/*
    * 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.plugin.internal;
  
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.io.File;
  import java.nio.file.Path;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.EnumSet;
  import java.util.HashMap;
  import java.util.LinkedHashMap;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  import java.util.Set;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.stream.Collectors;
  
  import org.apache.maven.eventspy.AbstractEventSpy;
  import org.apache.maven.execution.ExecutionEvent;
  import org.apache.maven.execution.MavenSession;
  import org.apache.maven.model.InputLocation;
  import org.apache.maven.plugin.PluginValidationManager;
  import org.apache.maven.plugin.descriptor.MojoDescriptor;
  import org.apache.maven.plugin.descriptor.PluginDescriptor;
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.artifact.Artifact;
  import org.eclipse.aether.util.ConfigUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  @Singleton
  @Named
  public final class DefaultPluginValidationManager extends AbstractEventSpy implements PluginValidationManager {
      /**
       * The collection of "G:A" combinations that do NOT belong to Maven Core, hence, should be excluded from
       * "expected in provided scope" type of checks.
       */
      static final Collection<String> EXPECTED_PROVIDED_SCOPE_EXCLUSIONS_GA =
              Collections.unmodifiableCollection(Arrays.asList(
                      "org.apache.maven:maven-archiver", "org.apache.maven:maven-jxr", "org.apache.maven:plexus-utils"));
  
      private static final String ISSUES_KEY = DefaultPluginValidationManager.class.getName() + ".issues";
  
      private static final String PLUGIN_EXCLUDES_KEY = DefaultPluginValidationManager.class.getName() + ".excludes";
  
      private static final String MAVEN_PLUGIN_VALIDATION_KEY = "maven.plugin.validation";
  
      private static final String MAVEN_PLUGIN_VALIDATION_EXCLUDES_KEY = "maven.plugin.validation.excludes";
  
      private static final ValidationReportLevel DEFAULT_VALIDATION_LEVEL = ValidationReportLevel.INLINE;
  
      private static final Collection<ValidationReportLevel> INLINE_VALIDATION_LEVEL = Collections.unmodifiableCollection(
              Arrays.asList(ValidationReportLevel.INLINE, ValidationReportLevel.BRIEF));
  
      private enum ValidationReportLevel {
          NONE, // mute validation completely (validation issue collection still happens, it is just not reported!)
          INLINE, // inline, each "internal" problem one line next to mojo invocation
          SUMMARY, // at end, list of plugin GAVs along with ANY validation issues
          BRIEF, // each "internal" problem one line next to mojo invocation
          // and at end list of plugin GAVs along with "external" issues
          VERBOSE // at end, list of plugin GAVs along with detailed report of ANY validation issues
      }
  
      private final Logger logger = LoggerFactory.getLogger(getClass());
  
      @Override
      public void onEvent(Object event) {
          if (event instanceof ExecutionEvent) {
              ExecutionEvent executionEvent = (ExecutionEvent) event;
              if (executionEvent.getType() == ExecutionEvent.Type.SessionStarted) {
                  RepositorySystemSession repositorySystemSession =
                          executionEvent.getSession().getRepositorySession();
                  validationReportLevel(repositorySystemSession); // this will parse and store it in session.data
                  validationPluginExcludes(repositorySystemSession);
              } else if (executionEvent.getType() == ExecutionEvent.Type.SessionEnded) {
                  reportSessionCollectedValidationIssues(executionEvent.getSession());
              }
         }
     }
 
     private List<?> validationPluginExcludes(RepositorySystemSession session) {
         return (List<?>) session.getData().computeIfAbsent(PLUGIN_EXCLUDES_KEY, () -> parsePluginExcludes(session));
     }
 
     private List<String> parsePluginExcludes(RepositorySystemSession session) {
         String excludes = ConfigUtils.getString(session, null, MAVEN_PLUGIN_VALIDATION_EXCLUDES_KEY);
         if (excludes == null || excludes.isEmpty()) {
             return Collections.emptyList();
         }
         return Arrays.stream(excludes.split(","))
                 .map(String::trim)
                 .filter(s -> !s.isEmpty())
                 .collect(Collectors.toList());
     }
 
