// Copyright (C) 2014 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.rest.project;

import static com.google.common.truth.Truth.assertThat;
import static com.google.common.truth.Truth8.assertThat;
import static com.google.gerrit.acceptance.testsuite.project.TestProjectUpdate.allow;
import static com.google.gerrit.acceptance.testsuite.project.TestProjectUpdate.block;
import static com.google.gerrit.entities.RefNames.REFS_HEADS;
import static com.google.gerrit.server.group.SystemGroupBackend.ANONYMOUS_USERS;
import static com.google.gerrit.server.group.SystemGroupBackend.REGISTERED_USERS;
import static com.google.gerrit.testing.GerritJUnit.assertThrows;

import com.google.common.collect.ImmutableList;
import com.google.gerrit.acceptance.AbstractDaemonTest;
import com.google.gerrit.acceptance.ExtensionRegistry;
import com.google.gerrit.acceptance.RestResponse;
import com.google.gerrit.acceptance.testsuite.project.ProjectOperations;
import com.google.gerrit.acceptance.testsuite.request.RequestScopeOperations;
import com.google.gerrit.common.data.Permission;
import com.google.gerrit.entities.Account;
import com.google.gerrit.entities.AccountGroup;
import com.google.gerrit.entities.BranchNameKey;
import com.google.gerrit.entities.RefNames;
import com.google.gerrit.extensions.api.projects.BranchApi;
import com.google.gerrit.extensions.api.projects.BranchInfo;
import com.google.gerrit.extensions.api.projects.BranchInput;
import com.google.gerrit.extensions.restapi.AuthException;
import com.google.gerrit.extensions.restapi.BadRequestException;
import com.google.gerrit.extensions.restapi.ResourceConflictException;
import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
import com.google.gerrit.extensions.restapi.RestApiException;
import com.google.gerrit.server.events.RefReceivedEvent;
import com.google.gerrit.server.git.validators.RefOperationValidationListener;
import com.google.gerrit.server.git.validators.ValidationMessage;
import com.google.gerrit.server.util.MagicBranch;
import com.google.gerrit.server.validators.ValidationException;
import com.google.inject.Inject;
import java.io.IOException;
import java.util.List;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.RefUpdate;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.junit.Before;
import org.junit.Test;

public class CreateBranchIT extends AbstractDaemonTest {
  @Inject private ProjectOperations projectOperations;
  @Inject private RequestScopeOperations requestScopeOperations;
  @Inject private ExtensionRegistry extensionRegistry;

  private BranchNameKey testBranch;

  @Before
  public void setUp() throws Exception {
    testBranch = BranchNameKey.create(project, "test");
  }

  @Test
  public void createBranchRestApi() throws Exception {
    BranchInput input = new BranchInput();
    input.ref = "foo";
    assertThat(gApi.projects().name(project.get()).branches().get().stream().map(i -> i.ref))
        .doesNotContain(REFS_HEADS + input.ref);
    RestResponse r =
        adminRestSession.put("/projects/" + project.get() + "/branches/" + input.ref, input);
    r.assertCreated();
    assertThat(gApi.projects().name(project.get()).branches().get().stream().map(i -> i.ref))
        .contains(REFS_HEADS + input.ref);
  }

  @Test
  public void createBranch_Forbidden() throws Exception {
    requestScopeOperations.setApiUser(user.id());
    assertCreateFails(testBranch, AuthException.class, "not permitted: create on refs/heads/test");
  }

  @Test
  public void createBranchByAdmin() throws Exception {
    assertCreateSucceeds(testBranch);
  }

  @Test
  public void branchAlreadyExists_Conflict() throws Exception {
    assertCreateSucceeds(testBranch);
    assertCreateFails(
        testBranch,
        ResourceConflictException.class,
        "branch \"" + testBranch.branch() + "\" already exists");
  }

  @Test
  public void createBranch_LockFailure() throws Exception {
    // check that the branch doesn't exist yet
    assertThrows(ResourceNotFoundException.class, () -> branch(testBranch).get());

