/*
 * Copyright (c) 2011-2015, Isode Limited, London, England.
 * All rights reserved.
 */
package com.isode.stroke.base;

import com.isode.stroke.base.SafeByteArray;
import com.isode.stroke.base.ByteArray;
import java.io.UnsupportedEncodingException;

/**
* It's currently not actually secure,
* and that we might consider if http://developer.android.com/reference/java/nio/ByteBuffer.html#allocateDirect(int) could help us in the future.
*/
public class SafeByteArray extends ByteArray {

	public SafeByteArray() {

	}

	public SafeByteArray(String s) {
		super(s);
	}

    public SafeByteArray(ByteArray b) {
        this.append(b.getData());
    }

    /**
     * Creates a new SafeByteArray object containing all 
     * the elements from two existing ByteArrays (immutable add).
     * 
     * @param a an existing SafeByteArray. Must not be null, but may be empty.
     * @param b an existing SafeByteArray. Must not be null, but may be empty.
     * @return a new SafeByteArray containing all the elements of <em>a</em>
     * followed by all the elements of <em>b</em>.
     */  
    public static SafeByteArray plus(SafeByteArray a, SafeByteArray b) {
        SafeByteArray x = new SafeByteArray().append(a.getData());
        x.append(b);
        return x;
    }
    
    /**
     * Updates the SafeByteArray by adding all the elements
     * of another SafeByteArray to the end of the array (mutable add).
     * @param b an existing SafeByteArray. Must not be null, but may be empty
     * @return a reference to the updated object 
     */
    public SafeByteArray append(ByteArray b) {
        append(b.getData());
        return this;
    }

    /** 
     * Updates the SafeByteArray by adding all the bytes
     * in a byte[] to the end of the array (mutable add).  
     * 
     * @param b an array of bytes. Must not be null, but may contain zero
     * elements.
     * 
     * @return a reference to the updated object
     */
    public SafeByteArray append(byte[] b) {
        return append(b, b.length);
    }

    /** Mutable add */
    public SafeByteArray append(byte[] b, int len) {
        for (int i = 0; i < len; i++) {
            append(b[i]);
        }
        return this;
    }

    /** 
     * Updates the SafeByteArray by adding a single byte
     * value to the end of the array (mutable add).
     * @param b a single byte
     * @return a reference to the updated object
     */
    public SafeByteArray append(byte b) {
        dataCopy_ = null; /* Invalidate cache */
        data_.add(Byte.valueOf(b));
        return this;
    }

    /**
     * Updates the SafeByteArray by adding all the bytes
     * obtained by UTF-8 encoding the provided String to the end of the array (mutable add).
     * @param s a String that must not be null.
     * @return a reference to the updated object.
     */ 
    public SafeByteArray append(String s) {
        byte[] bytes;
        try {
            bytes = s.getBytes("UTF-8");
        } catch (UnsupportedEncodingException ex) {
            throw new IllegalStateException("JVM has no 'UTF-8' encoding");
        }
        append(bytes);
        return this;
    }
}