// Copyright (C) 2013 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.gerrit.acceptance;

import static com.google.common.truth.Truth.assertThat;
import static com.google.common.truth.TruthJUnit.assume;
import static com.google.gerrit.acceptance.GitUtil.initSsh;
import static com.google.gerrit.extensions.api.changes.SubmittedTogetherOption.NON_VISIBLE_CHANGES;
import static com.google.gerrit.reviewdb.client.Patch.COMMIT_MSG;
import static com.google.gerrit.reviewdb.client.Patch.MERGE_LIST;
import static com.google.gerrit.server.group.SystemGroupBackend.REGISTERED_USERS;
import static com.google.gerrit.server.project.Util.category;
import static com.google.gerrit.server.project.Util.value;
import static java.nio.charset.StandardCharsets.UTF_8;
import static java.util.stream.Collectors.toList;
import static org.eclipse.jgit.lib.Constants.HEAD;
import static org.eclipse.jgit.lib.Constants.R_TAGS;

import com.google.common.base.Strings;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterables;
import com.google.common.jimfs.Jimfs;
import com.google.common.primitives.Chars;
import com.google.gerrit.acceptance.AcceptanceTestRequestScope.Context;
import com.google.gerrit.common.Nullable;
import com.google.gerrit.common.data.AccessSection;
import com.google.gerrit.common.data.ContributorAgreement;
import com.google.gerrit.common.data.GroupReference;
import com.google.gerrit.common.data.LabelFunction;
import com.google.gerrit.common.data.LabelType;
import com.google.gerrit.common.data.LabelValue;
import com.google.gerrit.common.data.Permission;
import com.google.gerrit.common.data.PermissionRule;
import com.google.gerrit.extensions.api.GerritApi;
import com.google.gerrit.extensions.api.changes.ReviewInput;
import com.google.gerrit.extensions.api.changes.RevisionApi;
import com.google.gerrit.extensions.api.changes.SubmittedTogetherInfo;
import com.google.gerrit.extensions.api.groups.GroupApi;
import com.google.gerrit.extensions.api.groups.GroupInput;
import com.google.gerrit.extensions.api.projects.BranchApi;
import com.google.gerrit.extensions.api.projects.BranchInput;
import com.google.gerrit.extensions.api.projects.ProjectInput;
import com.google.gerrit.extensions.client.InheritableBoolean;
import com.google.gerrit.extensions.client.ListChangesOption;
import com.google.gerrit.extensions.client.ProjectWatchInfo;
import com.google.gerrit.extensions.client.SubmitType;
import com.google.gerrit.extensions.common.ActionInfo;
import com.google.gerrit.extensions.common.ChangeInfo;
import com.google.gerrit.extensions.common.ChangeType;
import com.google.gerrit.extensions.common.DiffInfo;
import com.google.gerrit.extensions.common.EditInfo;
import com.google.gerrit.extensions.restapi.BinaryResult;
import com.google.gerrit.extensions.restapi.IdString;
import com.google.gerrit.extensions.restapi.RestApiException;
import com.google.gerrit.reviewdb.client.AccountGroup;
import com.google.gerrit.reviewdb.client.Branch;
import com.google.gerrit.reviewdb.client.PatchSet;
import com.google.gerrit.reviewdb.client.Project;
import com.google.gerrit.reviewdb.client.RefNames;
import com.google.gerrit.reviewdb.server.ReviewDb;
import com.google.gerrit.server.AnonymousUser;
import com.google.gerrit.server.ChangeFinder;
import com.google.gerrit.server.GerritPersonIdent;
import com.google.gerrit.server.IdentifiedUser;
import com.google.gerrit.server.OutputFormat;
import com.google.gerrit.server.PatchSetUtil;
import com.google.gerrit.server.account.AccountCache;
import com.google.gerrit.server.account.Accounts;
import com.google.gerrit.server.account.GroupCache;
import com.google.gerrit.server.change.Abandon;
import com.google.gerrit.server.change.ChangeResource;
import com.google.gerrit.server.change.FileContentUtil;
import com.google.gerrit.server.change.RevisionResource;
import com.google.gerrit.server.change.Revisions;
import com.google.gerrit.server.config.AllProjectsName;
import com.google.gerrit.server.config.CanonicalWebUrl;
import com.google.gerrit.server.config.GerritServerConfig;
import com.google.gerrit.server.config.PluginConfigFactory;
import com.google.gerrit.server.git.GitRepositoryManager;
import com.google.gerrit.server.git.MetaDataUpdate;
import com.google.gerrit.server.git.ProjectConfig;
import com.google.gerrit.server.group.Groups;
import com.google.gerrit.server.group.InternalGroup;
import com.google.gerrit.server.group.SystemGroupBackend;
import com.google.gerrit.server.index.change.ChangeIndex;
import com.google.gerrit.server.index.change.ChangeIndexCollection;
import com.google.gerrit.server.index.change.ChangeIndexer;
import com.google.gerrit.server.mail.Address;
import com.google.gerrit.server.mail.send.EmailHeader;
import com.google.gerrit.server.notedb.ChangeNoteUtil;
import com.google.gerrit.server.notedb.ChangeNotes;
import com.google.gerrit.server.notedb.MutableNotesMigration;
import com.google.gerrit.server.project.ProjectCache;
import com.google.gerrit.server.project.Util;
import com.google.gerrit.server.query.change.ChangeData;
import com.google.gerrit.server.query.change.InternalChangeQuery;
import com.google.gerrit.server.update.BatchUpdate;
import com.google.gerrit.testutil.ConfigSuite;
import com.google.gerrit.testutil.FakeAuditService;
import com.google.gerrit.testutil.FakeEmailSender;
import com.google.gerrit.testutil.FakeEmailSender.Message;
import com.google.gerrit.testutil.NoteDbMode;
import com.google.gerrit.testutil.SshMode;
import com.google.gerrit.testutil.TempFileUtil;
import com.google.gson.Gson;
import com.google.gwtorm.server.OrmException;
import com.google.gwtorm.server.SchemaFactory;
import com.google.inject.Inject;
import com.google.inject.Provider;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.file.DirectoryStream;
import java.nio.file.FileSystem;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.regex.Pattern;
import org.eclipse.jgit.api.Git;
import org.eclipse.jgit.errors.ConfigInvalidException;
import org.eclipse.jgit.errors.RepositoryNotFoundException;
import org.eclipse.jgit.internal.storage.dfs.InMemoryRepository;
import org.eclipse.jgit.junit.TestRepository;
import org.eclipse.jgit.lib.Config;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.NullProgressMonitor;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.PersonIdent;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevTree;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.transport.FetchResult;
import org.eclipse.jgit.transport.RefSpec;
import org.eclipse.jgit.transport.Transport;
import org.eclipse.jgit.transport.TransportBundleStream;
import org.eclipse.jgit.transport.URIish;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.Rule;
import org.junit.rules.ExpectedException;
import org.junit.rules.TestRule;
import org.junit.runner.Description;
import org.junit.runner.RunWith;
import org.junit.runners.model.Statement;

