/**
 * 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 org.apache.aurora.scheduler.storage.db;

import java.util.Map;
import java.util.stream.Collectors;

import com.google.common.base.Optional;
import com.google.inject.Inject;

import org.apache.aurora.scheduler.storage.QuotaStore;
import org.apache.aurora.scheduler.storage.db.views.DBResourceAggregate;
import org.apache.aurora.scheduler.storage.db.views.DBSaveQuota;
import org.apache.aurora.scheduler.storage.db.views.Pairs;
import org.apache.aurora.scheduler.storage.entities.IResourceAggregate;

import static java.util.Objects.requireNonNull;

import static org.apache.aurora.common.inject.TimedInterceptor.Timed;

/**
 * Quota store backed by a relational database.
 */
class DbQuotaStore implements QuotaStore.Mutable {

  private final QuotaMapper mapper;

  @Inject
  DbQuotaStore(QuotaMapper mapper) {
    this.mapper = requireNonNull(mapper);
  }

  @Timed("quota_store_fetch_quota")
  @Override
  public Optional<IResourceAggregate> fetchQuota(String role) {
    return Optional.fromNullable(mapper.select(role))
        .transform(DBResourceAggregate::toImmutable);
  }

  @Timed("quota_store_fetch_quotas")
  @Override
  public Map<String, IResourceAggregate> fetchQuotas() {
    return Pairs.toMap(mapper.selectAll().stream()
        .map(DBSaveQuota::toImmutable)
        .collect(Collectors.toList()));
  }

  @Timed("quota_store_delete_quotas")
  @Override
  public void deleteQuotas() {
    mapper.truncate();
  }

  @Timed("quota_store_remove_quota")
  @Override
  public void removeQuota(String role) {
    mapper.delete(role);
  }

  @Timed("quota_store_save_quota")
  @Override
  public void saveQuota(String role, IResourceAggregate quota) {
    mapper.delete(role);
    InsertResult quotaInsert = new InsertResult();
    mapper.insert(role, quota.newBuilder(), quotaInsert);
    mapper.insertResources(
        quotaInsert.getId(),
        Pairs.toMap(DBResourceAggregate.pairsFromResources(quota.getResources())));

  }
}