/*
    * 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.synccontext.named;
  
  import javax.inject.Inject;
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Map;
  
  import org.eclipse.aether.MultiRuntimeException;
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.impl.RepositorySystemLifecycle;
  import org.eclipse.aether.named.NamedLockFactory;
  import org.eclipse.aether.named.providers.FileLockNamedLockFactory;
  import org.eclipse.aether.named.providers.LocalReadWriteLockNamedLockFactory;
  import org.eclipse.aether.named.providers.LocalSemaphoreNamedLockFactory;
  import org.eclipse.aether.named.providers.NoopNamedLockFactory;
  import org.eclipse.aether.spi.locator.Service;
  import org.eclipse.aether.spi.locator.ServiceLocator;
  import org.eclipse.aether.util.ConfigUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Default implementation of {@link NamedLockFactoryAdapterFactory}. This implementation creates new instances of the
   * adapter on every call. In turn, on shutdown, it will shut down all existing named lock factories. This is merely for
   * simplicity, to not have to track "used" named lock factories, while it exposes all available named lock factories to
   * callers.
   * <p>
   * Most members and methods of this class are protected. It is meant to be extended in case of need to customize its
   * behavior. An exception from this are private static methods, mostly meant to provide out of the box
   * defaults and to be used when no Eclipse Sisu component container is used.
   *
   * @since 1.9.1
   */
  @Singleton
  @Named
  public class NamedLockFactoryAdapterFactoryImpl implements NamedLockFactoryAdapterFactory, Service {
      private static final String DEFAULT_FACTORY_NAME = LocalReadWriteLockNamedLockFactory.NAME;
  
      private static final String DEFAULT_NAME_MAPPER_NAME = NameMappers.GAECV_NAME;
  
      private static Map<String, NamedLockFactory> getManuallyCreatedFactories() {
          HashMap<String, NamedLockFactory> factories = new HashMap<>();
          factories.put(NoopNamedLockFactory.NAME, new NoopNamedLockFactory());
          factories.put(LocalReadWriteLockNamedLockFactory.NAME, new LocalReadWriteLockNamedLockFactory());
          factories.put(LocalSemaphoreNamedLockFactory.NAME, new LocalSemaphoreNamedLockFactory());
          factories.put(FileLockNamedLockFactory.NAME, new FileLockNamedLockFactory());
          return Collections.unmodifiableMap(factories);
      }
  
      private static Map<String, NameMapper> getManuallyCreatedNameMappers() {
          HashMap<String, NameMapper> mappers = new HashMap<>();
          mappers.put(NameMappers.STATIC_NAME, NameMappers.staticNameMapper());
          mappers.put(NameMappers.GAV_NAME, NameMappers.gavNameMapper());
          mappers.put(NameMappers.GAECV_NAME, NameMappers.gaecvNameMapper());
          mappers.put(NameMappers.DISCRIMINATING_NAME, NameMappers.discriminatingNameMapper());
          mappers.put(NameMappers.FILE_GAV_NAME, NameMappers.fileGavNameMapper());
          mappers.put(NameMappers.FILE_GAECV_NAME, NameMappers.fileGaecvNameMapper());
          mappers.put(NameMappers.FILE_HGAV_NAME, NameMappers.fileHashingGavNameMapper());
          mappers.put(NameMappers.FILE_HGAECV_NAME, NameMappers.fileHashingGaecvNameMapper());
          return Collections.unmodifiableMap(mappers);
      }
  
      protected static final String FACTORY_KEY = "aether.syncContext.named.factory";
  
      protected static final String NAME_MAPPER_KEY = "aether.syncContext.named.nameMapper";
  
      protected final Logger logger = LoggerFactory.getLogger(getClass());
  
      protected final Map<String, NamedLockFactory> factories;
  
      protected final String defaultFactoryName;
  
      protected final Map<String, NameMapper> nameMappers;
  
      protected final String defaultNameMapperName;
 
     /**
      * Default constructor for non Eclipse Sisu uses.
      *
      * @deprecated for use in SL only.
      */
     @Deprecated
     public NamedLockFactoryAdapterFactoryImpl() {
         this.factories = getManuallyCreatedFactories();
         this.defaultFactoryName = DEFAULT_FACTORY_NAME;
         this.nameMappers = getManuallyCreatedNameMappers();
         this.defaultNameMapperName = DEFAULT_NAME_MAPPER_NAME;
     }
 
     @Override
     public void initService(ServiceLocator locator) {
         locator.getService(RepositorySystemLifecycle.class).addOnSystemEndedHandler(this::shutdown);
     }
 
