// Copyright (C) 2023 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.googlesource.gerrit.plugins.spannerrefdb;

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 com.google.gerrit.entities.Project;
import java.util.Optional;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.Ref;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

public class SpannerRefDatabaseTest implements RefFixture {

  private EmulatedSpannerRefDb emulator;
  private SpannerRefDatabase refdb;

  @Before
  public void setup() throws Exception {
    emulator = new EmulatedSpannerRefDb();
    refdb = emulator.getSpannerRefDatabase();
  }

  @After
  public void cleanup() {
    emulator.cleanup();
  }

  @Test
  public void testCreateNewRef() throws Exception {
    createNewRef(PROJECT_NAME_KEY, REF_NAME, OBJECT_ID_1);

    createNewRef(PROJECT_NAME_KEY, PATCHSET_REF_NAME, OBJECT_ID_2);

    createNewRef(PROJECT_NAME_KEY, MULTISITE_VERSION_VALUE_REF_NAME, UNIX_TIMESTAMP_1.toString());
  }

  @Test
  public void testUpdateRef() throws Exception {
    createNewRef(PROJECT_NAME_KEY, REF_NAME, OBJECT_ID_1);
    updateRef(PROJECT_NAME_KEY, REF_NAME, OBJECT_ID_1, OBJECT_ID_2);

    createNewRef(PROJECT_NAME_KEY, PATCHSET_REF_NAME, OBJECT_ID_2);
    updateRef(PROJECT_NAME_KEY, PATCHSET_REF_NAME, OBJECT_ID_2, OBJECT_ID_3);

    createNewRef(PROJECT_NAME_KEY, MULTISITE_VERSION_VALUE_REF_NAME, UNIX_TIMESTAMP_1.toString());
    updateRef(
        PROJECT_NAME_KEY,
        MULTISITE_VERSION_VALUE_REF_NAME,
        UNIX_TIMESTAMP_1.toString(),
        UNIX_TIMESTAMP_2.toString());
  }

  @Test
  public void testDeleteRef() throws Exception {
    createNewRef(PROJECT_NAME_KEY, REF_NAME, OBJECT_ID_1);
    deleteRef(PROJECT_NAME_KEY, REF_NAME, OBJECT_ID_1);

    createNewRef(PROJECT_NAME_KEY, PATCHSET_REF_NAME, OBJECT_ID_2);
    deleteRef(PROJECT_NAME_KEY, PATCHSET_REF_NAME, OBJECT_ID_2);

    createNewRef(PROJECT_NAME_KEY, MULTISITE_VERSION_VALUE_REF_NAME, UNIX_TIMESTAMP_1.toString());
    deleteRef(PROJECT_NAME_KEY, MULTISITE_VERSION_VALUE_REF_NAME, UNIX_TIMESTAMP_1.toString());
  }

  private void createNewRef(Project.NameKey project, String refName, ObjectId newValue)
      throws Exception {
    Ref ref = nullRef(refName);
    try (AutoCloseable lock = refdb.lockRef(project, refName)) {
      assertTrue(refdb.compareAndPut(project, ref, newValue));
      Optional<ObjectId> oid = refdb.getObjectId(project, refName);
      assertFalse(oid.isEmpty());
      assertEquals(newValue, oid.get());
    }
  }

  private void updateRef(
      Project.NameKey project, String refName, ObjectId oldValue, ObjectId newValue)
      throws Exception {
    Ref expecRef = newRef(refName, oldValue);
    try (AutoCloseable lock = refdb.lockRef(project, refName)) {
      assertTrue(refdb.compareAndPut(project, expecRef, newValue));
      assertEquals(newValue, refdb.getObjectId(project, refName).get());
    }
  }

  private void deleteRef(Project.NameKey project, String refName, ObjectId oldValue)
      throws Exception {
    Ref expecRef = newRef(refName, oldValue);
    try (AutoCloseable lock = refdb.lockRef(project, refName)) {
      assertTrue(refdb.compareAndPut(project, expecRef, ObjectId.zeroId()));
      assertTrue(refdb.getObjectId(project, refName).isEmpty());
    }
  }

  private void createNewRef(Project.NameKey project, String refName, String newValue)
      throws Exception {
    try (AutoCloseable lock = refdb.lockRef(project, refName)) {
      assertTrue(refdb.compareAndPut(project, refName, ObjectId.zeroId().name(), newValue));
      assertNotNull(refdb.get(project, refName));
      assertEquals(newValue, refdb.get(project, refName));
    }
  }

  private void updateRef(Project.NameKey project, String refName, String oldValue, String newValue)
      throws Exception {
    try (AutoCloseable lock = refdb.lockRef(project, refName)) {
      assertTrue(refdb.compareAndPut(project, refName, oldValue, newValue));
      assertEquals(newValue, refdb.get(project, refName));
    }
  }

  private void deleteRef(Project.NameKey project, String refName, String oldValue)
      throws Exception {
    try (AutoCloseable lock = refdb.lockRef(project, refName)) {
      assertTrue(refdb.compareAndPut(project, refName, oldValue, ObjectId.zeroId().name()));
      assertNull(refdb.get(project, refName));
    }
  }
}