/*
    * Copyright (C) 2017, Matthias Sohn <matthias.sohn@sap.com>
    * 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,
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   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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  package org.eclipse.jgit.internal.storage.file;
  
  import static org.junit.Assert.assertTrue;
  
  import java.io.File;
  import java.io.IOException;
  import java.nio.file.Path;
  
  import org.eclipse.jgit.api.Git;
  import org.eclipse.jgit.api.errors.AbortedByHookException;
  import org.eclipse.jgit.api.errors.ConcurrentRefUpdateException;
  import org.eclipse.jgit.api.errors.GitAPIException;
  import org.eclipse.jgit.api.errors.NoFilepatternException;
  import org.eclipse.jgit.api.errors.NoHeadException;
  import org.eclipse.jgit.api.errors.NoMessageException;
  import org.eclipse.jgit.api.errors.UnmergedPathsException;
  import org.eclipse.jgit.api.errors.WrongRepositoryStateException;
  import org.eclipse.jgit.junit.JGitTestUtil;
  import org.eclipse.jgit.lib.ObjectId;
  import org.eclipse.jgit.revwalk.RevCommit;
  import org.eclipse.jgit.test.resources.SampleDataRepositoryTestCase;
  import org.junit.Test;
  
  public class AlternatesTest extends SampleDataRepositoryTestCase {
  
  	private FileRepository db2;
  
  	@Override
  	public void setUp() throws Exception {
  		super.setUp();
  		db2 = createWorkRepository();
  	}
  
  	private void setAlternate(FileRepository from, FileRepository to)
  			throws IOException {
  		File alt = new File(from.getObjectDatabase().getDirectory(),
  				"info/alternates");
  		alt.getParentFile().mkdirs();
  		File fromDir = from.getObjectDatabase().getDirectory();
  		File toDir = to.getObjectDatabase().getDirectory();
  		Path relative = fromDir.toPath().relativize(toDir.toPath());
  		write(alt, relative.toString() + "\n");
  	}
  
  	@Test
  	public void testAlternate() throws Exception {
  		setAlternate(db2, db);
  		RevCommit c = createCommit();
  		assertCommit(c);
  		assertAlternateObjects(db2);
  	}
  
  	@Test
  	public void testAlternateCyclic2() throws Exception {
  		setAlternate(db2, db);
  		setAlternate(db, db2);
  		RevCommit c = createCommit();
 		assertCommit(c);
 		assertAlternateObjects(db2);
 	}
 
 	@Test
 	public void testAlternateCyclic3() throws Exception {
 		FileRepository db3 = createBareRepository();
 		setAlternate(db2, db3);
 		setAlternate(db3, db);
 		setAlternate(db, db2);
 		RevCommit c = createCommit();
 		assertCommit(c);
 		assertAlternateObjects(db2);
 	}
 
 	private RevCommit createCommit() throws IOException, GitAPIException,
 			NoFilepatternException, NoHeadException, NoMessageException,
 			UnmergedPathsException, ConcurrentRefUpdateException,
 			WrongRepositoryStateException, AbortedByHookException {
 		JGitTestUtil.writeTrashFile(db, "test", "test");
 		Git git = Git.wrap(db2);
 		git.add().addFilepattern("test").call();
 		RevCommit c = git.commit().setMessage("adding test").call();
 		return c;
 	}
 
 	private void assertCommit(RevCommit c) {
 		ObjectDirectory od = db2.getObjectDatabase();
 		assertTrue("can't find expected commit" + c.name(),
 				od.has(c.toObjectId()));
 	}
 
 	private void assertAlternateObjects(FileRepository repo) {
 		// check some objects in alternate
 		final ObjectId alternateObjects[] = new ObjectId[] {
 				ObjectId.fromString("49322bb17d3acc9146f98c97d078513228bbf3c0"),
 				ObjectId.fromString("d0114ab8ac326bab30e3a657a0397578c5a1af88"),
 				ObjectId.fromString("f73b95671f326616d66b2afb3bdfcdbbce110b44"),
 				ObjectId.fromString("6020a3b8d5d636e549ccbd0c53e2764684bb3125"),
 				ObjectId.fromString("0a3d7772488b6b106fb62813c4d6d627918d9181"),
 				ObjectId.fromString("da0f8ed91a8f2f0f067b3bdf26265d5ca48cf82c"),
 				ObjectId.fromString(
 						"cd4bcfc27da62c6b840de700be1c60a7e69952a5") };
 		ObjectDirectory od = repo.getObjectDatabase();
 		for (ObjectId o : alternateObjects) {
 			assertTrue(String.format("can't find object %s in alternate",
 					o.getName()), od.has(o));
 		}
 	}
 }