     private ValidationReportLevel validationReportLevel(RepositorySystemSession session) {
         return (ValidationReportLevel) session.getData()
                 .computeIfAbsent(ValidationReportLevel.class, () -> parseValidationReportLevel(session));
     }
 
     private ValidationReportLevel parseValidationReportLevel(RepositorySystemSession session) {
         String level = ConfigUtils.getString(session, null, MAVEN_PLUGIN_VALIDATION_KEY);
         if (level == null || level.isEmpty()) {
             return DEFAULT_VALIDATION_LEVEL;
         }
         try {
             return ValidationReportLevel.valueOf(level.toUpperCase(Locale.ENGLISH));
         } catch (IllegalArgumentException e) {
             logger.warn(
                     "Invalid value specified for property {}: '{}'. Supported values are (case insensitive): {}",
                     MAVEN_PLUGIN_VALIDATION_KEY,
                     level,
                     Arrays.toString(ValidationReportLevel.values()));
             return DEFAULT_VALIDATION_LEVEL;
         }
     }
 
     private String pluginKey(String groupId, String artifactId, String version) {
         return groupId + ":" + artifactId + ":" + version;
     }
 
     private String pluginKey(MojoDescriptor mojoDescriptor) {
         PluginDescriptor pd = mojoDescriptor.getPluginDescriptor();
         return pluginKey(pd.getGroupId(), pd.getArtifactId(), pd.getVersion());
     }
 
     private String pluginKey(Artifact pluginArtifact) {
         return pluginKey(pluginArtifact.getGroupId(), pluginArtifact.getArtifactId(), pluginArtifact.getVersion());
     }
 
     private void mayReportInline(RepositorySystemSession session, IssueLocality locality, String issue) {
         if (locality == IssueLocality.INTERNAL) {
             ValidationReportLevel validationReportLevel = validationReportLevel(session);
             if (INLINE_VALIDATION_LEVEL.contains(validationReportLevel)) {
                 logger.warn(" {}", issue);
             }
         }
     }
 
     @Override
     public void reportPluginValidationIssue(
             IssueLocality locality, RepositorySystemSession session, Artifact pluginArtifact, String issue) {
         String pluginKey = pluginKey(pluginArtifact);
         if (validationPluginExcludes(session).contains(pluginKey)) {
             return;
         }
         PluginValidationIssues pluginIssues =
                 pluginIssues(session).computeIfAbsent(pluginKey, k -> new PluginValidationIssues());
         pluginIssues.reportPluginIssue(locality, null, issue);
         mayReportInline(session, locality, issue);
     }
 
     @Override
     public void reportPluginValidationIssue(
             IssueLocality locality, MavenSession mavenSession, MojoDescriptor mojoDescriptor, String issue) {
         String pluginKey = pluginKey(mojoDescriptor);
         if (validationPluginExcludes(mavenSession.getRepositorySession()).contains(pluginKey)) {
             return;
         }
         PluginValidationIssues pluginIssues = pluginIssues(mavenSession.getRepositorySession())
                 .computeIfAbsent(pluginKey, k -> new PluginValidationIssues());
         pluginIssues.reportPluginIssue(locality, pluginDeclaration(mavenSession, mojoDescriptor), issue);
         mayReportInline(mavenSession.getRepositorySession(), locality, issue);
     }
 
