/*
    * 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.named;
  
  import javax.inject.Inject;
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.Map;
  import java.util.Set;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.ConcurrentMap;
  import java.util.concurrent.TimeUnit;
  
  import org.eclipse.aether.ConfigurationProperties;
  import org.eclipse.aether.MultiRuntimeException;
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.impl.NamedLockFactorySelector;
  import org.eclipse.aether.impl.RepositorySystemLifecycle;
  import org.eclipse.aether.internal.impl.synccontext.named.NamedLockFactoryAdapter;
  import org.eclipse.aether.internal.impl.synccontext.named.NamedLockFactoryAdapterFactoryImpl;
  import org.eclipse.aether.named.NamedLockFactory;
  import org.eclipse.aether.named.providers.FileLockNamedLockFactory;
  import org.eclipse.aether.util.ConfigUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import static java.util.Objects.requireNonNull;
  
  @Singleton
  @Named
  public class DefaultNamedLockFactorySelector implements NamedLockFactorySelector {
      public static final String CONFIG_PROPS_PREFIX = ConfigurationProperties.PREFIX_SYSTEM + "named.";
  
      /**
       * Name of the lock factory to use in system. Out of the box supported ones are "file-lock", "rwlock-local",
       * "semaphore-local", "noop". By adding extensions one can extend available lock factories (for example IPC locking).
       *
       * @configurationSource {@link RepositorySystemSession#getConfigProperties()}
       * @configurationType {@link java.lang.String}
       * @configurationDefaultValue {@link #DEFAULT_FACTORY_NAME}
       */
      public static final String CONFIG_PROP_FACTORY_NAME = CONFIG_PROPS_PREFIX + "factory";
  
      public static final String DEFAULT_FACTORY_NAME = FileLockNamedLockFactory.NAME;
  
      /**
       * The maximum amount of time to be blocked, while obtaining a named lock.
       *
       * @configurationSource {@link RepositorySystemSession#getConfigProperties()}
       * @configurationType {@link java.lang.Long}
       * @configurationDefaultValue {@link #DEFAULT_LOCK_WAIT_TIME}
       */
      public static final String CONFIG_PROP_LOCK_WAIT_TIME = CONFIG_PROPS_PREFIX + "time";
  
      public static final long DEFAULT_LOCK_WAIT_TIME = 900L;
  
      /**
       * The unit of maximum amount of time. Accepts TimeUnit enum names.
       *
       * @configurationSource {@link RepositorySystemSession#getConfigProperties()}
       * @configurationType {@link java.lang.String}
       * @configurationDefaultValue {@link #DEFAULT_LOCK_WAIT_TIME_UNIT}
       */
      public static final String CONFIG_PROP_LOCK_WAIT_TIME_UNIT = CONFIG_PROPS_PREFIX + "timeUnit";
  
      public static final String DEFAULT_LOCK_WAIT_TIME_UNIT = "SECONDS";
  
      protected final Logger logger = LoggerFactory.getLogger(getClass());
  
      protected final Map<String, NamedLockFactory> factories;
  
      protected final ConcurrentMap<String, NamedLockFactory> usedFactories;
  
      @Inject
      public DefaultNamedLockFactorySelector(
              Map<String, NamedLockFactory> factories, RepositorySystemLifecycle lifecycle) {
          this.factories = requireNonNull(factories);
          this.usedFactories = new ConcurrentHashMap<>();
          lifecycle.addOnSystemEndedHandler(this::shutdown);
 
         logger.debug("Created lock factory selector; available lock factories {}", factories.keySet());
     }
 
     @Override
     public Set<String> getAvailableLockFactories() {
         return Collections.unmodifiableSet(new HashSet<>(factories.keySet()));
     }
 
     @Override
     public NamedLockFactory getNamedLockFactory(Map<String, ?> configuration) {
         String factoryName = ConfigUtils.getString(
                 configuration,
                 DEFAULT_FACTORY_NAME,
                 CONFIG_PROP_FACTORY_NAME,
                 NamedLockFactoryAdapterFactoryImpl.CONFIG_PROP_FACTORY_KEY);
         NamedLockFactory factory = factories.get(factoryName);
         if (factory == null) {
             throw new IllegalArgumentException(
                     "Unknown NamedLockFactory name: '" + factoryName + "', known ones: " + factories.keySet());
         }
         usedFactories.putIfAbsent(factoryName, factory);
         return factory;
     }
 
     @Override
     public long getLockWaitTime(Map<String, ?> configuration) {
         long result = ConfigUtils.getLong(
                 configuration,
                 DEFAULT_LOCK_WAIT_TIME,
                 CONFIG_PROP_LOCK_WAIT_TIME,
                 NamedLockFactoryAdapter.CONFIG_PROP_TIME);
         if (result <= 0) {
             throw new IllegalArgumentException(
                     "The " + CONFIG_PROP_LOCK_WAIT_TIME + " configuration must be greater than zero");
         }
         return result;
     }
 
     @Override
     public TimeUnit getLockWaitTimeUnit(Map<String, ?> configuration) {
         return TimeUnit.valueOf(ConfigUtils.getString(
                 configuration,
                 DEFAULT_LOCK_WAIT_TIME_UNIT,
                 CONFIG_PROP_LOCK_WAIT_TIME_UNIT,
                 NamedLockFactoryAdapter.CONFIG_PROP_TIME_UNIT));
     }
 
     private void shutdown() {
         logger.debug("Shutting down used lock factories {}", usedFactories.keySet());
         ArrayList<Exception> exceptions = new ArrayList<>();
         for (Map.Entry<String, NamedLockFactory> entry : usedFactories.entrySet()) {
             try {
                 logger.debug("Shutting down '{}' factory", entry.getKey());
                 entry.getValue().shutdown();
             } catch (Exception e) {
                 exceptions.add(e);
             }
         }
         MultiRuntimeException.mayThrow("Problem shutting down used lock factories", exceptions);
     }
 }