/*
    * 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.lifecycle;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.LinkedHashMap;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import org.apache.maven.lifecycle.internal.ExecutionPlanItem;
  import org.apache.maven.model.Plugin;
  import org.apache.maven.plugin.MojoExecution;
  import org.apache.maven.plugin.descriptor.MojoDescriptor;
  
  // TODO lifecycles being executed
  // TODO what runs in each phase
  // TODO plugins that need downloading
  // TODO project dependencies that need downloading
  // TODO unfortunately the plugins need to be downloaded in order to get the plugin.xml file. need to externalize this
  //      from the plugin archive.
  // TODO this will be the class that people get in IDEs to modify
  
  /**
   * MavenExecutionPlan
   */
  public class MavenExecutionPlan implements Iterable<ExecutionPlanItem> {
  
      /*
        At the moment, this class is totally immutable, and this is in line with thoughts about the
        pre-calculated execution plan that stays the same during the execution.
  
        If deciding to add mutable state to this class, it should be at least considered to
        separate this into a separate mutable structure.
  
      */
  
      private final List<ExecutionPlanItem> planItem;
  
      private final Map<String, ExecutionPlanItem> lastMojoExecutionForAllPhases;
  
      final List<String> phasesInExecutionPlan;
  
      public MavenExecutionPlan(List<ExecutionPlanItem> planItem, DefaultLifecycles defaultLifecycles) {
          this.planItem = planItem;
  
          lastMojoExecutionForAllPhases = new LinkedHashMap<>();
  
          LinkedHashSet<String> totalPhaseSet = new LinkedHashSet<>();
          if (defaultLifecycles != null) {
              for (String phase : getDistinctPhasesInOrderOfExecutionPlanAppearance(planItem)) {
                  final Lifecycle lifecycle = defaultLifecycles.get(phase);
                  if (lifecycle != null) {
                      totalPhaseSet.addAll(lifecycle.getPhases());
                  }
              }
          }
          this.phasesInExecutionPlan = new ArrayList<>(totalPhaseSet);
  
          Map<String, ExecutionPlanItem> lastInExistingPhases = new HashMap<>();
          for (ExecutionPlanItem executionPlanItem : getExecutionPlanItems()) {
              lastInExistingPhases.put(executionPlanItem.getLifecyclePhase(), executionPlanItem);
          }
  
          ExecutionPlanItem lastSeenExecutionPlanItem = null;
  
          for (String phase : totalPhaseSet) {
              ExecutionPlanItem forThisPhase = lastInExistingPhases.get(phase);
              if (forThisPhase != null) {
                  lastSeenExecutionPlanItem = forThisPhase;
              }
  
              lastMojoExecutionForAllPhases.put(phase, lastSeenExecutionPlanItem);
          }
      }
  
      public Iterator<ExecutionPlanItem> iterator() {
          return getExecutionPlanItems().iterator();
      }
 
     /**
      * Returns the last ExecutionPlanItem in the supplied phase. If no items are in the specified phase,
      * the closest executionPlanItem from an earlier phase item will be returned.
      *
      * @param requestedPhase the requested phase
      *                       The execution plan item
      * @return The ExecutionPlanItem or null if none can be found
      */
     public ExecutionPlanItem findLastInPhase(String requestedPhase) {
         return lastMojoExecutionForAllPhases.get(requestedPhase);
     }
 
     private List<ExecutionPlanItem> getExecutionPlanItems() {
         return planItem;
     }
 
     private static Iterable<String> getDistinctPhasesInOrderOfExecutionPlanAppearance(
             List<ExecutionPlanItem> planItems) {
         LinkedHashSet<String> result = new LinkedHashSet<>();
         for (ExecutionPlanItem executionPlanItem : planItems) {
             final String phase = executionPlanItem.getLifecyclePhase();
             if (!result.contains(phase)) {
                 result.add(phase);
             }
         }
         return result;
     }
 
     public List<MojoExecution> getMojoExecutions() {
         List<MojoExecution> result = new ArrayList<>();
         for (ExecutionPlanItem executionPlanItem : planItem) {
             result.add(executionPlanItem.getMojoExecution());
         }
         return result;
     }
 
     /**
      * Get set of plugins having a goal/mojo used but not marked @threadSafe
      *
      * @return the set of plugins (without info on which goal is concerned)
      */
     public Set<Plugin> getNonThreadSafePlugins() {
         Set<Plugin> plugins = new HashSet<>();
         for (ExecutionPlanItem executionPlanItem : planItem) {
             final MojoExecution mojoExecution = executionPlanItem.getMojoExecution();
             if (!mojoExecution.getMojoDescriptor().isThreadSafe()) {
                 plugins.add(mojoExecution.getPlugin());
             }
         }
         return plugins;
     }
 
     /**
      * Get set of mojos used but not marked @threadSafe
      *
      * @return the set of mojo descriptors
      */
     public Set<MojoDescriptor> getNonThreadSafeMojos() {
         Set<MojoDescriptor> mojos = new HashSet<>();
         for (ExecutionPlanItem executionPlanItem : planItem) {
             final MojoExecution mojoExecution = executionPlanItem.getMojoExecution();
             if (!mojoExecution.getMojoDescriptor().isThreadSafe()) {
                 mojos.add(mojoExecution.getMojoDescriptor());
             }
         }
         return mojos;
     }
 
     // Used by m2e but will be removed, really.
     @Deprecated
     public List<MojoExecution> getExecutions() {
         return getMojoExecutions();
     }
 
     public int size() {
         return planItem.size();
     }
 }