/*
    * Copyright (C) 2010, Mathias Kinzler <mathias.kinzler@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,
   * 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,
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   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  package org.eclipse.jgit.api;
  
  import static java.nio.charset.StandardCharsets.UTF_8;
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertNotNull;
  import static org.junit.Assert.assertNull;
  import static org.junit.Assert.assertTrue;
  
  import java.io.ByteArrayOutputStream;
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.util.concurrent.Callable;
  
  import org.eclipse.jgit.api.CreateBranchCommand.SetupUpstreamMode;
  import org.eclipse.jgit.api.MergeResult.MergeStatus;
  import org.eclipse.jgit.api.errors.NoHeadException;
  import org.eclipse.jgit.junit.JGitTestUtil;
  import org.eclipse.jgit.junit.RepositoryTestCase;
  import org.eclipse.jgit.lib.Constants;
  import org.eclipse.jgit.lib.ObjectId;
  import org.eclipse.jgit.lib.RefUpdate;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.lib.RepositoryState;
  import org.eclipse.jgit.lib.StoredConfig;
  import org.eclipse.jgit.revwalk.RevCommit;
  import org.eclipse.jgit.revwalk.RevSort;
  import org.eclipse.jgit.revwalk.RevWalk;
  import org.eclipse.jgit.transport.RefSpec;
  import org.eclipse.jgit.transport.RemoteConfig;
  import org.eclipse.jgit.transport.URIish;
  import org.junit.Before;
  import org.junit.Test;
  
  public class PullCommandTest extends RepositoryTestCase {
  	/** Second Test repository */
  	protected Repository dbTarget;
  
  	private Git source;
  
  	private Git target;
  
  	private File sourceFile;
  
  	private File targetFile;
  
  	@Test
  	public void testPullFastForward() throws Exception {
  		PullResult res = target.pull().call();
  		// nothing to update since we don't have different data yet
  		assertTrue(res.getFetchResult().getTrackingRefUpdates().isEmpty());
  		assertTrue(res.getMergeResult().getMergeStatus().equals(
  				MergeStatus.ALREADY_UP_TO_DATE));
  
  		assertFileContentsEqual(targetFile, "Hello world");
 
 		// change the source file
 		writeToFile(sourceFile, "Another change");
 		source.add().addFilepattern("SomeFile.txt").call();
 		source.commit().setMessage("Some change in remote").call();
 
 		res = target.pull().call();
 
 		assertFalse(res.getFetchResult().getTrackingRefUpdates().isEmpty());
 		assertEquals(res.getMergeResult().getMergeStatus(),
 				MergeStatus.FAST_FORWARD);
 		assertFileContentsEqual(targetFile, "Another change");
 		assertEquals(RepositoryState.SAFE, target.getRepository()
 				.getRepositoryState());
 
 		res = target.pull().call();
 		assertEquals(res.getMergeResult().getMergeStatus(),
 				MergeStatus.ALREADY_UP_TO_DATE);
 	}
 
 	@Test
 	public void testPullMerge() throws Exception {
 		PullResult res = target.pull().call();
 		// nothing to update since we don't have different data yet
 		assertTrue(res.getFetchResult().getTrackingRefUpdates().isEmpty());
 		assertTrue(res.getMergeResult().getMergeStatus()
 				.equals(MergeStatus.ALREADY_UP_TO_DATE));
 
 		writeToFile(sourceFile, "Source change");
 		source.add().addFilepattern("SomeFile.txt");
 		RevCommit sourceCommit = source.commit()
 				.setMessage("Source change in remote").call();
 
 		File targetFile2 = new File(dbTarget.getWorkTree(), "OtherFile.txt");
 		writeToFile(targetFile2, "Unconflicting change");
 		target.add().addFilepattern("OtherFile.txt").call();
 		RevCommit targetCommit = target.commit()
 				.setMessage("Unconflicting change in local").call();
 
 		res = target.pull().call();
 
 		MergeResult mergeResult = res.getMergeResult();
 		ObjectId[] mergedCommits = mergeResult.getMergedCommits();
 		assertEquals(targetCommit.getId(), mergedCommits[0]);
 		assertEquals(sourceCommit.getId(), mergedCommits[1]);
 		try (RevWalk rw = new RevWalk(dbTarget)) {
 			RevCommit mergeCommit = rw.parseCommit(mergeResult.getNewHead());
 			String message = "Merge branch 'master' of "
 					+ db.getWorkTree().getAbsolutePath();
 			assertEquals(message, mergeCommit.getShortMessage());
 		}
 	}
 
