/*
    * 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.apache.maven.surefire.providerapi;
  
  import javax.annotation.Nonnull;
  import javax.inject.Inject;
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.io.IOException;
  import java.util.Collections;
  import java.util.List;
  import java.util.Optional;
  import java.util.Set;
  
  import org.apache.maven.surefire.api.provider.SurefireProvider;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import static java.lang.Thread.currentThread;
  import static java.util.Arrays.stream;
  import static java.util.Collections.emptyList;
  import static java.util.stream.Collectors.toList;
  
  /**
   * @author Kristian Rosenvold
   */
  @Singleton
  @Named
  public final class ProviderDetector {
      private Logger logger = LoggerFactory.getLogger(getClass());
  
      @Inject
      private ServiceLoader serviceLoader;
  
      @Nonnull
      public List<ProviderInfo> resolve(ConfigurableProviderInfo dynamicProvider, ProviderInfo... wellKnownProviders) {
          Set<String> manuallyConfiguredProviders = getManuallyConfiguredProviders();
  
          List<ProviderInfo> providersToRun = manuallyConfiguredProviders.stream()
                  .map(name -> findByName(name, wellKnownProviders).orElseGet(() -> dynamicProvider.instantiate(name)))
                  .collect(toList());
  
          providersToRun.forEach(p -> logger.info("Using configured provider " + p.getProviderName()));
  
          if (providersToRun.isEmpty()) {
              return autoDetectOneWellKnownProvider(wellKnownProviders)
                      .map(Collections::singletonList)
                      .orElse(emptyList());
          } else {
              return Collections.unmodifiableList(providersToRun);
          }
      }
  
      private Optional<ProviderInfo> autoDetectOneWellKnownProvider(ProviderInfo... wellKnownProviders) {
          Optional<ProviderInfo> providerInfo =
                  stream(wellKnownProviders).filter(ProviderInfo::isApplicable).findFirst();
  
          providerInfo.ifPresent(p -> logger.info("Using auto detected provider " + p.getProviderName()));
  
          return providerInfo;
      }
  
      private Set<String> getManuallyConfiguredProviders() {
          try {
              ClassLoader cl = currentThread().getContextClassLoader();
              return serviceLoader.lookup(SurefireProvider.class, cl);
          } catch (IOException e) {
              throw new RuntimeException(e);
          }
      }
  
      @Nonnull
      private Optional<ProviderInfo> findByName(String providerClassName, ProviderInfo... wellKnownProviders) {
          return stream(wellKnownProviders)
                  .filter(p -> p.getProviderName().equals(providerClassName))
                  .findFirst();
      }
  }