/**
 * Copyright 2010 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.waveprotocol.wave.model.version;

import junit.framework.TestCase;

/**
 * Tests for {@link HashedVersion}.
 *
 * @author anorth@google.com (Alex North)
 */
public class HashedVersionTest extends TestCase {

  private static final byte[] AAA = "AAA".getBytes();
  private static final byte[] BBB = "BBB".getBytes();

  public void testEquality() {
    assertHashedVersionsEqual(10, AAA, 10, AAA);

    assertHashedVersionsDiffer(10, AAA, 10, BBB);
    assertHashedVersionsDiffer(10, AAA, 12, AAA);
    assertHashedVersionsDiffer(10, AAA, 12, BBB);
  }

  public void testComparisons() {
    assertHashedVersionsCompare(10, AAA, 10, AAA, 0);

    // Different versions.
    assertHashedVersionsCompare(10, AAA, 12, AAA, -1);
    // Different hashes.
    assertHashedVersionsCompare(10, AAA, 10, BBB, -1);
    // Both different, version takes precedence.
    assertHashedVersionsCompare(10, BBB, 12, AAA, -1);
  }

  public void testUnsigned() {
    assertEquals(10L, HashedVersion.unsigned(10).getVersion());
    assertEquals(0, HashedVersion.unsigned(10).getHistoryHash().length);
  }

  public void testUnsignedComparisons() {
    assertEquals(0, HashedVersion.unsigned(10).compareTo(HashedVersion.unsigned(10)));
    // unsigned(10) is smaller than every other hashed version with version number 10
    assertEquals(-1, HashedVersion.unsigned(10).compareTo(HashedVersion.of(10, AAA)));
    // and, of course, bigger than hashed versions with smaller version number
    assertEquals(1, HashedVersion.unsigned(10).compareTo(HashedVersion.of(9, AAA)));
  }

  private static void assertHashedVersionsEqual(long v1, byte[] h1, long v2, byte[] h2) {
    assertEquals(HashedVersion.of(v1, h1), HashedVersion.of(v2, h2));
  }

  private static void assertHashedVersionsDiffer(long v1, byte[] h1, long v2, byte[] h2) {
    assertFalse(HashedVersion.of(v1, h1).equals(HashedVersion.of(v2, h2)));
  }

  private static void assertHashedVersionsCompare(long v1, byte[] h1, long v2, byte[] h2, int cmp) {
    assertEquals(cmp, HashedVersion.of(v1, h1).compareTo(HashedVersion.of(v2, h2)));
    assertEquals(-cmp, HashedVersion.of(v2, h2).compareTo(HashedVersion.of(v1, h1)));
  }
}