 	@Test
 	public void testPullConflict() throws Exception {
 		PullResult res = target.pull().call();
 		// nothing to update since we don't have different data yet
 		assertTrue(res.getFetchResult().getTrackingRefUpdates().isEmpty());
 		assertTrue(res.getMergeResult().getMergeStatus().equals(
 				MergeStatus.ALREADY_UP_TO_DATE));
 
 		assertFileContentsEqual(targetFile, "Hello world");
 
 		// change the source file
 		writeToFile(sourceFile, "Source change");
 		source.add().addFilepattern("SomeFile.txt").call();
 		source.commit().setMessage("Source change in remote").call();
 
 		// change the target file
 		writeToFile(targetFile, "Target change");
 		target.add().addFilepattern("SomeFile.txt").call();
 		target.commit().setMessage("Target change in local").call();
 
 		res = target.pull().call();
 
 		String sourceChangeString = "Source change\n>>>>>>> branch 'master' of "
 				+ target.getRepository().getConfig().getString("remote",
 						"origin", "url");
 
 		assertFalse(res.getFetchResult().getTrackingRefUpdates().isEmpty());
 		assertEquals(res.getMergeResult().getMergeStatus(),
 				MergeStatus.CONFLICTING);
 		String result = "<<<<<<< HEAD\nTarget change\n=======\n"
 				+ sourceChangeString + "\n";
 		assertFileContentsEqual(targetFile, result);
 		assertEquals(RepositoryState.MERGING, target.getRepository()
 				.getRepositoryState());
 	}
 
 	@Test
 	public void testPullWithUntrackedStash() throws Exception {
 		target.pull().call();
 
 		// change the source file
 		writeToFile(sourceFile, "Source change");
 		source.add().addFilepattern("SomeFile.txt").call();
 		source.commit().setMessage("Source change in remote").call();
 
 		// write untracked file
 		writeToFile(new File(dbTarget.getWorkTree(), "untracked.txt"),
 				"untracked");
 		RevCommit stash = target.stashCreate().setIndexMessage("message here")
 				.setIncludeUntracked(true).call();
 		assertNotNull(stash);
 		assertTrue(target.status().call().isClean());
 
 		// pull from source
 		assertTrue(target.pull().call().isSuccessful());
 		assertEquals("[SomeFile.txt, mode:100644, content:Source change]",
 				indexState(dbTarget, CONTENT));
 		assertFalse(JGitTestUtil.check(dbTarget, "untracked.txt"));
 		assertEquals("Source change",
 				JGitTestUtil.read(dbTarget, "SomeFile.txt"));
 
 		// apply the stash
 		target.stashApply().setStashRef(stash.getName()).call();
 		assertEquals("[SomeFile.txt, mode:100644, content:Source change]",
 				indexState(dbTarget, CONTENT));
 		assertEquals("untracked", JGitTestUtil.read(dbTarget, "untracked.txt"));
 		assertEquals("Source change",
 				JGitTestUtil.read(dbTarget, "SomeFile.txt"));
 	}
 
 	@Test
 	public void testPullLocalConflict() throws Exception {
 		target.branchCreate().setName("basedOnMaster").setStartPoint(
 				"refs/heads/master").setUpstreamMode(SetupUpstreamMode.TRACK)
 				.call();
 		target.getRepository().updateRef(Constants.HEAD).link(
 				"refs/heads/basedOnMaster");
 		PullResult res = target.pull().call();
 		// nothing to update since we don't have different data yet
 		assertNull(res.getFetchResult());
 		assertTrue(res.getMergeResult().getMergeStatus().equals(
 				MergeStatus.ALREADY_UP_TO_DATE));
 
 		assertFileContentsEqual(targetFile, "Hello world");
 
 		// change the file in master
 		target.getRepository().updateRef(Constants.HEAD).link(
 				"refs/heads/master");
 		writeToFile(targetFile, "Master change");
 		target.add().addFilepattern("SomeFile.txt").call();
 		target.commit().setMessage("Source change in master").call();
 
 		// change the file in slave
 		target.getRepository().updateRef(Constants.HEAD).link(
 				"refs/heads/basedOnMaster");
 		writeToFile(targetFile, "Slave change");
 		target.add().addFilepattern("SomeFile.txt").call();
 		target.commit().setMessage("Source change in based on master").call();
 
 		res = target.pull().call();
 
 		String sourceChangeString = "Master change\n>>>>>>> branch 'master' of local repository";
 
 		assertNull(res.getFetchResult());
 		assertEquals(res.getMergeResult().getMergeStatus(),
 				MergeStatus.CONFLICTING);
 		String result = "<<<<<<< HEAD\nSlave change\n=======\n"
 				+ sourceChangeString + "\n";
 		assertFileContentsEqual(targetFile, result);
 		assertEquals(RepositoryState.MERGING, target.getRepository()
 				.getRepositoryState());
 	}
 