     @Inject
     public NamedLockFactoryAdapterFactoryImpl(
             final Map<String, NamedLockFactory> factories,
             final Map<String, NameMapper> nameMappers,
             final RepositorySystemLifecycle lifecycle) {
         this(factories, DEFAULT_FACTORY_NAME, nameMappers, DEFAULT_NAME_MAPPER_NAME, lifecycle);
     }
 
     public NamedLockFactoryAdapterFactoryImpl(
             final Map<String, NamedLockFactory> factories,
             final String defaultFactoryName,
             final Map<String, NameMapper> nameMappers,
             final String defaultNameMapperName,
             final RepositorySystemLifecycle lifecycle) {
         this.factories = requireNonNull(factories);
         this.defaultFactoryName = requireNonNull(defaultFactoryName);
         this.nameMappers = requireNonNull(nameMappers);
         this.defaultNameMapperName = requireNonNull(defaultNameMapperName);
         lifecycle.addOnSystemEndedHandler(this::shutdown);
 
         logger.debug(
                 "Created adapter factory; available factories {}; available name mappers {}",
                 factories.keySet(),
                 nameMappers.keySet());
     }
 
     /**
      * Current implementation simply delegates to {@link #createAdapter(RepositorySystemSession)}.
      */
     @Override
     public NamedLockFactoryAdapter getAdapter(RepositorySystemSession session) {
         return createAdapter(session);
     }
 
     /**
      * Creates a new adapter instance, never returns {@code null}.
      */
     protected NamedLockFactoryAdapter createAdapter(RepositorySystemSession session) {
         final String nameMapperName = requireNonNull(getNameMapperName(session));
         final String factoryName = requireNonNull(getFactoryName(session));
         final NameMapper nameMapper = selectNameMapper(nameMapperName);
         final NamedLockFactory factory = selectFactory(factoryName);
         logger.debug("Creating adapter using nameMapper '{}' and factory '{}'", nameMapperName, factoryName);
         return new NamedLockFactoryAdapter(nameMapper, factory);
     }
 
     /**
      * Returns the selected (user configured or default) named lock factory name, never {@code null}.
      */
     protected String getFactoryName(RepositorySystemSession session) {
         return ConfigUtils.getString(session, getDefaultFactoryName(), FACTORY_KEY);
     }
 
     /**
      * Returns the default named lock factory name, never {@code null}.
      */
     protected String getDefaultFactoryName() {
         return defaultFactoryName;
     }
 
     /**
      * Returns the selected (user configured or default) name mapper name, never {@code null}.
      */
     protected String getNameMapperName(RepositorySystemSession session) {
         return ConfigUtils.getString(session, getDefaultNameMapperName(), NAME_MAPPER_KEY);
     }
 
     /**
      * Returns the default name mapper name, never {@code null}.
      */
     protected String getDefaultNameMapperName() {
         return defaultNameMapperName;
     }
 
     /**
      * Selects a named lock factory, never returns {@code null}.
      */
     protected NamedLockFactory selectFactory(final String factoryName) {
         NamedLockFactory factory = factories.get(factoryName);
         if (factory == null) {
             throw new IllegalArgumentException(
                     "Unknown NamedLockFactory name: '" + factoryName + "', known ones: " + factories.keySet());
         }
         return factory;
     }
 
     /**
      * Selects a name mapper, never returns {@code null}.
      */
     protected NameMapper selectNameMapper(final String nameMapperName) {
         NameMapper nameMapper = nameMappers.get(nameMapperName);
         if (nameMapper == null) {
             throw new IllegalArgumentException(
                     "Unknown NameMapper name: '" + nameMapperName + "', known ones: " + nameMappers.keySet());
         }
         return nameMapper;
     }
 
     /**
      * To be invoked on repository system shut down. This method will shut down each {@link NamedLockFactory}.
      */
     protected void shutdown() {
         logger.debug(
                 "Shutting down adapter factory; available factories {}; available name mappers {}",
                 factories.keySet(),
                 nameMappers.keySet());
         ArrayList<Exception> exceptions = new ArrayList<>();
         for (Map.Entry<String, NamedLockFactory> entry : factories.entrySet()) {
             try {
                 logger.debug("Shutting down '{}' factory", entry.getKey());
                 entry.getValue().shutdown();
             } catch (Exception e) {
                 exceptions.add(e);
             }
         }
         MultiRuntimeException.mayThrow("Problem shutting down factories", exceptions);
     }
 }