@RunWith(ConfigSuite.class)
public abstract class AbstractDaemonTest {
  private static GerritServer commonServer;
  private static Description firstTest;

  @ConfigSuite.Parameter public Config baseConfig;
  @ConfigSuite.Name private String configName;

  @Rule public ExpectedException exception = ExpectedException.none();

  @Rule
  public TestRule testRunner =
      new TestRule() {
        @Override
        public Statement apply(Statement base, Description description) {
          return new Statement() {
            @Override
            public void evaluate() throws Throwable {
              if (firstTest == null) {
                firstTest = description;
              }
              beforeTest(description);
              try {
                base.evaluate();
              } finally {
                afterTest();
              }
            }
          };
        }
      };

  @Inject @CanonicalWebUrl protected Provider<String> canonicalWebUrl;
  @Inject @GerritPersonIdent protected Provider<PersonIdent> serverIdent;
  @Inject @GerritServerConfig protected Config cfg;
  @Inject protected AcceptanceTestRequestScope atrScope;
  @Inject protected AccountCache accountCache;
  @Inject protected AccountCreator accountCreator;
  @Inject protected Accounts accounts;
  @Inject protected AllProjectsName allProjects;
  @Inject protected BatchUpdate.Factory batchUpdateFactory;
  @Inject protected ChangeData.Factory changeDataFactory;
  @Inject protected ChangeFinder changeFinder;
  @Inject protected ChangeIndexer indexer;
  @Inject protected ChangeNoteUtil changeNoteUtil;
  @Inject protected ChangeResource.Factory changeResourceFactory;
  @Inject protected FakeEmailSender sender;
  @Inject protected FakeAuditService auditService;
  @Inject protected GerritApi gApi;
  @Inject protected GitRepositoryManager repoManager;
  @Inject protected GroupCache groupCache;
  @Inject protected IdentifiedUser.GenericFactory identifiedUserFactory;
  @Inject protected MetaDataUpdate.Server metaDataUpdateFactory;
  @Inject protected PatchSetUtil psUtil;
  @Inject protected ProjectCache projectCache;
  @Inject protected Provider<InternalChangeQuery> queryProvider;
  @Inject protected PushOneCommit.Factory pushFactory;
  @Inject protected PluginConfigFactory pluginConfig;
  @Inject protected Revisions revisions;
  @Inject protected SystemGroupBackend systemGroupBackend;
  @Inject protected MutableNotesMigration notesMigration;
  @Inject protected ChangeNotes.Factory notesFactory;
  @Inject protected Abandon changeAbandoner;

  protected EventRecorder eventRecorder;
  protected GerritServer server;
  protected Project.NameKey project;
  protected RestSession adminRestSession;
  protected RestSession userRestSession;
  protected ReviewDb db;
  protected SshSession adminSshSession;
  protected SshSession userSshSession;
  protected TestAccount admin;
  protected TestAccount user;
  protected TestRepository<InMemoryRepository> testRepo;
  protected String resourcePrefix;
  protected Description description;
  protected boolean testRequiresSsh;

  @Inject private ChangeIndexCollection changeIndexes;
  @Inject private EventRecorder.Factory eventRecorderFactory;
  @Inject private InProcessProtocol inProcessProtocol;
  @Inject private Provider<AnonymousUser> anonymousUser;
  @Inject private SchemaFactory<ReviewDb> reviewDbProvider;
  @Inject private Groups groups;

  private List<Repository> toClose;

  @Before
  public void clearSender() {
    sender.clear();
  }

  @Before
  public void startEventRecorder() {
    eventRecorder = eventRecorderFactory.create(admin);
  }

  @Before
  public void assumeSshIfRequired() {
    if (testRequiresSsh) {
      // If the test uses ssh, we use assume() to make sure ssh is enabled on
      // the test suite. JUnit will skip tests annotated with @UseSsh if we
      // disable them using the command line flag.
      assume().that(SshMode.useSsh()).isTrue();
    }
  }

  @After
  public void closeEventRecorder() {
    eventRecorder.close();
  }

  @AfterClass
  public static void stopCommonServer() throws Exception {
    if (commonServer != null) {
      try {
        commonServer.close();
      } catch (Throwable t) {
        throw new AssertionError(
            "Error stopping common server in "
                + (firstTest != null ? firstTest.getTestClass().getName() : "unknown test class"),
            t);
      } finally {
        commonServer = null;
      }
    }
    TempFileUtil.cleanup();
  }

  protected static Config submitWholeTopicEnabledConfig() {
    Config cfg = new Config();
    cfg.setBoolean("change", null, "submitWholeTopic", true);
    return cfg;
  }

  protected boolean isSubmitWholeTopicEnabled() {
    return cfg.getBoolean("change", null, "submitWholeTopic", false);
  }

  protected boolean isContributorAgreementsEnabled() {
    return cfg.getBoolean("auth", null, "contributorAgreements", false);
  }

  protected void beforeTest(Description description) throws Exception {
    this.description = description;
    GerritServer.Description classDesc =
        GerritServer.Description.forTestClass(description, configName);
    GerritServer.Description methodDesc =
        GerritServer.Description.forTestMethod(description, configName);

    baseConfig.setInt("receive", null, "changeUpdateThreads", 4);
    if (classDesc.equals(methodDesc) && !classDesc.sandboxed() && !methodDesc.sandboxed()) {
      if (commonServer == null) {
        commonServer = GerritServer.initAndStart(classDesc, baseConfig);
      }
      server = commonServer;
    } else {
      server = GerritServer.initAndStart(methodDesc, baseConfig);
    }

    server.getTestInjector().injectMembers(this);
    Transport.register(inProcessProtocol);
    toClose = Collections.synchronizedList(new ArrayList<Repository>());

    db = reviewDbProvider.open();

    // All groups which were added during the server start (e.g. in SchemaCreator) aren't contained
    // in the instance of the group index which is available here and in tests. There are two
    // reasons:
    // 1) No group index is available in SchemaCreator when using an in-memory database. (This could
    // be fixed by using the IndexManagerOnInit in InMemoryDatabase similar as BaseInit uses it.)
    // 2) During the on-init part of the server start, we use another instance of the index than
    // later on. As test indexes are non-permanent, closing an instance and opening another one
    // removes all indexed data.
    // As a workaround, we simply reindex all available groups here.
    Iterable<AccountGroup> allGroups = groups.getAll(db)::iterator;
    for (AccountGroup group : allGroups) {
      groupCache.evict(group.getGroupUUID(), group.getId(), group.getNameKey());
    }

    admin = accountCreator.admin();
    user = accountCreator.user();