 	@Test(expected = NoHeadException.class)
 	public void testPullEmptyRepository() throws Exception {
 		Repository empty = createWorkRepository();
 		RefUpdate delete = empty.updateRef(Constants.HEAD, true);
 		delete.setForceUpdate(true);
 		delete.delete();
 		Git.wrap(empty).pull().call();
 	}
 
 	@Test
 	public void testPullMergeProgrammaticConfiguration() throws Exception {
 		// create another commit on another branch in source
 		source.checkout().setCreateBranch(true).setName("other").call();
 		sourceFile = new File(db.getWorkTree(), "file2.txt");
 		writeToFile(sourceFile, "content");
 		source.add().addFilepattern("file2.txt").call();
 		RevCommit sourceCommit = source.commit()
 				.setMessage("source commit on branch other").call();
 
 		File targetFile2 = new File(dbTarget.getWorkTree(), "OtherFile.txt");
 		writeToFile(targetFile2, "Unconflicting change");
 		target.add().addFilepattern("OtherFile.txt").call();
 		RevCommit targetCommit = target.commit()
 				.setMessage("Unconflicting change in local").call();
 
 		PullResult res = target.pull().setRemote("origin")
 				.setRemoteBranchName("other")
 				.setRebase(false).call();
 
 		MergeResult mergeResult = res.getMergeResult();
 		ObjectId[] mergedCommits = mergeResult.getMergedCommits();
 		assertEquals(targetCommit.getId(), mergedCommits[0]);
 		assertEquals(sourceCommit.getId(), mergedCommits[1]);
 		try (RevWalk rw = new RevWalk(dbTarget)) {
 			RevCommit mergeCommit = rw.parseCommit(mergeResult.getNewHead());
 			String message = "Merge branch 'other' of "
 					+ db.getWorkTree().getAbsolutePath();
 			assertEquals(message, mergeCommit.getShortMessage());
 		}
 	}
 
 	@Test
 	public void testPullMergeProgrammaticConfigurationImpliedTargetBranch()
 			throws Exception {
 		// create another commit on another branch in source
 		source.checkout().setCreateBranch(true).setName("other").call();
 		sourceFile = new File(db.getWorkTree(), "file2.txt");
 		writeToFile(sourceFile, "content");
 		source.add().addFilepattern("file2.txt").call();
 		RevCommit sourceCommit = source.commit()
 				.setMessage("source commit on branch other").call();
 
 		target.checkout().setCreateBranch(true).setName("other").call();
 		File targetFile2 = new File(dbTarget.getWorkTree(), "OtherFile.txt");
 		writeToFile(targetFile2, "Unconflicting change");
 		target.add().addFilepattern("OtherFile.txt").call();
 		RevCommit targetCommit = target.commit()
 				.setMessage("Unconflicting change in local").call();
 
 		// the source branch "other" matching the target branch should be
 		// implied
 		PullResult res = target.pull().setRemote("origin").setRebase(false)
 				.call();
 
 		MergeResult mergeResult = res.getMergeResult();
 		ObjectId[] mergedCommits = mergeResult.getMergedCommits();
 		assertEquals(targetCommit.getId(), mergedCommits[0]);
 		assertEquals(sourceCommit.getId(), mergedCommits[1]);
 		try (RevWalk rw = new RevWalk(dbTarget)) {
 			RevCommit mergeCommit = rw.parseCommit(mergeResult.getNewHead());
 			String message = "Merge branch 'other' of "
 					+ db.getWorkTree().getAbsolutePath() + " into other";
 			assertEquals(message, mergeCommit.getShortMessage());
 		}
 	}
 
 	private enum TestPullMode {
 		MERGE, REBASE, REBASE_PREASERVE
 	}
 
 	@Test
 	/** global rebase config should be respected */
 	public void testPullWithRebasePreserve1Config() throws Exception {
 		Callable<PullResult> setup = new Callable<PullResult>() {
 			@Override
 			public PullResult call() throws Exception {
 				StoredConfig config = dbTarget.getConfig();
 				config.setString("pull", null, "rebase", "preserve");
 				config.save();
 				return target.pull().call();
 			}
 		};
 		doTestPullWithRebase(setup, TestPullMode.REBASE_PREASERVE);
 	}
 