    // Register a validation listener that creates the branch to simulate a concurrent request that
    // creates the same branch.
    try (ExtensionRegistry.Registration registration =
        extensionRegistry
            .newRegistration()
            .add(
                new RefOperationValidationListener() {
                  @Override
                  public List<ValidationMessage> onRefOperation(RefReceivedEvent refEvent)
                      throws ValidationException {
                    try (Repository repo = repoManager.openRepository(project)) {
                      RefUpdate u = repo.updateRef(testBranch.branch());
                      u.setExpectedOldObjectId(ObjectId.zeroId());
                      u.setNewObjectId(repo.exactRef("refs/heads/master").getObjectId());
                      RefUpdate.Result result = u.update();
                      if (result != RefUpdate.Result.NEW) {
                        throw new ValidationException(
                            "Concurrent creation of branch failed: " + result);
                      }
                      return ImmutableList.of();
                    } catch (IOException e) {
                      throw new ValidationException("Concurrent creation of branch failed.", e);
                    }
                  }
                })) {
      // Creating the branch is expected to fail, since it is created by the validation listener
      // right before the ref update to create the new branch is done.
      assertCreateFails(
          testBranch,
          ResourceConflictException.class,
          "branch \"" + testBranch.branch() + "\" already exists");
    }
  }

  @Test
  public void conflictingBranchAlreadyExists_Conflict() throws Exception {
    assertCreateSucceeds(testBranch);
    BranchNameKey testBranch2 = BranchNameKey.create(project, testBranch.branch() + "/foo/bar");
    assertCreateFails(
        testBranch2,
        ResourceConflictException.class,
        "Cannot create branch \""
            + testBranch2.branch()
            + "\" since it conflicts with branch \""
            + testBranch.branch()
            + "\"");
  }

  @Test
  public void createBranchByProjectOwner() throws Exception {
    grantOwner();
    requestScopeOperations.setApiUser(user.id());
    assertCreateSucceeds(testBranch);
  }

  @Test
  public void createBranchByAdminCreateReferenceBlocked_Forbidden() throws Exception {
    blockCreateReference();
    assertCreateFails(testBranch, AuthException.class, "not permitted: create on refs/heads/test");
  }

  @Test
  public void createBranchByProjectOwnerCreateReferenceBlocked_Forbidden() throws Exception {
    grantOwner();
    blockCreateReference();
    requestScopeOperations.setApiUser(user.id());
    assertCreateFails(testBranch, AuthException.class, "not permitted: create on refs/heads/test");
  }

  @Test
  public void createMetaBranch() throws Exception {
    String metaRef = RefNames.REFS_META + "foo";
    projectOperations
        .project(project)
        .forUpdate()
        .add(allow(Permission.CREATE).ref(metaRef).group(REGISTERED_USERS))
        .add(allow(Permission.PUSH).ref(metaRef).group(REGISTERED_USERS))
        .update();
    assertCreateSucceeds(BranchNameKey.create(project, metaRef));
  }

  @Test
  public void createUserBranch_Conflict() throws Exception {
    projectOperations
        .project(allUsers)
        .forUpdate()
        .add(allow(Permission.CREATE).ref(RefNames.REFS_USERS + "*").group(REGISTERED_USERS))
        .add(allow(Permission.PUSH).ref(RefNames.REFS_USERS + "*").group(REGISTERED_USERS))
        .update();
    assertCreateFails(
        BranchNameKey.create(allUsers, RefNames.refsUsers(Account.id(1))),
        RefNames.refsUsers(admin.id()),
        ResourceConflictException.class,
        "Not allowed to create user branch.");
  }

  @Test
  public void createGroupBranch_Conflict() throws Exception {
    projectOperations
        .project(allUsers)
        .forUpdate()
        .add(allow(Permission.CREATE).ref(RefNames.REFS_GROUPS + "*").group(REGISTERED_USERS))
        .add(allow(Permission.PUSH).ref(RefNames.REFS_GROUPS + "*").group(REGISTERED_USERS))
        .update();
    assertCreateFails(
        BranchNameKey.create(allUsers, RefNames.refsGroups(AccountGroup.uuid("foo"))),
        RefNames.refsGroups(adminGroupUuid()),
        ResourceConflictException.class,
        "Not allowed to create group branch.");
  }