    // Evict cached user state in case tests modify it.
    accountCache.evict(admin.getId());
    accountCache.evict(user.getId());

    adminRestSession = new RestSession(server, admin);
    userRestSession = new RestSession(server, user);

    testRequiresSsh = classDesc.useSshAnnotation() || methodDesc.useSshAnnotation();
    if (testRequiresSsh
        && SshMode.useSsh()
        && (adminSshSession == null || userSshSession == null)) {
      // Create Ssh sessions
      initSsh(admin);
      Context ctx = newRequestContext(user);
      atrScope.set(ctx);
      userSshSession = ctx.getSession();
      userSshSession.open();
      ctx = newRequestContext(admin);
      atrScope.set(ctx);
      adminSshSession = ctx.getSession();
      adminSshSession.open();
    }

    resourcePrefix =
        UNSAFE_PROJECT_NAME
            .matcher(description.getClassName() + "_" + description.getMethodName() + "_")
            .replaceAll("");

    Context ctx = newRequestContext(admin);
    atrScope.set(ctx);
    project = createProject(projectInput(description));
    testRepo = cloneProject(project, getCloneAsAccount(description));
  }

  private TestAccount getCloneAsAccount(Description description) {
    TestProjectInput ann = description.getAnnotation(TestProjectInput.class);
    return accountCreator.get(ann != null ? ann.cloneAs() : "admin");
  }

  private ProjectInput projectInput(Description description) {
    ProjectInput in = new ProjectInput();
    TestProjectInput ann = description.getAnnotation(TestProjectInput.class);
    in.name = name("project");
    if (ann != null) {
      in.parent = Strings.emptyToNull(ann.parent());
      in.description = Strings.emptyToNull(ann.description());
      in.createEmptyCommit = ann.createEmptyCommit();
      in.submitType = ann.submitType();
      in.useContentMerge = ann.useContributorAgreements();
      in.useSignedOffBy = ann.useSignedOffBy();
      in.useContentMerge = ann.useContentMerge();
      in.enableSignedPush = ann.enableSignedPush();
      in.requireSignedPush = ann.requireSignedPush();
    } else {
      // Defaults should match TestProjectConfig, omitting nullable values.
      in.createEmptyCommit = true;
    }
    updateProjectInput(in);
    return in;
  }

  private static final Pattern UNSAFE_PROJECT_NAME = Pattern.compile("[^a-zA-Z0-9._/-]+");

  protected Git git() {
    return testRepo.git();
  }

  protected InMemoryRepository repo() {
    return testRepo.getRepository();
  }

  /**
   * Return a resource name scoped to this test method.
   *
   * <p>Test methods in a single class by default share a running server. For any resource name you
   * require to be unique to a test method, wrap it in a call to this method.
   *
   * @param name resource name (group, project, topic, etc.)
   * @return name prefixed by a string unique to this test method.
   */
  protected String name(String name) {
    return resourcePrefix + name;
  }

  protected Project.NameKey createProject(String nameSuffix) throws RestApiException {
    return createProject(nameSuffix, null);
  }

  protected Project.NameKey createProject(String nameSuffix, Project.NameKey parent)
      throws RestApiException {
    // Default for createEmptyCommit should match TestProjectConfig.
    return createProject(nameSuffix, parent, true, null);
  }

  protected Project.NameKey createProject(
      String nameSuffix, Project.NameKey parent, boolean createEmptyCommit)
      throws RestApiException {
    // Default for createEmptyCommit should match TestProjectConfig.
    return createProject(nameSuffix, parent, createEmptyCommit, null);
  }

  protected Project.NameKey createProject(
      String nameSuffix, Project.NameKey parent, SubmitType submitType) throws RestApiException {
    // Default for createEmptyCommit should match TestProjectConfig.
    return createProject(nameSuffix, parent, true, submitType);
  }

  protected Project.NameKey createProject(
      String nameSuffix, Project.NameKey parent, boolean createEmptyCommit, SubmitType submitType)
      throws RestApiException {
    ProjectInput in = new ProjectInput();
    in.name = name(nameSuffix);
    in.parent = parent != null ? parent.get() : null;
    in.submitType = submitType;
    in.createEmptyCommit = createEmptyCommit;
    return createProject(in);
  }

  private Project.NameKey createProject(ProjectInput in) throws RestApiException {
    gApi.projects().create(in);
    return new Project.NameKey(in.name);
  }

  /**
   * Modify a project input before creating the initial test project.
   *
   * @param in input; may be modified in place.
   */
  protected void updateProjectInput(ProjectInput in) {
    // Default implementation does nothing.
  }

  protected TestRepository<InMemoryRepository> cloneProject(Project.NameKey p) throws Exception {
    return cloneProject(p, admin);
  }

  protected TestRepository<InMemoryRepository> cloneProject(
      Project.NameKey p, TestAccount testAccount) throws Exception {
    return GitUtil.cloneProject(p, registerRepoConnection(p, testAccount));
  }

  /**
   * Register a repository connection over the test protocol.
   *
   * @return a URI string that can be used to connect to this repository for both fetch and push.
   */
  protected String registerRepoConnection(Project.NameKey p, TestAccount testAccount)
      throws Exception {
    InProcessProtocol.Context ctx =
        new InProcessProtocol.Context(
            reviewDbProvider, identifiedUserFactory, testAccount.getId(), p);
    Repository repo = repoManager.openRepository(p);
    toClose.add(repo);
    return inProcessProtocol.register(ctx, repo).toString();
  }

  protected void afterTest() throws Exception {
    Transport.unregister(inProcessProtocol);
    for (Repository repo : toClose) {
      repo.close();
    }
    db.close();
    if (adminSshSession != null) {
      adminSshSession.close();
    }
    if (userSshSession != null) {
      userSshSession.close();
    }
    if (server != commonServer) {
      server.close();
      server = null;
    }
    NoteDbMode.resetFromEnv(notesMigration);
  }

  protected TestRepository<?>.CommitBuilder commitBuilder() throws Exception {
    return testRepo.branch("HEAD").commit().insertChangeId();
  }

  protected TestRepository<?>.CommitBuilder amendBuilder() throws Exception {
    ObjectId head = repo().exactRef("HEAD").getObjectId();
    TestRepository<?>.CommitBuilder b = testRepo.amendRef("HEAD");
    Optional<String> id = GitUtil.getChangeId(testRepo, head);
    // TestRepository behaves like "git commit --amend -m foo", which does not
    // preserve an existing Change-Id. Tests probably want this.
    if (id.isPresent()) {
      b.insertChangeId(id.get().substring(1));
    } else {
      b.insertChangeId();
    }
    return b;
  }

  protected PushOneCommit.Result createChange() throws Exception {
    return createChange("refs/for/master");
  }

  protected PushOneCommit.Result createChange(String ref) throws Exception {
    PushOneCommit push = pushFactory.create(db, admin.getIdent(), testRepo);
    PushOneCommit.Result result = push.to(ref);
    result.assertOkStatus();
    return result;
  }

  protected PushOneCommit.Result createMergeCommitChange(String ref) throws Exception {
    return createMergeCommitChange(ref, "foo");
  }

  protected PushOneCommit.Result createMergeCommitChange(String ref, String file) throws Exception {
    ObjectId initial = repo().exactRef(HEAD).getLeaf().getObjectId();

