/*
    * SPDX-FileCopyrightText: Copyright (c) 2011-2025 Yegor Bugayenko
    * SPDX-License-Identifier: MIT
    */
   package com.qulice.maven;
   
   import com.google.common.base.Predicate;
   import com.google.common.base.Predicates;
   import com.google.common.collect.Collections2;
  import com.jcabi.log.Logger;
  import com.qulice.spi.ValidationException;
  import java.util.Collection;
  import java.util.LinkedList;
  import org.apache.maven.artifact.Artifact;
  import org.apache.maven.shared.dependency.analyzer.ProjectDependencyAnalysis;
  import org.apache.maven.shared.dependency.analyzer.ProjectDependencyAnalyzer;
  import org.apache.maven.shared.dependency.analyzer.ProjectDependencyAnalyzerException;
  import org.cactoos.text.Joined;
  import org.codehaus.plexus.PlexusConstants;
  import org.codehaus.plexus.PlexusContainer;
  import org.codehaus.plexus.component.repository.exception.ComponentLookupException;
  import org.codehaus.plexus.context.ContextException;
  
  /**
   * Validator of dependencies.
   *
   * @since 0.3
   * @checkstyle ReturnCountCheck (100 line)
   */
  final class DependenciesValidator implements MavenValidator {
  
      /**
       * Separator between lines.
       */
      private static final String SEP = "\n\t";
  
      @Override
      @SuppressWarnings("PMD.OnlyOneReturn")
      public void validate(final MavenEnvironment env)
          throws ValidationException {
          if (!env.outdir().exists() || "pom".equals(env.project().getPackaging())) {
              Logger.info(this, "No dependency analysis in this project");
              return;
          }
          final Collection<String> excludes = env.excludes("dependencies");
          if (excludes.contains(".*")) {
              Logger.info(this, "Dependency analysis suppressed in the project via pom.xml");
              return;
          }
          final Collection<String> unused = Collections2.filter(
              DependenciesValidator.unused(env),
              Predicates.not(new DependenciesValidator.ExcludePredicate(excludes))
          );
          if (!unused.isEmpty()) {
              Logger.warn(
                  this,
                  "Unused declared dependencies found:%s%s",
                  DependenciesValidator.SEP,
                  new Joined(DependenciesValidator.SEP, unused).toString()
              );
          }
          final Collection<String> used = Collections2.filter(
              DependenciesValidator.used(env),
              Predicates.not(new DependenciesValidator.ExcludePredicate(excludes))
          );
          if (!used.isEmpty()) {
              Logger.warn(
                  this,
                  "Used undeclared dependencies found:%s%s",
                  DependenciesValidator.SEP,
                  new Joined(DependenciesValidator.SEP, used)
              );
          }
          if (!used.isEmpty() || !unused.isEmpty()) {
              Logger.info(
                  this,
                  "You can suppress this message by <exclude>dependencies:...</exclude> in pom.xml, where <...> is what the dependency name starts with (not a regular expression!)"
              );
          }
          final int failures = used.size() + unused.size();
          if (failures > 0) {
              throw new ValidationException(
                  "%d dependency problem(s) found",
                  failures
              );
          }
          Logger.info(this, "No dependency problems found");
      }
  
      /**
       * Analyze the project.
       * @param env The environment
       * @return The result of analysis
       */
      private static ProjectDependencyAnalysis analyze(
          final MavenEnvironment env) {
          try {
              return ((ProjectDependencyAnalyzer)
                  ((PlexusContainer)
                     env.context().get(PlexusConstants.PLEXUS_KEY)
                 ).lookup(ProjectDependencyAnalyzer.class.getName(), "default")
             ).analyze(env.project());
         } catch (final ContextException | ComponentLookupException
             | ProjectDependencyAnalyzerException ex) {
             throw new IllegalStateException(ex);
         }
     }
 
     /**
      * Find unused artifacts.
      * @param env Environment
      * @return Collection of unused artifacts
      */
     private static Collection<String> used(final MavenEnvironment env) {
         final ProjectDependencyAnalysis analysis =
             DependenciesValidator.analyze(env);
         final Collection<String> used = new LinkedList<>();
         for (final Object artifact : analysis.getUsedUndeclaredArtifacts()) {
             used.add(artifact.toString());
         }
         return used;
     }
 
     /**
      * Find unused artifacts.
      * @param env Environment
      * @return Collection of unused artifacts
      */
     private static Collection<String> unused(final MavenEnvironment env) {
         final ProjectDependencyAnalysis analysis =
             DependenciesValidator.analyze(env);
         final Collection<String> unused = new LinkedList<>();
         for (final Object obj : analysis.getUnusedDeclaredArtifacts()) {
             final Artifact artifact = (Artifact) obj;
             if (!Artifact.SCOPE_COMPILE.equals(artifact.getScope())) {
                 continue;
             }
             unused.add(artifact.toString());
         }
         return unused;
     }
 
     /**
      * Predicate for excluded dependencies.
      *
      * @since 0.1
      */
     private static class ExcludePredicate implements Predicate<String> {
 
         /**
          * List of excludes.
          */
         private final Collection<String> excludes;
 
         /**
          * Constructor.
          * @param excludes List of excludes.
          */
         ExcludePredicate(final Collection<String> excludes) {
             this.excludes = excludes;
         }
 
         @Override
         public boolean apply(final String name) {
             boolean ignore = false;
             for (final String exclude : this.excludes) {
                 if (name.startsWith(exclude)) {
                     ignore = true;
                     break;
                 }
             }
             return ignore;
         }
     }
 }