     return decode(buffer, 0, buffer.length);
 }
 
 /**
  * Decodes a US-ASCII string. Each byte not corresponding to a US-ASCII
  * character decodes to the Unicode replacement character U+FFFD.
  * @param buffer    the ASCII-encoded string to decode
  * @param off       where to start decoding
  * @param len       how many bytes to decode
  * @return  the corresponding string
  * @throws java.lang.IndexOutOfBoundsException
  */
 static public String decode(byte[] buffer, int off, int len) {
     return charset.decode(ByteBuffer.wrap(buffer, off, len)).toString();
 }
     
 /**
  * Constructs an ASCII reader.
  * @param in    The binary input stream
  * @return  the ASCII character reader.
  */
 static public Reader input(final InputStream in) {
     return new InputStreamReader(in, charset);
 }

 /**
  * Constructs an ASCII writer.
  * @param out the output stream.
  */
 static public Writer output(final OutputStream out) {
     return new OutputStreamWriter(out, charset);
 }
}