    PushOneCommit.Result p1 =
        pushFactory
            .create(
                db,
                admin.getIdent(),
                testRepo,
                "parent 1",
                ImmutableMap.of(file, "foo-1", "bar", "bar-1"))
            .to(ref);

    // reset HEAD in order to create a sibling of the first change
    testRepo.reset(initial);

    PushOneCommit.Result p2 =
        pushFactory
            .create(
                db,
                admin.getIdent(),
                testRepo,
                "parent 2",
                ImmutableMap.of(file, "foo-2", "bar", "bar-2"))
            .to(ref);

    PushOneCommit m =
        pushFactory.create(
            db,
            admin.getIdent(),
            testRepo,
            "merge",
            ImmutableMap.of(file, "foo-1", "bar", "bar-2"));
    m.setParents(ImmutableList.of(p1.getCommit(), p2.getCommit()));
    PushOneCommit.Result result = m.to(ref);
    result.assertOkStatus();
    return result;
  }

  protected PushOneCommit.Result createCommitAndPush(
      TestRepository<InMemoryRepository> repo,
      String ref,
      String commitMsg,
      String fileName,
      String content)
      throws Exception {
    PushOneCommit.Result result =
        pushFactory.create(db, admin.getIdent(), repo, commitMsg, fileName, content).to(ref);
    result.assertOkStatus();
    return result;
  }

  protected PushOneCommit.Result createChangeWithTopic() throws Exception {
    return createChangeWithTopic(testRepo, "topic", "message", "a.txt", "content\n");
  }

  protected PushOneCommit.Result createChangeWithTopic(
      TestRepository<InMemoryRepository> repo,
      String topic,
      String commitMsg,
      String fileName,
      String content)
      throws Exception {
    assertThat(topic).isNotEmpty();
    return createCommitAndPush(
        repo, "refs/for/master/" + name(topic), commitMsg, fileName, content);
  }

  protected PushOneCommit.Result createWorkInProgressChange() throws Exception {
    return pushTo("refs/for/master%wip");
  }

  protected PushOneCommit.Result createChange(String subject, String fileName, String content)
      throws Exception {
    PushOneCommit push =
        pushFactory.create(db, admin.getIdent(), testRepo, subject, fileName, content);
    return push.to("refs/for/master");
  }

  protected PushOneCommit.Result createChange(
      String subject, String fileName, String content, String topic) throws Exception {
    PushOneCommit push =
        pushFactory.create(db, admin.getIdent(), testRepo, subject, fileName, content);
    return push.to("refs/for/master/" + name(topic));
  }

  protected PushOneCommit.Result createChange(
      TestRepository<?> repo,
      String branch,
      String subject,
      String fileName,
      String content,
      String topic)
      throws Exception {
    PushOneCommit push = pushFactory.create(db, admin.getIdent(), repo, subject, fileName, content);
    return push.to("refs/for/" + branch + "/" + name(topic));
  }

  protected BranchApi createBranch(Branch.NameKey branch) throws Exception {
    return gApi.projects()
        .name(branch.getParentKey().get())
        .branch(branch.get())
        .create(new BranchInput());
  }

  protected BranchApi createBranchWithRevision(Branch.NameKey branch, String revision)
      throws Exception {
    BranchInput in = new BranchInput();
    in.revision = revision;
    return gApi.projects().name(branch.getParentKey().get()).branch(branch.get()).create(in);
  }

  private static final List<Character> RANDOM =
      Chars.asList(new char[] {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'});

  protected PushOneCommit.Result amendChange(String changeId) throws Exception {
    return amendChange(changeId, "refs/for/master");
  }

  protected PushOneCommit.Result amendChange(String changeId, String ref) throws Exception {
    return amendChange(changeId, ref, admin, testRepo);
  }

  protected PushOneCommit.Result amendChange(
      String changeId, String ref, TestAccount testAccount, TestRepository<?> repo)
      throws Exception {
    Collections.shuffle(RANDOM);
    return amendChange(
        changeId,
        ref,
        testAccount,
        repo,
        PushOneCommit.SUBJECT,
        PushOneCommit.FILE_NAME,
        new String(Chars.toArray(RANDOM)));
  }

  protected PushOneCommit.Result amendChange(
      String changeId, String subject, String fileName, String content) throws Exception {
    return amendChange(changeId, "refs/for/master", admin, testRepo, subject, fileName, content);
  }

  protected PushOneCommit.Result amendChange(
      String changeId,
      String ref,
      TestAccount testAccount,
      TestRepository<?> repo,
      String subject,
      String fileName,
      String content)
      throws Exception {
    PushOneCommit push =
        pushFactory.create(db, testAccount.getIdent(), repo, subject, fileName, content, changeId);
    return push.to(ref);
  }

  protected void merge(PushOneCommit.Result r) throws Exception {
    revision(r).review(ReviewInput.approve());
    revision(r).submit();
  }

  protected ChangeInfo info(String id) throws RestApiException {
    return gApi.changes().id(id).info();
  }

  protected ChangeInfo get(String id) throws RestApiException {
    return gApi.changes().id(id).get();
  }

  protected Optional<EditInfo> getEdit(String id) throws RestApiException {
    return gApi.changes().id(id).edit().get();
  }

  protected ChangeInfo get(String id, ListChangesOption... options) throws RestApiException {
    return gApi.changes().id(id).get(options);
  }

  protected List<ChangeInfo> query(String q) throws RestApiException {
    return gApi.changes().query(q).get();
  }

  private Context newRequestContext(TestAccount account) {
    return atrScope.newContext(
        reviewDbProvider,
        new SshSession(server, account),
        identifiedUserFactory.create(account.getId()));
  }