     @Override
     public void reportPluginMojoValidationIssue(
             IssueLocality locality,
             MavenSession mavenSession,
             MojoDescriptor mojoDescriptor,
             Class<?> mojoClass,
             String issue) {
         String pluginKey = pluginKey(mojoDescriptor);
         if (validationPluginExcludes(mavenSession.getRepositorySession()).contains(pluginKey)) {
             return;
         }
         PluginValidationIssues pluginIssues = pluginIssues(mavenSession.getRepositorySession())
                 .computeIfAbsent(pluginKey, k -> new PluginValidationIssues());
         pluginIssues.reportPluginMojoIssue(
                 locality, pluginDeclaration(mavenSession, mojoDescriptor), mojoInfo(mojoDescriptor, mojoClass), issue);
         mayReportInline(mavenSession.getRepositorySession(), locality, issue);
     }
 
     private void reportSessionCollectedValidationIssues(MavenSession mavenSession) {
         if (!logger.isWarnEnabled()) {
             return; // nothing can be reported
         }
         ValidationReportLevel validationReportLevel = validationReportLevel(mavenSession.getRepositorySession());
         if (validationReportLevel == ValidationReportLevel.NONE
                 || validationReportLevel == ValidationReportLevel.INLINE) {
             return; // we were asked to not report anything OR reporting already happened inline
         }
         ConcurrentHashMap<String, PluginValidationIssues> issuesMap = pluginIssues(mavenSession.getRepositorySession());
         EnumSet<IssueLocality> issueLocalitiesToReport = validationReportLevel == ValidationReportLevel.SUMMARY
                         || validationReportLevel == ValidationReportLevel.VERBOSE
                 ? EnumSet.allOf(IssueLocality.class)
                 : EnumSet.of(IssueLocality.EXTERNAL);
 
         if (hasAnythingToReport(issuesMap, issueLocalitiesToReport)) {
             logger.warn("");
             logger.warn("Plugin {} validation issues were detected in following plugin(s)", issueLocalitiesToReport);
             logger.warn("");
             for (Map.Entry<String, PluginValidationIssues> entry : issuesMap.entrySet()) {
                 PluginValidationIssues issues = entry.getValue();
                 if (!hasAnythingToReport(issues, issueLocalitiesToReport)) {
                     continue;
                 }
                 logger.warn(" * {}", entry.getKey());
                 if (validationReportLevel == ValidationReportLevel.VERBOSE) {
                     if (!issues.pluginDeclarations.isEmpty()) {
                         logger.warn("  Declared at location(s):");
                         for (String pluginDeclaration : issues.pluginDeclarations) {
                             logger.warn("   * {}", pluginDeclaration);
                         }
                     }
                     if (!issues.pluginIssues.isEmpty()) {
                         for (IssueLocality issueLocality : issueLocalitiesToReport) {
                             Set<String> pluginIssues = issues.pluginIssues.get(issueLocality);
                             if (pluginIssues != null && !pluginIssues.isEmpty()) {
                                 logger.warn("  Plugin {} issue(s):", issueLocality);
                                 for (String pluginIssue : pluginIssues) {
                                     logger.warn("   * {}", pluginIssue);
                                 }
                             }
                         }
                     }
                     if (!issues.mojoIssues.isEmpty()) {
                         for (IssueLocality issueLocality : issueLocalitiesToReport) {
                             Map<String, LinkedHashSet<String>> mojoIssues = issues.mojoIssues.get(issueLocality);
                             if (mojoIssues != null && !mojoIssues.isEmpty()) {
                                 logger.warn("  Mojo {} issue(s):", issueLocality);
                                 for (String mojoInfo : mojoIssues.keySet()) {
                                     logger.warn("   * Mojo {}", mojoInfo);
                                     for (String mojoIssue : mojoIssues.get(mojoInfo)) {
                                         logger.warn("     - {}", mojoIssue);
                                     }
                                 }
                             }
                         }
                     }
                     logger.warn("");
                 }
             }
             logger.warn("");
             if (validationReportLevel == ValidationReportLevel.VERBOSE) {
                 logger.warn(
                         "Fix reported issues by adjusting plugin configuration or by upgrading above listed plugins. If no upgrade available, please notify plugin maintainers about reported issues.");
             }
             logger.warn(
                     "For more or less details, use 'maven.plugin.validation' property with one of the values (case insensitive): {}",
                     Arrays.toString(ValidationReportLevel.values()));
             logger.warn("");
         }
     }
 