  @Test
  public void createWithRevision() throws Exception {
    RevCommit revision = projectOperations.project(project).getHead("master");

    // update master so that points to a different revision than the revision on which we create the
    // new branch
    pushTo("refs/heads/master");
    assertThat(projectOperations.project(project).getHead("master")).isNotEqualTo(revision);

    BranchInput input = new BranchInput();
    input.revision = revision.name();
    BranchInfo created = branch(testBranch).create(input).get();
    assertThat(created.ref).isEqualTo(testBranch.branch());
    assertThat(created.revision).isEqualTo(revision.name());
    assertThat(projectOperations.project(project).getHead(testBranch.branch())).isEqualTo(revision);
  }

  @Test
  public void createWithoutSpecifyingRevision() throws Exception {
    // If revision is not specified, the branch is created based on HEAD, which points to master.
    RevCommit expectedRevision = projectOperations.project(project).getHead("master");

    BranchInput input = new BranchInput();
    input.revision = null;
    BranchInfo created = branch(testBranch).create(input).get();
    assertThat(created.ref).isEqualTo(testBranch.branch());
    assertThat(created.revision).isEqualTo(expectedRevision.name());
    assertThat(projectOperations.project(project).getHead(testBranch.branch()))
        .isEqualTo(expectedRevision);
  }

  @Test
  public void createWithEmptyRevision() throws Exception {
    // If revision is not specified, the branch is created based on HEAD, which points to master.
    RevCommit expectedRevision = projectOperations.project(project).getHead("master");

    BranchInput input = new BranchInput();
    input.revision = "";
    BranchInfo created = branch(testBranch).create(input).get();
    assertThat(created.ref).isEqualTo(testBranch.branch());
    assertThat(created.revision).isEqualTo(expectedRevision.name());
    assertThat(projectOperations.project(project).getHead(testBranch.branch()))
        .isEqualTo(expectedRevision);
  }

  @Test
  public void createRevisionIsTrimmed() throws Exception {
    RevCommit revision = projectOperations.project(project).getHead("master");

    BranchInput input = new BranchInput();
    input.revision = "\t" + revision.name();
    BranchInfo created = branch(testBranch).create(input).get();
    assertThat(created.ref).isEqualTo(testBranch.branch());
    assertThat(created.revision).isEqualTo(revision.name());
    assertThat(projectOperations.project(project).getHead(testBranch.branch())).isEqualTo(revision);
  }

  @Test
  public void createWithBranchNameAsRevision() throws Exception {
    RevCommit expectedRevision = projectOperations.project(project).getHead("master");

    BranchInput input = new BranchInput();
    input.revision = "master";
    BranchInfo created = branch(testBranch).create(input).get();
    assertThat(created.ref).isEqualTo(testBranch.branch());
    assertThat(created.revision).isEqualTo(expectedRevision.name());
    assertThat(projectOperations.project(project).getHead(testBranch.branch()))
        .isEqualTo(expectedRevision);
  }

  @Test
  public void createWithFullBranchNameAsRevision() throws Exception {
    RevCommit expectedRevision = projectOperations.project(project).getHead("master");

    BranchInput input = new BranchInput();
    input.revision = "refs/heads/master";
    BranchInfo created = branch(testBranch).create(input).get();
    assertThat(created.ref).isEqualTo(testBranch.branch());
    assertThat(created.revision).isEqualTo(expectedRevision.name());
    assertThat(projectOperations.project(project).getHead(testBranch.branch()))
        .isEqualTo(expectedRevision);
  }

  @Test
  public void cannotCreateWithNonExistingBranchNameAsRevision() throws Exception {
    assertCreateFails(
        testBranch,
        "refs/heads/non-existing",
        BadRequestException.class,
        "invalid revision \"refs/heads/non-existing\"");
  }