  /**
   * Enforce a new request context for the current API user.
   *
   * <p>This recreates the IdentifiedUser, hence everything which is cached in the IdentifiedUser is
   * reloaded (e.g. the email addresses of the user).
   */
  protected Context resetCurrentApiUser() {
    return atrScope.set(newRequestContext(atrScope.get().getSession().getAccount()));
  }

  protected Context setApiUser(TestAccount account) {
    return atrScope.set(newRequestContext(account));
  }

  protected Context setApiUserAnonymous() {
    return atrScope.set(atrScope.newContext(reviewDbProvider, null, anonymousUser.get()));
  }

  protected Context disableDb() {
    notesMigration.setFailOnLoadForTest(true);
    return atrScope.disableDb();
  }

  protected void enableDb(Context preDisableContext) {
    notesMigration.setFailOnLoadForTest(false);
    atrScope.set(preDisableContext);
  }

  protected void disableChangeIndexWrites() {
    for (ChangeIndex i : changeIndexes.getWriteIndexes()) {
      if (!(i instanceof ReadOnlyChangeIndex)) {
        changeIndexes.addWriteIndex(new ReadOnlyChangeIndex(i));
      }
    }
  }

  protected void enableChangeIndexWrites() {
    for (ChangeIndex i : changeIndexes.getWriteIndexes()) {
      if (i instanceof ReadOnlyChangeIndex) {
        changeIndexes.addWriteIndex(((ReadOnlyChangeIndex) i).unwrap());
      }
    }
  }

  protected static Gson newGson() {
    return OutputFormat.JSON_COMPACT.newGson();
  }

  protected RevisionApi revision(PushOneCommit.Result r) throws Exception {
    return gApi.changes().id(r.getChangeId()).current();
  }

  protected void allow(String ref, String permission, AccountGroup.UUID id) throws Exception {
    allow(project, ref, permission, id);
  }

  protected void allow(Project.NameKey p, String ref, String permission, AccountGroup.UUID id)
      throws Exception {
    ProjectConfig cfg = projectCache.checkedGet(p).getConfig();
    Util.allow(cfg, permission, id, ref);
    saveProjectConfig(p, cfg);
  }

  protected void allowGlobalCapabilities(AccountGroup.UUID id, String... capabilityNames)
      throws Exception {
    allowGlobalCapabilities(id, Arrays.asList(capabilityNames));
  }

  protected void allowGlobalCapabilities(AccountGroup.UUID id, Iterable<String> capabilityNames)
      throws Exception {
    ProjectConfig cfg = projectCache.checkedGet(allProjects).getConfig();
    for (String capabilityName : capabilityNames) {
      Util.allow(cfg, capabilityName, id);
    }
    saveProjectConfig(allProjects, cfg);
  }

  protected void removeGlobalCapabilities(AccountGroup.UUID id, String... capabilityNames)
      throws Exception {
    removeGlobalCapabilities(id, Arrays.asList(capabilityNames));
  }

  protected void removeGlobalCapabilities(AccountGroup.UUID id, Iterable<String> capabilityNames)
      throws Exception {
    ProjectConfig cfg = projectCache.checkedGet(allProjects).getConfig();
    for (String capabilityName : capabilityNames) {
      Util.remove(cfg, capabilityName, id);
    }
    saveProjectConfig(allProjects, cfg);
  }

  protected void setUseContributorAgreements(InheritableBoolean value) throws Exception {
    try (MetaDataUpdate md = metaDataUpdateFactory.create(project)) {
      ProjectConfig config = ProjectConfig.read(md);
      config.getProject().setUseContributorAgreements(value);
      config.commit(md);
      projectCache.evict(config.getProject());
    }
  }

  protected void setUseSignedOffBy(InheritableBoolean value) throws Exception {
    try (MetaDataUpdate md = metaDataUpdateFactory.create(project)) {
      ProjectConfig config = ProjectConfig.read(md);
      config.getProject().setUseSignedOffBy(value);
      config.commit(md);
      projectCache.evict(config.getProject());
    }
  }

  protected void setRequireChangeId(InheritableBoolean value) throws Exception {
    try (MetaDataUpdate md = metaDataUpdateFactory.create(project)) {
      ProjectConfig config = ProjectConfig.read(md);
      config.getProject().setRequireChangeID(value);
      config.commit(md);
      projectCache.evict(config.getProject());
    }
  }

  protected void deny(String ref, String permission, AccountGroup.UUID id) throws Exception {
    deny(project, ref, permission, id);
  }

  protected void deny(Project.NameKey p, String ref, String permission, AccountGroup.UUID id)
      throws Exception {
    ProjectConfig cfg = projectCache.checkedGet(p).getConfig();
    Util.deny(cfg, permission, id, ref);
    saveProjectConfig(p, cfg);
  }

  protected PermissionRule block(String ref, String permission, AccountGroup.UUID id)
      throws Exception {
    return block(project, ref, permission, id);
  }

  protected PermissionRule block(
      Project.NameKey project, String ref, String permission, AccountGroup.UUID id)
      throws Exception {
    ProjectConfig cfg = projectCache.checkedGet(project).getConfig();
    PermissionRule rule = Util.block(cfg, permission, id, ref);
    saveProjectConfig(project, cfg);
    return rule;
  }

  protected void blockLabel(
      String label, int min, int max, AccountGroup.UUID id, String ref, Project.NameKey project)
      throws Exception {
    ProjectConfig cfg = projectCache.checkedGet(project).getConfig();
    Util.block(cfg, Permission.LABEL + label, min, max, id, ref);
    saveProjectConfig(project, cfg);
  }

  protected void saveProjectConfig(Project.NameKey p, ProjectConfig cfg) throws Exception {
    try (MetaDataUpdate md = metaDataUpdateFactory.create(p)) {
      md.setAuthor(identifiedUserFactory.create(admin.getId()));
      cfg.commit(md);
    }
    projectCache.evict(cfg.getProject());
  }

  protected void saveProjectConfig(ProjectConfig cfg) throws Exception {
    saveProjectConfig(project, cfg);
  }

  protected void grant(Project.NameKey project, String ref, String permission)
      throws RepositoryNotFoundException, IOException, ConfigInvalidException {
    grant(project, ref, permission, false);
  }

  protected void grant(Project.NameKey project, String ref, String permission, boolean force)
      throws RepositoryNotFoundException, IOException, ConfigInvalidException {
    InternalGroup adminGroup =
        groupCache.get(new AccountGroup.NameKey("Administrators")).orElse(null);
    grant(project, ref, permission, force, adminGroup.getGroupUUID());
  }

