package org.jaudiotagger.audio.real;

import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.RandomAccessFile;

import org.jaudiotagger.audio.exceptions.CannotReadException;
import org.jaudiotagger.audio.generic.Utils;

public class RealChunk {

	protected static final String RMF = ".RMF";
	protected static final String PROP = "PROP";
	protected static final String MDPR = "MDPR";
	protected static final String CONT = "CONT";
	protected static final String DATA = "DATA";
	protected static final String INDX = "INDX";

	private final String id;
	private final int size;
	private final byte[] bytes;

	public static RealChunk readChunk(RandomAccessFile raf)
			throws CannotReadException, IOException {
		final String id = Utils.readString(raf, 4);
		final int size = Utils.readUint32AsInt(raf);
		if (size < 8) {
			throw new CannotReadException(
					"Corrupt file: RealAudio chunk length at position "
							+ (raf.getFilePointer() - 4)
							+ " cannot be less than 8");
		}
		if (size > (raf.length() - raf.getFilePointer() + 8)) {
			throw new CannotReadException(
					"Corrupt file: RealAudio chunk length of " + size
							+ " at position " + (raf.getFilePointer() - 4)
							+ " extends beyond the end of the file");
		}
		final byte[] bytes = new byte[size - 8];
		raf.readFully(bytes);
		return new RealChunk(id, size, bytes);
	}

	public RealChunk(String id, int size, byte[] bytes) {
		super();
		this.id = id;
		this.size = size;
		this.bytes = bytes;
	}

	public DataInputStream getDataInputStream() {
		return new DataInputStream(new ByteArrayInputStream(getBytes()));
	}

	public boolean isCONT() {
		return CONT.equals(id);
	}

	public boolean isPROP() {
		return PROP.equals(id);
	}

	public byte[] getBytes() {
		return bytes;
	}

	public String getId() {
		return id;
	}

	public int getSize() {
		return size;
	}

	@Override
	public String toString() {
		return id + "\t" + size;
	}
}