1package eu.siacs.conversations.crypto.sasl;
 2
 3import java.util.ArrayList;
 4import java.util.Arrays;
 5import java.util.Iterator;
 6import java.util.List;
 7import java.util.NoSuchElementException;
 8
 9/**
10 * A tokenizer for GS2 header strings
11 */
12public final class Tokenizer implements Iterator<String>, Iterable<String> {
13	private final List<String> parts;
14	private int index;
15
16	public Tokenizer(final byte[] challenge) {
17		final String challengeString = new String(challenge);
18		parts = new ArrayList<>(Arrays.asList(challengeString.split(",")));
19		// Trim parts.
20		for (int i = 0; i < parts.size(); i++) {
21			parts.set(i, parts.get(i).trim());
22		}
23		index = 0;
24	}
25
26	/**
27	 * Returns true if there is at least one more element, false otherwise.
28	 *
29	 * @see #next
30	 */
31	@Override
32	public boolean hasNext() {
33		return parts.size() != index + 1;
34	}
35
36	/**
37	 * Returns the next object and advances the iterator.
38	 *
39	 * @return the next object.
40	 * @throws java.util.NoSuchElementException if there are no more elements.
41	 * @see #hasNext
42	 */
43	@Override
44	public String next() {
45		if (hasNext()) {
46			return parts.get(index++);
47		} else {
48			throw new NoSuchElementException("No such element. Size is: " + parts.size());
49		}
50	}
51
52	/**
53	 * Removes the last object returned by {@code next} from the collection.
54	 * This method can only be called once between each call to {@code next}.
55	 *
56	 * @throws UnsupportedOperationException if removing is not supported by the collection being
57	 *                                       iterated.
58	 * @throws IllegalStateException         if {@code next} has not been called, or {@code remove} has
59	 *                                       already been called after the last call to {@code next}.
60	 */
61	@Override
62	public void remove() {
63		if(index <= 0) {
64			throw new IllegalStateException("You can't delete an element before first next() method call");
65		}
66		parts.remove(--index);
67	}
68
69	/**
70	 * Returns an {@link java.util.Iterator} for the elements in this object.
71	 *
72	 * @return An {@code Iterator} instance.
73	 */
74	@Override
75	public Iterator<String> iterator() {
76		return parts.iterator();
77	}
78}