  protected void grant(
      Project.NameKey project,
      String ref,
      String permission,
      boolean force,
      AccountGroup.UUID groupUUID)
      throws RepositoryNotFoundException, IOException, ConfigInvalidException {
    try (MetaDataUpdate md = metaDataUpdateFactory.create(project)) {
      md.setMessage(String.format("Grant %s on %s", permission, ref));
      ProjectConfig config = ProjectConfig.read(md);
      AccessSection s = config.getAccessSection(ref, true);
      Permission p = s.getPermission(permission, true);
      PermissionRule rule = Util.newRule(config, groupUUID);
      rule.setForce(force);
      p.add(rule);
      config.commit(md);
      projectCache.evict(config.getProject());
    }
  }

  protected void grantLabel(
      String label,
      int min,
      int max,
      Project.NameKey project,
      String ref,
      boolean force,
      AccountGroup.UUID groupUUID,
      boolean exclusive)
      throws RepositoryNotFoundException, IOException, ConfigInvalidException {
    String permission = Permission.LABEL + label;
    try (MetaDataUpdate md = metaDataUpdateFactory.create(project)) {
      md.setMessage(String.format("Grant %s on %s", permission, ref));
      ProjectConfig config = ProjectConfig.read(md);
      AccessSection s = config.getAccessSection(ref, true);
      Permission p = s.getPermission(permission, true);
      p.setExclusiveGroup(exclusive);
      PermissionRule rule = Util.newRule(config, groupUUID);
      rule.setForce(force);
      rule.setMin(min);
      rule.setMax(max);
      p.add(rule);
      config.commit(md);
      projectCache.evict(config.getProject());
    }
  }

  protected void removePermission(Project.NameKey project, String ref, String permission)
      throws IOException, ConfigInvalidException {
    try (MetaDataUpdate md = metaDataUpdateFactory.create(project)) {
      md.setMessage(String.format("Remove %s on %s", permission, ref));
      ProjectConfig config = ProjectConfig.read(md);
      AccessSection s = config.getAccessSection(ref, true);
      Permission p = s.getPermission(permission, true);
      p.getRules().clear();
      config.commit(md);
      projectCache.evict(config.getProject());
    }
  }

  protected void blockRead(String ref) throws Exception {
    block(ref, Permission.READ, REGISTERED_USERS);
  }

  protected void blockForgeCommitter(Project.NameKey project, String ref) throws Exception {
    ProjectConfig cfg = projectCache.checkedGet(project).getConfig();
    Util.block(cfg, Permission.FORGE_COMMITTER, REGISTERED_USERS, ref);
    saveProjectConfig(project, cfg);
  }

  protected PushOneCommit.Result pushTo(String ref) throws Exception {
    PushOneCommit push = pushFactory.create(db, admin.getIdent(), testRepo);
    return push.to(ref);
  }

  protected void approve(String id) throws Exception {
    gApi.changes().id(id).revision("current").review(ReviewInput.approve());
  }

  protected void recommend(String id) throws Exception {
    gApi.changes().id(id).revision("current").review(ReviewInput.recommend());
  }

  protected Map<String, ActionInfo> getActions(String id) throws Exception {
    return gApi.changes().id(id).revision(1).actions();
  }

  protected String getETag(String id) throws Exception {
    return gApi.changes().id(id).current().etag();
  }

  private static Iterable<String> changeIds(Iterable<ChangeInfo> changes) {
    return Iterables.transform(changes, i -> i.changeId);
  }

  protected void assertSubmittedTogether(String chId, String... expected) throws Exception {
    List<ChangeInfo> actual = gApi.changes().id(chId).submittedTogether();
    SubmittedTogetherInfo info =
        gApi.changes().id(chId).submittedTogether(EnumSet.of(NON_VISIBLE_CHANGES));

    assertThat(info.nonVisibleChanges).isEqualTo(0);
    assertThat(actual).hasSize(expected.length);
    assertThat(changeIds(actual)).containsExactly((Object[]) expected).inOrder();
    assertThat(changeIds(info.changes)).containsExactly((Object[]) expected).inOrder();
  }

  protected PatchSet getPatchSet(PatchSet.Id psId) throws OrmException {
    return changeDataFactory.create(db, project, psId.getParentKey()).patchSet(psId);
  }

  protected IdentifiedUser user(TestAccount testAccount) {
    return identifiedUserFactory.create(testAccount.getId());
  }

  protected RevisionResource parseCurrentRevisionResource(String changeId) throws Exception {
    ChangeResource cr = parseChangeResource(changeId);
    int psId = cr.getChange().currentPatchSetId().get();
    return revisions.parse(cr, IdString.fromDecoded(Integer.toString(psId)));
  }

  protected RevisionResource parseRevisionResource(String changeId, int n) throws Exception {
    return revisions.parse(
        parseChangeResource(changeId), IdString.fromDecoded(Integer.toString(n)));
  }

  protected RevisionResource parseRevisionResource(PushOneCommit.Result r) throws Exception {
    PatchSet.Id psId = r.getPatchSetId();
    return parseRevisionResource(psId.getParentKey().toString(), psId.get());
  }

  protected ChangeResource parseChangeResource(String changeId) throws Exception {
    List<ChangeNotes> notes = changeFinder.find(changeId);
    assertThat(notes).hasSize(1);
    return changeResourceFactory.create(notes.get(0), atrScope.get().getUser());
  }

  protected String createGroup(String name) throws Exception {
    return createGroup(name, "Administrators");
  }

  protected String createGroupWithRealName(String name) throws Exception {
    GroupInput in = new GroupInput();
    in.name = name;
    in.ownerId = "Administrators";
    gApi.groups().create(in);
    return name;
  }

  protected String createGroup(String name, String owner) throws Exception {
    name = name(name);
    GroupInput in = new GroupInput();
    in.name = name;
    in.ownerId = owner;
    gApi.groups().create(in);
    return name;
  }

  protected String createAccount(String name, String group) throws Exception {
    name = name(name);
    accountCreator.create(name, group);
    return name;
  }

  protected RevCommit getHead(Repository repo, String name) throws Exception {
    try (RevWalk rw = new RevWalk(repo)) {
      Ref r = repo.exactRef(name);
      return r != null ? rw.parseCommit(r.getObjectId()) : null;
    }
  }

  protected RevCommit getHead(Repository repo) throws Exception {
    return getHead(repo, "HEAD");
  }

  protected RevCommit getRemoteHead(Project.NameKey project, String branch) throws Exception {
    try (Repository repo = repoManager.openRepository(project)) {
      return getHead(repo, branch.startsWith(Constants.R_REFS) ? branch : "refs/heads/" + branch);
    }
  }

  protected RevCommit getRemoteHead(String project, String branch) throws Exception {
    return getRemoteHead(new Project.NameKey(project), branch);
  }

  protected RevCommit getRemoteHead() throws Exception {
    return getRemoteHead(project, "master");
  }

