/*
 * Copyright (c) 2012, grossmann
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * * Neither the name of the jo-widgets.org nor the
 *   names of its contributors may be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL jo-widgets.org BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */

package org.jowidgets.util.io;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * This class provides an buffered input stream that creates its buffer lazily and destroys the buffer when
 * the stream get closed.
 * 
 * This class is not threadsafe
 */
public class LazyBufferedInputStream extends InputStream {

    private final InputStream original;
    private final int bufferSize;

    private BufferedInputStream bufferedInputStream;
    private boolean closed;

    public LazyBufferedInputStream(final InputStream original, final int bufferSize) {
        this.original = original;
        this.bufferSize = bufferSize;
    }

    @Override
    public int read() throws IOException {
        return getInputStream().read();
    }

    @Override
    public int read(final byte[] b) throws IOException {
        return getInputStream().read(b);
    }

    @Override
    public int read(final byte[] b, final int off, final int len) throws IOException {
        return getInputStream().read(b, off, len);
    }

    @Override
    public long skip(final long n) throws IOException {
        return getInputStream().skip(n);
    }

    @Override
    public int available() throws IOException {
        return getInputStream().available();
    }

    @Override
    public void close() throws IOException {
        closed = true;
        if (bufferedInputStream != null) {
            bufferedInputStream.close();
            bufferedInputStream = null;
        }
    }

    @Override
    public synchronized void mark(final int readlimit) {
        try {
            getInputStream().mark(readlimit);
        }
        catch (final IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public synchronized void reset() throws IOException {
        getInputStream().reset();
    }

    @Override
    public boolean markSupported() {
        return original.markSupported();
    }

    private InputStream getInputStream() throws IOException {
        if (closed) {
            throw new IOException("Stream was closed");
        }
        if (bufferedInputStream == null) {
            bufferedInputStream = new BufferedInputStream(original, bufferSize);
        }
        return bufferedInputStream;
    }

}