/*
 *                 Sun Public License Notice
 * 
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 * 
 * The Original Code is NetBeans. The Initial Developer of the Original
 * Code is Sun Microsystems, Inc. Portions Copyright 1997-2004 Sun
 * Microsystems, Inc. All Rights Reserved.
 */

package org.openide.util.io;

import java.io.*;

/**
* This class convert Reader to InputStream. It works by converting
* the characters to the encoding specified in constructor parameter.
*
* @author   Petr Hamernik, David Strupl
*/
public class ReaderInputStream extends InputStream {

    /** Input Reader class. */
    private Reader reader;

    private PipedOutputStream pos;
    private PipedInputStream pis;
    private OutputStreamWriter osw;
    
    /** Creates new input stream from the given reader.
     * Uses the platform default encoding.
    * @param reader Input reader
    */
    public ReaderInputStream(Reader reader) throws IOException {
        this.reader = reader;
        pos = new PipedOutputStream();
        pis = new PipedInputStream(pos);
        osw = new OutputStreamWriter(pos);
    }

    /** Creates new input stream from the given reader and encoding.
     * @param reader Input reader
     * @param encoding 
     */
    public ReaderInputStream(Reader reader, String encoding) throws IOException {
        this.reader = reader;
        pos = new PipedOutputStream();
        pis = new PipedInputStream(pos);
        osw = new OutputStreamWriter(pos, encoding);
    }
    
    public int read() throws IOException {
        if (pis.available() > 0) {
            return pis.read();
        }
        int c = reader.read();
        if (c == -1) {
            return c;
        }
        osw.write(c);
        osw.flush();
        pos.flush();
        return pis.read();
    }
    
    public int read(byte b[], int off, int len) throws IOException {
        int c = read();
        if (c == -1) {
            return -1;
        }
        b[off] = (byte)c;
        int i = 1;
        // Don't try to fill up the buffer if the reader is waiting.
        for (; i < len && reader.ready(); i++) {
            c = read();
            if (c == -1) {
                return i;
            }
            b[off + i] = (byte)c;
        }
        return i;
    }

    public int available() throws IOException {
        int i = pis.available();
        if (i > 0) {
            return i;
        }
        if (reader.ready()) {
            // Char must produce at least one byte.
            return 1;
        } else {
            return 0;
        }
    }

    public void close() throws IOException {
        reader.close();
        osw.close();
        pis.close();
    }
}