package org.eclipse.aether.internal.impl;

/*
 * 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.
 */

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import org.eclipse.aether.RepositorySystemSession;
import org.eclipse.aether.artifact.Artifact;
import org.eclipse.aether.impl.MetadataGenerator;
import org.eclipse.aether.impl.MetadataGeneratorFactory;
import org.eclipse.aether.impl.OfflineController;
import org.eclipse.aether.metadata.Metadata;
import org.eclipse.aether.repository.RemoteRepository;
import org.eclipse.aether.resolution.ResolutionErrorPolicy;
import org.eclipse.aether.resolution.ResolutionErrorPolicyRequest;
import org.eclipse.aether.transfer.RepositoryOfflineException;

Internal utility methods.
/**
 * Internal utility methods.
 */
final class Utils
{

    public static PrioritizedComponents<MetadataGeneratorFactory> sortMetadataGeneratorFactories(
            RepositorySystemSession session, Collection<? extends MetadataGeneratorFactory> factories )
    {
        PrioritizedComponents<MetadataGeneratorFactory> result = new PrioritizedComponents<>( session );
        for ( MetadataGeneratorFactory factory : factories )
        {
            result.add( factory, factory.getPriority() );
        }
        return result;
    }

    public static List<Metadata> prepareMetadata( List<? extends MetadataGenerator> generators,
                                                  List<? extends Artifact> artifacts )
    {
        List<Metadata> metadatas = new ArrayList<>();

        for ( MetadataGenerator generator : generators )
        {
            metadatas.addAll( generator.prepare( artifacts ) );
        }

        return metadatas;
    }

    public static List<Metadata> finishMetadata( List<? extends MetadataGenerator> generators,
                                                 List<? extends Artifact> artifacts )
    {
        List<Metadata> metadatas = new ArrayList<>();

        for ( MetadataGenerator generator : generators )
        {
            metadatas.addAll( generator.finish( artifacts ) );
        }

        return metadatas;
    }

    public static <T> List<T> combine( Collection<? extends T> first, Collection<? extends T> second )
    {
        List<T> result = new ArrayList<>( first.size() + second.size() );
        result.addAll( first );
        result.addAll( second );
        return result;
    }

    public static int getPolicy( RepositorySystemSession session, Artifact artifact, RemoteRepository repository )
    {
        ResolutionErrorPolicy rep = session.getResolutionErrorPolicy();
        if ( rep == null )
        {
            return ResolutionErrorPolicy.CACHE_DISABLED;
        }
        return rep.getArtifactPolicy( session, new ResolutionErrorPolicyRequest<>( artifact, repository ) );
    }

    public static int getPolicy( RepositorySystemSession session, Metadata metadata, RemoteRepository repository )
    {
        ResolutionErrorPolicy rep = session.getResolutionErrorPolicy();
        if ( rep == null )
        {
            return ResolutionErrorPolicy.CACHE_DISABLED;
        }
        return rep.getMetadataPolicy( session, new ResolutionErrorPolicyRequest<>( metadata, repository ) );
    }

    public static void appendClassLoader( StringBuilder buffer, Object component )
    {
        ClassLoader loader = component.getClass().getClassLoader();
        if ( loader != null && !loader.equals( Utils.class.getClassLoader() ) )
        {
            buffer.append( " from " ).append( loader );
        }
    }

    public static void checkOffline( RepositorySystemSession session, OfflineController offlineController,
                                     RemoteRepository repository )
        throws RepositoryOfflineException
    {
        if ( session.isOffline() )
        {
            offlineController.checkOffline( session, repository );
        }
    }

}