/*
 * 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.apache.maven.model.plugin;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import org.apache.maven.lifecycle.LifeCyclePluginAnalyzer;
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.ModelProblem.Severity;
import org.apache.maven.model.building.ModelProblem.Version;
import org.apache.maven.model.building.ModelProblemCollector;
import org.apache.maven.model.building.ModelProblemCollectorRequest;
import org.apache.maven.model.merge.MavenModelMerger;
import org.codehaus.plexus.component.annotations.Component;
import org.codehaus.plexus.component.annotations.Requirement;

/**
 * Handles injection of plugin executions induced by the lifecycle bindings for a packaging.
 *
 * @author Benjamin Bentmann
 */
@Component(role = LifecycleBindingsInjector.class)
public class DefaultLifecycleBindingsInjector implements LifecycleBindingsInjector {

    private LifecycleBindingsMerger merger = new LifecycleBindingsMerger();

    @Requirement
    private LifeCyclePluginAnalyzer lifecycle;

    public void injectLifecycleBindings(Model model, ModelBuildingRequest request, ModelProblemCollector problems) {
        String packaging = model.getPackaging();

        Collection<Plugin> defaultPlugins = lifecycle.getPluginsBoundByDefaultToAllLifecycles(packaging);

        if (defaultPlugins == null) {
            problems.add(new ModelProblemCollectorRequest(Severity.ERROR, Version.BASE)
                    .setMessage("Unknown packaging: " + packaging)
                    .setLocation(model.getLocation("packaging")));
        } else if (!defaultPlugins.isEmpty()) {
            Model lifecycleModel = new Model();
            lifecycleModel.setBuild(new Build());
            lifecycleModel.getBuild().getPlugins().addAll(defaultPlugins);

            merger.merge(model, lifecycleModel);
        }
    }

    /**
     *  The domain-specific model merger for lifecycle bindings
     */
    protected static class LifecycleBindingsMerger extends MavenModelMerger {

        private static final String PLUGIN_MANAGEMENT = "plugin-management";

        public void merge(Model target, Model source) {
            if (target.getBuild() == null) {
                target.setBuild(new Build());
            }

            Map<Object, Object> context = Collections.<Object, Object>singletonMap(
                    PLUGIN_MANAGEMENT, target.getBuild().getPluginManagement());

            mergePluginContainer_Plugins(target.getBuild(), source.getBuild(), false, context);
        }

        @SuppressWarnings({"checkstyle:methodname"})
        @Override
        protected void mergePluginContainer_Plugins(
                PluginContainer target, PluginContainer source, boolean sourceDominant, Map<Object, Object> context) {
            List<Plugin> src = source.getPlugins();
            if (!src.isEmpty()) {
                List<Plugin> tgt = target.getPlugins();

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

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

                Map<Object, Plugin> added = new LinkedHashMap<>();

                for (Plugin element : src) {
                    Object key = getPluginKey(element);
                    Plugin existing = merged.get(key);
                    if (existing != null) {
                        mergePlugin(existing, element, sourceDominant, context);
                    } else {
                        merged.put(key, element);
                        added.put(key, element);
                    }
                }

                if (!added.isEmpty()) {
                    PluginManagement pluginMgmt = (PluginManagement) context.get(PLUGIN_MANAGEMENT);
                    if (pluginMgmt != null) {
                        for (Plugin managedPlugin : pluginMgmt.getPlugins()) {
                            Object key = getPluginKey(managedPlugin);
                            Plugin addedPlugin = added.get(key);
                            if (addedPlugin != null) {
                                Plugin plugin = managedPlugin.clone();
                                mergePlugin(plugin, addedPlugin, sourceDominant, Collections.emptyMap());
                                merged.put(key, plugin);
                            }
                        }
                    }
                }

                List<Plugin> result = new ArrayList<>(merged.values());

                target.setPlugins(result);
            }
        }

        @Override
        protected void mergePluginExecution(
                PluginExecution target, PluginExecution source, boolean sourceDominant, Map<Object, Object> context) {
            super.mergePluginExecution(target, source, sourceDominant, context);

            target.setPriority(Math.min(target.getPriority(), source.getPriority()));
        }
    }
}
