package org.apache.maven.model.management;

/*
 * 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.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import javax.inject.Named;
import javax.inject.Singleton;

import org.apache.maven.model.Build;
import org.apache.maven.model.Model;
import org.apache.maven.model.Plugin;
import org.apache.maven.model.PluginContainer;
import org.apache.maven.model.PluginExecution;
import org.apache.maven.model.PluginManagement;
import org.apache.maven.model.building.ModelBuildingRequest;
import org.apache.maven.model.building.ModelProblemCollector;
import org.apache.maven.model.merge.MavenModelMerger;

/**
 * Handles injection of plugin management into the model.
 *
 * @author Benjamin Bentmann
 */
@SuppressWarnings( { "checkstyle:methodname" } )
@Named
@Singleton
public class DefaultPluginManagementInjector
    implements PluginManagementInjector
{

    private ManagementModelMerger merger = new ManagementModelMerger();

    @Override
    public void injectManagement( Model model, ModelBuildingRequest request, ModelProblemCollector problems )
    {
        merger.mergeManagedBuildPlugins( model );
    }

    /**
     * ManagementModelMerger
     */
    protected static class ManagementModelMerger
        extends MavenModelMerger
    {

        public void mergeManagedBuildPlugins( Model model )
        {
            Build build = model.getBuild();
            if ( build != null )
            {
                PluginManagement pluginManagement = build.getPluginManagement();
                if ( pluginManagement != null )
                {
                    mergePluginContainerPlugins( build, pluginManagement );
                }
            }
        }

        private void mergePluginContainerPlugins( PluginContainer target, PluginContainer source )
        {
            List<Plugin> src = source.getPlugins();
            if ( !src.isEmpty() )
            {
                List<Plugin> tgt = target.getPlugins();

                Map<Object, Plugin> managedPlugins = new LinkedHashMap<>( src.size() * 2 );

                Map<Object, Object> context = Collections.emptyMap();

                for ( Plugin element : src )
                {
                    Object key = getPluginKey( element );
                    managedPlugins.put( key, element );
                }

                for ( Plugin element : tgt )
                {
                    Object key = getPluginKey( element );
                    Plugin managedPlugin = managedPlugins.get( key );
                    if ( managedPlugin != null )
                    {
                        mergePlugin( element, managedPlugin, false, context );
                    }
                }
            }
        }

        @Override
        protected void mergePlugin_Executions( Plugin target, Plugin source, boolean sourceDominant,
                                               Map<Object, Object> context )
        {
            List<PluginExecution> src = source.getExecutions();
            if ( !src.isEmpty() )
            {
                List<PluginExecution> tgt = target.getExecutions();

                Map<Object, PluginExecution> merged =
                    new LinkedHashMap<>( ( src.size() + tgt.size() ) * 2 );

                for ( PluginExecution element : src )
                {
                    Object key = getPluginExecutionKey( element );
                    merged.put( key, element.clone() );
                }

                for ( PluginExecution element : tgt )
                {
                    Object key = getPluginExecutionKey( element );
                    PluginExecution existing = merged.get( key );
                    if ( existing != null )
                    {
                        mergePluginExecution( element, existing, sourceDominant, context );
                    }
                    merged.put( key, element );
                }

                target.setExecutions( new ArrayList<>( merged.values() ) );
            }
        }
    }

}