     private boolean hasAnythingToReport(
             Map<String, PluginValidationIssues> issuesMap, EnumSet<IssueLocality> issueLocalitiesToReport) {
         for (PluginValidationIssues issues : issuesMap.values()) {
             if (hasAnythingToReport(issues, issueLocalitiesToReport)) {
                 return true;
             }
         }
         return false;
     }
 
     private boolean hasAnythingToReport(PluginValidationIssues issues, EnumSet<IssueLocality> issueLocalitiesToReport) {
         for (IssueLocality issueLocality : issueLocalitiesToReport) {
             Set<String> pluginIssues = issues.pluginIssues.get(issueLocality);
             if (pluginIssues != null && !pluginIssues.isEmpty()) {
                 return true;
             }
             Map<String, LinkedHashSet<String>> mojoIssues = issues.mojoIssues.get(issueLocality);
             if (mojoIssues != null && !mojoIssues.isEmpty()) {
                 return true;
             }
         }
         return false;
     }
 
     private String pluginDeclaration(MavenSession mavenSession, MojoDescriptor mojoDescriptor) {
         InputLocation inputLocation =
                 mojoDescriptor.getPluginDescriptor().getPlugin().getLocation("");
         if (inputLocation != null && inputLocation.getSource() != null) {
             StringBuilder stringBuilder = new StringBuilder();
             stringBuilder.append(inputLocation.getSource().getModelId());
             String location = inputLocation.getSource().getLocation();
             if (location != null) {
                 if (location.contains("://")) {
                     stringBuilder.append(" (").append(location).append(")");
                 } else {
                     Path topLevelBasedir =
                             mavenSession.getTopLevelProject().getBasedir().toPath();
                     Path locationPath =
                             new File(location).toPath().toAbsolutePath().normalize();
                     if (locationPath.startsWith(topLevelBasedir)) {
                         locationPath = topLevelBasedir.relativize(locationPath);
                     }
                     stringBuilder.append(" (").append(locationPath).append(")");
                 }
             }
             stringBuilder.append(" @ line ").append(inputLocation.getLineNumber());
             return stringBuilder.toString();
         } else {
             return "unknown";
         }
     }
 
     private String mojoInfo(MojoDescriptor mojoDescriptor, Class<?> mojoClass) {
         return mojoDescriptor.getFullGoalName() + " (" + mojoClass.getName() + ")";
     }
 
     @SuppressWarnings("unchecked")
     private ConcurrentHashMap<String, PluginValidationIssues> pluginIssues(RepositorySystemSession session) {
         return (ConcurrentHashMap<String, PluginValidationIssues>)
                 session.getData().computeIfAbsent(ISSUES_KEY, ConcurrentHashMap::new);
     }
 
     private static class PluginValidationIssues {
         private final LinkedHashSet<String> pluginDeclarations;
 
         private final HashMap<IssueLocality, LinkedHashSet<String>> pluginIssues;
 
         private final HashMap<IssueLocality, LinkedHashMap<String, LinkedHashSet<String>>> mojoIssues;
 
         private PluginValidationIssues() {
             this.pluginDeclarations = new LinkedHashSet<>();
             this.pluginIssues = new HashMap<>();
             this.mojoIssues = new HashMap<>();
         }
 
         private synchronized void reportPluginIssue(
                 IssueLocality issueLocality, String pluginDeclaration, String issue) {
             if (pluginDeclaration != null) {
                 pluginDeclarations.add(pluginDeclaration);
             }
             pluginIssues
                     .computeIfAbsent(issueLocality, k -> new LinkedHashSet<>())
                     .add(issue);
         }
 
         private synchronized void reportPluginMojoIssue(
                 IssueLocality issueLocality, String pluginDeclaration, String mojoInfo, String issue) {
             if (pluginDeclaration != null) {
                 pluginDeclarations.add(pluginDeclaration);
             }
             mojoIssues
                     .computeIfAbsent(issueLocality, k -> new LinkedHashMap<>())
                     .computeIfAbsent(mojoInfo, k -> new LinkedHashSet<>())
                     .add(issue);
         }
     }
 }