/*******************************************************************************
 * Copyright 2010 Atos Worldline SAS

 * 
 * Licensed by Atos Worldline SAS under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * Atos Worldline SAS licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *       http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/
package net.padaf.preflight.font.type1;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

import org.apache.commons.io.IOUtils;

public class PeekInputStream extends InputStream {
	private byte[] content = new byte[0];
	private int position = 0;
	
	public PeekInputStream(InputStream source) throws IOException {
		ByteArrayOutputStream bos = new ByteArrayOutputStream();
		try {
			IOUtils.copyLarge(source, bos);
			content = bos.toByteArray();
		} finally {
			IOUtils.closeQuietly(source);
			IOUtils.closeQuietly(bos);
		}
	}

	@Override
	public int read() throws IOException {
		if (position >= content.length) {
			throw new IOException("No more content in this stream");
		}

		int currentByte = (content[position] & 0xFF);
		++position;
		return currentByte;
	}

	public int peek() throws IOException {
		if (position >= content.length) {
			throw new IOException("No more content in this stream");
		}

		return (content[position] & 0xFF);
	}
	
	public byte[] peek(int numberOfBytes) throws IOException {
		if ( numberOfBytes < 0 || (position + numberOfBytes) >= content.length) {
			throw new IOException("No more content in this stream, can't return the next " + numberOfBytes + " bytes");
		}

		byte[] nextBytes = new byte[numberOfBytes];
		System.arraycopy(this.content, this.position, nextBytes, 0, numberOfBytes);
		return nextBytes; 
	}
}