/*
    * Copyright (c) 2020, Google LLC  and others
    *
    * This program and the accompanying materials are made available under the
    * terms of the Eclipse Distribution License v. 1.0 which is available at
    * http://www.eclipse.org/org/documents/edl-v10.php.
    *
    * SPDX-License-Identifier: BSD-3-Clause
    */
  package org.eclipse.jgit.internal.storage.dfs;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertNotNull;
  import static org.junit.Assert.assertTrue;
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.util.Collections;
  import java.util.Set;
  
  import org.eclipse.jgit.api.GarbageCollectCommand;
  import org.eclipse.jgit.api.Git;
  import org.eclipse.jgit.junit.TestRepository;
  import org.eclipse.jgit.lib.NullProgressMonitor;
  import org.eclipse.jgit.lib.Ref;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.revwalk.RevCommit;
  import org.eclipse.jgit.transport.FetchResult;
  import org.eclipse.jgit.transport.RefSpec;
  import org.eclipse.jgit.transport.TransportBundleStream;
  import org.eclipse.jgit.transport.URIish;
  import org.junit.Before;
  import org.junit.Test;
  
  public class DfsBundleWriterTest {
  	private TestRepository<InMemoryRepository> git;
  
  	private InMemoryRepository repo;
  
  	@Before
  	public void setUp() throws IOException {
  		DfsRepositoryDescription desc = new DfsRepositoryDescription("test");
  		git = new TestRepository<>(new InMemoryRepository(desc));
  		repo = git.getRepository();
  	}
  
  	@Test
  	public void makeBundle_containsUnreferencedObject() throws Exception {
  		RevCommit commit0 = git.commit().message("0").create();
  		RevCommit commit1 = git.commit().message("1").parent(commit0).create();
  		git.update("master", commit1);
  
  		RevCommit commit2 = git.commit().message("0").create();
  
  		byte[] bundle = makeBundle();
  		try (Repository newRepo = new InMemoryRepository(
  				new DfsRepositoryDescription("copy"))) {
  			fetchFromBundle(newRepo, bundle);
  			Ref ref = newRepo.exactRef("refs/heads/master");
  			assertNotNull(ref);
  			assertEquals(commit1.toObjectId(), ref.getObjectId());
  
  			// Unreferenced objects are included as well.
  			assertTrue(newRepo.getObjectDatabase().has(commit2));
  		}
  	}
  
  	@Test
  	public void makeBundle_containsObjectInGcRestPack() throws Exception {
  		RevCommit commit0 = git.commit().message("0").create();
  		RevCommit commit1 = git.commit().message("1").parent(commit0).create();
  		git.update("master", commit1);
  
  		RevCommit commit2 = git.commit().message("0").create();
  
  		// This moves unreachable commit2 to GC_REST pack.
  		GarbageCollectCommand gc = Git.wrap(repo).gc();
  		gc.call();
  
  		byte[] bundle = makeBundle();
  		try (Repository newRepo = new InMemoryRepository(
  				new DfsRepositoryDescription("copy"))) {
  			fetchFromBundle(newRepo, bundle);
  			Ref ref = newRepo.exactRef("refs/heads/master");
  			assertNotNull(ref);
  			assertEquals(commit1.toObjectId(), ref.getObjectId());
  
  			// Unreferenced objects in GC_REST pack are included as well.
  			assertTrue(newRepo.getObjectDatabase().has(commit2));
  		}
  	}
  
  	private byte[] makeBundle() throws IOException {
  		ByteArrayOutputStream out = new ByteArrayOutputStream();
  		DfsBundleWriter.writeEntireRepositoryAsBundle(
  				NullProgressMonitor.INSTANCE, out, repo);
  		return out.toByteArray();
  	}
 
 	private static FetchResult fetchFromBundle(Repository newRepo,
 			byte[] bundle) throws Exception {
 		URIish uri = new URIish("in-memory://");
 		ByteArrayInputStream in = new ByteArrayInputStream(bundle);
 		RefSpec rs = new RefSpec("refs/heads/*:refs/heads/*");
 		Set<RefSpec> refs = Collections.singleton(rs);
 		try (TransportBundleStream transport = new TransportBundleStream(
 				newRepo, uri, in)) {
 			return transport.fetch(NullProgressMonitor.INSTANCE, refs);
 		}
 	}
 }