/*
    * 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.plugins.pmd;
  
  import java.io.FileReader;
  import java.io.IOException;
  import java.io.LineNumberReader;
  import java.util.ArrayList;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  import net.sourceforge.pmd.cpd.Mark;
  import net.sourceforge.pmd.cpd.Match;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugins.pmd.model.CpdFile;
  import org.apache.maven.plugins.pmd.model.Duplication;
  
  /**
   * This class contains utility methods to load property files which define which files
   * should be excluded from the CPD duplication results.
   * See property <code>pmd.excludeFromFailureFile</code>.
   *
   * @author Andreas Dangel
   */
  public class ExcludeDuplicationsFromFile implements ExcludeFromFile<Duplication> {
  
      private final List<Set<String>> exclusionList = new ArrayList<>();
  
      @Override
      public boolean isExcludedFromFailure(final Duplication errorDetail) {
          final Set<String> uniquePaths = new HashSet<>();
          for (final CpdFile cpdFile : errorDetail.getFiles()) {
              uniquePaths.add(cpdFile.getPath());
          }
          return isExcludedFromFailure(uniquePaths);
      }
  
      /**
       * Checks whether the given {@link Match} is excluded.
       * Note: The exclusion must have been loaded before via {@link #loadExcludeFromFailuresData(String)}.
       *
       * @param errorDetail the duplication to check
       * @return <code>true</code> if the given duplication should be excluded, <code>false</code> otherwise.
       */
      public boolean isExcludedFromFailure(final Match errorDetail) {
          final Set<String> uniquePaths = new HashSet<>();
          for (Mark mark : errorDetail.getMarkSet()) {
              uniquePaths.add(mark.getFilename());
          }
          return isExcludedFromFailure(uniquePaths);
      }
  
      private boolean isExcludedFromFailure(Set<String> uniquePaths) {
          for (final Set<String> singleExclusionGroup : exclusionList) {
              if (uniquePaths.size() == singleExclusionGroup.size()
                      && duplicationExcludedByGroup(uniquePaths, singleExclusionGroup)) {
                  return true;
              }
          }
          return false;
      }
  
      private boolean duplicationExcludedByGroup(final Set<String> uniquePaths, final Set<String> singleExclusionGroup) {
          for (final String path : uniquePaths) {
              if (!fileExcludedByGroup(path, singleExclusionGroup)) {
                  return false;
              }
          }
          return true;
      }
  
      private boolean fileExcludedByGroup(final String path, final Set<String> singleExclusionGroup) {
          final String formattedPath = path.replace('\\', '.').replace('/', '.');
          for (final String className : singleExclusionGroup) {
              if (formattedPath.contains(className)) {
                  return true;
              }
          }
          return false;
      }
  
      @Override
     public void loadExcludeFromFailuresData(final String excludeFromFailureFile) throws MojoExecutionException {
         if (excludeFromFailureFile == null || excludeFromFailureFile.isEmpty()) {
             return;
         }
 
         try (LineNumberReader reader = new LineNumberReader(new FileReader(excludeFromFailureFile))) {
             String line;
             while ((line = reader.readLine()) != null) {
                 if (!line.startsWith("#")) {
                     exclusionList.add(createSetFromExclusionLine(line));
                 }
             }
         } catch (final IOException e) {
             throw new MojoExecutionException("Cannot load file " + excludeFromFailureFile, e);
         }
     }
 
     private Set<String> createSetFromExclusionLine(final String line) {
         final Set<String> result = new HashSet<>();
         for (final String className : line.split(",")) {
             result.add(className.trim());
         }
         return result;
     }
 
     @Override
     public int countExclusions() {
         return exclusionList.size();
     }
 }