/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2000 Blacksmith, Inc.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see http://www.gnu.org
*/

package net.wotonomy.foundation;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;

/**
 * A pure java implementation of NSData, which is basically a wrapper on a byte
 * array.
 *
 * @author michael@mpowers.net
 * @author $Author: cgruber $
 * @version $Revision: 893 $
 */
public class NSData {
	public static final NSData EmptyData = new NSData();

	protected byte[] bytes;

	/**
	 * Default constructor creates a zero-data object.
	 */
	public NSData() {
		bytes = new byte[0];
	}

	/**
	 * Creates an object containing a copy of the specified bytes.
	 */
	public NSData(byte[] data) {
		this(data, 0, data.length);
	}

	/**
	 * Creates an object containing a copy of the bytes from the specified array
	 * within the specified range.
	 */
	public NSData(byte[] data, int start, int length) {
		bytes = new byte[length];
		for (int i = 0; i < length; i++) {
			bytes[i] = data[start + i];
		}
	}

	/**
	 * Creates an object containing the bytes of the specified string.
	 */
	public NSData(String aString) {
		this(aString.getBytes());
	}

	/**
	 * Creates an object containing the contents of the specified file. Errors
	 * reading the file will produce an empty or partially blank array.
	 */
	public NSData(File aFile) {
		int len = (int) aFile.length();
		byte[] data = new byte[len];
		try (FileInputStream fis = new java.io.FileInputStream(aFile)) {
			fis.read(data);
		} catch (Exception exc) {
			// produce an empty or partially blank array
		}
		bytes = data;
	}

	/**
	 * Creates an object containing the contents of the specified URL.
	 */
	public NSData(java.net.URL aURL) {
		throw new RuntimeException("Not Implemented");
	}

	/**
	 * Creates an object containing a copy of the contents of the specified NSData
	 * object.
	 */
	public NSData(NSData aData) {
		this(aData.bytes());
	}

	/**
	 * Creates a new NSData object from the bytes in the input stream. The input
	 * stream is read fully and is not closed.
	 * 
	 * @param stream    The stream to read from.
	 * @param chunkSize The buffer size used to read from the stream.
	 * @throws IOException if the stream cannot be read from.
	 */
	public NSData(InputStream stream, int chunkSize) throws IOException {
		super();
		byte[] b = new byte[chunkSize];
		ByteArrayOutputStream bout = new ByteArrayOutputStream();
		int read = 0;
		do {
			read = stream.read(b);
			if (read > 0)
				bout.write(b, 0, read);
		} while (read > 0);
		bytes = bout.toByteArray();
	}

	/**
	 * Returns the length of the contained data.
	 */
	public int length() {
		return bytes.length;
	}

	/**
	 * Returns whether the specified data is equivalent to these data.
	 */
	public boolean isEqualToData(NSData aData) {
		if (length() != aData.length())
			return false;
		byte[] a = bytes();
		byte[] b = aData.bytes();

		for (int i = 0; i < a.length; i++) {
			if (a[i] != b[i])
				return false;
		}
		return true;
	}

	/**
	 * Return the bytes within the data that fall within the specified range.
	 */
	public NSData subdataWithRange(NSRange aRange) {
		int loc = aRange.location();
		byte[] src = bytes();
		byte[] data = new byte[aRange.length()];
		System.arraycopy(src, loc, data, 0, data.length);
		return new NSData(data);
	}

	/**
	 * Writes the contents of this data to the specified URL. If atomically is true,
	 * then the data is written to a temporary file and then renamed to the name
	 * specified by the URL when the data transfer is complete.
	 */
	public boolean writeToURL(java.net.URL aURL, boolean atomically) {
		throw new RuntimeException("Not Implemented");
	}

	/**
	 * Convenience to return the contents of the specified file.
	 */
	public static NSData dataWithContentsOfMappedFile(java.io.File aFile) {
		return new NSData(aFile);
	}

	/**
	 * Returns a copy of the bytes starting at the specified location and ranging
	 * for the specified length.
	 */
	public byte[] bytes(int location, int length) {
		byte[] data = new byte[length];
		for (int i = 0; i < length; i++) {
			data[i] = bytes[location + i];
		}
		return data;
	}

	/**
	 * Returns a copy of the bytes backing this data object. NOTE: This method is
	 * not in the NSData spec and is included for convenience only.
	 */
	public byte[] bytes() {
		return bytes(0, length());
	}

	@Override
	public String toString() {
		String hex = "0123456789ABCDEF";
		StringBuffer buf = new StringBuffer();
		buf.append(NSPropertyListSerialization.TOKEN_BEGIN[NSPropertyListSerialization.PLIST_DATA]);
		for (int i = 0; i < bytes.length; i++) {
			byte b = bytes[i];
			buf.append(hex.charAt((b & 0xf0) >> 4));
			buf.append(hex.charAt(b & 0x0f));
			if (i % 5 == 4)
				buf.append(' ');
		}
		buf.append(NSPropertyListSerialization.TOKEN_END[NSPropertyListSerialization.PLIST_DATA]);
		return buf.toString();
	}

	public boolean isEqual(Object obj) {
		if (obj == this)
			return true;
		if (obj instanceof NSData)
			return isEqualToData((NSData) obj);
		return false;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + Arrays.hashCode(bytes);
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		return isEqual(obj);
	}
}

/*
 * $Log$ Revision 1.2 2006/02/16 13:15:00 cgruber Check in all sources in
 * eclipse-friendly maven-enabled packages.
 *
 * Revision 1.5 2003/08/19 01:53:52 chochos added constructor with an
 * InputStream
 *
 * Revision 1.4 2003/08/05 00:51:31 chochos get the enclosing tokens from
 * NSPropertyListSerialization
 *
 * Revision 1.3 2003/08/04 22:45:47 chochos toString() prints out the bytes in
 * hex (in property list format)
 *
 * Revision 1.2 2003/08/02 01:52:00 chochos added EmptyData
 *
 * Revision 1.1.1.1 2000/12/21 15:47:26 mpowers Contributing wotonomy.
 *
 * Revision 1.3 2000/12/20 16:25:38 michael Added log to all files.
 *
 *
 */