/*
 * Copyright (C) 2019, Google LLC.
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
 *
 * - Neither the name of the Eclipse Foundation, Inc. nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package com.google.gitiles;

import static com.google.common.truth.Truth.assertThat;

import java.io.IOException;
import java.util.Map;
import java.util.Set;
import org.eclipse.jgit.internal.storage.dfs.DfsRepositoryDescription;
import org.eclipse.jgit.internal.storage.dfs.InMemoryRepository;
import org.eclipse.jgit.junit.TestRepository;
import org.eclipse.jgit.lib.Config;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.transport.resolver.ServiceNotAuthorizedException;
import org.eclipse.jgit.transport.resolver.ServiceNotEnabledException;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

@RunWith(JUnit4.class)
public class VisibilityCacheTest {

  private InMemoryRepository repo;
  private GitilesAccess access = new FakeGitilesAccess();

  private RevCommit baseCommit;
  private RevCommit commit1;
  private RevCommit commit2;
  private RevCommit commitA;
  private RevCommit commitB;
  private RevCommit commitC;

  private VisibilityCache visibilityCache;
  private RevWalk walk;

  @Before
  public void setUp() throws Exception {
    /**
     *
     *
     * <pre>
     *               commitC
     *                 |
     *   commit2     commitB
     *      |          |
     *   commit1     commitA <--- refs/tags/v0.1
     *       \         /
     *        \       /
     *        baseCommit
     * </pre>
     */
    repo = new InMemoryRepository(new DfsRepositoryDescription());
    try (TestRepository<InMemoryRepository> git = new TestRepository<>(repo)) {
      baseCommit = git.commit().message("baseCommit").create();
      commit1 = git.commit().parent(baseCommit).message("commit1").create();
      commit2 = git.commit().parent(commit1).message("commit2").create();

      commitA = git.commit().parent(baseCommit).message("commitA").create();
      commitB = git.commit().parent(commitA).message("commitB").create();
      commitC = git.commit().parent(commitB).message("commitC").create();

      git.update("master", commit2);
      git.update("refs/tags/v0.1", commitA);
    }

    visibilityCache = new VisibilityCache(true);
    walk = new RevWalk(repo);
    walk.setRetainBody(false);
  }

  @After
  public void tearDown() {
    repo.close();
  }

  @Test
  public void isTip() throws IOException {
    ObjectId[] known = new ObjectId[0];
    assertThat(visibilityCache.isVisible(repo, walk, access, commit2.getId(), known)).isTrue();
  }

  @Test
  public void reachableFromHeads() throws Exception {
    ObjectId[] known = new ObjectId[0];
    assertThat(visibilityCache.isVisible(repo, walk, access, commit1.getId(), known)).isTrue();
  }

  @Test
  public void reachableFromTags() throws Exception {
    ObjectId[] known = new ObjectId[0];
    assertThat(visibilityCache.isVisible(repo, walk, access, commitA.getId(), known)).isTrue();
  }

  @Test
  public void unreachableFromAnyTip() throws Exception {
    ObjectId[] known = new ObjectId[0];
    assertThat(visibilityCache.isVisible(repo, walk, access, commitB.getId(), known)).isFalse();
  }

  @Test
  public void reachableFromAnotherId() throws Exception {
    ObjectId[] known = new ObjectId[] {commitC.getId()};
    assertThat(visibilityCache.isVisible(repo, walk, access, commitB.getId(), known)).isTrue();
  }

  private static class FakeGitilesAccess implements GitilesAccess {
    @Override
    public Map<String, RepositoryDescription> listRepositories(String prefix, Set<String> branches)
        throws ServiceNotEnabledException, ServiceNotAuthorizedException, IOException {
      throw new UnsupportedOperationException();
    }

    @Override
    public Object getUserKey() {
      return "Test";
    }

    @Override
    public String getRepositoryName() {
      return "VisibilityCache-Test";
    }

    @Override
    public RepositoryDescription getRepositoryDescription() throws IOException {
      throw new UnsupportedOperationException();
    }

    @Override
    public Config getConfig() throws IOException {
      throw new UnsupportedOperationException();
    }
  }
}