/*
    * Copyright 2017 LINE Corporation
    *
    * LINE Corporation licenses this file to you 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:
    *
    *   https://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.linecorp.centraldogma.server.internal.storage.repository.cache;
  
  import static com.linecorp.centraldogma.server.internal.storage.repository.RepositoryCache.logger;
  import static java.util.Objects.requireNonNull;
  
  import java.util.Map;
  import java.util.Objects;
  import java.util.concurrent.CompletableFuture;
  
  import com.google.common.base.MoreObjects.ToStringHelper;
  
  import com.linecorp.centraldogma.common.Change;
  import com.linecorp.centraldogma.common.Revision;
  import com.linecorp.centraldogma.server.storage.repository.AbstractCacheableCall;
  import com.linecorp.centraldogma.server.storage.repository.DiffResultType;
  import com.linecorp.centraldogma.server.storage.repository.Repository;
  
  final class CacheableMultiDiffCall extends AbstractCacheableCall<Map<String, Change<?>>> {
  
      private final Revision from;
      private final Revision to;
      private final String pathPattern;
      private final DiffResultType diffResultType;
      private final int hashCode;
  
      CacheableMultiDiffCall(Repository repo, Revision from, Revision to, String pathPattern,
                             DiffResultType diffResultType) {
          super(repo);
  
          this.from = requireNonNull(from, "from");
          this.to = requireNonNull(to, "to");
          this.pathPattern = requireNonNull(pathPattern, "pathPattern");
          this.diffResultType = requireNonNull(diffResultType, "diffResultType");
  
          hashCode = Objects.hash(from, to, pathPattern, diffResultType) * 31 + System.identityHashCode(repo);
  
          assert !from.isRelative();
          assert !to.isRelative();
      }
  
      @Override
      public int weigh(Map<String, Change<?>> value) {
          int weight = 0;
          weight += pathPattern.length();
          for (Change<?> e : value.values()) {
              weight += e.path().length();
              final String content = e.contentAsText();
              if (content != null) {
                  weight += content.length();
              }
          }
          return weight;
      }
  
      @Override
      public CompletableFuture<Map<String, Change<?>>> execute() {
          logger.debug("Cache miss: {}", this);
          return repo().diff(from, to, pathPattern, diffResultType);
      }
  
      @Override
      public int hashCode() {
          return hashCode;
      }
  
      @Override
      public boolean equals(Object o) {
          if (!super.equals(o)) {
              return false;
          }
  
          final CacheableMultiDiffCall that = (CacheableMultiDiffCall) o;
          return from.equals(that.from) &&
                 to.equals(that.to) &&
                 pathPattern.equals(that.pathPattern) &&
                 diffResultType == that.diffResultType;
      }
  
      @Override
      protected void toString(ToStringHelper helper) {
          helper.add("from", from)
                .add("to", to)
                .add("pathPattern", pathPattern)
               .add("diffResultType", diffResultType);
     }
 }