/*
 * SonarQube
 * Copyright (C) 2009-2022 SonarSource SA
 * mailto:info AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package org.sonar.scm.git;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.LinkOption;
import java.nio.file.Path;
import java.util.Date;
import java.util.LinkedList;
import java.util.List;
import org.apache.commons.io.FileUtils;
import org.eclipse.jgit.api.Git;
import org.eclipse.jgit.api.errors.GitAPIException;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.TemporaryFolder;
import org.sonar.api.batch.scm.BlameLine;
import org.sonar.api.utils.DateUtils;
import org.sonar.api.utils.System2;
import org.sonar.api.utils.log.LogTester;

import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assertions.assertThatThrownBy;
import static org.junit.Assume.assumeTrue;
import static org.sonar.scm.git.GitUtils.createFile;
import static org.sonar.scm.git.GitUtils.createRepository;
import static org.sonar.scm.git.Utils.javaUnzip;

public class GitBlameCommandTest {
  private static final String DUMMY_JAVA = "src/main/java/org/dummy/Dummy.java";

  @Rule
  public TemporaryFolder temp = new TemporaryFolder();
  @Rule
  public LogTester logTester = new LogTester();
  private final GitBlameCommand blameCommand = new GitBlameCommand();

  @Before
  public void skipTestsIfNoGitFound() {
    assumeTrue(blameCommand.isEnabled());
  }

  @Test
  public void blame_collects_all_lines() throws Exception {
    File projectDir = createNewTempFolder();
    javaUnzip("dummy-git.zip", projectDir);
    File baseDir = new File(projectDir, "dummy-git");

    List<BlameLine> blame = blameCommand.blame(baseDir.toPath(), DUMMY_JAVA);

    Date revisionDate1 = DateUtils.parseDateTime("2012-07-17T16:12:48+0200");
    String revision1 = "6b3aab35a3ea32c1636fee56f996e677653c48ea";
    String author1 = "david@gageot.net";

    // second commit, which has a commit date different than the author date
    Date revisionDate2 = DateUtils.parseDateTime("2015-05-19T13:31:09+0200");
    String revision2 = "0d269c1acfb8e6d4d33f3c43041eb87e0df0f5e7";
    String author2 = "duarte.meneses@sonarsource.com";

    List<BlameLine> expectedBlame = new LinkedList<>();
    for (int i = 0; i < 25; i++) {
      expectedBlame.add(new BlameLine().revision(revision1).date(revisionDate1).author(author1));
    }
    for (int i = 0; i < 3; i++) {
      expectedBlame.add(new BlameLine().revision(revision2).date(revisionDate2).author(author2));
    }
    for (int i = 0; i < 1; i++) {
      expectedBlame.add(new BlameLine().revision(revision1).date(revisionDate1).author(author1));
    }

    assertThat(blame).isEqualTo(expectedBlame);
  }

  @Test
  public void modified_file_returns_no_blame() throws Exception {
    File projectDir = createNewTempFolder();
    javaUnzip("dummy-git.zip", projectDir);

    Path baseDir = projectDir.toPath().resolve("dummy-git");

    // Emulate a modification
    Files.write(baseDir.resolve(DUMMY_JAVA), "modification and \n some new line".getBytes());

    assertThat(blameCommand.blame(baseDir, DUMMY_JAVA)).isEmpty();
  }

  @Test
  public void throw_exception_if_symlink_found() throws Exception {
    assumeTrue(!System2.INSTANCE.isOsWindows());
    File projectDir = temp.newFolder();
    javaUnzip("dummy-git.zip", projectDir);

    Path baseDir = projectDir.toPath().resolve("dummy-git");
    String relativePath2 = "src/main/java/org/dummy/Dummy2.java";

    // Create symlink
    Files.createSymbolicLink(baseDir.resolve(relativePath2), baseDir.resolve(DUMMY_JAVA));

    blameCommand.blame(baseDir, DUMMY_JAVA);
    assertThatThrownBy(() -> blameCommand.blame(baseDir, relativePath2)).isInstanceOf(IllegalStateException.class);
  }

  @Test
  public void git_should_be_detected() {
    GitBlameCommand blameCommand = new GitBlameCommand();
    assertThat(blameCommand.isEnabled()).isTrue();
  }

  @Test
  public void git_should_not_be_detected() {
    GitBlameCommand blameCommand = new GitBlameCommand("randomcmdthatwillneverbefound");
    assertThat(blameCommand.isEnabled()).isFalse();
  }

  @Test
  public void throw_exception_if_command_fails() throws Exception {
    Path baseDir = temp.newFolder().toPath();
    GitBlameCommand blameCommand = new GitBlameCommand("randomcmdthatwillneverbefound");
    assertThatThrownBy(() -> blameCommand.blame(baseDir, "file")).isInstanceOf(IOException.class);
  }

  @Test
  public void blame_without_email_doesnt_fail() throws Exception {
    Path baseDir = temp.newFolder().toPath();
    Git git = createRepository(baseDir);
    String filePath = "file.txt";
    createFile(filePath, "line", baseDir);
    commitWithNoEamil(git, filePath);

    GitBlameCommand blameCommand = new GitBlameCommand();
    List<BlameLine> blame = blameCommand.blame(baseDir, filePath);
    assertThat(blame).hasSize(1);
    BlameLine blameLine = blame.get(0);
    assertThat(blameLine.author()).isNull();
    assertThat(blameLine.revision()).isNotNull();
    assertThat(blameLine.date()).isNotNull();
  }

  private void commitWithNoEamil(Git git, String path) throws GitAPIException {
    git.add().addFilepattern(path).call();
    git.commit().setCommitter("joe", "").setMessage("msg").call();
  }

  private File createNewTempFolder() throws IOException {
    //This is needed for Windows, otherwise the created File point to invalid (shortened by Windows) temp folder path
    return temp.newFolder().toPath().toRealPath(LinkOption.NOFOLLOW_LINKS).toFile();
  }
}