// Copyright (C) 2017 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.git;

import static com.google.common.base.Preconditions.checkState;
import static com.google.common.truth.Truth.assertThat;
import static com.google.gerrit.testing.GerritJUnit.assertThrows;

import com.google.common.collect.ImmutableList;
import java.io.IOException;
import java.util.function.Consumer;
import org.eclipse.jgit.internal.storage.dfs.DfsRepositoryDescription;
import org.eclipse.jgit.internal.storage.dfs.InMemoryRepository;
import org.eclipse.jgit.lib.BatchRefUpdate;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.transport.ReceiveCommand;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

@RunWith(JUnit4.class)
public class RefUpdateUtilTest {
  @Test
  public void checkBatchRefUpdateResults() throws Exception {
    checkResults();
    checkResults(RefUpdateUtilTest::ok);
    checkResults(RefUpdateUtilTest::ok, RefUpdateUtilTest::ok);

    assertIoException(RefUpdateUtilTest::rejected);
    assertIoException(RefUpdateUtilTest::ok, RefUpdateUtilTest::rejected);
    assertIoException(RefUpdateUtilTest::lockFailure, RefUpdateUtilTest::rejected);
    assertIoException(RefUpdateUtilTest::lockFailure, RefUpdateUtilTest::ok);
    assertIoException(
        RefUpdateUtilTest::lockFailure, RefUpdateUtilTest::rejected, RefUpdateUtilTest::ok);
    assertIoException(
        RefUpdateUtilTest::lockFailure,
        RefUpdateUtilTest::lockFailure,
        RefUpdateUtilTest::rejected);
    assertIoException(
        RefUpdateUtilTest::lockFailure, RefUpdateUtilTest::aborted, RefUpdateUtilTest::rejected);
    assertIoException(
        RefUpdateUtilTest::lockFailure, RefUpdateUtilTest::aborted, RefUpdateUtilTest::ok);

    assertLockFailureException(RefUpdateUtilTest::lockFailure);
    assertLockFailureException(RefUpdateUtilTest::lockFailure, RefUpdateUtilTest::lockFailure);
    assertLockFailureException(
        RefUpdateUtilTest::lockFailure, RefUpdateUtilTest::lockFailure, RefUpdateUtilTest::aborted);
    assertLockFailureException(
        RefUpdateUtilTest::lockFailure,
        RefUpdateUtilTest::lockFailure,
        RefUpdateUtilTest::aborted,
        RefUpdateUtilTest::aborted);
    assertLockFailureException(RefUpdateUtilTest::aborted);
    assertLockFailureException(RefUpdateUtilTest::aborted, RefUpdateUtilTest::aborted);
  }

  @SafeVarargs
  private static void checkResults(Consumer<ReceiveCommand>... resultSetters) throws Exception {
    RefUpdateUtil.checkResults(newBatchRefUpdate(resultSetters));
  }

  @SafeVarargs
  private static void assertIoException(Consumer<ReceiveCommand>... resultSetters) {
    IOException thrown =
        assertThrows(
            IOException.class, () -> RefUpdateUtil.checkResults(newBatchRefUpdate(resultSetters)));
    assertThat(thrown).isNotInstanceOf(LockFailureException.class);
  }

  @SafeVarargs
  private static void assertLockFailureException(Consumer<ReceiveCommand>... resultSetters)
      throws Exception {
    assertThrows(
        LockFailureException.class,
        () -> RefUpdateUtil.checkResults(newBatchRefUpdate(resultSetters)));
  }

  @SafeVarargs
  private static BatchRefUpdate newBatchRefUpdate(Consumer<ReceiveCommand>... resultSetters) {
    try (Repository repo = new InMemoryRepository(new DfsRepositoryDescription("repo"))) {
      BatchRefUpdate bru = repo.getRefDatabase().newBatchUpdate();
      for (int i = 0; i < resultSetters.length; i++) {
        ReceiveCommand cmd =
            new ReceiveCommand(
                ObjectId.fromString(String.format("%039x1", i)),
                ObjectId.fromString(String.format("%039x2", i)),
                "refs/heads/branch" + i);
        bru.addCommand(cmd);
        resultSetters[i].accept(cmd);
      }
      return bru;
    }
  }

  private static void ok(ReceiveCommand c) {
    c.setResult(ReceiveCommand.Result.OK);
  }

  private static void lockFailure(ReceiveCommand c) {
    c.setResult(ReceiveCommand.Result.LOCK_FAILURE);
  }

  private static void rejected(ReceiveCommand c) {
    c.setResult(ReceiveCommand.Result.REJECTED_OTHER_REASON);
  }

  private static void aborted(ReceiveCommand c) {
    c.setResult(ReceiveCommand.Result.NOT_ATTEMPTED);
    ReceiveCommand.abort(ImmutableList.of(c));
    checkState(
        c.getResult() != ReceiveCommand.Result.NOT_ATTEMPTED
            && c.getResult() != ReceiveCommand.Result.LOCK_FAILURE
            && c.getResult() != ReceiveCommand.Result.OK,
        "unexpected state after abort: %s",
        c);
  }
}