  protected void grantTagPermissions() throws Exception {
    grant(project, R_TAGS + "*", Permission.CREATE);
    grant(project, R_TAGS + "", Permission.DELETE);
    grant(project, R_TAGS + "*", Permission.CREATE_TAG);
    grant(project, R_TAGS + "*", Permission.CREATE_SIGNED_TAG);
  }

  protected void assertMailReplyTo(Message message, String email) throws Exception {
    assertThat(message.headers()).containsKey("Reply-To");
    EmailHeader.String replyTo = (EmailHeader.String) message.headers().get("Reply-To");
    assertThat(replyTo.getString()).contains(email);
  }

  protected ContributorAgreement configureContributorAgreement(boolean autoVerify)
      throws Exception {
    ContributorAgreement ca;
    if (autoVerify) {
      String g = createGroup("cla-test-group");
      GroupApi groupApi = gApi.groups().id(g);
      groupApi.description("CLA test group");
      InternalGroup caGroup =
          groupCache.get(new AccountGroup.UUID(groupApi.detail().id)).orElse(null);
      GroupReference groupRef = new GroupReference(caGroup.getGroupUUID(), caGroup.getName());
      PermissionRule rule = new PermissionRule(groupRef);
      rule.setAction(PermissionRule.Action.ALLOW);
      ca = new ContributorAgreement("cla-test");
      ca.setAutoVerify(groupRef);
      ca.setAccepted(ImmutableList.of(rule));
    } else {
      ca = new ContributorAgreement("cla-test-no-auto-verify");
    }
    ca.setDescription("description");
    ca.setAgreementUrl("agreement-url");

    ProjectConfig cfg = projectCache.checkedGet(allProjects).getConfig();
    cfg.replace(ca);
    saveProjectConfig(allProjects, cfg);
    return ca;
  }

  protected BinaryResult submitPreview(String changeId) throws Exception {
    return gApi.changes().id(changeId).current().submitPreview();
  }

  protected BinaryResult submitPreview(String changeId, String format) throws Exception {
    return gApi.changes().id(changeId).current().submitPreview(format);
  }

  protected Map<Branch.NameKey, ObjectId> fetchFromSubmitPreview(String changeId) throws Exception {
    try (BinaryResult result = submitPreview(changeId)) {
      return fetchFromBundles(result);
    }
  }

  /**
   * Fetches each bundle into a newly cloned repository, then it applies the bundle, and returns the
   * resulting tree id.
   *
   * <p>Omits NoteDb meta refs.
   */
  protected Map<Branch.NameKey, ObjectId> fetchFromBundles(BinaryResult bundles) throws Exception {
    assertThat(bundles.getContentType()).isEqualTo("application/x-zip");

    FileSystem fs = Jimfs.newFileSystem();
    Path previewPath = fs.getPath("preview.zip");
    try (OutputStream out = Files.newOutputStream(previewPath)) {
      bundles.writeTo(out);
    }
    Map<Branch.NameKey, ObjectId> ret = new HashMap<>();
    try (FileSystem zipFs = FileSystems.newFileSystem(previewPath, null);
        DirectoryStream<Path> dirStream =
            Files.newDirectoryStream(Iterables.getOnlyElement(zipFs.getRootDirectories()))) {
      for (Path p : dirStream) {
        if (!Files.isRegularFile(p)) {
          continue;
        }
        String bundleName = p.getFileName().toString();
        int len = bundleName.length();
        assertThat(bundleName).endsWith(".git");
        String repoName = bundleName.substring(0, len - 4);
        Project.NameKey proj = new Project.NameKey(repoName);
        TestRepository<?> localRepo = cloneProject(proj);

        try (InputStream bundleStream = Files.newInputStream(p);
            TransportBundleStream tbs =
                new TransportBundleStream(
                    localRepo.getRepository(), new URIish(bundleName), bundleStream)) {
          FetchResult fr =
              tbs.fetch(
                  NullProgressMonitor.INSTANCE,
                  Arrays.asList(new RefSpec("refs/*:refs/preview/*")));
          for (Ref r : fr.getAdvertisedRefs()) {
            String refName = r.getName();
            if (RefNames.isNoteDbMetaRef(refName)) {
              continue;
            }
            RevCommit c = localRepo.getRevWalk().parseCommit(r.getObjectId());
            ret.put(new Branch.NameKey(proj, refName), c.getTree().copy());
          }
        }
      }
    }
    assertThat(ret).isNotEmpty();
    return ret;
  }

  /** Assert that the given branches have the given tree ids. */
  protected void assertTrees(Project.NameKey proj, Map<Branch.NameKey, ObjectId> trees)
      throws Exception {
    TestRepository<?> localRepo = cloneProject(proj);
    GitUtil.fetch(localRepo, "refs/*:refs/*");
    Map<String, Ref> refs = localRepo.getRepository().getAllRefs();
    Map<Branch.NameKey, RevTree> refValues = new HashMap<>();

    for (Branch.NameKey b : trees.keySet()) {
      if (!b.getParentKey().equals(proj)) {
        continue;
      }

      Ref r = refs.get(b.get());
      assertThat(r).isNotNull();
      RevWalk rw = localRepo.getRevWalk();
      RevCommit c = rw.parseCommit(r.getObjectId());
      refValues.put(b, c.getTree());

      assertThat(trees.get(b)).isEqualTo(refValues.get(b));
    }
    assertThat(refValues.keySet()).containsAnyIn(trees.keySet());
  }

  protected void assertDiffForNewFile(
      DiffInfo diff, RevCommit commit, String path, String expectedContentSideB) throws Exception {
    List<String> expectedLines = new ArrayList<>();
    for (String line : expectedContentSideB.split("\n")) {
      expectedLines.add(line);
    }

    assertThat(diff.binary).isNull();
    assertThat(diff.changeType).isEqualTo(ChangeType.ADDED);
    assertThat(diff.diffHeader).isNotNull();
    assertThat(diff.intralineStatus).isNull();
    assertThat(diff.webLinks).isNull();

    assertThat(diff.metaA).isNull();
    assertThat(diff.metaB).isNotNull();
    assertThat(diff.metaB.commitId).isEqualTo(commit.name());