 	@Test
 	/** the branch-local config should win over the global config */
 	public void testPullWithRebasePreserveConfig2() throws Exception {
 		Callable<PullResult> setup = new Callable<PullResult>() {
 			@Override
 			public PullResult call() throws Exception {
 				StoredConfig config = dbTarget.getConfig();
 				config.setString("pull", null, "rebase", "false");
 				config.setString("branch", "master", "rebase", "preserve");
 				config.save();
 				return target.pull().call();
 			}
 		};
 		doTestPullWithRebase(setup, TestPullMode.REBASE_PREASERVE);
 	}
 
 	@Test
 	/** the branch-local config should be respected */
 	public void testPullWithRebasePreserveConfig3() throws Exception {
 		Callable<PullResult> setup = new Callable<PullResult>() {
 			@Override
 			public PullResult call() throws Exception {
 				StoredConfig config = dbTarget.getConfig();
 				config.setString("branch", "master", "rebase", "preserve");
 				config.save();
 				return target.pull().call();
 			}
 		};
 		doTestPullWithRebase(setup, TestPullMode.REBASE_PREASERVE);
 	}
 
 	@Test
 	/** global rebase config should be respected */
 	public void testPullWithRebaseConfig1() throws Exception {
 		Callable<PullResult> setup = new Callable<PullResult>() {
 			@Override
 			public PullResult call() throws Exception {
 				StoredConfig config = dbTarget.getConfig();
 				config.setString("pull", null, "rebase", "true");
 				config.save();
 				return target.pull().call();
 			}
 		};
 		doTestPullWithRebase(setup, TestPullMode.REBASE);
 	}
 
 	@Test
 	/** the branch-local config should win over the global config */
 	public void testPullWithRebaseConfig2() throws Exception {
 		Callable<PullResult> setup = new Callable<PullResult>() {
 			@Override
 			public PullResult call() throws Exception {
 				StoredConfig config = dbTarget.getConfig();
 				config.setString("pull", null, "rebase", "preserve");
 				config.setString("branch", "master", "rebase", "true");
 				config.save();
 				return target.pull().call();
 			}
 		};
 		doTestPullWithRebase(setup, TestPullMode.REBASE);
 	}
 
 	@Test
 	/** the branch-local config should be respected */
 	public void testPullWithRebaseConfig3() throws Exception {
 		Callable<PullResult> setup = new Callable<PullResult>() {
 			@Override
 			public PullResult call() throws Exception {
 				StoredConfig config = dbTarget.getConfig();
 				config.setString("branch", "master", "rebase", "true");
 				config.save();
 				return target.pull().call();
 			}
 		};
 		doTestPullWithRebase(setup, TestPullMode.REBASE);
 	}
 
 	@Test
 	/** without config it should merge */
 	public void testPullWithoutConfig() throws Exception {
 		Callable<PullResult> setup = new Callable<PullResult>() {
 			@Override
 			public PullResult call() throws Exception {
 				return target.pull().call();
 			}
 		};
 		doTestPullWithRebase(setup, TestPullMode.MERGE);
 	}
 
 	@Test
 	/** the branch local config should win over the global config */
 	public void testPullWithMergeConfig() throws Exception {
 		Callable<PullResult> setup = new Callable<PullResult>() {
 			@Override
 			public PullResult call() throws Exception {
 				StoredConfig config = dbTarget.getConfig();
 				config.setString("pull", null, "rebase", "true");
 				config.setString("branch", "master", "rebase", "false");
 				config.save();
 				return target.pull().call();
 			}
 		};
 		doTestPullWithRebase(setup, TestPullMode.MERGE);
 	}
 
 	@Test
 	/** the branch local config should win over the global config */
 	public void testPullWithMergeConfig2() throws Exception {
 		Callable<PullResult> setup = new Callable<PullResult>() {
 			@Override
 			public PullResult call() throws Exception {
 				StoredConfig config = dbTarget.getConfig();
 				config.setString("pull", null, "rebase", "false");
 				config.save();
 				return target.pull().call();
 			}
 		};
 		doTestPullWithRebase(setup, TestPullMode.MERGE);
 	}
 
 	private void doTestPullWithRebase(Callable<PullResult> pullSetup,
 			TestPullMode expectedPullMode) throws Exception {
 		// simple upstream change
 		writeToFile(sourceFile, "content");
 		source.add().addFilepattern(sourceFile.getName()).call();
 		RevCommit sourceCommit = source.commit().setMessage("source commit")
 				.call();
 
 		// create a merge commit in target
 		File loxalFile = new File(dbTarget.getWorkTree(), "local.txt");
 		writeToFile(loxalFile, "initial\n");
 		target.add().addFilepattern("local.txt").call();
 		RevCommit t1 = target.commit().setMessage("target commit 1").call();
 
 		target.checkout().setCreateBranch(true).setName("side").call();
 
