/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF 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
    *
   *   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.eclipse.aether.internal.impl;
  
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.ConcurrentMap;
  
  import org.eclipse.aether.ConfigurationProperties;
  import org.eclipse.aether.Keys;
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.repository.RemoteRepository;
  import org.eclipse.aether.repository.RepositoryKeyFunction;
  import org.eclipse.aether.spi.remoterepo.RepositoryKeyFunctionFactory;
  import org.eclipse.aether.util.ConfigUtils;
  import org.eclipse.aether.util.repository.RepositoryIdHelper;
  
  import static java.util.Objects.requireNonNull;
  
  @Singleton
  @Named
  public class DefaultRepositoryKeyFunctionFactory implements RepositoryKeyFunctionFactory {
      /**
       * Returns system-wide repository key function.
       *
       * @since 2.0.14
       * @see #repositoryKeyFunction(Class, RepositorySystemSession, String, String)
       */
      @Override
      public RepositoryKeyFunction systemRepositoryKeyFunction(RepositorySystemSession session) {
          return repositoryKeyFunction(
                  DefaultRepositoryKeyFunctionFactory.class,
                  session,
                  ConfigurationProperties.DEFAULT_REPOSITORY_SYSTEM_REPOSITORY_KEY_FUNCTION,
                  ConfigurationProperties.REPOSITORY_SYSTEM_REPOSITORY_KEY_FUNCTION);
      }
  
      /**
       * Method that based on configuration returns the "repository key function". The returned function will be session
       * cached if session is equipped with cache, otherwise it will be non cached. Method never returns {@code null}.
       * Only the {@code configurationKey} parameter may be {@code null} in which case no configuration lookup happens
       * but the {@code defaultValue} is directly used instead.
       *
       * @since 2.0.14
       */
      @SuppressWarnings("unchecked")
      @Override
      public RepositoryKeyFunction repositoryKeyFunction(
              Class<?> owner, RepositorySystemSession session, String defaultValue, String configurationKey) {
          requireNonNull(session);
          requireNonNull(defaultValue);
          final RepositoryKeyFunction repositoryKeyFunction = RepositoryIdHelper.getRepositoryKeyFunction(
                  configurationKey != null
                          ? ConfigUtils.getString(session, defaultValue, configurationKey)
                          : defaultValue);
          if (session.getCache() != null) {
              // both are expensive methods; cache it in session (repo -> context -> ID)
              return (repository, context) -> ((ConcurrentMap<RemoteRepository, ConcurrentMap<String, String>>)
                              session.getCache()
                                      .computeIfAbsent(
                                              session, Keys.of(owner, "repositoryKeyFunction"), ConcurrentHashMap::new))
                      .computeIfAbsent(repository, k1 -> new ConcurrentHashMap<>())
                      .computeIfAbsent(
                              context == null ? "" : context, k2 -> repositoryKeyFunction.apply(repository, context));
          } else {
              return repositoryKeyFunction;
          }
      }
  }