    String expectedContentType = "text/plain";
    if (COMMIT_MSG.equals(path)) {
      expectedContentType = FileContentUtil.TEXT_X_GERRIT_COMMIT_MESSAGE;
    } else if (MERGE_LIST.equals(path)) {
      expectedContentType = FileContentUtil.TEXT_X_GERRIT_MERGE_LIST;
    }
    assertThat(diff.metaB.contentType).isEqualTo(expectedContentType);

    assertThat(diff.metaB.lines).isEqualTo(expectedLines.size());
    assertThat(diff.metaB.name).isEqualTo(path);
    assertThat(diff.metaB.webLinks).isNull();

    assertThat(diff.content).hasSize(1);
    DiffInfo.ContentEntry contentEntry = diff.content.get(0);
    assertThat(contentEntry.b).containsExactlyElementsIn(expectedLines).inOrder();
    assertThat(contentEntry.a).isNull();
    assertThat(contentEntry.ab).isNull();
    assertThat(contentEntry.common).isNull();
    assertThat(contentEntry.editA).isNull();
    assertThat(contentEntry.editB).isNull();
    assertThat(contentEntry.skip).isNull();
  }

  protected TestRepository<?> createProjectWithPush(
      String name, @Nullable Project.NameKey parent, SubmitType submitType) throws Exception {
    Project.NameKey project = createProject(name, parent, true, submitType);
    grant(project, "refs/heads/*", Permission.PUSH);
    grant(project, "refs/for/refs/heads/*", Permission.SUBMIT);
    return cloneProject(project);
  }

  protected void assertPermitted(ChangeInfo info, String label, Integer... expected) {
    assertThat(info.permittedLabels).isNotNull();
    Collection<String> strs = info.permittedLabels.get(label);
    if (expected.length == 0) {
      assertThat(strs).isNull();
    } else {
      assertThat(strs.stream().map(s -> Integer.valueOf(s.trim())).collect(toList()))
          .containsExactlyElementsIn(Arrays.asList(expected));
    }
  }

  protected void assertNotifyTo(TestAccount expected) {
    assertNotifyTo(expected.emailAddress);
  }

  protected void assertNotifyTo(Address expected) {
    assertThat(sender.getMessages()).hasSize(1);
    Message m = sender.getMessages().get(0);
    assertThat(m.rcpt()).containsExactly(expected);
    assertThat(((EmailHeader.AddressList) m.headers().get("To")).getAddressList())
        .containsExactly(expected);
    assertThat(m.headers().get("CC").isEmpty()).isTrue();
  }

  protected void assertNotifyCc(TestAccount expected) {
    assertNotifyCc(expected.emailAddress);
  }

  protected void assertNotifyCc(Address expected) {
    assertThat(sender.getMessages()).hasSize(1);
    Message m = sender.getMessages().get(0);
    assertThat(m.rcpt()).containsExactly(expected);
    assertThat(m.headers().get("To").isEmpty()).isTrue();
    assertThat(((EmailHeader.AddressList) m.headers().get("CC")).getAddressList())
        .containsExactly(expected);
  }

  protected void assertNotifyBcc(TestAccount expected) {
    assertThat(sender.getMessages()).hasSize(1);
    Message m = sender.getMessages().get(0);
    assertThat(m.rcpt()).containsExactly(expected.emailAddress);
    assertThat(m.headers().get("To").isEmpty()).isTrue();
    assertThat(m.headers().get("CC").isEmpty()).isTrue();
  }

  protected interface ProjectWatchInfoConfiguration {
    void configure(ProjectWatchInfo pwi);
  }

  protected void watch(String project, ProjectWatchInfoConfiguration config)
      throws RestApiException {
    ProjectWatchInfo pwi = new ProjectWatchInfo();
    pwi.project = project;
    config.configure(pwi);
    gApi.accounts().self().setWatchedProjects(ImmutableList.of(pwi));
  }

  protected void watch(PushOneCommit.Result r, ProjectWatchInfoConfiguration config)
      throws OrmException, RestApiException {
    watch(r.getChange().project().get(), config);
  }

  protected void watch(String project, String filter) throws RestApiException {
    watch(
        project,
        pwi -> {
          pwi.filter = filter;
          pwi.notifyAbandonedChanges = true;
          pwi.notifyNewChanges = true;
          pwi.notifyAllComments = true;
        });
  }

  protected void watch(String project) throws RestApiException {
    watch(project, (String) null);
  }

  protected void assertContent(PushOneCommit.Result pushResult, String path, String expectedContent)
      throws Exception {
    BinaryResult bin =
        gApi.changes()
            .id(pushResult.getChangeId())
            .revision(pushResult.getCommit().name())
            .file(path)
            .content();
    ByteArrayOutputStream os = new ByteArrayOutputStream();
    bin.writeTo(os);
    String res = new String(os.toByteArray(), UTF_8);
    assertThat(res).isEqualTo(expectedContent);
  }

  protected RevCommit createNewCommitWithoutChangeId(String branch, String file, String content)
      throws Exception {
    try (Repository repo = repoManager.openRepository(project);
        RevWalk walk = new RevWalk(repo)) {
      Ref ref = repo.exactRef(branch);
      RevCommit tip = null;
      if (ref != null) {
        tip = walk.parseCommit(ref.getObjectId());
      }
      TestRepository<?> testSrcRepo = new TestRepository<>(repo);
      TestRepository<?>.BranchBuilder builder = testSrcRepo.branch(branch);
      RevCommit revCommit =
          tip == null
              ? builder.commit().message("commit 1").add(file, content).create()
              : builder.commit().parent(tip).message("commit 1").add(file, content).create();
      assertThat(GitUtil.getChangeId(testSrcRepo, revCommit).isPresent()).isFalse();
      return revCommit;
    }
  }

  protected RevCommit parseCurrentRevision(RevWalk rw, PushOneCommit.Result r) throws Exception {
    return parseCurrentRevision(rw, r.getChangeId());
  }

  protected RevCommit parseCurrentRevision(RevWalk rw, String changeId) throws Exception {
    return rw.parseCommit(
        ObjectId.fromString(get(changeId, ListChangesOption.CURRENT_REVISION).currentRevision));
  }

  protected void enableCreateNewChangeForAllNotInTarget() throws Exception {
    ProjectConfig config = projectCache.checkedGet(project).getConfig();
    config.getProject().setCreateNewChangeForAllNotInTarget(InheritableBoolean.TRUE);
    saveProjectConfig(project, config);
  }

  protected void configLabel(String label, LabelFunction func) throws Exception {
    configLabel(label, func, ImmutableList.of());
  }

  protected void configLabel(String label, LabelFunction func, List<String> refPatterns)
      throws Exception {
    configLabel(
        project,
        label,
        func,
        refPatterns,
        value(1, "Passes"),
        value(0, "No score"),
        value(-1, "Failed"));
  }

  private void configLabel(
      Project.NameKey project,
      String label,
      LabelFunction func,
      List<String> refPatterns,
      LabelValue... value)
      throws Exception {
    ProjectConfig cfg = projectCache.checkedGet(project).getConfig();
    LabelType labelType = category(label, value);
    labelType.setFunction(func);
    labelType.setRefPatterns(refPatterns);
    cfg.getLabelSections().put(labelType.getName(), labelType);
    saveProjectConfig(project, cfg);
  }
}