1package eu.siacs.conversations.crypto.sasl;
 2
 3import android.util.Base64;
 4
 5import java.util.ArrayList;
 6import java.util.Arrays;
 7import java.util.Iterator;
 8import java.util.List;
 9import java.util.NoSuchElementException;
10
11/**
12 * A tokenizer for GS2 header strings
13 */
14public final class Tokenizer implements Iterator<String>, Iterable<String> {
15	private final List<String> parts;
16	private int index;
17
18	public Tokenizer(final byte[] challenge) {
19		final String challengeString = new String(challenge);
20		parts = new ArrayList<>(Arrays.asList(challengeString.split(",")));
21		index = 0;
22	}
23
24	/**
25	 * Returns true if there is at least one more element, false otherwise.
26	 *
27	 * @see #next
28	 */
29	@Override
30	public boolean hasNext() {
31		return parts.size() != index + 1;
32	}
33
34	/**
35	 * Returns the next object and advances the iterator.
36	 *
37	 * @return the next object.
38	 * @throws java.util.NoSuchElementException if there are no more elements.
39	 * @see #hasNext
40	 */
41	@Override
42	public String next() {
43		if (hasNext()) {
44			return parts.get(index++);
45		} else {
46			throw new NoSuchElementException("No such element. Size is: " + parts.size());
47		}
48	}
49
50	/**
51	 * Removes the last object returned by {@code next} from the collection.
52	 * This method can only be called once between each call to {@code next}.
53	 *
54	 * @throws UnsupportedOperationException if removing is not supported by the collection being
55	 *                                       iterated.
56	 * @throws IllegalStateException         if {@code next} has not been called, or {@code remove} has
57	 *                                       already been called after the last call to {@code next}.
58	 */
59	@Override
60	public void remove() {
61		if(index <= 0) {
62			throw new IllegalStateException("You can't delete an element before first next() method call");
63		}
64		parts.remove(--index);
65	}
66
67	/**
68	 * Returns an {@link java.util.Iterator} for the elements in this object.
69	 *
70	 * @return An {@code Iterator} instance.
71	 */
72	@Override
73	public Iterator<String> iterator() {
74		return parts.iterator();
75	}
76}