  @Test
  public void cannotCreateWithNonExistingRevision() throws Exception {
    assertCreateFails(
        testBranch,
        "deadbeefdeadbeefdeadbeefdeadbeefdeadbeef",
        BadRequestException.class,
        "invalid revision \"deadbeefdeadbeefdeadbeefdeadbeefdeadbeef\"");
  }

  @Test
  public void cannotCreateWithInvalidRevision() throws Exception {
    assertCreateFails(
        testBranch,
        "invalid\trevision",
        BadRequestException.class,
        "invalid revision \"invalid\trevision\"");
  }

  @Test
  public void cannotCreateBranchInMagicBranchNamespace() throws Exception {
    assertCreateFails(
        BranchNameKey.create(project, MagicBranch.NEW_CHANGE + "foo"),
        BadRequestException.class,
        "not allowed to create branches under \"" + MagicBranch.NEW_CHANGE + "\"");
  }

  @Test
  public void cannotCreateBranchWithInvalidName() throws Exception {
    assertCreateFails(
        BranchNameKey.create(project, RefNames.REFS_HEADS),
        BadRequestException.class,
        "invalid branch name \"" + RefNames.REFS_HEADS + "\"");
  }

  @Test
  public void createBranchLeadingSlashesAreRemoved() throws Exception {
    BranchNameKey expectedNameKey = BranchNameKey.create(project, "test");

    // check that the branch doesn't exist yet
    assertThrows(
        ResourceNotFoundException.class,
        () -> gApi.projects().name(project.get()).branch(expectedNameKey.branch()).get());

    // create the branch, but include leading slashes in the branch name,
    // when creating the branch ensure that the branch name in the URL matches the branch name in
    // the input (if there is a mismatch the creation request is rejected)
    BranchInput branchInput = new BranchInput();
    branchInput.ref = "////" + expectedNameKey.shortName();
    gApi.projects().name(project.get()).branch(branchInput.ref).create(branchInput);

    // verify that the branch was created without the leading slashes in the name
    assertThat(gApi.projects().name(project.get()).branch(expectedNameKey.branch()).get().ref)
        .isEqualTo(expectedNameKey.branch());
  }

  @Test
  public void branchNameInInputMustMatchBranchNameInUrl() throws Exception {
    BranchInput branchInput = new BranchInput();
    branchInput.ref = "foo";
    BadRequestException ex =
        assertThrows(
            BadRequestException.class,
            () -> gApi.projects().name(project.get()).branch("bar").create(branchInput));
    assertThat(ex).hasMessageThat().isEqualTo("ref must match URL");
  }

  private void blockCreateReference() throws Exception {
    projectOperations
        .project(project)
        .forUpdate()
        .add(block(Permission.CREATE).ref("refs/*").group(ANONYMOUS_USERS))
        .update();
  }

  private void grantOwner() throws Exception {
    projectOperations
        .project(project)
        .forUpdate()
        .add(allow(Permission.OWNER).ref("refs/*").group(REGISTERED_USERS))
        .update();
  }

  private BranchApi branch(BranchNameKey branch) throws Exception {
    return gApi.projects().name(branch.project().get()).branch(branch.branch());
  }

  private void assertCreateSucceeds(BranchNameKey branch) throws Exception {
    BranchInfo created = branch(branch).create(new BranchInput()).get();
    assertThat(created.ref).isEqualTo(branch.branch());
  }

  private void assertCreateFails(
      BranchNameKey branch, Class<? extends RestApiException> errType, String errMsg)
      throws Exception {
    assertCreateFails(branch, null, errType, errMsg);
  }

  private void assertCreateFails(
      BranchNameKey branch,
      String revision,
      Class<? extends RestApiException> errType,
      String errMsg)
      throws Exception {
    BranchInput in = new BranchInput();
    in.revision = revision;
    RestApiException thrown = assertThrows(errType, () -> branch(branch).create(in));
    if (errMsg != null) {
      assertThat(thrown).hasMessageThat().contains(errMsg);
    }
  }
}