/*
    * 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.Inject;
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  import java.util.Set;
  
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.repository.RemoteRepository;
  import org.eclipse.aether.spi.connector.transport.Transporter;
  import org.eclipse.aether.spi.connector.transport.TransporterFactory;
  import org.eclipse.aether.spi.connector.transport.TransporterProvider;
  import org.eclipse.aether.spi.locator.Service;
  import org.eclipse.aether.spi.locator.ServiceLocator;
  import org.eclipse.aether.transfer.NoTransporterException;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   */
  @Singleton
  @Named
  public final class DefaultTransporterProvider implements TransporterProvider, Service {
  
      private static final Logger LOGGER = LoggerFactory.getLogger(DefaultTransporterProvider.class);
  
      private Collection<TransporterFactory> factories = new ArrayList<>();
  
      public DefaultTransporterProvider() {
          // enables default constructor
      }
  
      @Inject
      DefaultTransporterProvider(Set<TransporterFactory> transporterFactories) {
          setTransporterFactories(transporterFactories);
      }
  
      public void initService(ServiceLocator locator) {
          setTransporterFactories(locator.getServices(TransporterFactory.class));
      }
  
      public DefaultTransporterProvider addTransporterFactory(TransporterFactory factory) {
          factories.add(requireNonNull(factory, "transporter factory cannot be null"));
          return this;
      }
  
      public DefaultTransporterProvider setTransporterFactories(Collection<TransporterFactory> factories) {
          if (factories == null) {
              this.factories = new ArrayList<>();
          } else {
              this.factories = factories;
          }
          return this;
      }
  
      public Transporter newTransporter(RepositorySystemSession session, RemoteRepository repository)
              throws NoTransporterException {
          requireNonNull(session, "session cannot be null");
          requireNonNull(repository, "repository cannot be null");
  
          PrioritizedComponents<TransporterFactory> factories = new PrioritizedComponents<>(session);
          for (TransporterFactory factory : this.factories) {
              factories.add(factory, factory.getPriority());
          }
  
          List<NoTransporterException> errors = new ArrayList<>();
          for (PrioritizedComponent<TransporterFactory> factory : factories.getEnabled()) {
              try {
                  Transporter transporter = factory.getComponent().newInstance(session, repository);
  
                  if (LOGGER.isDebugEnabled()) {
                      StringBuilder buffer = new StringBuilder(256);
                      buffer.append("Using transporter ")
                              .append(transporter.getClass().getSimpleName());
                      Utils.appendClassLoader(buffer, transporter);
                     buffer.append(" with priority ").append(factory.getPriority());
                     buffer.append(" for ").append(repository.getUrl());
                     LOGGER.debug(buffer.toString());
                 }
 
                 return transporter;
             } catch (NoTransporterException e) {
                 // continue and try next factory
                 errors.add(e);
             }
         }
         if (LOGGER.isDebugEnabled() && errors.size() > 1) {
             for (Exception e : errors) {
                 LOGGER.debug("Could not obtain transporter factory for {}", repository, e);
             }
         }
 
         StringBuilder buffer = new StringBuilder(256);
         if (factories.isEmpty()) {
             buffer.append("No transporter factories registered");
         } else {
             buffer.append("Cannot access ").append(repository.getUrl());
             buffer.append(" using the registered transporter factories: ");
             factories.list(buffer);
         }
 
         throw new NoTransporterException(repository, buffer.toString(), errors.size() == 1 ? errors.get(0) : null);
     }
 }