/*
 * Copyright (C) 2013, Google Inc. 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
 * https://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

package org.eclipse.jgit.api;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

import java.util.Map;

import org.eclipse.jgit.junit.RepositoryTestCase;
import org.eclipse.jgit.junit.TestRepository;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.junit.Before;
import org.junit.Test;

public class NameRevCommandTest extends RepositoryTestCase {
	private TestRepository<Repository> tr;
	private Git git;

	@Override
	@Before
	public void setUp() throws Exception {
		super.setUp();
		tr = new TestRepository<>(db);
		git = new Git(db);
	}

	@Test
	public void nameExact() throws Exception {
		RevCommit c = tr.commit().create();
		tr.update("master", c);
		assertOneResult("master", c);
	}

	@Test
	public void prefix() throws Exception {
		RevCommit c = tr.commit().create();
		tr.update("refs/heads/master", c);
		tr.update("refs/tags/tag", c);
		assertOneResult("master", c);
		assertOneResult("master",
				git.nameRev().addPrefix("refs/heads/").addPrefix("refs/tags/"),
				c);
		assertOneResult("tag",
				git.nameRev().addPrefix("refs/tags/").addPrefix("refs/heads/"),
				c);
	}

	@Test
	public void ref() throws Exception {
		RevCommit c = tr.commit().create();
		tr.update("refs/heads/master", c);
		tr.update("refs/tags/tag", c);
		assertOneResult("master",
				git.nameRev().addRef(db.exactRef("refs/heads/master")), c);
		assertOneResult("tag",
				git.nameRev().addRef(db.exactRef("refs/tags/tag")), c);
	}

	@Test
	public void annotatedTags() throws Exception {
		RevCommit c = tr.commit().create();
		tr.update("refs/heads/master", c);
		tr.update("refs/tags/tag1", c);
		tr.update("refs/tags/tag2", tr.tag("tag2", c));
		assertOneResult("tag2", git.nameRev().addAnnotatedTags(), c);
	}

	@Test
	public void annotatedTagsNoResult() throws Exception {
		RevCommit c = tr.commit().create();
		tr.update("refs/heads/master", c);
		tr.update("refs/tags/tag1", c);
		tr.update("refs/tags/tag2", c);
		Map<ObjectId, String> result = git.nameRev()
				.add(c)
				.addAnnotatedTags()
				.call();
		assertTrue(result.toString(), result.isEmpty());
	}

	@Test
	public void simpleAncestor() throws Exception {
		// 0--1--2
		RevCommit c0 = tr.commit().create();
		RevCommit c1 = tr.commit().parent(c0).create();
		RevCommit c2 = tr.commit().parent(c1).create();
		tr.update("master", c2);
		Map<ObjectId, String> result = git.nameRev().add(c0).add(c1).add(c2).call();
		assertEquals(3, result.size());
		assertEquals("master~2", result.get(c0));
		assertEquals("master~1", result.get(c1));
		assertEquals("master", result.get(c2));
	}

	@Test
	public void multiplePathsNoMerge() throws Exception {
		// 0--1    <- master
		//  \-2--3 <- branch
		RevCommit c0 = tr.commit().create();
		RevCommit c1 = tr.commit().parent(c0).create();
		RevCommit c2 = tr.commit().parent(c0).create();
		RevCommit c3 = tr.commit().parent(c2).create();
		tr.update("master", c1);
		tr.update("branch", c3);
		assertOneResult("master~1", c0);
	}

	@Test
	public void onePathMerge() throws Exception {
		// 0--1--3
		//  \-2-/
		RevCommit c0 = tr.commit().create();
		RevCommit c1 = tr.commit().parent(c0).create();
		RevCommit c2 = tr.commit().parent(c0).create();
		RevCommit c3 = tr.commit().parent(c1).parent(c2).create();
		tr.update("master", c3);
		assertOneResult("master~2", c0);
	}

	@Test
	public void onePathMergeSecondParent() throws Exception {
		// 0--1-----4
		//  \-2--3-/
		RevCommit c0 = tr.commit().create();
		RevCommit c1 = tr.commit().parent(c0).create();
		RevCommit c2 = tr.commit().parent(c0).create();
		RevCommit c3 = tr.commit().parent(c2).create();
		RevCommit c4 = tr.commit().parent(c1).parent(c3).create();
		tr.update("master", c4);
		assertOneResult("master^2", c3);
		assertOneResult("master^2~1", c2);
	}

	@Test
	public void onePathMergeLongerFirstParentPath() throws Exception {
		// 0--1--2--4
		//  \--3---/
		RevCommit c0 = tr.commit().create();
		RevCommit c1 = tr.commit().parent(c0).create();
		RevCommit c2 = tr.commit().parent(c1).create();
		RevCommit c3 = tr.commit().parent(c0).create();
		RevCommit c4 = tr.commit().parent(c2).parent(c3).create();
		tr.update("master", c4);
		assertOneResult("master^2", c3);
		assertOneResult("master~3", c0);
	}

	@Test
	public void multiplePathsSecondParent() throws Exception {
		// 0--...--2
		//  \--1--/
		RevCommit c0 = tr.commit().create();
		RevCommit c1 = tr.commit().parent(c0).create();
		RevCommit c = c0;
		int mergeCost = 5;
		for (int i = 0; i < mergeCost; i++) {
			c = tr.commit().parent(c).create();
		}
		RevCommit c2 = tr.commit().parent(c).parent(c1).create();
		tr.update("master", c2);
		assertOneResult("master^2~1", git.nameRev().setMergeCost(mergeCost), c0);
	}

	private static void assertOneResult(String expected, NameRevCommand nameRev,
			ObjectId id) throws Exception {
		Map<ObjectId, String> result = nameRev.add(id).call();
		assertEquals(1, result.size());
		assertEquals(expected, result.get(id));
	}

	private void assertOneResult(String expected, ObjectId id) throws Exception {
		assertOneResult(expected, git.nameRev(), id);
	}
}