 		String newContent = "initial\n" + "and more\n";
 		writeToFile(loxalFile, newContent);
 		target.add().addFilepattern("local.txt").call();
 		RevCommit t2 = target.commit().setMessage("target commit 2").call();
 
 		target.checkout().setName("master").call();
 
 		MergeResult mergeResult = target.merge()
 				.setFastForward(MergeCommand.FastForwardMode.NO_FF).include(t2)
 				.call();
 		assertEquals(MergeStatus.MERGED, mergeResult.getMergeStatus());
 		assertFileContentsEqual(loxalFile, newContent);
 		ObjectId merge = mergeResult.getNewHead();
 
 		// pull
 		PullResult res = pullSetup.call();
 		assertNotNull(res.getFetchResult());
 
 		if (expectedPullMode == TestPullMode.MERGE) {
 			assertEquals(MergeStatus.MERGED, res.getMergeResult()
 					.getMergeStatus());
 			assertNull(res.getRebaseResult());
 		} else {
 			assertNull(res.getMergeResult());
 			assertEquals(RebaseResult.OK_RESULT, res.getRebaseResult());
 		}
 		assertFileContentsEqual(sourceFile, "content");
 
 		try (RevWalk rw = new RevWalk(dbTarget)) {
 			rw.sort(RevSort.TOPO);
 			rw.markStart(rw.parseCommit(dbTarget.resolve("refs/heads/master")));
 
 			RevCommit next;
 			if (expectedPullMode == TestPullMode.MERGE) {
 				next = rw.next();
 				assertEquals(2, next.getParentCount());
 				assertEquals(merge, next.getParent(0));
 				assertEquals(sourceCommit, next.getParent(1));
 				// since both parents are known do no further checks here
 			} else {
 				if (expectedPullMode == TestPullMode.REBASE_PREASERVE) {
 					next = rw.next();
 					assertEquals(2, next.getParentCount());
 				}
 				next = rw.next();
 				assertEquals(t2.getShortMessage(), next.getShortMessage());
 				next = rw.next();
 				assertEquals(t1.getShortMessage(), next.getShortMessage());
 				next = rw.next();
 				assertEquals(sourceCommit, next);
 				next = rw.next();
 				assertEquals("Initial commit for source",
 						next.getShortMessage());
 				next = rw.next();
 				assertNull(next);
 			}
 		}
 	}
 
 	@Override
 	@Before
 	public void setUp() throws Exception {
 		super.setUp();
 		dbTarget = createWorkRepository();
 		source = new Git(db);
 		target = new Git(dbTarget);
 
 		// put some file in the source repo
 		sourceFile = new File(db.getWorkTree(), "SomeFile.txt");
 		writeToFile(sourceFile, "Hello world");
 		// and commit it
 		source.add().addFilepattern("SomeFile.txt").call();
 		source.commit().setMessage("Initial commit for source").call();
 
 		// configure the target repo to connect to the source via "origin"
 		StoredConfig targetConfig = dbTarget.getConfig();
 		targetConfig.setString("branch", "master", "remote", "origin");
 		targetConfig
 				.setString("branch", "master", "merge", "refs/heads/master");
 		RemoteConfig config = new RemoteConfig(targetConfig, "origin");
 
 		config
 				.addURI(new URIish(source.getRepository().getWorkTree()
 						.getAbsolutePath()));
 		config.addFetchRefSpec(new RefSpec(
 				"+refs/heads/*:refs/remotes/origin/*"));
 		config.update(targetConfig);
 		targetConfig.save();
 
 		targetFile = new File(dbTarget.getWorkTree(), "SomeFile.txt");
 		// make sure we have the same content
 		target.pull().call();
 		assertFileContentsEqual(targetFile, "Hello world");
 	}
 
 	private static void writeToFile(File actFile, String string)
 			throws IOException {
 		try (FileOutputStream fos = new FileOutputStream(actFile)) {
 			fos.write(string.getBytes(UTF_8));
 		}
 	}
 
 	private static void assertFileContentsEqual(File actFile, String string)
 			throws IOException {
 		ByteArrayOutputStream bos = new ByteArrayOutputStream();
 		byte[] buffer = new byte[100];
 		try (FileInputStream fis = new FileInputStream(actFile)) {
 			int read = fis.read(buffer);
 			while (read > 0) {
 				bos.write(buffer, 0, read);
 				read = fis.read(buffer);
 			}
 			String content = new String(bos.toByteArray(), UTF_8);
 			assertEquals(string, content);
 		}
 	}
 }